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Sample records for shergottites dar al

  1. Exposure History of Shergottites Dar Al Gani 476/489/670/735 and Sayh Al Uhaymir 005

    SciTech Connect

    Nishiizumi, N.; Caffee, M.; Jull, A.J.T.; Klandrud, S.E.

    2001-04-01

    Four basaltic shergottites, Dar al Gani (DaG) 476, 489, 670, and 735 were found in the Libyan Sahara [1-3]; two basaltic shergottites, Sayh al Uhaymir (SaU) 005 and 008 were found in Oman [4]. Recently SaU 051 was also recognized as a possible pair of SaU 005/008. Although the collection sites were different, the texture, bulk chemical compositions, and noble gas compositions of these shergottites are similar [e.g. 4]. However, cosmic-ray-produced noble gases alone cannot unambiguously constrain the irradiation history for these objects. From a combination of cosmogenic stable- and radionuclides, exposure histories, and ejection conditions from the hypothesized Martian parent body, and genetic relationships between the Martian meteorites can be determined. In addition to those nuclides produced by galactic cosmic rays (GCR) are those produced by solar cosmic rays (SCR). Radionuclides produced by SCRs reside in the uppermost few centimeters of extraterrestrial bodies and their presence in meteorites indicates the degree to which a meteorite has been ablated. Previous work shows ablation is less than 1-2 cm in at least three shergottites, ALH 77005, Shergotty, and EETA79001 [e.g. 5] and so it is possible some SCR signal may be observed in these meteorites. This suggests that the atmospheric entry velocity and/or entry angle of these shergottites is much lower than the velocity and/or entry angle of most ordinary chondrites. We report here preliminary results of cosmogenic nuclides, {sup 14}C (half-life = 5,730 yr), {sup 36}Cl (3.01 x 10{sup 5} yr), {sup 26}Al (7.05 x 10{sup 5} yr), and {sup 10}Be(1.5 x 10{sup 6} yr).

  2. Exposure history of shergottites

    NASA Technical Reports Server (NTRS)

    Nishizumi, K.; Arnold, J. R.; Klein, J.; Middleton, R.; Elmore, D.

    1986-01-01

    The cosmogenic nuclides Cl-36, Al-26, Be-10, and Mn-53 were analyzed in Shergotty, ALHA 77005, and EETA 79001 shergottites by means of accelerator mass spectrometry and neutron activation. The cosmogenic radionuclide data were combined with noble gas data and cosmic ray track data to obtain the exposure ages, terrestrial ages, preatmospheric radii, and ablation depths for the three shergottites. The results indicate that none of the three meteorites was irradiated measurably by cosmic rays on its parent body, and that all three objects were ejected from greater than a 3-m depth in their parent bodies. The EETA 79001 meteorite was ejected in an event distinct from that of ALHA 77005 and Shergotty. All three shergottites show a very small amount of ablation, suggesting low velocities on entry into the earth's atmosphere.

  3. Isotopic Petrology: The Curious Case of the Shergottite Meteorites

    NASA Astrophysics Data System (ADS)

    Jones, J. H.

    2009-05-01

    -enriched melt. Interestingly, the 180 m.y. shergottites require only two Sm-Nd components, because they fall along a two-component mixing line. This implies that these shergottites were derived from a single magma, that was generated from a single, LREE-melt-extracted source region, which subsequently assimilated various amounts of enriched crust. Otherwise, the amount of assimilated crust for each shergottite would be required to be linked to the amount of missing, LREE-enriched magma, in such a way that a two-component linear array is generated. Since LREE melt extraction had to occur before depleted-shergottite petrogenesis and since crustal assimilation must have occurred after, these two physical processes have little chance of being coupled. In addition, this linear shergottite mixing array must be of sufficient quality that it could initially be interpreted as an isochron [2]. This interpretation of 180 m.y. shergottite petrogenesis reinforces Longhi's inference of the Nd isotopic composition of the martian crust [5], at least in one particular martian terrain. Bottom line: In order to understand martian chronology, you have to understand martian petrology. And in order to understand martian petrology, you have to understand martian chronology. This is an aphorism that (I think) John would endorse. [1] Chen and Wassserburg (1986) Geochim. Cosmochim. Acta 50, 955-968. [2] Shih et al. (1982 Geochim. Cosmochim. Acta 46, 2323-2344. [3] Jagoutz and Wanke (1986) Geochim. Cosmochim. Acta 50, 939-953. [4] Jones (1986) Geochim. Cosmochim. Acta 50, 969-977. [5] Longhi (1991) Proc. Lunar Planet. Sci. Conf. 21st, 695-709. [6] Nyquist et al. (2001) In Chronology and Evolution of Mars 96, pp. 105-164. [7] Borg (2003) Geochim. Cosmochim. Acta 67, 3519-3536.

  4. Crystallization kinetics of olivine-phyric shergottites

    NASA Astrophysics Data System (ADS)

    Ennis, Megan E.; McSween, Harry Y.

    2014-08-01

    Crystal size distribution (CSD) and spatial distribution pattern (SDP) analyses are applied to the early crystallizing phases, olivine and pyroxene, in olivine-phyric shergottites (Elephant moraine [EET] 79001A, Dar al Gani [DaG] 476, and dhofar [Dho] 019) from each sampling locality inferred from Mars ejection ages. Trace element zonation patterns (P and Cr) in olivine are also used to characterize the crystallization history of these Martian basalts. Previously reported 2-D CSDs for these meteorites are re-evaluated using a newer stereographically corrected methodology. Kinks in the olivine CSD plots suggest several populations that crystallized under different conditions. CSDs for pyroxene in DaG 476 and EET 79001A reveal single populations that grew under steady-state conditions; pyroxenes in Dho 019 were too intergrown for CSD analysis. Magma chamber residence times of several days for small grains to several months for olivine megacrysts are calculated using the CSD slopes and growth rates inferred from previous experimental data. Phosphorus imaging in olivines in DaG 476 and Dho 019 indicate rapid growth of skeletal, sector-zoned, or patchy cores, probably in response to delayed nucleation, followed by slow growth, and finally rapid dendritic growth with back-filling to form oscillatory zoning in rims. SPD analyses indicate that olivine and pyroxene crystals grew or accumulated in clusters rather than as randomly distributed grains. These data reveal complex solidification histories for Martian basalts, and are generally consistent with the formation at depth of olivine megacryst cores, which were entrained in ascending magmas that crystallized pyroxenes, small olivines, and oscillatory rims on megacrysts.

  5. Solubility of Sulfur in Shergottitic Silicate Melts Up to 0.8 GPA: Implications for S Contents of Shergottites

    NASA Technical Reports Server (NTRS)

    Righter, K.; Pando, K.M.; Danielson, L.

    2009-01-01

    Shergottites have high S contents (1300 to 4600 ppm; [1]), but it is unclear if they are sulfide saturated or under-saturated. This issue has fundamental implications for determining the long term S budget of the martian surface and atmosphere (from mantle degassing), as well as evolution of the highly siderophile elements (HSE) Au, Pd, Pt, Re, Rh, Ru, Ir, and Os, since concentrations of the latter are controlled by sulfide stability. Resolution of sulfide saturation depends upon temperature, pressure, oxygen fugacity (and FeO), and magma composition [2]. Expressions derived from experimental studies allow prediction of S contents, though so far they are not calibrated for shergottitic liquids [3-5]. We have carried out new experiments designed to test current S saturation models, and then show that existing calibrations are not suitable for high FeO and low Al2O3 compositions characteristic of shergottitic liquids. The new results show that existing models underpredict S contents of sulfide saturated shergottitic liquids by a factor of 2.

  6. Petrography and mineralogy of the ungrouped type 3 carbonaceous chondrite Dar al Gani 978

    NASA Astrophysics Data System (ADS)

    Zhang, Ai-Cheng; Yurimoto, Hisayoshi

    2013-09-01

    Dar al Gani (DaG) 978 is an ungrouped type 3 carbonaceous chondrite. In this study, we report the petrography and mineralogy of Ca,Al-rich inclusions (CAI), amoeboid olivine aggregates (AOAs), chondrules, mineral fragments, and the matrix in DaG 978. Twenty-seven CAIs were found: 13 spinel-diopside-rich inclusions, 2 anorthite-rich inclusions, 11 spinel-troilite-rich inclusions, and 1 spinel-melilite-rich inclusion. Most CAIs have a layered texture that indicates a condensation origin and are most similar to those in R chondrites. Compound chondrules represent a high proportion (approximately 8%) of chondrules in DaG 978, which indicates a local dusty chondrule-forming region and multiple heating events. Most spinel and olivine in DaG 978 are highly Fe-rich, which corresponds to a petrologic type of >3.5 and a maximum metamorphic temperature of approximately 850-950 K. This conclusion is also supported by other observations in DaG 978: the presence of coarse inclusions of silicate and phosphate in Fe-Ni metal, restricted Ni-Co distributions in kamacite and taenite, and low S concentrations in the matrix. Mineralogic records of iron-alkali-halogen metasomatism, such as platy and porous olivine, magnetite, hedenbergite, nepheline, Na-rich in CAIs, and chlorapatite, are present, but relatively limited, in DaG 978. The fine-grained, intergrowth texture of spinel-troilite-rich inclusions was probably formed by reaction between pre-existing Al-rich silicates and shock-induced, high-temperature S-rich gas on the surface of the parent body of DaG 978. A shock-induced vein is present in the matrix of DaG 978, which indicates that the parent body of DaG 978 at least experienced a shock event with a shock stage up to S3.

  7. Geochemical diversity of shergottite basalts: Mixing and fractionation, and their relation to Mars surface basalts

    NASA Astrophysics Data System (ADS)

    Treiman, Allan H.; Filiberto, Justin

    2015-04-01

    The chemical compositions of shergottite meteorites, basaltic rocks from Mars, provide a broad view of the origins and differentiation of these Martian magmas. The shergottite basalts are subdivided based on their Al contents: high-Al basalts (Al > 5% wt) are distinct from low-Al basalts and olivine-phyric basalts (both with Al < 4.5% wt). Abundance ratios of highly incompatible elements (e.g., Th, La) are comparable in all the shergottites. Abundances of less incompatible elements (e.g., Ti, Lu, Hf) in olivine-phyric and low-Al basalts correlate well with each other, but the element abundance ratios are not constant; this suggests mixing between components, both depleted and enriched. High-Al shergottites deviate from these trends consistent with silicate mineral fractionation. The "depleted" component is similar to the Yamato-980459 magma; approximately, 67% crystal fractionation of this magma would yield a melt with trace element abundances like QUE 94201. The "enriched" component is like the parent magma for NWA 1068; approximately, 30% crystal fractionation from it would yield a melt with trace element abundances like the Los Angeles shergottite. This component mixing is consistent with radiogenic isotope and oxygen fugacity data. These mixing relations are consistent with the compositions of many of the Gusev crater basalts analyzed on Mars by the Spirit rover (although with only a few elements to compare). Other Mars basalts fall off the mixing relations (e.g., Wishstone at Gusev, Gale crater rocks). Their compositions imply that basalt source areas in Mars include significant complexities that are not present in the source areas for the shergottite basalts.

  8. Terrestrial and Martian weathering signatures of xenon components in shergottite mineral separates

    NASA Astrophysics Data System (ADS)

    Cartwright, J. A.; Ocker, K. D.; Crowther, S. A.; Burgess, R.; Gilmour, J. D.

    2010-08-01

    Xenon-isotopic ratios, step-heating release patterns, and gas concentrations of mineral separates from Martian shergottites Roberts Massif (RBT) 04262, Dar al Gani (DaG) 489, Shergotty, and Elephant Moraine (EET) 79001 lithology B are reported. Concentrations of Martian atmospheric xenon are similar in mineral separates from all meteorites, but more weathered samples contain more terrestrial atmospheric xenon. The distributions of xenon from the Martian and terrestrial atmospheres among minerals in any one sample are similar, suggesting similarities in the processes by which they were acquired. However, in opaque and maskelynite fractions, Martian atmospheric xenon is released at higher temperatures than terrestrial atmospheric xenon. It is suggested that both Martian and terrestrial atmospheric xenon were initially introduced by weathering (low temperature alteration processes). However, the Martian component was redistributed by shock, accounting for its current residence in more retentive sites. The presence or absence of detectable 129Xe from the Martian atmosphere in mafic minerals may correspond to the extent of crustal contamination of the rock's parent melt. Variable contents of excess 129Xe contrast with previously reported consistent concentrations of excess 40Ar, suggesting distinct sources contributed these gases to the parent magma.

  9. Yamato 980459: The Most Primitive Shergottite?

    NASA Technical Reports Server (NTRS)

    McKay, G.; Le, L.; Schwandt, C.; Mikouchi, T.; Koizumi, E.; Jones, J.

    2004-01-01

    The Antarctic Research Center of the Japanese National Institute of Polar Research (NIPR) recently announced the discovery of a new Martian shergottite, Y98(0459). This sample is a member of the subgroup of basaltic shergottites that contain abundant olivine phenocrysts, and are thus olivine- phyric. Y98 may have special significance among the basaltic shergottites because (1) it appears to have been the most magnesian Martian magma yet found, and thus can provide valuable clues to magma petrogenesis on Mars; (2) it contains no late-crystallizing phases, but instead contains approx. 30% interstitial glass, which can provide unambiguous incompatible element patterns of the parent melt; and (3) it carries an LREE-depleted signature similar to QUE 94201, whose isotopic characteristics are the most primitive of all basaltic shergottites.

  10. The source crater of martian shergottite meteorites.

    PubMed

    Werner, Stephanie C; Ody, Anouck; Poulet, François

    2014-03-21

    Absolute ages for planetary surfaces are often inferred by crater densities and only indirectly constrained by the ages of meteorites. We show that the <5 million-year-old and 55-km-wide Mojave Crater on Mars is the ejection source for the meteorites classified as shergottites. Shergottites and this crater are linked by their coinciding meteorite ejection ages and the crater formation age and by mineralogical constraints. Because Mojave formed on 4.3 billion-year-old terrain, the original crystallization ages of shergottites are old, as inferred by Pb-Pb isotope ratios, and the much-quoted shergottite ages of <600 million years are due to resetting. Thus, the cratering-based age determination method for Mars is now calibrated in situ, and it shifts the absolute age of the oldest terrains on Mars backward by 200 million years.

  11. The Martian Surface is old and so are Shergottites

    NASA Astrophysics Data System (ADS)

    Bouvier, A.; Blichert-Toft, J.; Vervoort, J. D.; Albarede, F.

    2005-12-01

    very old and formed mostly over the first one billion years of the planet's history, thus eliminating the above paradox. We further interpret the young shergottite Rb-Sr, Sm-Nd, and Lu-Hf ages to be the result of the resetting of these isotopic systems by acidic groundwater percolation through the Martian crust, ending approximately 150-300 My ago. We argue that throughout much of Martian history, large acid lakes of regional extent collected and mixed groundwaters and redistributed 142Nd and 182W between rocks of different ages, some of them nearly as old as the planet itself and carrying strong isotopic anomalies. From an interpretation of satellite images, it has been argued (10) that over the planet's first billion years of evolution, one third of its surface was covered by bodies of standing water and ice floodwaters derived from a subpermafrost aquifer. The last pools of liquid water occupying various spots on the Martian surface may have disappeared either by evaporation or by retreating into a permafrost layer now buried beneath thick wind-blown deposits. 1. Chen and Wasserburg, GCA 50, 955 (1986). 2. Nyquist et al., Space Sci. Rev. 96, 105 (2001). 3. Clayton and Mayeda, GCA 60, 1999 (1996). 4. Franchi et al., Phil. Trans. R. Soc. London, 359, 2019 (2001). 5. Squyres et al., Science 306, 1698 (2004). 6. Gendrin et al., Science 307, 1587 (2005). 7. Fairen et al., Nature 431, 423 (2004). 8. McCoy et al., GCA 63, 1249 (1999). 9. Dreibus et al., LPS 27, 323 (1996). 10. Clifford, Icarus 154, 40 (2001).

  12. Petrology and Geochemistry of a Mg- and Al-Rich Orthopyroxenite Xenolith in the EETA79001 Shergottite: Implications for Mars Crustal Evolution

    NASA Technical Reports Server (NTRS)

    Berkley, John L.

    1999-01-01

    EETA79001 is a Mars meteorite (SNC) consisting of multiple rock types, including two basalt types, olivine and pyroxene xenocrysts, and ultramafic xenoliths. This study is focused on the petrology and geochemistry of one orthopyroxenite xenolith in PTS 68, designated X-1. It consists of chemically homogeneous orthopyroxene cores with exceptionally high Mg/Fe (mg#=85) and Al. Cores are permeated by minute high-Si+Al glassy inclusions, some with augite microlites. Magnesian core areas are mantled by more Fe-rich orthopyroxene rims grading to pigeonite away from cores. The xenolith is transected by cross-cutting shear planes, some of pre-incorporation origin. Major and minor element composition and variation suggest that core areas are primarily igneous, crystallized from a high temperature mafic melt. However, nearly constant mg# across cores suggest metamorphic equilibration. Si+Al inclusions may result from, among other processes, exsolution of feldspathic material during subsolidus cooling, or may be solid materials (alkali feldspar) poikilitically enclosed by growing igneous orthopyroxene crystals. Late reaction with more fractionated melts produced Fe-rich mantles, the whole assemblage later cut by tectonic micro-shear planes. Raw electron microprobe data produced during this study are available on request from the author.

  13. The age of the martian meteorite Northwest Africa 1195 and the differentiation history of the shergottites

    SciTech Connect

    Symes, S; Borg, L; Shearer, C; Irving, A

    2007-04-05

    Samarium-neodymium isotopic analyses of unleached and acid-leached mineral fractions from the recently identified olivine-bearing shergottite Northwest Africa 1195 yield a crystallization age of 348 {+-} 19 Ma and an {var_epsilon}{sub Nd}{sup 143} value of +40.1 {+-} 1.3. Maskelynite fractions do not lie on the Sm-Nd isochron and appear to contain a martian surface component with low {sup 147}Sm/{sup 144}Nd and {sup 143}Nd/{sup 144}Nd ratios that was added during shock. The Rb-Sr system is disturbed and does not yield an isochron. Terrestrial Sr appears to have affected all of the mineral fractions, although a maximum initial {sup 87}Sr/{sup 86}Sr ratio of 0.701614 {+-} 16 is estimated by passing a 348 Ma reference isochron through the maskelynite fraction that is least affected by contamination. The high initial {var_epsilon}{sub Nd}{sup 143} value and the low initial {sup 87}Sr/{sup 86}Sr ratio, combined with the geologically young crystallization age, indicate that Northwest Africa 1195 is derived from a source region characterized by a long-term incompatible element depletion. The age and initial Sr and Nd isotopic compositions of Northwest Africa 1195 are very similar to those of Queen Alexandra Range 94201, indicating these samples were derived from source regions with nearly identical Sr-Nd isotopic systematics. These similarities suggest that these two meteorites share a close petrogenetic relationship and might have been erupted from a common volcano. The meteorites Yamato 980459, Dar al Gani 476, Sayh al Uhaymir 005/008, and Dhofar 019 also have relatively old ages between 474-575 Ma and trace element and/or isotopic systematics that are indicative of derivation from incompatible-element-depleted sources. This suggests that the oldest group of meteorites is more closely related to one another than they are to the younger meteorites that are derived from less incompatible-element-depleted sources. Closed-system fractional crystallization of this suite of

  14. The age of the martian meteorite Northwest Africa 1195 and the differentiation history of the shergottites

    NASA Astrophysics Data System (ADS)

    Symes, Steven J. K.; Borg, Lars E.; Shearer, Charles K.; Irving, Anthony J.

    2008-03-01

    Samarium-neodymium isotopic analyses of unleached and acid-leached mineral fractions from the recently identified olivine-bearing shergottite Northwest Africa 1195 yield a crystallization age of 347 ± 13 Ma and an ɛNd143 value of +40.1 ± 0.9. Maskelynite fractions do not lie on the Sm-Nd isochron and appear to contain a martian surface component with low 147Sm/ 144Nd and 143Nd/ 144Nd ratios that was added during shock. The Rb-Sr system is disturbed and does not yield an isochron. Terrestrial Sr appears to have affected all of the mineral fractions, although a maximum initial 87Sr/ 86Sr ratio of 0.7016 is estimated by passing a 347 Ma reference line through the maskelynite fraction that is least affected by contamination. The high initial ɛNd143 value and the low initial 87Sr/ 86Sr ratio, combined with the geologically young crystallization age, indicate that Northwest Africa 1195 is derived from a source region characterized by a long-term incompatible-element depletion. The age and initial Sr and Nd isotopic compositions of Northwest Africa 1195 are very similar to those of Queen Alexandra Range 94201, indicating these samples were derived from source regions with similar Sr-Nd isotopic systematics. These similarities suggest that these two meteorites share a close petrogenetic relationship and might have been erupted from a common volcano. The meteorites Yamato 980459, Dar al Gani 476, Sayh al Uhaymir 005/008, and Dhofar 019 also have relatively old ages between 474 and 575 Ma and trace element and/or isotopic systematics that are indicative of derivation from incompatible-element-depleted sources. This suggests that the oldest group of meteorites is more closely related to one another than they are to the younger meteorites that are derived from less incompatible-element-depleted sources. Closed-system fractional crystallization of this suite of meteorites is modeled with the MELTS algorithm using the bulk composition of Yamato 980459 as a parent. These

  15. Solar proton produced neon in shergottite meteorites

    NASA Technical Reports Server (NTRS)

    Garrison, D. H.; Rao, M. N.; Bogard, D. D.

    1994-01-01

    Cosmogenic radionuclides produced by near-surface, nuclear interactions of energetic solar protons (approx. 10-100 MeV) were reported in several lunar rocks and a very small meteorites. We recently documented the existence and isotopic compositions of solar-produced (SCR) Ne in two lunar rocks. Here we present the first documented evidence for SCR Ne in a meteorite, ALH77005, which was reported to contain SCR radionuclides. Examination of literature data for other shergottites suggests that they may also contain a SCR Ne component. The existence of SCR Ne in shergottites may be related to a Martian origin.

  16. An Exploration of the Viability of Partnership between "Dar Al-Ulum" and Higher Education Institutions in North West England Focusing upon Pedagogy and Relevance

    ERIC Educational Resources Information Center

    Geaves, Ron

    2015-01-01

    The article explores possibilities of collaboration between Muslim providers of traditional education ("dar al-ulums") and HE/FE institutions in close geographical proximity in the North West England. It reports the outcomes of a project carried out in 2011/2012 influenced by the findings of the Makadam/Scott-Baumann report in 2010, in…

  17. Sulfur Isotopes in Gas-rich Impact-Melt Glasses in Shergottites

    NASA Technical Reports Server (NTRS)

    Rao, M. N.; Hoppe, P.; Sutton, S. R.; Nyquist, Laurence E.; Huth, J.

    2010-01-01

    Large impact melt glasses in some shergottites contain huge amounts of Martian atmospheric gases and they are known as gas-rich impact-melt (GRIM) glasses. By studying the neutron-induced isotopic deficits and excesses in Sm-149 and Sm-150 isotopes resulting from Sm-149 (n,gamma) 150Sm reaction and 80Kr excesses produced by Br-79 (n,gamma) Kr-80 reaction in the GRIM glasses using mass-spectrometric techniques, it was shown that these glasses in shergottites EET79001 and Shergotty contain regolith materials irradiated by a thermal neutron fluence of approx.10(exp 15) n/sq cm near Martian surface. Also, it was shown that these glasses contain varying amounts of sulfates and sulfides based on the release patterns of SO2 (sulfate) and H2S (sulfide) using stepwise-heating mass-spectrometric techniques. Furthermore, EMPA and FE-SEM studies in basaltic-shergottite GRIM glasses EET79001, LithB (,507& ,69), Shergotty (DBS I &II), Zagami (,992 & ,994) showed positive correlation between FeO and "SO3" (sulfide + sulfate), whereas those belonging to olivine-phyric shergottites EET79001, LithA (,506, & ,77) showed positive correlation between CaO/Al2O3 and "SO3".

  18. Basaltic Shergottite NWA 856: Differentiation of a Martian Magma

    NASA Technical Reports Server (NTRS)

    Ferdous, J.; Brandon, A. D.; Peslier, A. H.; Pirotte, Z.

    2016-01-01

    NWA 856 or Djel Ibone, is a basaltic shergottite discovered as a single stone of 320 g in South Morocco in April, 2001. This meteorite is fresh, i.e. shows minimal terrestrial weathering for a desert find. No shergottite discovered in North Africa can be paired with NWA 856. The purpose of this study is to constrain its crystallization history using textural observations, crystallization sequence modeling and in-situ trace element analysis in order to understand differentiation in shergottite magmatic systems.

  19. Uls LiDAR Supported Analyses of Laser Beam Penetration from Different ALS Systems Into Vegetation

    NASA Astrophysics Data System (ADS)

    Wieser, M.; Hollaus, M.; Mandlburger, G.; Glira, P.; Pfeifer, N.

    2016-06-01

    This study analyses the underestimation of tree and shrub heights for different airborne laser scanner systems and point cloud distribution within the vegetation column. Reference data was produced by a novel UAV-borne laser scanning (ULS) with a high point density in the complete vegetation column. With its physical parameters (e.g. footprint) and its relative accuracy within the block as stated in Section 2.2 the reference data is supposed to be highly suitable to detect the highest point of the vegetation. An airborne topographic (ALS) and topo-bathymetric (ALB) system were investigated. All data was collected in a period of one month in leaf-off condition, while the dominant tree species in the study area are deciduous trees. By robustly estimating the highest 3d vegetation point of each laser system the underestimation of the vegetation height was examined in respect to the ULS reference data. This resulted in a higher under-estimation of the airborne topographic system with 0.60 m (trees) and 0.55 m (shrubs) than for the topo-bathymetric system 0.30 m (trees) and 0.40 m (shrubs). The degree of the underestimation depends on structural characteristics of the vegetation itself and physical specification of the laser system.

  20. Shock Metamorphism of the Dhofar 378 Basaltic Shergottite

    NASA Technical Reports Server (NTRS)

    Mikouchi, T.; McKay, G.

    2006-01-01

    Shock metamorphism is one of the most fundamental processes in the history of Martian meteorites, especially shergottites, which affect their mineralogy and chronology. The formation of "maskelynite" from plagioclase and shock melts is such major mineralogical effects. Dhofar 378 is one of the recently found desert shergottites that is mainly composed of plagioclase and pyroxene. This shergottite is important because of its highly shocked nature and unique plagioclase texture, and thus has a great potential for assessing a "shock" age of shergottites. We have been working on a combined study of mineralogy and chronology of the same rock chip of Dhofar 378. This abstract reports its mineralogical part.

  1. A More Reduced Mantle Source for Enriched Shergottites; Insights from the Olivine-Phyric Shergottite Lar 06319

    NASA Technical Reports Server (NTRS)

    Peslier, A. H.; Hnatyshin, D.; Herd, C. D. K.; Walton, E. L.; Brandon, A. D.; Lapen, T. J.; Shafer, J.

    2010-01-01

    A detailed petrographic study of melt inclusions and Cr-Fe-Ti oxides of LAR 06319 leads to two main conclusions: 1) this enriched oxidized olivine- phyric shergottite represents nearly continuous crystallization of a basaltic shergottite melt, 2) the melt became more oxidized during differentiation. The first crystallized mineral assemblages record the oxygen fugacity which is closest to that of the melt s mantle source, and which is lower than generally attributed to the enriched shergottite group.

  2. Volatile compounds in shergottite and nakhlite meteorites

    NASA Technical Reports Server (NTRS)

    Gooding, James L.; Aggrey, Kwesi E.; Muenow, David W.

    1990-01-01

    Since discovery of apparent carbonate carbon in Nakhla, significant evidence has accumulated for occurrence of volatile compounds in shergotties and nakhlites. Results are presented from a study of volatile compounds in three shergottites, one nakhlite, and three eucrite control samples. Shergotties ALHA77005, EETA79001, and Shergotty, and the nakhlite Nakhla, all contain oxidized sulfur (sulfate) of preterrestrial origin; sulfur oxidation is most complete in EETA79001/Lith-C. Significant bulk carbonate was confirmed in Nakhla and trace carbonate was substantiated for EETA79001, all of which appears to be preterrestrial in origin. Chlorine covaries with oxidized sulfur, whereas carbonate and sulfate are inversely related. These volatile compounds were probably formed in a highly oxidizing, aqueous environment sometime in the late stage histories of the rocks that are now represented as meteorites. They are consistent with the hypothesis that shergottite and nakhlite meteorites originated on Mars and that Mars has supported aqueous geochemistry during its history.

  3. Northwest Africa 5298: A Basaltic Shergottite

    NASA Technical Reports Server (NTRS)

    Hui, Hejiu; Peslier, Anne; Lapen, Thomas J.; Brandon, Alan; Shafer, John

    2009-01-01

    NWA 5298 is a single 445 g meteorite found near Bir Gandouz, Morocco in March 2008 [1]. This rock has a brown exterior weathered surface instead of a fusion crust and the interior is composed of green mineral grains with interstitial dark patches containing small vesicles and shock melts [1]. This meteorite is classified as a basaltic shergottite [2]. A petrologic study of this Martian meteorite is being carried out with electron microprobe analysis and soon trace element analyses by laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). Oxygen fugacity is calculated from Fe-Ti oxides pairs in the sample. The data from this study constrains the petrogenesis of basaltic shergottites.

  4. Chemical Composition of Four Shergottites from Northwest Africa (NWA 2800, NWA, 5214, NWA 5990, NWA 6342)

    NASA Technical Reports Server (NTRS)

    Yang, S.; Humayun, M.; Jefferson, G.; Fields, D.; Righter, K.; Irving, A. J.

    2013-01-01

    Shergottites represent the majority of recovered Martian meteorites. As basic igneous rocks, they formed from magmas that were emplaced in the Martian crust [1]. Due to the low ambient pressure of the Martian atmosphere, subaerial lavas and shallow magma chambers are expected to outgas volatile metals (e.g., Cd, Te, Re, Bi) [2]. The planetary abundances of the volatile siderophile and chalcophile elements are important at establishing the depth of core formation for Mars, and must be known as a baseline for understanding volcanic outgassing on Mars, particularly the large enrichments of S and Cl observed in modern Martian soils [3]. There is little data on volatile siderophile and chalcophile elements from Martian meteorites, excluding a few well-analyzed samples [2]. Further, a large number of shergottites being recovered from North West Africa are in need of chemical analysis. All of the shergottites are in need of state-of-the art analysis for such ratios as Ge/Si and Ga/Al, which can now be accomplished by LA-ICP-MS [2].

  5. Petrology and chemistry of the basaltic shergottite North West Africa 480

    NASA Astrophysics Data System (ADS)

    Barrat, J. A.; Gillet, Ph.; Sautter, V.; Jambon, A.; Javoy, M.; Göpel, C.; Lesourd, M.; Keller, F.; Petit, E.

    2002-04-01

    North West Africa (NWA) 480 is a new martian meteorite of 28 g found in the Moroccan Sahara in November 2000. It consists mainly of large gray pyroxene crystals (the largest grains are up to 5 mm in length) and plagioclase converted to maskelynite. Excluding the melt pocket areas, modal analyses indicate the following mineral proportions: 72 vol% pyroxenes extensively zoned, 25% maskelynite, 1% phosphates (merrillite and chlorapatite), 1% opaque oxides (ilmenite, ulvospinel and chromite) and sulfides, and 1% others such as silica and fayalite. The compositional trend of NWA 480 pyroxenes is similar to that of Queen Alexandra Range (QUE) 94201 but in NWA 480 the pyroxene cores are more Mg-rich (En77-En65). Maskelynites display a limited zoning (An42-50Ab54-48Or2-4). Our observations suggest that NWA 480 formed from a melt with a low nuclei density at a slow cooling rate. The texture was achieved via a single-stage cooling where pyroxenes grew continuously. A similar model was previously proposed for QUE 94201 by McSween et al. (1996). NWA 480 is an Al-poor ferroan basaltic rock and resembles Zagami or Shergotty for major elements and compatible trace element abundances. The bulk rock analysis for oxygen isotopes yields V17O = +0.42%o, a value in agreement at the high margin, with those measured on other shergottites (Clayton and Mayeda, 1996; Romanek et al., 1998; Franchi et al., 1999). Its CI-normalized rare earth element pattern is similar to those of peridotitic shergottites such as Allan Hills (ALH)A77005, suggesting that these shergottites shared a similar parent liquid, or at least the same mantle source.

  6. Complex Formation History of Highly Evolved Basaltic Shergottite, Zagami

    NASA Technical Reports Server (NTRS)

    Niihara, T.; Misawa, K.; Mikouchi, T.; Nyquist, L. E.; Park, J.; Hirata, D.

    2012-01-01

    Zagami, a basaltic shergottite, contains several kinds of lithologies such as Normal Zagami consisting of Fine-grained (FG) and Coarse-grained (CG), Dark Mottled lithology (DML), and Olivine-rich late-stage melt pocket (DN). Treiman and Sutton concluded that Zagami (Normal Zagami) is a fractional crystallization product from a single magma. It has been suggested that there were two igneous stages (deep magma chamber and shallow magma chamber or surface lava flow) on the basis of chemical zoning features of pyroxenes which have homogeneous Mg-rich cores and FeO, CaO zoning at the rims. Nyquist et al. reported that FG has a different initial Sr isotopic ratio than CG and DML, and suggested the possibility of magma mixing on Mars. Here we report new results of petrology and mineralogy for DML and the Olivine-rich lithology (we do not use DN here), the most evolved lithology in this rock, to understand the relationship among lithologies and reveal Zagami s formation history

  7. Shock-induced deformation of Shergottites: Shock-pressures and perturbations of magmatic ages on Mars

    NASA Astrophysics Data System (ADS)

    El Goresy, Ahmed; Gillet, Ph.; Miyahara, M.; Ohtani, E.; Ozawa, S.; Beck, P.; Montagnac, G.

    2013-01-01

    Shergottites and Chassignites practiced major deformation effects whose nature, magnitude and relevance were controversially evaluated and disputatively debated. Our studies of many shocked shergottites present, contrary to numerous previous reports, ample evidence for pervasive shock-induced melting amounting of at least 23 vol.% of the shergottite consisting of maskelynite and pyrrhotite, partial melting of pyroxene, titanomagnetite, ilmenite and finding of several high-pressure polymorphs and pressure-induced dissociation reactions. Our results cast considerable doubt on using the refractive index (RI) or cathodoluminescence (CL) spectra of maskelynite, in estimating the magnitudes of peak-shock pressure in both shergottites and ordinary chondrites. RI of maskelynite was set after quenching of the feldspar liquid before decompression to maskelynite glass followed by glass relaxation after decompression at the closure temperature of relaxation. The RI procedure widely practiced in the past 38 years revealed unrealistic very high-pressure estimates discrepant with the high-pressure mineral inventory in shocked shergottites and ordinary chondrites and with results obtained by robust laboratory static experiments. Shergottites contain the silica high-pressure polymorphs: the scrutinyite-structured polymorph seifertite, a monoclinic ultra dense polymorph of silica with ZrO2-structure, stishovite, a dense liquidus assemblage consisting of stishovite + Na-hexa-aluminosilicate (Na-CAS) and both K-lingunite and Ca-lingunite. Applying individual high-pressure silica polymorphs alone like stishovite, to estimate the equilibrium shock pressure, is inadequate due to the considerable shift of their nominal upper pressure bounds intrinsically induced by spatially variable absorptions of minor oxides like Al2O3, Na2O, FeO, MgO and TiO2. This practice revealed variable pressure estimates even within the same shergottite subjected to the same peak-shock pressure. Occurrence of Na

  8. Acid-Sulfate-Weathering Activity in Shergottite Sites on Mars Recorded in Grim Glasses

    NASA Technical Reports Server (NTRS)

    Rao, M. N.; Nyquist, L. E.; Ross, K.; Sutton, S. R.; Schwandt, C. S.

    2011-01-01

    Based on mass spectrometric studies of sulfur species in Shergotty and EET79001, [1] and [2] showed that sulfates and sulfides occur in different proportions in shergottites. Sulfur speciation studies in gas-rich impact-melt (GRIM) glasses in EET79001 by the XANES method [3] showed that S K-XANES spectra in GRIM glasses from Lith A indicate that S is associated with Ca and Al presumably as sulfides/sulfates whereas the XANES spectra of amorphous sulfide globules in GRIM glasses from Lith B indicate that S is associated with Fe as FeS. In these amorphous iron sulfide globules, [4] found no Ni using FE-SEM and suggested that the globules resulting from immiscible sulfide melt may not be related to the igneous iron sulfides having approximately 1-3% Ni. Furthermore, in the amorphous iron sulfides from 507 GRIM glass, [5] determined delta(sup 34)S values ranging from +3.5%o to -3.1%o using Nano-SIMS. These values plot between the delta(sup 34)S value of +5.25%o determined in the sulfate fraction in Shergotty [6] at one extreme and the value of -1.7%o obtained for igneous sulfides in EET79001 and Shergotty [7] at the other. These results suggest that the amorphous Fe-S globules likely originated by shock reduction of secondary iron sulfate phases occurring in the regolith precursor materials during impact [7]. Sulfates in the regolith materials near the basaltic shergottite sites on Mars owe their origin to surficial acid-sulfate interactions. We examine the nature of these reactions by studying the composition of the end products in altered regolith materials. For the parent material composition, we use that of the host shergottite material in which the impact glasses are situated.

  9. Lead Isotopes in Olivine-Phyric Shergottite Tissint: Implications for the Geochemical Evolution of the Shergottite Source Mantle

    NASA Technical Reports Server (NTRS)

    Moriwaki, R.; Usui, T.; Simon, J. I.; Jones, J. H.; Yokoyama, T.

    2015-01-01

    Geochemically-depleted shergottites are basaltic rocks derived from a martian mantle source reservoir. Geochemical evolution of the martian mantle has been investigated mainly based on the Rb-Sr, Sm-Nd, and Lu-Hf isotope systematics of the shergottites [1]. Although potentially informative, U-Th- Pb isotope systematics have been limited because of difficulties in interpreting the analyses of depleted meteorite samples that are more susceptible to the effects of near-surface processes and terrestrial contamination. This study conducts a 5-step sequential acid leaching experiment of the first witnessed fall of the geochemically-depleted olivinephyric shergottite Tissint to minimize the effect of low temperature distrubence. Trace element analyses of the Tissint acid residue (mostly pyroxene) indicate that Pb isotope compositions of the residue do not contain either a martian surface or terrestrial component, but represent the Tissint magma source [2]. The residue has relatively unradiogenic initial Pb isotopic compositions (e.g., 206Pb/204Pb = 10.8136) that fall within the Pb isotope space of other geochemically-depleted shergottites. An initial µ-value (238U/204Pb = 1.5) of Tissint at the time of crystallization (472 Ma [3]) is similar to a time-integrated mu- value (1.72 at 472 Ma) of the Tissint source mantle calculated based on the two-stage mantle evolution model [1]. On the other hand, the other geochemically-depleted shergottites (e.g., QUE 94201 [4]) have initial µ-values of their parental magmas distinctly lower than those of their modeled source mantle. These results suggest that only Tissint potentially reflects the geochemical signature of the shergottite mantle source that originated from cumulates of the martian magma ocean

  10. Rare Earth elements in individual minerals in Shergottites

    NASA Technical Reports Server (NTRS)

    Wadhwa, Meenakshi; Crozaz, Ghislaine

    1993-01-01

    Shergottites (i.e., Shergotty, Zagami, EETA79001, ALHA77005, and LEW88516) are an important set of achondrites because they comprise the majority of the SNC group of meteorites (nine, in total, known to us), which are likely to be samples of the planet Mars. Study of these meteorites may therefore provide valuable information about petrogenetic processes on a large planetary body other than Earth. Rare earth element (REE) distributions between various mineral phases were found to be useful in geochemically modeling the petrogenesis of various rock types (terrestrial and meteoritic). However, with the exception of a few ion microprobe studies and analyses of mineral separates, there has previously not been any comprehensive effort to characterize and directly compare REE in individual minerals in each of the five known shergottites. Ion microprobe analyses were made on thin sections of each of the shergottites. Minerals analyzed were pyroxenes (pigeonite and augite), maskelynite, and whitlockite. The REE concentrations in each mineral type in each shergottite is given.

  11. Provenance and Concentration of Water in the Shergottite Mantle

    NASA Technical Reports Server (NTRS)

    Jones, J. H.; Usui, T.; Alexander, C. M. O'D.; Simon, J. I.; Wang, J.

    2012-01-01

    The water content of the martian mantle is controversial. In particular, the role of water in the petrogenesis of the shergottites has been much debated. Although the shergottites, collectively, contain very little water [e.g., 1,2], some experiments have been interpreted to show that percent levels of water are required for the petrogenesis of shergottites such as Shergotty and Zagami [3]. In this latter interpretation, the general paucity of water in the shergottites and their constituent minerals is attributed to late-stage degassing. Y980459 (Y98) is a very primitive, perhaps even parental, martian basalt, with a one-bar liquidus temperature of approx.1400 C. Olivine is the liquidus phase, and olivine core compositions are in equilibrium with the bulk rock [e.g., 4]. Petrogenetically, therefore, Y98 has had a rather simple history and can potentially help constrain the role of water in martian igneous processes. In particular, once trapped, melt inclusions should not be affected by subsequent degassing.

  12. The Role of Garnet in Martian Mantle Evolution: Further Evidence from Shergottite Rare Earth Patterns

    NASA Astrophysics Data System (ADS)

    Gleason, J. D.; Kring, D. A.; Boynton, W. V.

    1996-03-01

    REE fractionation and isotopic decoupling effects in SNC meteorites have been attributed in the past to the presence of garnet in their mantle source regions. Quantifying the garnet effect is now possible using the parent melt REE compositions determined by for the shergottites, a group of SNC meteorites characterized by complex rare earth element (REE) patterns and 180 Ma isotopic ages. Below, we develop a multi-stage REE evolution model for a shergottite source which underwent fractional fusion at earlier stages with garnet present. Similar processes may account for (1) the decoupling of the Sm-Nd isotopic system from the Rb-Sr and U-Th-Pb isotopic systems in SNC meteorites, and (2) non-chondritic abundance ratios for certain refractory lithophile elements (e.g., high Th/La, U/La, and low Al/Ti) in SNC's. If this model is generally correct, it then requires a planet large enough to have crystallized substantial garnet in its mantle source regions, consistent with a martian origin for the SNC's.

  13. AR-39-AR-40 "Age" of Basaltic Shergottite NWA-3171

    NASA Technical Reports Server (NTRS)

    Bogard, Donald D.; Park, Jisun

    2007-01-01

    North-West-Africa 3171 is a 506 g, relatively fresh appearing, basaltic shergottite with similarities to Zagami and Shergotty, but not obviously paired with any of the other known African basaltic shergottites. Its exposure age has the range of 2.5-3.1 Myr , similar to those of Zagami and Shergotty. We made AR-39-AR-40 analyses of a "plagioclase" (now shock-converted to maskelynite) separate and of a glass hand-picked from a vein connected to shock melt pockets.. Plagioclase was separated using its low magnetic susceptibility and then heavy liquid with density of <2.85 g/cm(exp 3). The AR-39-AR-40 age spectrum of NWA-317 1 plag displays a rise in age over 20-100% of the 39Ar release, from 0.24 Gyr to 0.27 Gy.

  14. An Experimental Investigation of the Shergottite NWA 6162

    NASA Technical Reports Server (NTRS)

    Barnett, R. Gaylen; Jones, John H.; Draper, David S.; Le, Loan H.

    2012-01-01

    The Martian meteorite North West Africa 6162 (NWA 6162) is a shergottite found in Morocco in 2010. The meteorite has large olivine crystals with Mg-depleted rims as low as FO(sub 65) and Mg-rich cores of up to FO(sub 74). It is similar both in appearance and composition to another shergottite, SaU 005. Our objective is to determine if NWA 6162 represents a liquid or if it is a product of olivine accumulation. Olivine accumulation would leave the parent melt Mg-depleted and the complementary olivine cumulates would be Mg-enriched. Therefore, if NWA 6162 is a partial cumulate we would expect that liquidus olivines grown from this bulk composition would be more magnesium than olivines in the natural sample.

  15. APXS ANALYSES OF BOUNCE ROCK: THE FIRST SHERGOTTITE ON MARS

    NASA Technical Reports Server (NTRS)

    Ming, Douglas W.; Zipfel, J.; Anderson, R.; Brueckner, J.; Clark, B. C.; Dreibus, G.; Economou, T.; Gellert, R.; Lugmair, G. W.; Klingelhoefer, G.

    2005-01-01

    During the MER Mission, an isolated rock at Meridiani Planum was analyzed by the Athena instrument suite [1]. Remote sensing instruments noticed its distinct appearance. Two areas on the untreated rock surface and one area that was abraded with the Rock Abrasion Tool were analyzed by Microscopic Imager, Mossbauer Mimos II [2], and Alpha Particle X-ray Spectrometer (APXS). Results of all analyses revealed a close relationship of this rock with known basaltic shergottites.

  16. LiDAR: Providing structure

    USGS Publications Warehouse

    Vierling, Lee A.; Martinuzzi, Sebastián; Asner, Gregory P.; Stoker, Jason M.; Johnson, Brian R.

    2011-01-01

    Since the days of MacArthur, three-dimensional (3-D) structural information on the environment has fundamentally transformed scientific understanding of ecological phenomena (MacArthur and MacArthur 1961). Early data on ecosystem structure were painstakingly laborious to collect. However, as reviewed and reported in recent volumes of Frontiers(eg Vierling et al. 2008; Asner et al.2011), advances in light detection and ranging (LiDAR) remote-sensing technology provide quantitative and repeatable measurements of 3-D ecosystem structure that enable novel ecological insights at scales ranging from the plot, to the landscape, to the globe. Indeed, annual publication of studies using LiDAR to interpret ecological phenomena increased 17-fold during the past decade, with over 180 new studies appearing in 2010 (ISI Web of Science search conducted on 23 Mar 2011: [{lidar AND ecol*} OR {lidar AND fores*} OR {lidar AND plant*}]).

  17. Sulfur Speciation in the Martian Regolith Component in Shergottite Glasses

    NASA Technical Reports Server (NTRS)

    Rao, M. N.; Nyquist, Laurence E.; Sutton, S.; Huth, J.

    2009-01-01

    We have shown that Gas-Rich Impact-Melt (GRIM) glasses in Shergotty, Zagami, and EET79001 (Lith A and Lith B) contain Martian regolith components that were molten during impact and quenched into glasses in voids of host rock materials based on neutron-capture isotopes, i.e., Sm-150 excesses and Sm-149 deficits in Sm, and Kr-80 excesses produced from Br [1, 2]. These GRIM glasses are rich in S-bearing secondary minerals [3.4]. Evidence for the occurrence of CaSO4 and S-rich aluminosilicates in these glasses is provided by CaO-SO3 and Al2O3-SO3 correlations, which are consistent with the finding of gypsum laths protruding from the molten glass in EET79001 (Lith A) [5]. However, in the case of GRIM glasses from EET79001 (Lith B), Shergotty and Zagami, we find a different set of secondary minerals that show a FeO-SO3 correlation (but no MgOSO3 correlation), instead of CaO-SO3 and Al2O3-SO3 correlations observed in Lith A. These results might indicate different fluidrock interactions near the shergottite source region on Mars. The speciation of sulfur in these salt assemblages was earlier studied by us using XANES techniques [6], where we found that Lith B predominantly contains Fe-sulfide globules (with some sulfate). On the other hand, Lith A showed predominantly Casulfite/ sulfate with some FeS. Furthermore, we found Fe to be present as Fe2+ indicating little oxidation, if any, in these glasses. To examine the sulfide-sulfate association in these glasses, we studied their Fe/Ni ratios with a view to find diagnostic clues for the source fluid. The Fe-sulfide mineral (Fe(0.93)Ni(0.3)S) in EET79001, Lith A is pyrrhotite [7, 8]. It yields an Fe/Ni ratio of 31. In Shergotty, pyrrhotite occurs with a molar ratio of Fe:S of 0.94 and a Ni abundance of 0.12% yielding a Fe/Ni ratio of approx.500 [8]. In this study, we determined a NiO content of approx.0.1% and FeO/NiO ratio of approx.420 in S-rich globules in #507 (EET79001, Lith B) sample using FE-SEM. In the same sample

  18. Enriched Shergottite NWA 5298 As An Evolved Parent Melt: Trace Element Inventory

    NASA Technical Reports Server (NTRS)

    Hui, Hejiu; Peslier, Anne H.; Lapen, Thomas J.; Shafer, John; Brandon, Alan; Irving, Anthony

    2010-01-01

    Martian meteorite Northwest Africa 5298 is a basaltic shergottite that was found near Bir Gandouz (Morocco). Its martian origin was confirmed by oxygen isotopes [1], as well as Mn/Fe ratios in the pyroxenes and K/anorthite ratios in the plagioclases [2]. Here we present a petrographic and geochemical study of NWA 5298. Comparison of mineralogical and geochemical characteristics of this meteorite with other Martian rocks shows that NWA 5298 is not likely paired with any other known shergottites, but it has similarities to another basaltic shergottite Dhofar 378.

  19. Sm-Nd isotopic systematics of lherzolitic shergottite Yamato-793605

    USGS Publications Warehouse

    Misawa, K.; Yamada, K.; Nakamura, N.; Morikawa, N.; Yamashita, K.; Premo, W.R.

    2006-01-01

    We have undertaken Sm-Nd isotopic studies on Yamato-793605 lherzolitic shergottite. The Sm-Nd internal isochron obtained for acid leachates and residues of whole-rock and separated mineral fractions yields an age of 185 ??16 Ma with an initial ??Nd value of +9.7??0.2. The obtained Sm-Nd age is, within analytical errors, identical to the Rb-Sr age of this meteorite as well as to the previous Rb-Sr and Sm-Nd ages of Allan Hills-77005 and Lewis Cliff 88516, although the ??Nd values are not identical to each other. Elemental abundances of lithophile trace elements remain nearly unaffected by aqueous alteration on the Martian surface. The isotopic systems of lherzolitic shergottites, thus, are considered to be indigenous, although disturbances by shock metamorphism are clearly observed. "Young ages of ??? 180 Ma" have been consistently obtained from this and previous Rb-Sr, Sm-Nd and U-Pb isotopic studies and appear to represent crystallization events. ?? 2006 National Institute of Polar Research.

  20. Rare earth patterns in shergottite phosphates and residues

    NASA Technical Reports Server (NTRS)

    Laul, J. C.

    1987-01-01

    Leaching experiments with 1M HCl on ALHA 77005 powder show that rare earth elements (REE) are concentrated in accessory phosphate phases (whitlockite, apatite) that govern the REE patterns of bulk shergottites. The REE patterns of whitlockite are typically light REE-depleted with a negative Eu anomaly and show a hump at the heavy REE side, while the REE pattern of apatite (in Shergotty) is light REE-enriched. Parent magmas are calculated from the modal compositions of residues of ALHA 77005, Shergotty, and EETA 79001. The parent magmas lack a Eu anomaly, indicating that plagioclase was a late-stage crystallizing phase and that it probably crystallized before the phosphates. The parent magmas of ALHA 77005 and Shergotty have similar REE patterns, with a subchondritic Nd/Sm ratio. However, the Sm/Nd isotopoics require a light REE-depleted source for ALHA 77005 (if the crystallization age is less than 600 Myr) and a light REE-enriched source for Shergotty. Distant Nd and Sr isotopic signatures may suggest different source regions for shergottites.

  1. Lead Isotope Compositions of Acid Residues from Olivine-Phyric Shergottite Tissint: Implications for Heterogeneous Shergottite Source Reservoirs

    NASA Technical Reports Server (NTRS)

    Moriwaki, R.; Usui, T.; Yokoyama, T.; Simon, J. I.; Jones, J. H.

    2015-01-01

    Geochemical studies of shergottites suggest that their parental magmas reflect mixtures between at least two distinct geochemical source reservoirs, producing correlations between radiogenic isotope compositions and trace element abundances. These correlations have been interpreted as indicating the presence of a reduced, incompatible element- depleted reservoir and an oxidized, incompatible- element-enriched reservoir. The former is clearly a depleted mantle source, but there is ongoing debate regarding the origin of the enriched reservoir. Two contrasting models have been proposed regarding the location and mixing process of the two geochemical source reservoirs: (1) assimilation of oxidized crust by mantle derived, reduced magmas, or (2) mixing of two distinct mantle reservoirs during melting. The former requires the ancient Martian crust to be the enriched source (crustal assimilation), whereas the latter requires isolation of a long-lived enriched mantle domain that probably originated from residual melts formed during solidification of a magma ocean (heterogeneous mantle model). This study conducts Pb isotope and trace element concentration analyses of sequential acid-leaching fractions (leachates and the final residues) from the geochemically depleted olivine-phyric shergottite Tissint. The results suggest that the Tissint magma is not isotopically uniform and sampled at least two geochemical source reservoirs, implying that either crustal assimilation or magma mixing would have played a role in the Tissint petrogenesis.

  2. Jarosite in the Shergottite Que 94201

    NASA Technical Reports Server (NTRS)

    Ross, D. K.; Ito, M.; Rao, M. N.; Hervig, R.; Williams, L. B.; Nyquist, Laurence E.; Peslier, A.

    2010-01-01

    Veins of the hydroxylated, potassium ferric sulfate mineral jarosite - KFe3(SO4)2(OH)6 - have been identified in the martian meteorite Queen Alexandra Range (QUE) 94201. Iron potassium sulfate had been reported in QUE 94201 by Wentworth and Gooding. Jarosite has been reported in other Martian meteorites - Roberts Massif (RBT) 04262, Miller Range (MIL) 03346, and Yamato 000593 - and it has been identified on the Martian surface by Moessbauer spectroscopy. Given the presence of jarosite on Mars, and the burgeoning interest in water-rock interactions on Mars, the question arises whether jarosite in Martian meteorites is formed by aqueous alteration on Mars, or in Antarctica. Hydrogen isotopes are potentially sensitive indicators of the site of formation or last equilibration of hydrous alteration minerals, because of the large difference between D/H ratio of the Martian atmosphere (and also presumably the cryosphere) and terrestrial hydrogen. The Martian atmospheric delta D(sub SMOW) ratio is approximately +4200%o, igneous minerals with substantial hydrogen (phosphates) have high D, +2000%o to +4700%o versus terrestrial waters with approximately 480%o to +130%o. The crystal chemistry and structure of jarosite are reviewed in Papi ke et al. Here we report hydrogen isotopes measured in jarosite in QUE 94201 by ion microprobe, and also report on the major element composition of jarosite measured by electron microprobe.

  3. Cathodoluminescence Characterization of Maskelynite and Alkali Feldspar in Shergottite (Dhofar 019)

    SciTech Connect

    Kayama, M.; Nakazato, T.; Nishido, H.; Ninagawa, K.; Gucsik, A.

    2009-08-17

    Dhofar 019 is classified as an olivine-bearing basaltic shergottite and consists of subhedral grains of pyroxene, olivine, feldspar mostly converted to maskelynite and minor alkali feldspar. The CL spectrum of its maskelynite exhibits an emission band at around 380 nm. Similar UV-blue emission has been observed in the plagioclase experimentally shocked at 30 and 40 GPa, but not in terrestrial plagioclase. This UV-blue emission is a notable characteristic of maskelynite. CL spectrum of alkali feldspar in Dhofar 019 has an emission bands at around 420 nm with no red emission. Terrestrial alkali feldspar actually consists of blue and red emission at 420 and 710 nm assigned to Al-O{sup -}-Al and Fe{sup 3+} centers, respectively. Maskelynite shows weak and broad Raman spectral peaks at around 500 and 580 cm{sup -1}. The Raman spectrum of alkali feldspar has a weak peak at 520 cm{sup -1}, whereas terrestrial counterpart shows the emission bands at 280, 400, 470, 520 and 1120 cm{sup -1}. Shock pressure on this meteorite transformed plagioclase and alkali feldspar into maskelynite and almost glass phase, respectively. It eliminates their luminescence centers, responsible for disappearance of yellow and/or red emission in CL of maskelynite and alkali feldspar. The absence of the red emission band in alkali feldspar can also be due to the lack of Fe{sup 3+} in the feldspar as it was reported for some lunar feldspars.

  4. Martian Pyroxenes in the Shergottite Meteorites; Zagami, SAU005, DAG476 and EETA79001

    NASA Astrophysics Data System (ADS)

    Stephen, N.; Benedix, G. K.; Bland, P.; Hamilton, V. E.

    2010-12-01

    The geology and surface mineralogy of Mars is characterised using remote sensing techniques such as thermal emission spectroscopy (TES) from instruments on a number of spacecraft currently orbiting Mars or gathered from roving missions on the Martian surface. However, the study of Martian meteorites is also important in efforts to further understand the geological history of Mars or to interpret mission data as they are believed to be the only available samples that give us direct clues as to Martian igneous processes [1]. We have recently demonstrated that the spectra of Martian-specific minerals can be determined using micro-spectroscopy [2] and that these spectra can be reliably obtained from thin sections of Martian meteorites [3]. Accurate modal mineralogy of these meteorites is also important [4]. In this study we are using a variety of techniques to build upon previous studies of these particular samples in order to fully characterise the nature of the 2 common pyroxenes found in Martian Shergottites; pigeonite and augite [5], [6]. Previous studies have shown that the Shergottite meteorites are dominated by pyroxene (pigeonite and augite in varying quantities) [4], [5], commonly but not always olivine, plagioclase or maskelynite/glass and also hydrous minerals, which separate the Martian meteorites from other achondrites [7]. Our microprobe study of meteorites Zagami, EETA79001, SAU005 and DAG476 in thin-section at the Natural History Museum, London shows a chemical variability within both the pigeonite and augite composition across individual grains in all thin sections; variation within either Mg or Ca concentration varies from core to rim within the grains. This variation can also be seen in modal mineralogy maps using SEM-derived element maps and the Photoshop® technique previously described [4], and in new micro-spectroscopy data, particularly within the Zagami meteorite. New mineral spectra have been gathered from the Shergottite thin-sections by

  5. Constraints on the Parental Melts of Enriched Shergottites from Image Analysis and High Pressure Experiments

    NASA Technical Reports Server (NTRS)

    Collinet, M.; Medard, E.; Devouard, B.; Peslier, A.

    2012-01-01

    Martian basalts can be classified in at least two geochemically different families: enriched and depleted shergottites. Enriched shergottites are characterized by higher incompatible element concentrations and initial Sr-87/Sr-86 and lower initial Nd-143/Nd-144 and Hf-176/Hf-177 than depleted shergottites [e.g. 1, 2]. It is now generally admitted that shergottites result from the melting of at least two distinct mantle reservoirs [e.g. 2, 3]. Some of the olivine-phyric shergottites (either depleted or enriched), the most magnesian Martian basalts, could represent primitive melts, which are of considerable interest to constrain mantle sources. Two depleted olivine-phyric shergottites, Yamato (Y) 980459 and Northwest Africa (NWA) 5789, are in equilibrium with their most magnesian olivine (Fig. 1) and their bulk rock compositions are inferred to represent primitive melts [4, 5]. Larkman Nunatak (LAR) 06319 [3, 6, 7] and NWA 1068 [8], the most magnesian enriched basalts, have bulk Mg# that are too high to be in equilibrium with their olivine megacryst cores. Parental melt compositions have been estimated by subtracting the most magnesian olivine from the bulk rock composition, assuming that olivine megacrysts have partially accumulated [3, 9]. However, because this technique does not account for the actual petrography of these meteorites, we used image analysis to study these rocks history, reconstruct their parent magma and understand the nature of olivine megacrysts.

  6. An "Andesitic" Component in Shergottites with Restored LREE Abundances?

    NASA Technical Reports Server (NTRS)

    Nyquist, L. E.; Shih, C.-Y.; Wiesmann, H.; Barrat, J. A.

    2002-01-01

    The shergottite Martian meteorites present a variety of oft-confusing petrologic features. In particular, represented among this subgroup are basalts with very depleted LREE abundances, as well as those with nearly chondritic overall REE abundances. The LREE-depleted basalts appear to more closely record the REE and isotopic features of their mantle source legions. Those basalts with more nearly chondritic REE abundances appear to contain an extra component often referred to as a "crustal" component. The addition of the crustal component tends to restore the overall REE abundance pattern towards chondritic relative abundances. Here we suggest that the crustal component could derive from andesitic rocks observed remotely to occur on the Martian surface, and which were analysed at the Pathfinder site.

  7. An "Andestic" Component in Shergottites with Restored LREE Abundances?

    NASA Technical Reports Server (NTRS)

    Nyquist, L. E.; Shih, C.-Y.; Wiesmann, H.; Barrat, J. A.

    2002-01-01

    The shergottite Martian meteorites present a variety of oft-confusing petrologic features. In particular, represented among this subgroup are basalts with very depleted LREE abundances, as well as those with nearly chondritic overall REE abundances. The LREE-depleted basalts appear to more closely record the REE and isotopic features of their mantle source regions. Those basalts with more nearly chondritic REE abundances appear to contain an extra component often referred to as a "crustal" component. The addition of the crustal component tends to restore the overall REE abundance pattern towards chondritic relative abundances. Here we suggest that the crustal component could derive from "andesitic" rocks observed remotely to occur on the Martian surface, and which were analysed at the Pathfinder site.

  8. Petrology and trace element geochemistry of Tissint, the newest shergottite fall

    NASA Astrophysics Data System (ADS)

    Balta, J. Brian; Sanborn, Matthew E.; Udry, Arya; Wadhwa, Meenakshi; McSween, Harry Y.

    2015-01-01

    AbstractThe fall and recovery of the Tissint meteorite in 2011 created a rare opportunity to examine a Martian sample with a known, short residence time on Earth. Tissint is an olivine-phyric <span class="hlt">shergottite</span> that accumulated olivine antecrysts within a single magmatic system. Coarse olivine grains with nearly homogeneous cores of Mg# >80 suggest slow re-equilibration. Many macroscopic features of this sample resemble those of LAR 06319, including the olivine crystal size distribution and the presence of evolved oxide and olivine compositions. Unlike LAR 06319, however, no magmatic hydrous phases were found in the analyzed samples of Tissint. Minor and trace element compositions indicate that the meteorite is the product of closed-system crystallization from a parent melt derived from a depleted source, with no obvious addition of a LREE-rich (crustal?) component prior to or during crystallization. The whole-rock REE pattern is similar to that of intermediate olivine-phyric <span class="hlt">shergottite</span> EETA 79001 lithology A, and could also be approximated by a more olivine-rich version of depleted basaltic <span class="hlt">shergottite</span> QUE 94201. Magmatic oxygen fugacities are at the low end of the <span class="hlt">shergottite</span> range, with log fO2 of QFM-3.5 to -4.0 estimated based on early-crystallized minerals and QFM-2.4 estimated based on the Eu in pyroxene oxybarometer. These values are similarly comparable to other depleted <span class="hlt">shergottites</span>, including SaU 005 and QUE 94201. Tissint occupies a previously unsampled niche in <span class="hlt">shergottite</span> chemistry: containing olivines with Mg# >80, resembling the enriched olivine-phyric <span class="hlt">shergottite</span> LAR 06319 in its crystallization path, and comparable to intermediate olivine-phyric <span class="hlt">shergottite</span> EETA 79001A, depleted olivine-phyric <span class="hlt">shergottite</span> DaG 476, and depleted basaltic <span class="hlt">shergottite</span> QUE 94201 in its trace element abundances and oxygen fugacity. The apparent absence of evidence for terrestrial alteration in Tissint</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080026134','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080026134"><span>Concordant Rb-Sr and Sm-Nd Ages for NWA 1460: A 340 Ma Old Basaltic <span class="hlt">Shergottite</span> Related to Lherzolitic <span class="hlt">Shergottites</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nyquist, L. E.; Shih, C-Y; Reese, Y. D.; Irving, A. J.</p> <p>2006-01-01</p> <p>Preliminary Rb-Sr and Sm-Nd ages reported by [1] for the NWA 1460 basaltic <span class="hlt">shergottite</span> are refined to 336+/-14 Ma and 345+/-21 Ma, respectively. These concordant ages are interpreted as dating a lava flow on the Martian surface. The initial Sr and Nd isotopic compositions of NWA 1460 suggest it is an earlier melting product of a Martian mantle source region similar to those of the lherzolitic <span class="hlt">shergottites</span> and basaltic <span class="hlt">shergottite</span> EETA79001, lithology B. We also examine the suggestion that generally "young" ages for other Martian meteorites should be reinterpreted in light of Pb-207/Pb-206 - Pb-204/Pb-206 isotopic systematics [2]. Published U-Pb isotopic data for nakhlites are consistent with ages of approx.1.36 Ga. The UPb isotopic systematics of some Martian <span class="hlt">shergottites</span> and lherzolites that have been suggested to be approx.4 Ga old [2] are complex. We nevertheless suggest the data are consistent with crystallization ages of approx.173 Ma when variations in the composition of in situ initial Pb as well as extraneous Pb components are considered.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20170001698','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20170001698"><span>Evaluating Crustal Contamination Effects On The Lithophile Trace Element Budget Of <span class="hlt">Shergottites</span>, NWA 856 As A Test Case</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Brandon, A. D.; Ferdous, J.; Peslier, A. H.</p> <p>2017-01-01</p> <p>The issue of whether crustal contamination has affected the lithophile trace element budget of <span class="hlt">shergottites</span> has been a point of contention for decades. The evaluation has focused on the enriched <span class="hlt">shergottite</span> compositions as an outcome of crustal contamination of mantle-derived parent magmas or, alternatively, the compositions of these stones reflect an incompatible trace element (ITE) enriched mantle source.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20090022361','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20090022361"><span>Rb-Sr Isotopic Studies Of Antarctic Lherzolitic <span class="hlt">Shergottite</span> Yamato 984028</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shih, C.-Y.; Nyquist, L. E.; Reese, Y.; Misawa, K.</p> <p>2009-01-01</p> <p>Yamato 984028 is a Martian meteorite found in the Yamato Mountains of Antarctica. It is classified as a lherzolitic <span class="hlt">shergottite</span> and petrographically resembles several other lherzolitic <span class="hlt">shergottites</span>, i.e. ALHA 77005, LEW 88516, Y-793605 and Y-000027/47/97 [e.g. 2-5]. These meteorites have similarly young crystallization ages (152-185 Ma) as enriched basaltic <span class="hlt">shergottites</span> (157-203 Ma), but have very different ejection ages (approximately 4 Ma vs. approximately 2.5 Ma), thus they came from different martian target crater areas. Lherzolitic <span class="hlt">shergottites</span> have mg-values approximately 0.70 and represent the most mafic olivine-pyroxene cumulates. Their parental magmas were melts derived probably from the primitive Martian mantle. Here we present Rb-Sr isotopic data for Y-984028 and compare these data with those obtained from other lherzolitic and olivine-phyric basaltic <span class="hlt">shergottites</span> to better understand the isotopic characteristics of their primitive mantle source regions. Corresponding Sm-Nd analyses for Y-984028 are in progress.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1983LPSC...14..229S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1983LPSC...14..229S"><span>Mineral chemistry of the <span class="hlt">shergottites</span>, nakhlites, Chassigny, Brachina, pallasites and urelites</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Smith, J. V.; Steele, I. M.; Leitch, C. A.</p> <p>1983-11-01</p> <p>The mineral chemistry is compared for selected achondrites. Olivine in the ALHA 77005 and EETA 79001 <span class="hlt">shergottites</span>, olivine-rich Chassigny and Brachina, and the nakhlites, contains Ni indicative of oxidizing conditions, whereas pallasitic and ureilitic olivines contain much lower Ni due to reducing conditions. The Brachina olivine and pyroxene have distinctively higher Fe/Mn than the <span class="hlt">shergottites</span> and Chassigny, further indicating that Brachina is unique. The Chassigny and 77005 olivines contain lower Cr2O3 (0.03 wt. pct) than the Brachina and 79001 olivines. Values of Fe/Mn for cumulus augites in nakhlites are higher than for the <span class="hlt">shergottites</span>, whereas those for ferropigeonites are not. The 77005 <span class="hlt">shergottite</span> contains troilite FeS in contrast to 79001, Shergotty, Zagami, and Chassigny, which contain pyrrhotite. Further analyses are needed, but the present survey indicates that at least Brachina is not chemically cogenetic with the other 'oxidized achondrites', and that the Fe/Mn ratio of the cumulus augites in nakhlites is a problem for the assignment of the nakhlites, <span class="hlt">shergottites</span>, and Chassigny to a single genetic group.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150001623','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150001623"><span>Melt Inclusion Analysis of RBT 04262 with Relationship to <span class="hlt">Shergottites</span> and Mars Surface Compositions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Potter, S. A.; Brandon, A. D.; Peslier, A. H.</p> <p>2015-01-01</p> <p>Martian meteorite RBT 04262 is in the <span class="hlt">shergottite</span> class. It displays the two lithologies typically found in "lherzolitic <span class="hlt">shergottites</span>": one with a poikilitic texture of large pyroxene enclosing olivine and another with non-poikilitic texture. In the case of RBT 04262, the latter strongly ressembles an olivine- phyric <span class="hlt">shergottite</span> which led the initial classification of this meteorite in that class. RBT 04262 has been studied with regards to its petrology, geochemistry and cosmic ray exposure and belongs to the enriched oxidized end-member of the <span class="hlt">shergottites</span>. Studies on RBT 04262 have primarily focused on the bulk rock composition or each of the lithologies independently. To further elucidate RBT 04262's petrology and use it to better understand Martian geologic history, an in-depth study of its melt inclusions (MI) is being conducted. The MI chosen for this study are found within olivine grains. MI are thought to be trapped melts of the crystallizing magma preserved by the encapsulating olivine and offer snapshots of the composition of the magma as it evolves. Some MI, in the most Mg-rich part of the olivine of olivine-pyric <span class="hlt">shergottites</span>, may even be representative of the meteorite parent melt.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870038806&hterms=Beryllium&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DBeryllium','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870038806&hterms=Beryllium&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DBeryllium"><span>Beryllium-10 contents of <span class="hlt">shergottites</span>, nakhlites, and Chassigny</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Pal, D. K.; Tuniz, C.; Moniot, R. K.; Savin, W.; Kruse, T.</p> <p>1986-01-01</p> <p>Accelerator mass spectrometry gives the following Be-10 contents (dpm/kg) for the SNC meteorites: Shergotty, 13.0 + or - 1.5 and 17.3 + or - 2.7; Zagami, 18.6 + or - 2.5 and 20.0 + or - 3.2; ALHA 77005, 15 + or - 3; EETA 79001A, 7.8 + or - 1.1 and 6.3 + or - 0.5; EETA 79001B, 8.5 + or - 1.1; Nakhla, 19.7 + or - 3.3; Lafayette, 18.1 + or - 2.5; Governador Valadares, 25.6 + or - 3.6; Chassigny, 20.5 + or - 3.1. The Be-10 contents of the NC meteorites indicate that significant accumulation of cosmogenic nuclides occurred in decimeter rather than planetary-size bodies. The agreement of the He-3, Ne-21, and Be-10 exposure ages of the <span class="hlt">shergottites</span> also supports small-body irradiation. A long terrestrial age for EETA 79001 appears unlikely.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006AGUFM.P23C0070W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006AGUFM.P23C0070W"><span>A Search for <span class="hlt">Shergottite</span>-like Outliers in Orbital TES Data Using the Mini-TES Spectrum of Bounce Rock</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wright, S. P.; Wyatt, M. B.; Christensen, P. R.</p> <p>2006-12-01</p> <p>Bounce Rock was found by the MER Opportunity rover and is interpreted as an anomalous distal impact ejecta deposited on the windblown sands of the Meridiani plains [Squyres et <span class="hlt">al</span>., Science, 2004]. X-Ray, Moessbauer, and thermal infrared (TIR) spectra of Bounce Rock are distinct from any measured at either Rover landing site and are best matched by various basaltic <span class="hlt">shergottites</span> such as Shergotty and Zagami. Recent work on the TIR spectra of experimentally shocked plagioclases and basalts [Johnson et <span class="hlt">al</span>., JGR, 2002; 2006] and shocked terrestrial basalt [Wright et <span class="hlt">al</span>., LPSC, 2006] suggest that the Mini-TES spectrum of Bounce Rock appears to be an unshocked version of Zagami or perhaps Shergotty. Spectral observations of unshocked martian lithologies similar in composition to martian meteorites are important for constraining the extent of SNC-like lithologies in orbital data as all meteorite samples display some degree of shock effect and may not be representative of the bulk of martian surface compositions. The Mini-TES spectrum of Bounce Rock thus represents a rare unshocked pigeonite-augite-plagioclase basalt spectrum that would never be available in meteorite collections or spectral libraries. This fact and the difficulties of both producing an artificial pigeonite spectrum and finding pigeonite-rich regions on Mars make the Bounce Rock spectrum an excellent end-member in the search for potential <span class="hlt">shergottite</span> source regions with global TIR data. Previous work locating Thermal Emission Spectrometer (TES) pixels high in olivine, orthopyroxene [Hamilton et <span class="hlt">al</span>., MaPS, 2003], and quartzofeldspathic minerals [Bandfield et <span class="hlt">al</span>., JGR, 2004] have shown the utility of using lithologic end-members rather than large mineral spectral libraries. However, minerals with higher polymerization than feldspar such as olivines and pyroxenes do not show changes in TIR spectra at the shock level all <span class="hlt">shergottites</span> have been subjected to [Johnson et <span class="hlt">al</span>., JGR, 2002]. In this work, global TES</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19980018466','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19980018466"><span>The <span class="hlt">Shergottite</span> Age Paradox and the Relative Probabilities of Ejecting Martian Meteorites of Differing Ages</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Borg, L. E.; Shih, C.-Y.; Nyquist, L. E.</p> <p>1998-01-01</p> <p>The apparent paradox that the majority of impacts yielding Martian meteorites appear to have taken place on only a few percent of the Martian surface can be resolved if all the <span class="hlt">shergottites</span> were ejected in a single event rather than in multiple events as expected from variations in their cosmic ray exposure and crystallization ages. If the <span class="hlt">shergottite</span>-ejection event is assigned to one of three craters in the vicinity of Olympus Mons that were previously identified as candidate source craters for the SNC (<span class="hlt">Shergottites</span>, Nakhlites, Chassigny) meteorites, and the nakhlite event to another candidate crater in the vicinity of Ceraunius Tholus, the implied ages of the surrounding terranes agree well with crater density ages. EN,en for high cratering rates (minimum ages), the likely origin of the <span class="hlt">shergottites</span> is in the Tharsis region, and the paradox of too many meteorites from too little terrane remains for multiple <span class="hlt">shergottite</span>-ejection events. However, for high cratering rates it is possible to consider sources for the nakhlltes which are away from the Tharsis region. The meteorite-yielding impacts may have been widely dispersed with sources of the young SNC meteorites in the northern plains, and the source of the ancient orthopyroxenite, ALH84001, in the ancient southern uplands. Oblique-impact craters can be identified with the sources of the nakhlites and the orthopyroxenite,, respectively, in the nominal cratering rate model, and with the <span class="hlt">shergottites</span> and orthopyroxenite, respectively, in the high cratering rate model. Thus, oblique impacts deserve renewed attention as an ejection mechanism for Martian meteorites.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100026407','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100026407"><span>39Ar - 40Ar Studies of Lherzolitic <span class="hlt">Shergottites</span> Yamato 000097 and 984028</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Park, J.; Nyquist, L. E.; Bogard, D. D.; Garrison, D. H.; Shih, C.-Y.; Mikouchi, T.; Misawa, K.</p> <p>2010-01-01</p> <p>Yamato 984028 (Y984028) was discovered by the Japanese Antarctic Research Expedition (JARE) in 1998 and recently classified as a lherzolitic <span class="hlt">shergottite</span> with large pyroxene oikocrysts enclosing rounded olivine and chromites. It also contains shock veining and maskelynite. Y984028 is paired with the more recent lherzolitic <span class="hlt">shergottite</span> finds Y000027/47/97 based on similarities in mineralogy and chemistry, as well as isotopic composition. We present here the studied Ar-39-Ar-40 of Y-984028 whole rock (WR) and pyroxene (Px), in order to gain better understanding of trapped Ar components with a comparison of the possibly-paired Y000097 Ar release.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20130003564','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20130003564"><span>Water in Nominally Anhydrous Minerals from Nakhlites and <span class="hlt">Shergottites</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Peslier, Anne H.</p> <p>2013-01-01</p> <p>Estimating the amount of water in the interior of terrestrial planets has tremendous implications on our understanding of solar nebula evolution, planet formation and geological history, and extraterrestrial volcanism. Mars has been a recent focus of such enquiry with complementary datasets from spacecrafts, rovers and martian meteorite studies. In planetary interiors, water can be dissolved in fluids or melts and hydrous phases, but can also be locked as protons attached to structural oxygen in lattice defects in nominally anhydrous minerals (NAM) such as olivine, pyroxene, or feldspar [1-3]. Measuring water in Martian meteorite NAM is challenging because the minerals are fragile and riddled with fractures from impact processes that makes them break apart during sample processing. Moreover, curing the sample in epoxy causes problems for the two main water analysis techniques, Fourier transform infrared spectrometry (FTIR) and secondary ionization mass spectrometry (SIMS). Measurements to date have resulted in a heated debate on how much water the mantle of Mars contains. SIMS studies of NAM [4], amphiboles [5], and apatites [6-8] from Martian meteorites report finding enough water in these phases to infer that the martian mantle is as hydrous as that of the Earth. On the other hand, a SIMS study of glass in olivine melt inclusions from <span class="hlt">shergottites</span> concludes that the Martian mantle is much drier [9]. The latter interpretation is also supported by the fact that most martian hydrous minerals generally have the relevant sites filled with Cl and F instead of H [10,11]. As for experimental results, martian basalt compositions can be reproduced using water as well as Cl in the parent melts [12,13]. Here FTIR is used to measure water in martian meteorite minerals in order to constrain the origin of the distribution of water in martian meteorite phases.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110007848','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110007848"><span>Rb-Sr And Sm-Nd Ages, and Petrogenesis of Depleted <span class="hlt">Shergottite</span> Northwest Africa 5990</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shih, C. Y.; Nyquist, L. E.; Reese, Y.; Irving, A. J.</p> <p>2011-01-01</p> <p>Northwest Africa (NWA) 5990 is a very fresh Martian meteorite recently found on Hamada du Draa, Morocco and was classified as an olivine-bearing diabasic igneous rock related to depleted <span class="hlt">shergottites</span> [1]. The study of [1] also showed that NWA 5990 resembles QUE 94201 in chemical, textural and isotopic aspects, except QUE 94201 contains no olivine. The depleted <span class="hlt">shergottites</span> are characterized by REE patterns that are highly depleted in LREE, older Sm-Nd ages of 327-575 Ma and highly LREE-depleted sources with Nd= +35+48 [2-7]. Age-dating these samples by Sm-Nd and Rb-Sr methods is very challenging because they have been strongly shocked and contain very low abundances of light rare earth elements (Sm and Nd), Rb and Sr. In addition, terrestrial contaminants which are commonly present in desert meteorites will compromise the equilibrium of isotopic systems. Since NWA 5990 is a very fresh meteorite, it probably has not been subject to significant desert weathering and thus is a good sample for isotopic studies. In this report, we present Rb-Sr and Sm-Nd isotopic results for NWA 5990, discuss the correlation of the determined ages with those of other depleted <span class="hlt">shergottites</span>, especially QUE 94201, and discuss the petrogenesis of depleted <span class="hlt">shergottites</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015M%26PS...50.2024H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015M%26PS...50.2024H"><span>Petrography and geochemistry of the enriched basaltic <span class="hlt">shergottite</span> Northwest Africa 2975</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>He, Qi; Xiao, Long; Balta, J. Brian; Baziotis, Ioannis P.; Hsu, Weibiao; Guan, Yunbin</p> <p>2015-12-01</p> <p>We present a study of the petrology and geochemistry of basaltic <span class="hlt">shergottite</span> Northwest Africa 2975 (NWA 2975). NWA 2975 is a medium-grained basalt with subophitic to granular texture. Electron microprobe (EMP) analyses show two distinct pyroxene compositional trends and patchy compositional zoning patterns distinct from those observed in other meteorites such as Shergotty or QUE 94201. As no bulk sample was available to us for whole rock measurements, we characterized the fusion crust and its variability by secondary ion mass spectrometer (SIMS) measurements and laser ablation inductively coupled plasma spectroscopy (LA-ICP-MS) analyses as a best-available proxy for the bulk rock composition. The fusion crust major element composition is comparable to the bulk composition of other enriched basaltic <span class="hlt">shergottites</span>, placing NWA 2975 within that sample group. The CI-normalized REE (rare earth element) patterns are flat and also parallel to those of other enriched basaltic <span class="hlt">shergottites</span>. Merrillite is the major REE carrier and has a flat REE pattern with slight depletion of Eu, parallel to REE patterns of merrillites from other basaltic <span class="hlt">shergottites</span>. The oxidation state of NWA 2975 calculated from Fe-Ti oxide pairs is NNO-1.86, close to the QFM buffer. NWA 2975 represents a sample from the oxidized and enriched <span class="hlt">shergottite</span> group, and our measurements and constraints on its origin are consistent with the hypothesis of two distinct Martian mantle reservoirs: a reduced, LREE-depleted reservoir and an oxidized, LREE-enriched reservoir. Stishovite, possibly seifertite, and dense SiO2 glass were also identified in the meteorite, allowing us to infer that NWA 2975 experienced a realistic shock pressure of ~30 GPa.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_1");'>1</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li class="active"><span>3</span></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_3 --> <div id="page_4" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active"><span>4</span></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="61"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009M%26PS...44..905B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009M%26PS...44..905B"><span>39Ar-40Ar "ages" and origin of excess 40Ar in Martian <span class="hlt">shergottites</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bogard, Donald; Park, Jisun; Garrison, Daniel</p> <p>2009-06-01</p> <p>We report new 39Ar-40Ar measurements on 15 plagioclase, pyroxene, and/or whole rock samples of 8 Martian <span class="hlt">shergottites</span>. All age spectra suggest ages older than the meteorite formation ages, as defined by Sm-Nd and Rb-Sr isochrons. Employing isochron plots, only Los Angeles plagioclase and possibly Northwest Africa (NWA) 3171 plagioclase give ages in agreement with their formation ages. Isochrons for all <span class="hlt">shergottite</span> samples reveal the presence of trapped Martian 40Ar (40Arxs), which exists in variable amounts in different lattice locations. Some 40Arxs is uniformly distributed throughout the lattice, resulting in a positive isochron intercept, and other 40Arxs occurs in association with K-bearing minerals and increases the isochron slope. These samples demonstrate situations where linear Ar isochrons give false ages that are too old. After subtracting 40Ar*that would accumulate by 40K decay since meteorite formation and small amounts of terrestrial 40Ar, all young age samples give similar 40Arxs concentrations of ˜1-2 × 10-6cm3/g, but a variation in K content by a factor of ˜80. Previously reported NASA Johnson Space Center data for Zagami, Shergotty, Yamato (Y-) 000097, Y-793605, and Queen Alexandra Range (QUE) 94201 <span class="hlt">shergottites</span> show similar concentrations of 40Arxs to the new meteorite data reported here. Similar 40Arxs in different minerals and meteorites cannot be explained as arising from Martian atmosphere carried in strongly shocked phases such as melt veins. We invoke the explanation given by Bogard and Park (2008) for Zagami, that this 40Arxs in <span class="hlt">shergottites</span> was acquired from the magma. Similarity in 40Arxs among <span class="hlt">shergottites</span> may reveal common magma sources and/or similar magma generation and emplacement processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015LPICo1879.1017W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015LPICo1879.1017W"><span>An Exploration Zone in Cerberus Containing Young and Old Terrains, Including Fossae/Faults and <span class="hlt">Shergottite</span> Distal Ejecta</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wright, S. P.; Niles, P. B.; Bell, M. S.; Milbury, C.; Rice, J. W.; Burton, A. S.; Archer, P. D.; Rampe, E. B.; Piqueux, S.</p> <p>2015-10-01</p> <p>Cerberus contains Amazonian lava flows embaying a range of photogeologic units: ridged plains, heavily cratered terrain, highland knobs, and perhaps the Medusa Fossae Fm. Zunil Crater distal ejecta produced secondary crater fields (of <span class="hlt">shergottites</span>?).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20030111635&hterms=Age+Anger&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DAge%2BAnger','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20030111635&hterms=Age+Anger&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3DAge%2BAnger"><span>Age and Petrogenesis of Picritic <span class="hlt">Shergottite</span> NWA1068: Sm-Nd and Rb-Sr Isotopic Studies</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shih, C.-Y.; Nyquist, L. E.; Wiesmann, H.; Barrat, J. A.</p> <p>2003-01-01</p> <p>NWA 1068 is a 577g picritic <span class="hlt">shergottite</span> found in the Moroccan Sahara in 2001. The meteorite resembles several other picritic <span class="hlt">shergottites</span>, e.g. EETA79001B, DaG476, SaU005 and Dho019, in major-element chemistry and mineralogy, but it differs significantly from these meteorites in REE distribution pattern. It has a slightly LREE-depleted pattern commonly shared by some olivine-free basaltic <span class="hlt">shergottites</span>, e.g. Shergotty, Zagami and Los Angeles, but not QUE94201. Detailed geochemical and mineral-petrological studies were given in. We performed Rb-Sr and Sm-Nd isotopic analyses on this rock to determine its crystallization age and to study the petrogenetic relationship between this meteorite and other basaltic and pricritic <span class="hlt">shergottites</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150002838','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150002838"><span>Gusev-Meridiani-Type Soil Component Dissolved in Some Shock Glasses in <span class="hlt">Shergottites</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ross, D. K.; Rao, M. N.; Nyquist, L. E.; Shi, C. Y.; Sutton, S.; Harrison, D. H.</p> <p>2015-01-01</p> <p>Modal analysis, based on APXS, MiniTES and Mossbauer results obtained at Gusev and Meridiani sites on Mars, indicates that Martian soils consist predominantly of igneous minerals such as olivine, pyroxene and feldspar (approximately70 - 80%), with the balance consisting of alteration minerals such as sulfates, silica and chlorides]. These studies also showed that soil alteration did not occur in-situ and igneous and alteration components are derived from different sources. Below, we analyse the chemical abundance data obtained from shock glasses in <span class="hlt">shergottites</span> using mass balance mixing models. In these models, the two main end members used are (a) host rock chemical composition and (b) the GM soils average composition as the second component. Here, we consider the S-bearing phases as indicators of added alteration phases in the shock glasses and GM soils. Although the S-bearing phase in shock glasses occurs as micron sized sulfide blebs, we showed in earlier abstracts that sulfur was originally present as sulfate in impact glass-precursor materials and was subsequently reduced to sulfide during shock melting. This conclusion is based on results obtained from S-K XANES studies, Fe/S atomic ratios in sulfide blebs and 34S/32S isotopic measurements in these sulfide blebs. Additionally, sulfur in several EET79001 Lith. A glasses is found to correlate positively with <span class="hlt">Al</span>2O3 and CaO (and negatively with FeO and MgO), suggesting the presence of <span class="hlt">Al</span>- and Ca- sul-fate-bearing phases. The distribution of the 87Sr/86Sr iso-topic ratios determined in Lith. A glasses (,27 &,188 and,54) indicate that Martian soil gypsum and host rock material were mixed with each other in the glass precursors. In some vugs in Lith A glass,27 detected gypsum laths. Furthermore, the Martian regolith-de-rived component (where sulfur typically occurs as sul-fate) is identified in these glasses by determining neutron produced isotopic excesses/deficits in 80Kr and 149Sm isotopes. Moreover, the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1984GeCoA..48.1723B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1984GeCoA..48.1723B"><span>Noble gas contents of <span class="hlt">shergottites</span> and implications for the Martian origin of SNC meteorites</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bogard, D. D.; Nyquist, L. E.; Johnson, P.</p> <p>1984-09-01</p> <p>Three meteorites belonging to the rare group of SNC achondrites, which may have originated in the planet Mars, have been subjected to noble gas isotopic concentration measurements. The elemental and isotopic ratios obtained are unlike those for any other noble gas components except those obtained in analyses of the Martian atmosphere by Viking spacecraft. It is hypothesized that the Kr and Xe gases represent a portion of the Martian atmosphere which was shock-implanted in the case of Elephant Moraine A79001, and that they constitute direct evidence of a Martian origin for the <span class="hlt">shergottite</span> meteorites. If the SNC meteorites were ejected from Mars at the <span class="hlt">shergottite</span> shock age of about 180 My ago, they must have been objects more than 6 m in diameter which experienced at least three space collisions to initiate cosmic ray exposure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19850029870&hterms=elephant+evolution&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Delephant%2Bevolution','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19850029870&hterms=elephant+evolution&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Delephant%2Bevolution"><span>Noble gas contents of <span class="hlt">shergottites</span> and implications for the Martian origin of SNC meteorites</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bogard, D. D.; Nyquist, L. E.; Johnson, P.</p> <p>1984-01-01</p> <p>Three meteorites belonging to the rare group of SNC achondrites, which may have originated in the planet Mars, have been subjected to noble gas isotopic concentration measurements. The elemental and isotopic ratios obtained are unlike those for any other noble gas components except those obtained in analyses of the Martian atmosphere by Viking spacecraft. It is hypothesized that the Kr and Xe gases represent a portion of the Martian atmosphere which was shock-implanted in the case of Elephant Moraine A79001, and that they constitute direct evidence of a Martian origin for the <span class="hlt">shergottite</span> meteorites. If the SNC meteorites were ejected from Mars at the <span class="hlt">shergottite</span> shock age of about 180 My ago, they must have been objects more than 6 m in diameter which experienced at least three space collisions to initiate cosmic ray exposure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150002847','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150002847"><span>Correlations Between Surficial Sulfur and a REE Crustal Assimilation Signature in Martian <span class="hlt">Shergottites</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jones, J. H.; Franz, H. B.</p> <p>2015-01-01</p> <p>Compared to terrestrial basalts, the Martian <span class="hlt">shergottite</span> meteorites have an extraordinary range of Sr and Nd isotopic signatures. In addition, the S isotopic compositions of many <span class="hlt">shergottites</span> show evidence of interaction with the Martian surface/ atmosphere through mass-independent isotopic fractionations (MIF, positive, non-zero delta(exp 33)S) that must have originated in the Martian atmosphere, yet ultimately were incorporated into igneous sulfides (AVS - acid-volatile sulfur). These positive delta(exp 33)S signatures are thought to be governed by solar UV photochemical processes. And to the extent that S is bound to Mars and not lost to space from the upper atmosphere, a positive delta(exp 33)S reservoir must be mass balanced by a complementary negative reservoir.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/618157','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/618157"><span>Sulfide isotopic compositions in <span class="hlt">shergottites</span> and ALH84001, and possible implications for life on Mars</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Greenwood, J.P.; McSween, H.Y. Jr.; Riciputi, L.R.</p> <p>1997-10-01</p> <p>The <span class="hlt">shergottite</span> and ALH84001 meteorites hold keys for understanding geologic and possibly biologic processes on Mars. Recently, it has been proposed that carbonates in ALH84001, and the Fe-sulfides they contain, are products of extraterrestrial biogenic activity. Here we report ion microprobe analyses of sulfides in <span class="hlt">shergottites</span> and ALH84001. The sulfur isotope ratios of igneous pyrrhotites in <span class="hlt">shergottites</span> (mean {delta}{sup 34}S{sub CDT}: Shergotty = -0.4{per_thousand}, Zagami = +2.7{per_thousand}, EETA79001A = 1.9{per_thousand}, EETA79001B = -1.7{per_thousand}, LEW88516 = -1.9{per_thousand}, QUE94201 = +0.8{per_thousand}) are similar to those of terrestrial ocean-floor basalts, suggesting that the sulfur isotopic composition of the Martian mantle may be similar to that of the mantle of the Earth. The sulfur isotopic systematics of ALH84001 sulfides are distinct from the <span class="hlt">shergottites</span>. Measured sulfur isotope ratios of eight pyrite grains ({delta}{sup 34}S{sub CDT} = +2.0 to +7.3{per_thousand}) in crushed zones confirm previously reported analyses of isotopically heavy sulfides and are indistinguishable from an Fe-sulfide zone within a carbonate globule ({delta}{sup 34}S{sub CDT} = +6.0{per_thousand}). Analyses of synthesized, fine-grained mixtures of sulfide, carbonate, and magnetite indicate than the measured sulfur isotope ratio is independent of the presence of carbonate and magnetite in the sputtered volume, confirming the accuracy of the analysis of the fine-grained sulfide in the carbonate globule. Terrestrial biogenic sulfate reduction typically results in light isotopic enrichments. The similarity of {delta}{sup 34}S values of the sulfides in ALH84001 imply that the Fe-sulfide zones within ALH84001 carbonates are probably not the result of bacterial reduction of sulfate. 38 refs., 3 figs., 1 tab.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110012697','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110012697"><span>Stabile Chlorine Isotope Study of Martian <span class="hlt">Shergottites</span> and Nakhlites; Whole Rock and Acid Leachates and Residues</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nakamura, N.; Nyquist, L. E.; Reese, Y.; Shih, C-Y; Fujitani, T.; Okano, O.</p> <p>2011-01-01</p> <p>We have established a precise analytical technique for stable chlorine isotope measurements of tiny planetary materials by TIMS (Thermal Ionization Mass Spectrometry) [1], for which the results are basically consistent with the IRMS tech-nique (gas source mass spectrometry) [2,3,4]. We present here results for Martian <span class="hlt">shergottites</span> and nakhlites; whole rocks, HNO3-leachates and residues, and discuss the chlorine isotope evolution of planetary Mars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70033801','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70033801"><span>Bounce Rock-A <span class="hlt">shergottite</span>-like basalt encountered at Meridiani Planum, Mars</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Zipfel, J.; Schroder, C.; Jolliff, B.L.; Gellert, Ralf; Herkenhoff, K. E.; Rieder, R.; Anderson, R.; Bell, J.F.; Brückner, J.; Crisp, J.A.; Christensen, P.R.; Clark, B. C.; de Souza, P.A.; Dreibus, G.; D'uston, C.; Economou, T.; Gorevan, S.P.; Hahn, B.C.; Klingelhofer, G.; McCoy, T.J.; McSween, H.Y.; Ming, D. W.; Morris, R.V.; Rodionov, D.S.; Squyres, S. W.; Wanke, H.; Wright, S.P.; Wyatt, M.B.; Yen, A. S.</p> <p>2011-01-01</p> <p>The Opportunity rover of the Mars Exploration Rover mission encountered an isolated rock fragment with textural, mineralogical, and chemical properties similar to basaltic <span class="hlt">shergottites</span>. This finding was confirmed by all rover instruments, and a comprehensive study of these results is reported here. Spectra from the miniature thermal emission spectrometer and the Panoramic Camera reveal a pyroxene-rich mineralogy, which is also evident in M??ssbauer spectra and in normative mineralogy derived from bulk chemistry measured by the alpha particle X-ray spectrometer. The correspondence of Bounce Rock's chemical composition with the composition of certain basaltic <span class="hlt">shergottites</span>, especially Elephant Moraine (EET) 79001 lithology B and Queen Alexandra Range (QUE) 94201, is very close, with only Cl, Fe, and Ti exhibiting deviations. Chemical analyses further demonstrate characteristics typical of Mars such as the Fe/Mn ratio and P concentrations. Possible shock features support the idea that Bounce Rock was ejected from an impact crater, most likely in the Meridiani Planum region. Bopolu crater, 19.3km in diameter, located 75km to the southwest could be the source crater. To date, no other rocks of this composition have been encountered by any of the rovers on Mars. The finding of Bounce Rock by the Opportunity rover provides further direct evidence for an origin of basaltic <span class="hlt">shergottite</span> meteorites from Mars. ?? The Meteoritical Society, 2011.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070021571','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070021571"><span>Excess Ar-40 in the Zagami <span class="hlt">Shergottite</span>: Does It Reveal Crystallization History?</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Bogard, Donald D.; Park, Jisun</p> <p>2007-01-01</p> <p>The Zagami basaltic <span class="hlt">shergottite</span> has fine- and coarse-grained (FG & CG) areas, which may reflect partial crystallization in a deep, slowly cooled magma chamber to form Mg-rich pyroxene cores, followed by entrainment of these crystals into a magma that rose and crystallized near the surface. Late-stage melt pockets formed mesostasis and feldspar (maskelynite) having a range of compositions, but low water abundance. Higher I(sub Sr) in the FG portion may result from the second stage having incorporated old crustal rocks that failed to reach isotopic equilibrium. Zagami, like other <span class="hlt">shergottites</span>, contains excess Ar-40(sub xs) beyond that expected from internal decay of K-40 during its Sm-Nd age of 177 Myr. We suggest that at least a portion of this Ar-40(sub xs) in Zagami and some other <span class="hlt">shergottites</span> was inherited from the magma, much as is the case of MORBs on Earth. We made Ar-39-Ar-40 age determinations on feldspar and pyroxene separates from both the FG and CG portions of Zagami. If Zagami experienced an evolving fractional crystallization history, including possible crustal contamination of the magma, that might be indicated in differing amounts of Ar-40(sub xs) between mineral phases and between FG and CG portions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011M%26PS...46....1Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011M%26PS...46....1Z"><span>Bounce Rock - A <span class="hlt">shergottite</span>-like basalt encountered at Meridiani Planum, Mars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zipfel, Jutta; Schräder, Christian; Jolliff, Bradley L.; Gellert, Ralf; Herkenhoff, Kenneth E.; Rieder, Rudolf; Anderson, Robert; Bell, James F., III; Brückner, Johannes; Crisp, Joy A.; Christensen, Philip R.; Clark, Benton C.; de Souza, Paulo A., Jr.; Dreibus, Gerlind; D'Uston, Claude; Economou, Thanasis; Gorevan, Steven P.; Hahn, Brian C.; Klingelhäfer, Göstar; McCoy, Timothy J.; McSween, Harry Y., Jr.; Ming, Douglas W.; Morris, Richard V.; Rodionov, Daniel S.; Squyres, Steven W.; Wńnke, Heinrich; Wright, Shawn P.; Wyatt, Michael B.; Yen, Albert S.</p> <p>2011-01-01</p> <p>Abstract- The Opportunity rover of the Mars Exploration Rover mission encountered an isolated rock fragment with textural, mineralogical, and chemical properties similar to basaltic <span class="hlt">shergottites</span>. This finding was confirmed by all rover instruments, and a comprehensive study of these results is reported here. Spectra from the miniature thermal emission spectrometer and the Panoramic Camera reveal a pyroxene-rich mineralogy, which is also evident in Mössbauer spectra and in normative mineralogy derived from bulk chemistry measured by the alpha particle X-ray spectrometer. The correspondence of Bounce Rock’s chemical composition with the composition of certain basaltic <span class="hlt">shergottites</span>, especially Elephant Moraine (EET) 79001 lithology B and Queen Alexandra Range (QUE) 94201, is very close, with only Cl, Fe, and Ti exhibiting deviations. Chemical analyses further demonstrate characteristics typical of Mars such as the Fe/Mn ratio and P concentrations. Possible shock features support the idea that Bounce Rock was ejected from an impact crater, most likely in the Meridiani Planum region. Bopolu crater, 19.3 km in diameter, located 75 km to the southwest could be the source crater. To date, no other rocks of this composition have been encountered by any of the rovers on Mars. The finding of Bounce Rock by the Opportunity rover provides further direct evidence for an origin of basaltic <span class="hlt">shergottite</span> meteorites from Mars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140011745','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140011745"><span>Tracking the Martian Mantle Signature in Olivine-Hosted Melt Inclusions of Basaltic <span class="hlt">Shergottites</span> Yamato 980459 and Tissint</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Peters, T. J.; Simon, J. I.; Jones, J. H.; Usui, T.; Moriwaki, R.; Economos, R.; Schmitt, A.; McKeegan, K.</p> <p>2014-01-01</p> <p>The Martian <span class="hlt">shergottite</span> meteorites are basaltic to lherzolitic igneous rocks that represent a period of relatively young mantle melting and volcanism, approximately 600-150 Ma (e.g. [1,2]). Their isotopic and elemental composition has provided important constraints on the accretion, evolution, structure and bulk composition of Mars. Measurements of the radiogenic isotope and trace element concentrations of the <span class="hlt">shergottite</span> meteorite suite have identified two end-members; (1) incompatible trace element enriched, with radiogenic Sr and negative epsilon Nd-143, and (2) incompatible traceelement depleted, with non-radiogenic Sr and positive epsilon 143-Nd(e.g. [3-5]). The depleted component represents the <span class="hlt">shergottite</span> martian mantle. The identity of the enriched component is subject to debate, and has been proposed to be either assimilated ancient martian crust [3] or from enriched domains in the martian mantle that may represent a late-stage magma ocean crystallization residue [4,5]. Olivine-phyric <span class="hlt">shergottites</span> typically have the highest Mg# of the <span class="hlt">shergottite</span> group and represent near-primitive melts having experienced minimal fractional crystallization or crystal accumulation [6]. Olivine-hosted melt inclusions (MI) in these <span class="hlt">shergottites</span> represent the most chemically primitive components available to understand the nature of their source(s), melting processes in the martian mantle, and origin of enriched components. We present trace element compositions of olivine hosted melt inclusions in two depleted olivinephyric <span class="hlt">shergottites</span>, Yamato 980459 (Y98) and Tissint (Fig. 1), and the mesostasis glass of Y98, using Secondary Ionization Mass Spectrometry (SIMS). We discuss our data in the context of understanding the nature and origin of the depleted martian mantle and the emergence of the enriched component.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19940030961','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19940030961"><span>The parent magma of xenoliths in <span class="hlt">shergottite</span> EETA79001: Bulk and trace element composition inferred from magmatic inclusions</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Treiman, Allan H.; Lindstrom, David J.; Martinez, Rene R.</p> <p>1994-01-01</p> <p>The SNC meteorites are samples of the Martian crust, so inferences about their origins and parent magmas are of wide planetologic significance. The EETA79001 <span class="hlt">shergottite</span>, a basalt, contains xenoliths of pyroxene-olivine cumulate rocks which are possibly related to the ALHA77005 and LEW88516 SNC lherzolites. Olivines in the xenoliths contain magmatic inclusions, relics of magma trapped within the growing crystals. The magmatic inclusions allow a parent magma composition to be retrieved; it is similar to the composition reconstructed from xenolith pyroxenes by element distribution coefficients. The xenolith parent magma is similar but not identical to parent magmas for the <span class="hlt">shergottite</span> lherzolites.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017M%26PS...52..391H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017M%26PS...52..391H"><span>Trace elements in olivine and the petrogenesis of the intermediate, olivine-phyric <span class="hlt">shergottite</span> NWA 10170</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Howarth, Geoffrey H.; Udry, Arya</p> <p>2017-02-01</p> <p>Olivine-phyric <span class="hlt">shergottites</span> represent primitive basaltic to picritic rocks, spanning a large range of Mg# and olivine abundances. As primitive olivine-bearing magmas are commonly representative of their mantle source on Earth, understanding the petrology and evolution of olivine-phyric <span class="hlt">shergottites</span> is critical in our understanding of Martian mantle compositions. We present data for the olivine-phyric <span class="hlt">shergottite</span> Northwest Africa (NWA) 10170 to constrain the petrology with specific implications for magma plumbing-system dynamics. The calculated oxygen fugacity and bulk-rock REE concentrations (based on modal abundance) are consistent with a geochemically intermediate classification for NWA 10170, and overall similarity with NWA 6234. In addition, we present trace element data using laser ablation ICP-MS for coarse-grained olivine cores, and compare these data with terrestrial and Martian data sets. The olivines in NWA 10170 contain cores with compositions of Fo77 that evolve to rims with composition of Fo58, and are characterized by cores with low Ni contents (400-600 ppm). Nickel is compatible in olivine and such low Ni content for olivine cores in NWA 10170 suggests either early-stage fractionation and loss of olivine from the magma in a staging chamber at depth, or that Martian magmas have lower Ni than terrestrial magmas. We suggest that both are true in this case. Therefore, the magma does not represent a primary mantle melt, but rather has undergone 10-15% fractionation in a staging chamber prior to extrusion/intrusion at the surface of Mars. This further implies that careful evaluation of not only the Mg# but also the trace element concentrations of olivine needs to be conducted to evaluate pristine mantle melts versus those that have fractionated olivine (±pyroxene and oxide minerals) in staging chambers.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080009608','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080009608"><span>Petrology and Mineral Chemistry of New Olivine-Phyric <span class="hlt">Shergottite</span> RBT04262</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dalton, H. A.; Peslier, A. H.; Brandon, A. D.; Lee, C.-T. A.; Lapen, T. J.</p> <p>2008-01-01</p> <p>RBT04262 was found by the 2004-2005 ANSMET team at the Roberts Massif in Antarctica. It is paired with RBT04261 and is classified as an olivine-phyric <span class="hlt">shergottite</span>. RBT04261 is 4.0 x 3.5 x 2.5 cm and 78.8 g, and RBT04262 is 6.5 x 5.5 x 3.5 cm and 204.6 g. Both were partially covered by a fusion crust [1]. Chemical analysis and mapping of this meteorite was performed using the Cameca SX100 electron microprobe at NASA Johnson Space Center.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.osti.gov/scitech/biblio/1009042','SCIGOV-STC'); return false;" href="https://www.osti.gov/scitech/biblio/1009042"><span>Sulfur and iron speciation in gas-rich impact-melt glasses from basaltic <span class="hlt">shergottites</span> determined by microXANES</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Sutton, S.R.; Rao, M.N.; Nyquist, L.E.</p> <p>2008-04-28</p> <p>Sulfur and iron K XANES measurements were made on GRIM glasses from EET 79001. Iron is in the ferrous state. Sulfur speciation is predominately sulfide coordination but is Fe coordinated in Lith B and, most likely, Ca coordinated in Lith A. Sulfur is abundantly present as sulfate near Martian surface based on chemical and mineralogical investigations on soils and rocks in Viking, Pathfinder and MER missions. Jarosite is identified by Moessbauer studies on rocks at Meridian and Gusev, whereas MgSO{sub 4} is deduced from MgO-SO{sub 3} correlations in Pathfinder MER and Viking soils. Other sulfate minerals such as gypsum and alunogen/S-rich aluminosilicates and halides are detected only in martian meteorites such as <span class="hlt">shergottites</span> and nakhlites using SEM/FE-SEM and EMPA techniques. Because sulfur has the capacity to occur in multiple valence states, determination of sulfur speciation (sulfide/sulfate) in secondary mineral assemblages in soils and rocks near Mars surface may help us understand whether the fluid-rock interactions occurred under oxidizing or reducing conditions. On Earth, volcanic rocks contain measurable quantities of sulfur present as both sulfide and sulfate. Carroll and Rutherford showed that oxidized forms of sulfur may comprise a significant fraction of total dissolved sulfur, if the oxidation state is higher than {approx}2 log fO{sub 2} units relative to the QFM buffer. Terrestrial samples containing sulfates up to {approx}25% in fresh basalts from the Galapagos Rift on one hand and high sulfide contents present in oceanic basalts on the other indicate that the relative abundance of sulfide and sulfate varies depending on the oxygen fugacity of the system. Basaltic <span class="hlt">shergottites</span> (bulk) such as Shergotty, EET79001 and Zagami usually contain small amounts of sulfur ({approx}0.5%) as pyrrhotite. But, in isolated glass pockets containing secondary salts (known as GRIM glasses) in these meteorites, sulfur is present in high abundance ({approx}1-12%). To</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2002M%26PS...37..835G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2002M%26PS...37..835G"><span>Sayh <span class="hlt">al</span> Uhaymir 094: A new martian meteorite from the Oman desert</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gnos, E.; Hofmann, B.; Franchi, I. A.; Al-Kathiri, A.; Hauser, M.; Moser, L.</p> <p>2002-06-01</p> <p>Sayh <span class="hlt">al</span> Uhaymir (SaU) 094 is a 223.3 g, partially crusted, strongly to very strongly shocked melanocratic olivine-porphyric rock of the <span class="hlt">shergottite</span> group showing a microgabbroic texture. The rock consists of pyroxene (52.0-58.2 vol%)-dominantly prismatic pigeonite (En60-68Fs20-27Wo7-9) associated with minor augite (En46-49Fs15-16Wo28-31)-brown (shock-oxidized) olivine (Fo65-69; 22.1-31%), completely isotropic interstitial plagioclase glass (maskelynite; An50-64Or0.3-0.9; 8.6-13.0%), chromite and titanian magnesian chromite (0.9-1.0%), traces of ilmenite (Ilm80-86), pyrrhotite (Fe92-100; 0.1-0.2%), merrillite (<<0.1%), and pockets (4.8-6.7%) consisting of green basaltic to basaltic andesitic shock glass that is partially devitrified into a brown to black product along boundaries with the primary minerals. The average maximum dimensions of minerals are: olivine (1.5 mm), pyroxene (0.3 mm) and maskelynite (0.3 mm). Primary melt inclusions in olivine and chromite are common and account for 0.1-0.6% of the rock. X-ray tomography revealed that the specimen contains ~0.4 vol% of shock-melt associated vesicles, up to 3 mm in size, which show a preferred orientation. Fluidization of the maskelynite, melting and recrystallization of pyroxene, olivine and pyrrhotite indicate shock stage S6. Minor terrestrial weathering resulted in calcite-veining and minor oxidation of sulfides. The meteorite is interpreted as paired with SaU 005/008/051. The modal composition is similar to <span class="hlt">Dar</span> <span class="hlt">al</span> Gani 476/489/670/735/876, with the exception that neither mesostasis nor titanomagnetite nor apatite are present and that all phases show little zonation. The restricted mineral composition, predominance of chromite among the oxides, and abundance of olivine indicate affinities to the lherzolitic <span class="hlt">shergottites</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.P31B1709S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.P31B1709S"><span>EBSD analysis of the <span class="hlt">Shergottite</span> Meteorites: New developments within the technique and their implication on what we know about the preferred orientation of Martian minerals</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stephen, N.; Benedix, G. K.; Bland, P.; Berlin, J.; Salge, T.; Goran, D.</p> <p>2011-12-01</p> <p>What we know about the geology and mineralogy of the Martian surface has been characterised by both the use of remote sensing techniques and the analysis of Martian meteorites. Various techniques are employed to conduct these analyses including crystallographic, geochemical and spectral measurements, all of which enable us to infer a geological history for these rocks. Several references have been made to the potential for preferred orientation of crystals within the <span class="hlt">Shergottites</span> [1] and their implication for the cooling history of the respective magmas on Mars [2]. We have already shown that a preferred orientation of the two pyroxenes, augite and pigeonite, can be seen in the Zagami meteorite using electron back-scatter diffraction (EBSD) analysis [3]. However, when compared to previous modal studies of the same meteorites [4], it becomes apparent that the current EBSD datasets for Martian meteorites are incomplete. Indexing of some minerals can be hampered by the lack of available matches within library databases for EBSD, or become difficult to resolve between minerals where crystallographic differences between similar minerals fall below the technical limitations of the instrument [3]. Recent advances in EBSD technologies combined with the simultaneous acquisition of energy-dispersive spectra (EDS) however now allow us to determine a more comprehensive set of analyses in a much shorter period of time, fully resolving even similar minerals where areas have been left with no indexing previously [5]. Preliminary investigations suggest that the new technology can successfully index >90% of the sample. The most recent EBSD analyses potentially reveals previously unseen fabrics in the meteorites alongside the EDS hyper-spectral imaging helping to resolve any unknown or questionable phases within them. In this study we will present new data from an investigation using EDS alongside EBSD analysis on 2 <span class="hlt">Shergottite</span> meteorites, SAU 005 and Zagami, to further resolve</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1986GeCoA..50.1039R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1986GeCoA..50.1039R"><span>Nuclear tracks, SM isotopes and neutron capture effects in the Elephant Morraine <span class="hlt">shergottite</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rajan, R. S.; Lugmair, G.; Tamhane, A. S.; Poupeau, G.</p> <p>1986-06-01</p> <p>Nuclear track studies, uranium concentration measurements and Sm-isotope studies have been performed on both lithologies A and B of the Elephant Morraine <span class="hlt">shergottite</span>, EETA 79001. Track studies show that EETA 79001 was a rather small object in space with a preatmospheric radius of 12 + or - 2 cm, corresponding to a preatmospheric mass of 28 + or - 13 kg. Phosphates have U concentrations ranging from 0.3 to 1.3 ppm. There are occasional phosphates with excess fission tracks, possibly produced from neutron-induced fission of U and Th, during the regolith exposure in the <span class="hlt">shergottite</span> parent body (SPB). Sm-isotope studies, while not showing any clear-cut excess in Sm-150, make it possible to derive meaningful upper limits to thermal neutron fluences of 2 to 3 x 10 to the 15th n/sq cm, during a possible regolith irradiation. These limits are consistent with the track data and also make it possible to derive an upper limit to the neutron exposure age of EETA 79001 of 55 Myr in the SPB regolith.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_2");'>2</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li class="active"><span>4</span></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_4 --> <div id="page_5" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="81"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19860063603&hterms=elephant+evolution&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Delephant%2Bevolution','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19860063603&hterms=elephant+evolution&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Delephant%2Bevolution"><span>Nuclear tracks, Sm isotopes and neutron capture effects in the Elephant Morraine <span class="hlt">shergottite</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rajan, R. S.; Lugmair, G.; Tamhane, A. S.; Poupeau, G.</p> <p>1986-01-01</p> <p>Nuclear track studies, uranium concentration measurements and Sm-isotope studies have been performed on both lithologies A and B of the Elephant Morraine <span class="hlt">shergottite</span>, EETA 79001. Track studies show that EETA 79001 was a rather small object in space with a preatmospheric radius of 12 + or - 2 cm, corresponding to a preatmospheric mass of 28 + or - 13 kg. Phosphates have U concentrations ranging from 0.3 to 1.3 ppm. There are occasional phosphates with excess fission tracks, possibly produced from neutron-induced fission of U and Th, during the regolith exposure in the <span class="hlt">shergottite</span> parent body (SPB). Sm-isotope studies, while not showing any clear-cut excess in Sm-150, make it possible to derive meaningful upper limits to thermal neutron fluences of 2 to 3 x 10 to the 15th n/sq cm, during a possible regolith irradiation. These limits are consistent with the track data and also make it possible to derive an upper limit to the neutron exposure age of EETA 79001 of 55 Myr in the SPB regolith.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150002923','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150002923"><span>Formation and Preservation of the Depleted and Enriched <span class="hlt">Shergottite</span> Isotopic Reservoirs in a Convecting Martian Mantle</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kiefer, Walter S.; Jones, John H.</p> <p>2015-01-01</p> <p>There is compelling isotopic and crater density evidence for geologically recent volcanism on Mars, in the last 100-200 million years and possibly in the last 50 million years. This volcanism is due to adiabatic decompression melting and thus requires some type of present-day convective upwelling in the martian mantle. On the other hand, martian meteorites preserve evidence for at least 3 distinct radiogenic isotopic reservoirs. Anomalies in short-lived isotopic systems (Sm-146, Nd-142, Hf-182, W-182) require that these reservoirs must have developed in the first 50 to 100 million years of Solar System history. The long-term preservation of chemically distinct reservoirs has sometimes been interpreted as evidence for the absence of mantle convection and convective mixing on Mars for most of martian history, a conclusion which is at odds with the evidence for young volcanism. This apparent paradox can be resolved by recognizing that a variety of processes, including both inefficient mantle mixing and geographic separation of isotopic reservoirs, may preserve isotopic heterogeneity on Mars in an actively convecting mantle. Here, we focus on the formation and preservation of the depleted and enriched isotopic and trace element reservoirs in the <span class="hlt">shergottites</span>. In particular, we explore the possible roles of processes such as chemical diffusion and metasomatism in dikes and magma chambers for creating the isotopically enriched <span class="hlt">shergottites</span>. We also consider processes that may preserve the enriched reservoir against convective mixing for most of martian history.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19860063602&hterms=thermoluminescence&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dthermoluminescence','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19860063602&hterms=thermoluminescence&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dthermoluminescence"><span>Thermoluminescence and the shock and reheating history of meteorites. III - The <span class="hlt">shergottites</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Hasan, F. A.; Haq, M.; Sears, D. W. G.</p> <p>1986-01-01</p> <p>Thermoluminescence (TL) measurements on Shergotty, ALHA 77005, Zagami, and EETA 79001 (lithology A) have been used to obtain further information on the shock history of these meteorites. The level of TL sensitivity in the <span class="hlt">shergottites</span> varied by a factor of 10, but was always low, probably reflecting the amount of crystalline material in the maskelynite. There are trends in the TL peak temperature, peak width, and TL sensitivity which are believed to be associated with different proportions of feldspar in high- and low-temperature forms. This interpretation is consistent with the observed changes induced in the TL properties by annealing <span class="hlt">shergottites</span> at 400-900 C. It is suggested that the observed trends were produced during postshock crystallization at a variety of cooling rates, the increasing order of cooling rate being EETA 79001, Zagami, ALHA 77005, and Shergotty, and that there is high-temperature feldspar present in all the samples. This implies a postshock temperature above 600 C, and a small (less than 10 m) size of the ejecta. Current theories are well able to explain how objects of this size could have been ejected from Mars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19870046806&hterms=single+parent&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dsingle%2Bparent','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19870046806&hterms=single+parent&qs=N%3D0%26Ntk%3DAll%26Ntx%3Dmode%2Bmatchall%26Ntt%3Dsingle%2Bparent"><span>Core formation in the <span class="hlt">shergottite</span> parent body and comparison with the earth</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Treiman, Allan H.; Jones, John H.; Drake, Michael J.</p> <p>1987-01-01</p> <p>Abundances of elements in <span class="hlt">shergottite</span>, nakhlite, and Chassigny meteorites which originated on a single planet, the <span class="hlt">shergottite</span> parent body (SPB), were examined with the aim of elucidating the chemical conditions of metal separation and core formation in the SPB and of testing present models of planetary core formation. Using partition coefficients and the SPB mantle composition determined in earlier studies, the abundances of Ag, Au, Co, Ga, Mo, Ni, P, Re, S, and W were modeled, with free parameters being oxygen fugacity, proportion of solid metal formed, proportion of metallic liquid formed, and proportion of silicate that is molten. It is shown that the abundances of all elements (except Mo) could be reproduced using models with these four free parameters. In contrast to the SPB, an equivalent model used to predict element abundances in the earth's mantle was shown by Jones and Drake (1986) to be inadequate; there is at present no hypothesis capable of quantitatively reproducing the elemental abundances of the earth's mantle. The contrast suggests that these two terrestrial planets (assuming that the SPB is Mars) may have accreted or differentiated differently.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120007400','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120007400"><span>Iron Redox Systematics of <span class="hlt">Shergottites</span> and Martian Magmas</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Righter, Kevin; Danielson, L. R.; Martin, A. M.; Newville, M.; Choi, Y.</p> <p>2010-01-01</p> <p>Martian meteorites record a range of oxygen fugacities from near the IW buffer to above FMQ buffer [1]. In terrestrial magmas, Fe(3+)/ SigmaFe for this fO2 range are between 0 and 0.25 [2]. Such variation will affect the stability of oxides, pyroxenes, and how the melt equilibrates with volatile species. An understanding of the variation of Fe(3+)/SigmaFe for martian magmas is lacking, and previous work has been on FeO-poor and <span class="hlt">Al</span>2O3-rich terrestrial basalts. We have initiated a study of the iron redox systematics of martian magmas to better understand FeO and Fe2O3 stability, the stability of magnetite, and the low Ca/high Ca pyroxene [3] ratios observed at the surface.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA562501','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA562501"><span>Automated Aerial Refueling Position Estimation Using a Scanning Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>2012-03-22</p> <p>early analysis of algorithms that use Li<span class="hlt">DAR</span> measurements [20]. Powell et <span class="hlt">al</span>. [21] have shown Li<span class="hlt">DAR</span> simulation with commercial ray tracing software is... tracing , where ray tracing is considered the true measurement. The speedup from using these two methods over the brute force methods is required to...as dark green arrows, are used to determine the green set of points. These points trace out the base of a cone created by all the slope lines</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012E%26PSL.357..119U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012E%26PSL.357..119U"><span>Origin of water and mantle-crust interactions on Mars inferred from hydrogen isotopes and volatile element abundances of olivine-hosted melt inclusions of primitive <span class="hlt">shergottites</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Usui, Tomohiro; Alexander, Conel M. O'D.; Wang, Jianhua; Simon, Justin I.; Jones, John H.</p> <p>2012-12-01</p> <p>Volatile elements have influenced the differentiation and eruptive behavior of Martian magmas and played an important role in the evolution of Martian climate and near-surface environments. However, the abundances of volatiles, and in particular the amount of water in the Martian interior, are disputed. A record of volatile reservoirs is contained in primitive Martian basalts (<span class="hlt">shergottites</span>). Olivine-hosted melt inclusions from a geochemically depleted <span class="hlt">shergottite</span> (Yamato 980459, representing a very primitive Martian melt) possess undegassed water with a chondritic and Earth-like D/H ratio (δD≤275‰). Based on volatile measurements in these inclusions, the water content of the depleted <span class="hlt">shergottite</span> mantle is calculated to be 15-47 ppm, which is consistent with the dry mantle hypothesis. In contrast to D/H in the depleted <span class="hlt">shergottite</span>, melt from an enriched <span class="hlt">shergottite</span> (Larkman Nunatak 06319), which either formed by melting of an enriched mantle or by assimilation of crust, exhibits an extreme δD of ˜5000‰, indicative of a surface reservoir (e.g., the Martian atmosphere or crustal hydrosphere). These data provide strong evidence that the Martian mantle had retained the primordial low-δD component until at least the time of <span class="hlt">shergottite</span> formation, and that young Martian basalts assimilated old Martian crust.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140000409','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140000409"><span>Ar-Ar and Rb-Sr Ages of the Tissint Olivine-phyric Martian <span class="hlt">Shergottite</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Park, J.; Herzog, G. F.; Nyquist, L. E.; Shih, C.-Y.; Turin, B.; Lindsay, F. N.; Delaney, J. S.; Swisher, C. C., III; Agee, C.</p> <p>2013-01-01</p> <p>The fifth martian meteorite fall, Tissint, is an olivine-phyric <span class="hlt">shergottite</span> that contains olivine macrocrysts (approximately 1.5 mm) [1]. [2] reported the Sm-Nd age of Tissint as 596 plus or minus 23 Ma along with Rb-Sr data that defined no isochron. [3] reported Lu-Hf and Sm-Nd ages of 583 plus or minus 86 Ma and 616 plus or minus 67 Ma, respectively. The cosmic-ray exposure ages of Tissint are 1.10 plus or minus 0.15 Ma based on 10Be [4], and 1.0-1.1 Ma, based on 3He, 21Ne, and 38Ar [5,6].We report Ar-Ar ages and Rb-Sr data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20395507','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20395507"><span>A younger age for ALH84001 and its geochemical link to <span class="hlt">shergottite</span> sources in Mars.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lapen, T J; Righter, M; Brandon, A D; Debaille, V; Beard, B L; Shafer, J T; Peslier, A H</p> <p>2010-04-16</p> <p>Martian meteorite ALH84001 (ALH) is the oldest known igneous rock from Mars and has been used to constrain its early history. Lutetium-hafnium (Lu-Hf) isotope data for ALH indicate an igneous age of 4.091 +/- 0.030 billion years, nearly coeval with an interval of heavy bombardment and cessation of the martian core dynamo and magnetic field. The calculated Lu/Hf and Sm/Nd (samarium/neodymium) ratios of the ALH parental magma source indicate that it must have undergone extensive igneous processing associated with the crystallization of a deep magma ocean. This same mantle source region also produced the <span class="hlt">shergottite</span> magmas (dated 150 to 570 million years ago), possibly indicating uniform igneous processes in Mars for nearly 4 billion years.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140012799','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140012799"><span>Preliminary Report on U-Th-Pb Isotope Systematics of the Olivine-Phyric <span class="hlt">Shergottite</span> Tissint</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Moriwaki, R.; Usui, T.; Yokoyama, T.; Simon, J. I.; Jones, J. H.</p> <p>2014-01-01</p> <p>Geochemical studies of <span class="hlt">shergottites</span> suggest that their parental magmas reflect mixtures between at least two distinct geochemical source reservoirs, producing correlations between radiogenic isotope compositions, and trace element abundances.. These correlations have been interpreted as indicating the presence of a reduced, incompatible-element- depleted reservoir and an oxidized, incompatible-element-rich reservoir. The former is clearly a depleted mantle source, but there has been a long debate regarding the origin of the enriched reservoir. Two contrasting models have been proposed regarding the location and mixing process of the two geochemical source reservoirs: (1) assimilation of oxidized crust by mantle derived, reduced magmas, or (2) mixing of two distinct mantle reservoirs during melting. The former clearly requires the ancient martian crust to be the enriched source (crustal assimilation), whereas the latter requires a long-lived enriched mantle domain that probably originated from residual melts formed during solidification of a magma ocean (heterogeneous mantle model). This study conducts Pb isotope and U-Th-Pb concentration analyses of the olivine-phyric <span class="hlt">shergottite</span> Tissint because U-Th-Pb isotope systematics have been intensively used as a powerful radiogenic tracer to characterize old crust/sediment components in mantle- derived, terrestrial oceanic island basalts. The U-Th-Pb analyses are applied to sequential acid leaching fractions obtained from Tissint whole-rock powder in order to search for Pb isotopic source components in Tissint magma. Here we report preliminary results of the U-Th-Pb analyses of acid leachates and a residue, and propose the possibility that Tissint would have experienced minor assimilation of old martian crust.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/1984LPSC...14..612S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/1984LPSC...14..612S"><span>Petrogenesis of the SNC (<span class="hlt">shergottites</span>, nakhlites, chassignites) meteorites - Implications for their origin from a large dynamic planet, possibly Mars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Smith, M. R.; Laul, J. C.; Ma, M.-S.; Huston, T.; Verkouteren, R. M.; Lipschutz, M. E.; Schmitt, R. A.</p> <p>1984-02-01</p> <p>Comprehensive chemical data are presented on the <span class="hlt">shergottites</span> Shergotty, Zagami, Allan Hills (ALHA) 77005, and the new member Elephant Moraine (EETA) 79001 using results of sequential instrumental and radiochemical neutron activation analysis. The close relationship of the Antarctic shergotites indicates that ALHA 77005 is a residual source produced by incongruent melting of a source similar in bulk composition to EETA 79001A and that EETA 79001B and the interstitial phases in EETA 79001A are the melts produced by such melting episodes. The large ion lithophile LIL) trace element abundanced of the <span class="hlt">shergottites</span> require variable but extensive degrees of nomodal melting of isotopically constrained parent sources. The SNG sources are consistent with their derivation by extensive fractionation of a primitive magma initially produced from a source having chondritic refractory LIL trace element abundances. Petrogenetic and age relationships among SNC meteorites suggest a single complex-provenance on a dynamic planet not unlike earth, probably Mars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19840043311&hterms=elephant+evolution&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Delephant%2Bevolution','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19840043311&hterms=elephant+evolution&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Delephant%2Bevolution"><span>Petrogenesis of the SNC (<span class="hlt">shergottites</span>, nakhlites, chassignites) meteorites - Implications for their origin from a large dynamic planet, possibly Mars</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Smith, M. R.; Laul, J. C.; Ma, M. S.; Huston, T.; Verkouteren, R. M.; Lipschutz, M. E.; Schmitt, R. A.</p> <p>1984-01-01</p> <p>Comprehensive chemical data are presented on the <span class="hlt">shergottites</span> Shergotty, Zagami, Allan Hills (ALHA) 77005, and the new member Elephant Moraine (EETA) 79001 using results of sequential instrumental and radiochemical neutron activation analysis. The close relationship of the Antarctic shergotites indicates that ALHA 77005 is a residual source produced by incongruent melting of a source similar in bulk composition to EETA 79001A and that EETA 79001B and the interstitial phases in EETA 79001A are the melts produced by such melting episodes. The large ion lithophile LIL) trace element abundanced of the <span class="hlt">shergottites</span> require variable but extensive degrees of nomodal melting of isotopically constrained parent sources. The SNG sources are consistent with their derivation by extensive fractionation of a primitive magma initially produced from a source having chondritic refractory LIL trace element abundances. Petrogenetic and age relationships among SNC meteorites suggest a single complex-provenance on a dynamic planet not unlike earth, probably Mars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140012817','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140012817"><span>Identification of Martian Regolith Sulfur Components in <span class="hlt">Shergottites</span> Using Sulfur K Xanes and Fe/S Ratios</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sutton, S. R.; Ross, D. K.; Rao, M. N.; Nyquist, L. E.</p> <p>2014-01-01</p> <p>Based on isotopic anomalies in Kr and Sm, Sr-isotopes, S-isotopes, XANES results on S-speciation, Fe/S ratios in sulfide immiscible melts [5], and major element correlations with S determined in impact glasses in EET79001 Lith A & Lith B and Tissint, we have provided very strong evidence for the occurrence of a Martian regolith component in some impact melt glasses in <span class="hlt">shergottites</span>. Using REE measurements by LA-ICP-MS in <span class="hlt">shergottite</span> impact glasses, Barrat and co-workers have recently reported conflicting conclusions about the occurrence of Martian regolith components: (a) Positive evidence was reported for a Tissint impact melt, but (b) Negative evidence for impact melt in EET79001 and another impact melt in Tissint. Here, we address some specific issues related to sulfur speciation and their relevance to identifying Martian regolith components in impact glasses in EET79001 and Tissint using sulfur K XANES and Fe/S ratios in sulfide immiscible melts. XANES and FE-SEM measurements in approx. 5 micron size individual sulfur blebs in EET79001 and Tissint glasses are carried out by us using sub-micron size beams, whereas Barrat and coworkers used approx. 90 micron size laser spots for LA- ICP-MS to determine REE abundances in bulk samples of the impact melt glasses. We contend that Martian regolith components in some <span class="hlt">shergottite</span> impact glasses are present locally, and that studying impact melts in various <span class="hlt">shergottites</span> can give evidence both for and against regolith components because of sample heterogeneity.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140002468','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140002468"><span>Tracking the Depleted Mantle Signature in Melt Inclusions and Residual Glass of Basaltic Martian <span class="hlt">Shergottites</span> using Secondary Ionization Mass Spectrometry</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Peters, Timothy J.; Simon, Justin I.; Jones, John H.; Usui, Tomohiro; Economos, Rita C.; Schmitt, Axel K.; McKeegan, Kevin D.</p> <p>2013-01-01</p> <p>Trace element abundances of depleted <span class="hlt">shergottite</span> magmas recorded by olivine-hosted melt inclusions (MI) and interstitial mesostasis glass were measured using the Cameca ims-1270 ion microprobe. Two meteorites: Tissint, an olivine-­phyric basaltic <span class="hlt">shergottite</span> which fell over Morocco July 18th 2001; and the Antarctic meteorite Yamato 980459 (Y98), an olivine-phyric basaltic <span class="hlt">shergottite</span> with abundant glassy mesostasis have been studied. Chondrite-­normalized REE patterns for MI in Tissint and Y98 are characteristically LREE depleted and, within analytical uncertainty, parallel those of their respective whole rock composition; supporting each meteorite to represent a melt composition that has experienced closed-­system crystallization. REE profiles for mesostasis glass in Y98 lie about an order of magnitude higher than those from the MI; with REE profiles for Tissint MI falling in between. Y98 MI have the highest average Sm/Nd and Y/Ce ratios, reflecting their LREE depletion and further supporting Y98 as one of our best samples to probe the depleted shergotitte mantle. In general, Zr/Nb ratios overlap between Y98 and Tissint MI, Ce/Nb ratios overlap between Y98 MI and mesostasis glass, and Sm/Nd ratios overlap between Y98 mesostasis glass and Tissint MI. These features support similar sources for both, but with subtle geochemical differences that may reflect different melting conditions or fractionation paths during ascent from the mantle. Interestingly, the REE patterns for both Y98 bulk and MI analyses display a flattening of the LREE that suggests a crustal contribution to the Y98 parent melt. This observation has important implications for the origins of depleted and enriched <span class="hlt">shergottites</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150001926','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150001926"><span>Mineralogical Comparison of Olivine in <span class="hlt">Shergottites</span> and A Shocked L Chondrite: Implications for Shock Histories of Brown Olivine</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Takenouchi, A.; Mikouchi, T.; Yamaguchi, A.; Zolensky, M. E.</p> <p>2015-01-01</p> <p>Most Martian meteorites are heavily shocked, exhibiting numerous shock features, for example undulatory extinction of olivine and pyroxene, the presence of diaplectic glass ("maskelynite") and the formation of shock melt. Among these shock features, olivine darkening ("brown" olivine) is unique in Martian meteorites because no other meteorite group shows such a feature. Although the presence of brown olivine in <span class="hlt">shergottites</span> was reported thirty years ago, detailed observation by TEM has not been performed until the NWA 2737 chassignite was discovered, whose olivine is darkened, being completely black in hand specimen. Fe metal nano-particles were found in NWA 2737 olivine which are considered to have been formed by olivine reduction during heavy shock. Subsequently, magnetite nano-particles were also found in other Martian meteorites and the coexistence of Fe metal and magnetite nano-particles was reported in the NWA 1950 <span class="hlt">shergottite</span> and some Fe metal nano-particles were mantled by magnetite. Therefore, the formation process of nano-particles seems to be complex. Because "brown" olivine is unique to Martian meteorites, they have a potential to constrain their shock conditions. In order to better understand the shock history of Martian meteorites, we compared olivine in several <span class="hlt">shergottites</span> with that in a highly-shocked L chondrite which contains ringwoodite.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016M%26PS...51.2011F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016M%26PS...51.2011F"><span>Effect of chlorine on near-liquidus crystallization of olivine-phyric <span class="hlt">shergottite</span> NWA 6234 at 1 GPa: Implication for volatile-induced melting of the Martian mantle</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Farcy, Benjamin J.; Gross, Juliane; Carpenter, Paul; Hicks, Jacob; Filiberto, Justin</p> <p>2016-11-01</p> <p>Martian magmas are thought to be rich in chlorine compared with their terrestrial counterparts. Here, we experimentally investigate the effect of chlorine on liquidus depression and near-liquidus crystallization of olivine-phyric <span class="hlt">shergottite</span> NWA 6234 and compare these results with previous experimental results on the effect of chlorine on near-liquidus crystallization of the surface basalts Humphrey and Fastball. Previous experimental results showed that the change in liquidus temperature is dependent on the bulk composition of the basalt. The effect of chlorine on liquidus depression is greater for lower SiO2 and higher <span class="hlt">Al</span>2O3 magmas than for higher SiO2 and lower <span class="hlt">Al</span>2O3 magmas. The bulk composition for this study has lower <span class="hlt">Al</span>2O3 and higher FeO contents than previous work; therefore, we provide additional constraints on the effect of the bulk composition on the influence of chlorine on near-liquidus crystallization. High pressure and temperature crystallization experiments were performed at 1 GPa on a synthetic basalt, of the bulk composition of NWA 6234, with 0-4 wt% Cl added to the sample as AgCl. The results are consistent with previous notions that with increasing wt% Cl in the melt, the crystallization temperature decreases. Importantly, our results have a liquidus depression ∆T (°C) from added chlorine that is consistent with the difference in bulk composition and suggest a dependence on both the bulk <span class="hlt">Al</span>2O3 and FeO content. Our results suggest that the addition of chlorine to the Martian mantle may lower magma genesis temperatures and potentially aid in the petrogenesis of Martian magmas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016M%26PS...51.2061H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016M%26PS...51.2061H"><span>Postcrystallization metasomatism in <span class="hlt">shergottites</span>: Evidence from the paired meteorites LAR 06319 and LAR 12011</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Howarth, Geoffrey H.; Liu, Yang; Chen, Yang; Pernet-Fisher, John F.; Taylor, Lawrence A.</p> <p>2016-11-01</p> <p>Apatite is the major volatile-bearing phase in Martian meteorites, containing structurally bound fluorine, chlorine, and hydroxyl ions. In apatite, F is more compatible than Cl, which in turn is more compatible than OH. During degassing, Cl strongly partitions into the exsolved phase, whereas F remains in the melt. For these reasons, the volatile concentrations within apatite are predictable during magmatic differentiation and degassing. Here, we present compositional data for apatite and merrillite in the paired enriched, olivine-phyric <span class="hlt">shergottites</span> LAR 12011 and LAR 06319. In addition, we calculate the relative volatile fugacities of the parental melts at the time of apatite formation. The apatites are dominantly OH-rich (calculated by stoichiometry) with variable yet high Cl contents. Although several other studies have found evidence for degassing in the late-stage mineral assemblage of LAR 06319, the apatite evolutionary trends cannot be reconciled with this interpretation. The variable Cl contents and high OH contents measured in apatites are not consistent with fractionation either. Volatile fugacity calculations indicate that water and fluorine activities remain relatively constant, whereas there is a large variation in the chlorine activity. The Martian crust is Cl-rich indicating that changes in Cl contents in the apatites may be related to an external crustal source. We suggest that the high and variable Cl contents and high OH contents of the apatite are the results of postcrystallization interaction with Cl-rich, and possibly water-rich, crustal fluids circulating in the Martian crust.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016M%26PS...51.1233F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016M%26PS...51.1233F"><span>Igneous cooling history of olivine-phyric <span class="hlt">shergottite</span> Yamato 980459 constrained by dynamic crystallization experiments</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>First, Emily; Hammer, Julia</p> <p>2016-07-01</p> <p>Dynamic crystallization experiments were performed on a liquid having the bulk composition of olivine-phyric <span class="hlt">shergottite</span> Yamato 980459, to constrain the igneous thermal history of this meteorite. Key characteristics of the meteorite's mineralogy and texture, including several morphologically distinct olivine and pyroxene crystal populations and a glassy mesostasis devoid of plagioclase, were replicated upon cooling from 1435 to 909 °C at 1 atmosphere under reducing conditions. Three sequential cooling ramps are required to produce synthetic samples with textures and compositions matching Yamato 980459. Olivine phenocrysts formed at <1 °C h-1, presumably at depth in the Martian crust. Pyroxene phenocrysts formed mainly at ~10 °C h-1, consistent with crystallization within a lava flow at depths of 25-45 cm. Increased cooling rate (~100 °C h-1) in a third stage suppressed the formation of plagioclase and produced groundmass crystals, consistent with crystallization at lava flow depths of 5-7 cm. Although Y 980459 is unique among Martian meteorites (i.e., preserving a primary glassy mesostasis), its emplacement did not require unique physical conditions. Rather, the second and third cooling stages may reflect cooling within the core of a pāhoehoe-like flow and subsequent breakout on the surface of Mars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016M%26PS...51...80U','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016M%26PS...51...80U"><span>Lithium isotopes and light lithophile element abundances in <span class="hlt">shergottites</span>: Evidence for both magmatic degassing and subsolidus diffusion</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Udry, Arya; McSween, Harry Y.; Hervig, Richard L.; Taylor, Lawrence A.</p> <p>2016-01-01</p> <p>Degassed magmatic water was potentially the major source of surficial water on Mars. We measured Li, B, and Be abundances and Li isotope profiles in pyroxenes, olivines, and maskelynite from four compositionally different shergottites—Shergotty, QUE 94201, LAR 06319, and Tissint—using secondary ion mass spectrometry (SIMS). All three light lithophile elements (LLE) are incompatible: Li and B are soluble in H2O-rich fluids, whereas Be is insoluble. In the analyzed <span class="hlt">shergottites</span>, Li concentration decreases and Be concentration increases from cores to rims in pyroxenes. However, B concentrations do not vary consistently with Li and Be abundances, except in QUE 94201 pyroxenes. Additionally, abundances of these three elements in olivines show a normal igneous-fractionation trend consistent with the crystallization of olivine before magma ascent and degassing. We expect that kinetic effects would lead to fractionation of 6Li in the vapor phase compared to 7Li during degassing. The Li isotope profiles, with increasing δ7Li from cores to rims, as well as Li and B profiles indicate possible degassing of hydrous fluids only for the depleted <span class="hlt">shergottite</span> QUE 94201, as also supported by degassing models. Conversely, Shergotty, LAR 06319, and Tissint appear to have been affected by postcrystallization diffusion, based on their LLE and Li isotope profiles, accompanied by diffusion models. This process may represent an overlay on a degassing pattern. The LLE profiles and isotope profiles in QUE 94201 support the hypothesis that degassing of some basaltic <span class="hlt">shergottite</span> magmas provided water to the Martian surface, although evidence may be obscured by subsolidus diffusion processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050167804','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050167804"><span>Experimental Petrology of the Basaltic <span class="hlt">Shergottite</span> Yamato 980459: Implications for the Thermal Structure of the Martian Mantle</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Dalton, H. A.; Musselwhite, D. S.; Kiefer, W.; Treiman, A. H.</p> <p>2005-01-01</p> <p>Yamato 980459 (Y98) is an olivine-phyric basaltic <span class="hlt">shergottite</span> composed of 48% pyroxene, 26% olivine, 25% mesostasis, and 1% other minerals. Unlike the other Martian basalts, it contains no plagioclase. Olivine in Y98 is the most magnesian of all Martian meteorites. Thus Y98 is believed to be the most primitive and its composition may be the closest to a primary or direct melt of the Martian mantle. As such, it provides a very useful probe of the mineralogy and depth of its mantle source region. Toward this end, we are conducting crystallization experiments on a synthetic Y98 composition at Martian mantle pressures and temperatures.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_3");'>3</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li class="active"><span>5</span></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_5 --> <div id="page_6" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="101"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20110007805','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20110007805"><span>Recognizing the Effects of Terrestrial Contamination on D/H Ratios in <span class="hlt">Shergottite</span> Phosphates</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ross, D. K.; Ito, M.; Hervig, R.; Rao, M. N.; Nyquist, L. E.</p> <p>2011-01-01</p> <p>Hydrogen isotope ratios in <span class="hlt">shergottite</span> phosphate minerals have been investigated by SIMS in the meteorites Queen Alexandra Range (QUE) 94201 and Los Angeles. We have also collected electron probe data on these phosphates in order to characterize the phosphate minerals and attempt to document any potential hydrogen isotopic differences between chlor-apatite and whitlockite. In the section of Los Angeles we studied (748), we found both chlor-apatite and whitlockite, but in the section of QUE 94201,38 studied, we found only whitlockite. In both meteorites, D/H ratios (expressed in units of delta D (sub SMOW) vary, from terrestrial values up to approximately 5400%o in QUE 94201, and to approximately 3800%o in Los Angeles. We have carefully examined the ion probed pits with high-resolution FE-SEM. In most cases where the D/H ratios are low, we have iden-tified cracks that instersect the ion probe pit. These cracks are not visible in the optical microscope attached to the SIMS instument, making them impossible to avoid during SIMS data collection. We contend that the low ratios are a function of substantial terrestrial contamination, and that similar contamination is a likely factor in previously published studies on D/H ratios in martian phosphates. Here we highlight the difficulty of attempts to constrain the martian mantle D/H ratio using phosphate data, given that both terrestrial contamination and martian mantle hydrogen will move phosphate D/H ratios in the same direction, toward lower values. We note that our data include some of the most deuterium-rich values ever reported for martian phosphates. It is clear that some of our measurements are only minimally or totally uncontaminated, but the question arises, are intermediate values diminished because of true martian variability, or do they reflect contamination?</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20020046467&hterms=Rutherford&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DRutherford','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20020046467&hterms=Rutherford&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DRutherford"><span>An Experimental Study of Eu/Gd Partitioning Between a <span class="hlt">Shergottite</span> Melt and Pigeonite: Implications for the Oxygen Fugacity of the Martian Interior</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>McCanta, M. C.; Rutherford, M. J.; Jones, J. H.</p> <p>2002-01-01</p> <p>We experimentally investigated the partitioning behavior of Eu/Gd between a synthetic <span class="hlt">shergottite</span> melt and pigeonite as a function of oxygen fugacity. This has implications for the oxidation state of the source region of the martian meteorites. Additional information is contained in the original extended abstract.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013GeCoA.108....1L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013GeCoA.108....1L"><span>New constraints on the formation of <span class="hlt">shergottite</span> Elephant Moraine 79001 lithology A</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Yang; Balta, J. Brian; Goodrich, Cyrena A.; McSween, Harry Y.; Taylor, Lawrence A.</p> <p>2013-05-01</p> <p>Previous studies of Elephant Moraine (EET) 79001 disagreed upon the nature of the magnesian olivine and orthopyroxene grains, and generally considered the formation of EET 79001 at low pressure conditions. New observations on mineral associations, and trace-element abundances of olivine-hosted melt inclusions, in lithology A (EET-A) of EET 79001 lead to new constraints on the formation of this meteorite. The abundances and chondrite-normalized REE pattern of the average melt inclusions in olivine of Mg# 75-61 are similar to those of the bulk-rock composition of lithology A, suggesting that the Mg# <77 olivines are phenocrysts. We also report the widespread occurrence of round orthopyroxene (En78.9-77.9Wo2.2-2.5) inclusions in disequilibrium contact with their olivine hosts (Mg# 73-68). Compositions of these inclusions are similar to xenocrystic cores (Mg# ⩾77; Wo ⩽4) in pyroxene megacrysts. These observations indicate that orthopyroxene xenocrysts were being resorbed while Mg# 77-73 olivine was crystallizing. Combined, these observations suggest that only small portions of the megacrysts are xenocrystic, namely orthopyroxene of Mg# ⩾77 and Wo ⩽4, and possibly also olivine of Mg# ⩾77. The volume percentages of the xenocrystic materials in the rock are small (⩽1 vol.% for each mineral). Compositions of the xenocrystic minerals are similar to cores of megacrysts in olivine-phyric <span class="hlt">shergottite</span> Yamato (Y) 980459 and Northwest Africa (NWA) 5789. Considering the small fraction of xenocrysts and the similarity between REE abundances of the early-trapped melt and those in bulk EET-A, we re-evaluated the possibility that the bulk-rock composition of EET-A is close to that of its parent melt. Results of pMELTS modeling indicate that polybaric crystallization of the EET-A bulk composition (corrected by removal of xenocryst material) can reproduce the crystallization sequence of EET-A, in contrast to the conclusions of previous workers. We estimate that the EET</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070009871','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070009871"><span>Lu-Hf and Sm-Nd Isotopic Studies of <span class="hlt">Shergottites</span> and Nakhlites: Implications for Martian Mantle Sources</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Debaille, V.; Yin, Q.-Z.; Brandon, A. D.; Jacobsen, B.; Treiman, A. H.</p> <p>2007-01-01</p> <p>We present a new Lu-Hf and Sm-Nd isotope systematics study of four enriched <span class="hlt">shergottites</span> (Zagami, Shergotty, NWA856 and Los Angeles), and three nakhlites (Nakhla, MIL03346 and Yamato 000593) in order to further understand processes occurring during the early differentiation of Mars and the crystallization of its magma ocean. Two fractions of the terrestrial petrological analogue of nakhlites, the Archaean Theo's flow (Ontario, Canada) were also measured. The coupling of Nd and Hf isotopes provide direct insights on the mineralogy of the melt sources. In contrast to Sm/Nd, Lu/Hf ratios can be very large in minerals such as garnet. Selective partial melting of garnet bearing mantle sources can therefore lead to characteristic Lu/Hf signatures that can be recognized with Hf-176/Hf-177Hf ratios.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19860047526&hterms=indigenous&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dindigenous','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19860047526&hterms=indigenous&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3Dindigenous"><span>The case for a Martian origin of the <span class="hlt">shergottites</span>. II - Trapped and indigenous gas components in EETA 79001 glass</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Wiens, R. C.; Becker, R. H.; Pepin, R. O.</p> <p>1986-01-01</p> <p>The isotopic composition of N, Ar, Ne, and He, trapped in an uncrushed sample of the antarctic <span class="hlt">shergottite</span> EETA 79001, was analyzed by subjecting the evacuated sample to stepped heating in the presence of 100 mtorr of oxygen. The isotopic composition of nitrogen (with the delta-N-15 value of greater than 300 percent) and the elemental ratios Ar-36/N-14 and Ar-40/N-14 were covariant along mixing lines passing through the Martian atmospheric composition. The results of this and previous analyses are consistent with a two-component nitrogen system in which about 84 ppb of trapped Martian atmospheric N is mixed in variable proportions with another, more thermally labile N component during stepped heating. The isotopic Ar-36/Ar-38 ratio of the EETA 79001 is different from that of the earth atmosphere by about 25 percent.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19910025973&hterms=Cerium&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DCerium','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19910025973&hterms=Cerium&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D70%26Ntt%3DCerium"><span>Rare earth elements in minerals of the ALHA77005 <span class="hlt">shergottite</span> and implications for its parent magma and crystallization history</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Lundberg, Laura L.; Crozaz, Ghislaine; Mcsween, Harry Y., Jr.</p> <p>1990-01-01</p> <p>Analyses of mineral REE and selected minor and trace elements were carried out on individual grains of pyroxenes, whitlockite, maskelynite, and olivine of the Antarctic <span class="hlt">shergottite</span> ALHA77005, and the results are used to interpret its parent magma and crystallization history. The results of mineral compositions and textural observations suggest that ALHA77005 is a cumulate with about half cumulus material (olivine + chromite) and half postcumulus phases. Most of the REEs in ALHA77005 reside in whitlockite whose modal concentration is about 1 percent. Mineral REE data support previous suggestions that plagioclase and whitlockite crystallized late, and that low-Ca pyroxene initiated crystallization before high-Ca pyroxene. The REE patterns for the intercumulus liquid, calculated from distribution coefficients for ALHA77005 pyroxene, plagioclase, and whitlockite, are in very good agreement and are similar to that of Shergotty.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.B33A0387R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.B33A0387R"><span>Modelling Sensor and Target effects on Li<span class="hlt">DAR</span> Waveforms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rosette, J.; North, P. R.; Rubio, J.; Cook, B. D.; Suárez, J.</p> <p>2010-12-01</p> <p>The aim of this research is to explore the influence of sensor characteristics and interactions with vegetation and terrain properties on the estimation of vegetation parameters from Li<span class="hlt">DAR</span> waveforms. This is carried out using waveform simulations produced by the FLIGHT radiative transfer model which is based on Monte Carlo simulation of photon transport (North, 1996; North et <span class="hlt">al</span>., 2010). The opportunities for vegetation analysis that are offered by Li<span class="hlt">DAR</span> modelling are also demonstrated by other authors e.g. Sun and Ranson, 2000; Ni-Meister et <span class="hlt">al</span>., 2001. Simulations from the FLIGHT model were driven using reflectance and transmittance properties collected from the Howland Research Forest, Maine, USA in 2003 together with a tree list for a 200m x 150m area. This was generated using field measurements of location, species and diameter at breast height. Tree height and crown dimensions of individual trees were calculated using relationships established with a competition index determined for this site. Waveforms obtained by the Laser Vegetation Imaging Sensor (LVIS) were used as validation of simulations. This provided a base from which factors such as slope, laser incidence angle and pulse width could be varied. This has enabled the effect of instrument design and laser interactions with different surface characteristics to be tested. As such, waveform simulation is relevant for the development of future satellite Li<span class="hlt">DAR</span> sensors, such as NASA’s forthcoming DESDynI mission (NASA, 2010), which aim to improve capabilities of vegetation parameter estimation. ACKNOWLEDGMENTS We would like to thank scientists at the Biospheric Sciences Branch of NASA Goddard Space Flight Center, in particular to Jon Ranson and Bryan Blair. This work forms part of research funded by the NASA DESDynI project and the UK Natural Environment Research Council (NE/F021437/1). REFERENCES NASA, 2010, DESDynI: Deformation, Ecosystem Structure and Dynamics of Ice. http</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMNH41D..05D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMNH41D..05D"><span>Characterizing Lava Flows With Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Deligne, N. I.; Cashman, K. V.; Deardorff, N.; Dietterich, H. R.; House, P. K.; Soule, S.</p> <p>2009-12-01</p> <p>Digital elevation models (DEMs) have been used in volcanology in predictive modeling of lava flow paths, both for assessment of potential hazards and specific predictions of lava flow paths. Topographic analysis of a lava flow is potentially useful for mapping and quantifying flow surface morphologies, which in turn can be used to determine flow emplacement conditions, such as effusion rate, steadiness of flow, and interactions with pre-existing topography and surface water. However, this has been limited in application because of the coarse resolution of most DEMs. In recent years, use of Light Detection and Ranging (Li<span class="hlt">DAR</span>) airborne laser altimetry, capable of producing high resolution (≤ 1 meter) DEMs, has become increasingly common in the geomorphic and mapping community. However, volcanologists have made little use of airborne Li<span class="hlt">DAR</span>. Here we compare information obtained using field observations and standard (10 meter) DEMs against Li<span class="hlt">DAR</span> high resolution DEMs to assess the usefulness, capabilities, and limitations of Li<span class="hlt">DAR</span> as applicable to lava flows. We compare morphologic characteristics of five lava flows of different compositions, tectonic settings, flow extents, slopes, and eruption duration: (1) 1984 Mauna Loa lava flow, Hawaii; (2) December 1974 Kilauea lava flow, Hawaii; (3) c. 1600 ybp Collier Cone lava flow, central Oregon Cascades; (4) Holocene lava flows from the Sand Mountain volcanic chain, central Oregon Cascades; and (5) Pleistocene lava flows along the Owyhee River, eastern Oregon basin and range. These lava flows range in composition from basalt to andesite, and have eruption durations ranging from 6 hours (observed) to years (inferred). We measure channel width, levee and flow front heights, compression ridge amplitude, wavelength and tumuli dimensions, and surface roughness. For all but the smallest scale features, Li<span class="hlt">DAR</span> is easily used to quantify these features, which often is impossible or technically challenging to do in the field, while</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19860063595&hterms=Igneous+rocks&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DIgneous%2Brocks','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19860063595&hterms=Igneous+rocks&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3DIgneous%2Brocks"><span>A discussion of isotopic systematics and mineral zoning in the <span class="hlt">shergottites</span> - Evidence for a 180 m.y. igneous crystallization age</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Jones, J. H.</p> <p>1986-01-01</p> <p>The chronologies of the Shergotty, Zagami, ALHA 77005, and EETA 79001 meteorites were reexamined on the basis of <span class="hlt">shergottites</span>' petrography and mineral chemistry data. Among the various isochrons, the concordant Rb-Sr (about 180 Myr) and U-Th-Pb (about 190 Myr) internal isochrons are interpreted as representing the time of igneous crystallization, while the Rb-Sr, Sm-Nd, and Pb-Pb whole-rock isochrons are interpreted as mixing lines, and are reasonably attributed to igneous processes such as wall-rock assimilation and magma mixing. If the approximated age of less than 200 Myr is correct, the <span class="hlt">shergottites</span> represent the youngest known extraterrestrial basalts. This conclusion supports the hypothesis that the SNC meteorites are samples of Mars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20140011731','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20140011731"><span>Sm-Nd and Rb-Sr Isotopic Systematics of a Heavily Shocked Martian Meteorite Tissint and Petrogenesis of Depleted <span class="hlt">Shergottites</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shih, C.-Y.; Nyquist, L. E.; Park, J.; Agee, Carl B.</p> <p>2014-01-01</p> <p>Tissint is a very fresh Martian meteorite that fell near the town of Tissint in Morocco on July 18, 2011. It contains abundant olivine megacrysts (23%) in a fine-grained matrix of pyroxene (55%), maskelynitized plagioclase (15%), opaques (4%) and melt pockets (3%) and is petrographically similar to lithologies A and C of picritic <span class="hlt">shergottite</span> EETA 79001 [1,2]. The presence of 2 types of shock-induced glasses and all 7 high-pressure mineral phases that were ever found in melt pockets of Martian meteorites suggests it underwent an intensive shock metamorphism of 25 GPa and 2000 C localized in melt pockets [2]. Mineral textures suggest that olivines, pyroxenes and plagioclases probably did not experience such hightemperature. Earlier determinations of its age yielded 596+/-23 Ma [3] and 616+/-67 Ma [4], respectively, for the Sm-Nd system and 583+/-86 Ma for the Lu-Hf system [4], in agreement with the 575+/-18 Ma age of the oldest olivine-phyric depleted <span class="hlt">shergottite</span> Dho 019 [5]. However, the exposure ages of Tissint (1 Ma [1, 6, 7]) and Dho 019 (20 Ma [8]) are very different requiring two separate ejection events. These previously determined Sm-Nd and Lu-Hf ages are older than the Ar-Ar maskelynite plateau age of 524+/-15 Ma [9], reversing the pattern usually observed for Martian meteorites. In order to clarify these age issues and place models for Tissint's petrogenesis on a firm basis, we present new Rb-Sr and Sm- Nd isotopic results for Tissint, and discuss (a) the shock effects on them and the Ar-Ar chronometer, (b) correlation of the determined ages with those of other depleted <span class="hlt">shergottites</span>, and (c) the petrogenesis of depleted <span class="hlt">shergottites</span>. Since the meteorite is a recent fall, terrestrial contamination is expected to be minimal, but, the strong shock metamorphism might be expected to compromise the equilibrium of the isotopic systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA565824','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA565824"><span>DoD Architecture Registry System (<span class="hlt">DARS</span>)</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>2012-04-30</p> <p>Communications-Electronics Research, Development and Engineering Center (CERDEC), S ft E i i Di t t (SED) UNCLASSIFIED 5 o ware ng neer ng rec ora e...Army 1245 (1183, 5 %)  Air Force 960 (889, 8%)  OSD 358 (346, 3%) M i 223 ( %) ar nes 209, 7  Combatant Command 156 (155, 1%)  Joint Staff...Program • Deployed <span class="hlt">DARS</span> Release 5 6 in April 29 2011 This releaseCompleted Support . . included: • Migrate Community Management and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015GeCoA.166..234H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015GeCoA.166..234H"><span>Evidence for the exsolution of Cl-rich fluids in martian magmas: Apatite petrogenesis in the enriched lherzolitic <span class="hlt">shergottite</span> Northwest Africa 7755</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Howarth, G. H.; Pernet-Fisher, J. F.; Bodnar, R. J.; Taylor, L. A.</p> <p>2015-10-01</p> <p>Martian meteorite Northwest Africa 7755 is a new example of an enriched, lherzolitic <span class="hlt">shergottite</span>, containing some of the coarsest-grained apatite yet identified in <span class="hlt">shergottite</span> meteorites. Their size has permitted detailed observations of volatile distributions within single grains. We have demonstrated that some apatites have been invaded by shock melts, which act to devolatilize parts of grains, resulting in significant Cl-enrichment in the adjacent regions. The extent of chemical heterogeneity within single grains must be carefully considered in other <span class="hlt">shergottites</span>, so that the effects of secondary modification of apatites are well-constrained, prior to interpreting the volatile contents and primary magmatic processes. Apatite grains unaffected by shock melts are OH-F enriched and Cl-poor (∼F50Cl14OH36), relative to interstitial apatites reported in other <span class="hlt">shergottites</span>. The volatile compositions are similar to interstitial apatites reported in terrestrial mafic intrusions. Such apatites in terrestrial intrusions are argued to have formed after significant Cl-loss due to the exsolution and migration of Cl-rich brines. Calculated relative F2, Cl2, and H2O fugacities for NWA 7755 apatites show a trend of degassing rather than fractionation, noted in previous studies. Indeed, we interpret the volatile contents of apatites analyzed in the cumulate <span class="hlt">shergottite</span> NWA 7755 to represent snapshots of the evolving late-stage residual liquid during exsolution of a Cl-rich brine. This fluid phase has subsequently been lost from an open magma system, migrating upward through the cumulate sequence enriching residual liquids in Cl. Alternatively, it formed a hydrothermal system in the martian crust surrounding the intrusion. Furthermore, by comparison with terrestrial examples, we suggest that the late-stage evolution of volatile-bearing phases in NWA 7755 is similar to that of comparable terrestrial mafic rocks. Primary cumulus apatites are F-rich, whereas interstitial apatites</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE10156E..0IW','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE10156E..0IW"><span>Recent development of hyperspectral Li<span class="hlt">DAR</span> using supercontinuum laser</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Zhen; Li, Chuanrong; Zhou, Mei; Zhang, Huijing; He, Wenjing; Li, Wei; Qiu, Yuanyuan</p> <p>2016-10-01</p> <p>Hyperspectral Light Detection And Ranging (Hyperspectral Li<span class="hlt">DAR</span>), a recently developed technique, combines the advantages of the Li<span class="hlt">DAR</span> and hyperspectral imaging and has been attractive for many applications. Supercontinuum laser (SC laser), a rapidly developing technique offers hyperspectral Li<span class="hlt">DAR</span> a suitable broadband laser source and makes hyperspectral Lidar become an installation from a theory. In this paper, the recent research and progressing of the hyperspectral Li<span class="hlt">DAR</span> are reviewed. The hyperspectral Li<span class="hlt">DAR</span> has been researched in theory, prototype system, instrument, and application experiment. However, the pulse energy of the SC laser is low so that the range of the hyperspectral Li<span class="hlt">DAR</span> is limited. Moreover, considering the characteristics of sensors and A/D converter, in order to obtain the full waveform of the echo, the repetition rate and the pulse width of the SC laser needs to be limited. Recently, improving the detection ability of hyperspectral Li<span class="hlt">DAR</span>, especially improving the detection range, is a main research area. A higher energy pulse SC laser, a more sensitive sensor, or some algorithms are applied in hyperspectral Li<span class="hlt">DAR</span> to improve the detection distance from 12 m to 1.5 km. At present, a lot of research has been focused on this novel technology which would be applied in more applications.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=19820048232&hterms=rare+earths&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3D%2527%2527rare%2Bearths%2527%2527','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=19820048232&hterms=rare+earths&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D90%26Ntt%3D%2527%2527rare%2Bearths%2527%2527"><span>Complementary rare earth element patterns in unique achondrites, such as ALHA 77005 and <span class="hlt">shergottites</span>, and in the earth</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ma, M.-S.; Schmitt, R. A.; Laul, J. C.</p> <p>1982-01-01</p> <p>Abundances of major, minor, and trace elements are determined in the Antarctic achondrite Allan Hills (ALHA) 77005 via sequential instrumental and radiochemical neutron activation analysis. The rare earth element (REE) abundances of ALHA 77005 reveal a unique chondritic normalized pattern; that is, the REEs are nearly unfractionated from La to Pr at approximately 1.0X chondrites, monotonically increased from Pr to Gd at approximately 3.4X with no Eu anomaly, nearly unfractionated from Gd and Ho and monotonically decreased from Ho to Lu at approximately 2.2X. It is noted that this unique REE pattern of ALHA 77005 can be modeled by a melting process involving a continuous melting and progressive partial removal of melt from a light REE enriched source material. In a model of this type, ALHA 77005 could represent either a crystallized cumulate from such a melt or the residual source material. Calculations show that the parent liquids for the <span class="hlt">shergottites</span> could also be derived from a light REE enriched source material similar to that for ALHA 77005.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080013380','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080013380"><span>Sulfur and Iron Speciation in Gas-rich Impact-melt Glasses from Basaltic <span class="hlt">Shergottites</span> Determined by Microxanes</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Sutton, S. R.; Rao, M. N.; Nyquist, L. E.</p> <p>2008-01-01</p> <p>Sulfur is abundantly present as sulfate near Martian surface based on chemical and mineralogical investigations on soils and rocks in Viking, Pathfinder and MER missions. Jarosite is identified by Mossbauer studies on rocks at Meridian and Gusev, whereas MgSO4 is deduced from MgO - SO3 correlations in Pathfinder MER and Viking soils. Other sulfate minerals such as gypsum and alunogen/ S-rich aluminosilicates and halides are detected only in martian meteorites such as <span class="hlt">shergottites</span> and nakhlites using SEM/FE-SEM and EMPA techniques. Because sulfur has the capacity to occur in multiple valence states, determination of sulfur speciation (sulfide/ sulfate) in secondary mineral assemblages in soils and rocks near Mars surface may help us understand whether the fluid-rock interactions occurred under oxidizing or reducing conditions. To understand the implications of these observations for the formation of the Gas-rich Impact-melt (GRIM) glasses, we determined the oxidation state of Fe in the GRIM glasses using Fe K micro-XANES techniques.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.rmag.org/outcrop-2012','USGSPUBS'); return false;" href="http://www.rmag.org/outcrop-2012"><span>Li<span class="hlt">DAR</span> - An emerging tool for geological applications</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Stoker, Jason M.</p> <p>2012-01-01</p> <p>Over the past five to ten years the use and applicability of light detection and ranging (Li<span class="hlt">DAR</span>) technology has increased dramatically. As a result, more and more Li<span class="hlt">DAR</span> data now are being collected across the country for a wide range of applications, and Li<span class="hlt">DAR</span> currently is the technology of choice for high resolution terrain model creation, 3-D city and infrastructure modeling, forestry, and a wide range of scientific applications. Li<span class="hlt">DAR</span> is a key technology for geological applications both within and outside the U.S. Geological Survey, and efforts are underway to try to collect high resolution Li<span class="hlt">DAR</span> data for the entire United States (https://pubs.usgs.gov/fs/2012/3089/pdf/fs2012-3089.pdf).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1816266K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1816266K"><span>Approach to voxel-based carbon stock quanticiation using Li<span class="hlt">DAR</span> data in tropical rainforest, Brunei</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, Eunji; Piao, Dongfan; Lee, Jongyeol; Lee, Woo-Kyun; Yoon, Mihae; Moon, Jooyeon</p> <p>2016-04-01</p> <p>Forest is an important means to adapt climate change as the only carbon sink recognized by the international community (KFS 2009). According to the Intergovernmental Panel on Climate Change (IPCC) 5th Assessment Report (AR5), Agriculture, Forestry, and Other Land Use (AFOLU) sectors including forestry contributed 24% of total anthropogenic emissions in 2010 (IPCC 2014; Tubiello et <span class="hlt">al</span>. 2015). While all sectors excluding AFOLU have increased Greenhouse Gas (GHG) emissions, land use sectors including forestry remains similar level as before due to decreasing deforestation and increasing reforestation. In earlier researches, optical imagery has been applied for analysis (Jakubowski et <span class="hlt">al</span>. 2013). Optical imagery collects spectral information in 2D. It is difficult to effectively quantify forest stocks, especially in dense forest (Cui et <span class="hlt">al</span>. 2012). To detect individual trees information from remotely sensed data, Light detection and ranging (Li<span class="hlt">DAR</span>) has been used (Hyyppäet <span class="hlt">al</span>. 2001; Persson et <span class="hlt">al</span>. 2002; Chen et <span class="hlt">al</span>. 2006). Moreover, Li<span class="hlt">DAR</span> has the ability to actively acquire vertical tree information such as tree height using geo-registered 3D points (Kwak et <span class="hlt">al</span>. 2007). In general, however, geo-register 3D point was used with a raster format which contains only 2D information by missing all the 3D data. Therefore, this research aimed to use the volumetric pixel (referred as "voxel") approach using Li<span class="hlt">DAR</span> data in tropical rainforest, Brunei. By comparing the parameters derived from voxel based Li<span class="hlt">DAR</span> data and field measured data, we examined the relationships between them for the quantification of forest carbon. This study expects to be more helpful to take advantage of the strategic application of climate change adaption.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMIN21A1387C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMIN21A1387C"><span>Classification and Characterization of Neotropical Rainforest Vegetation from Hyperspectral and Li<span class="hlt">DAR</span> Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Crawford, M. M.; Prasad, S.; Jung, J.; Yang, H.; Zhang, Y.</p> <p>2013-12-01</p> <p>Mapping species and forest vertical structure at regional, continental, and global scale is of increasing importance for climate science and decision support systems. Remote sensing technologies have been widely utilized to achieve this goal since they help overcome limitations of the direct and indirect measurement approaches. While the use of multi-sensor data for characterizing forest structure has gained significant attention in recent years, research on the integration of full waveform Li<span class="hlt">DAR</span> and hyperspectral data for a) classification and b) characterization of vegetation structure has been limited. Given sufficient labeled ground reference samples, supervised learning methods have evolved to effectively classify data in a high dimensional feature space. However, it is expensive and time-consuming to obtain labeled data, although the very high dimensionality of feature spaces from hyperspectral and Li<span class="hlt">DAR</span> inputs make it difficult to design reliable classifiers with a limited quantity of labeled data. Therefore, it is important to concentrate on developing training data sets which are the most 'informative' and 'useful' for the classification task. Active learning (<span class="hlt">AL</span>) was developed in the machine learning community, and has been demonstrated to be useful for classification of remote sensing data. In the active learning framework, classifiers are initially trained on a very limited pool of training samples, but additional informative and representative samples are identified from the abundant unlabeled data, labeled, and then inducted into this pool, thereby growing the training dataset in a systematic way. The goal is to choose data points such that a more accurate classification boundary is learned. We propose a novel Multi-kernel Active Learning (MKL-<span class="hlt">AL</span>) approach that incorporates features from multiple sensors with an automatically optimized kernel composite ¬function, and kernel parameters are selected intelligently during the <span class="hlt">AL</span> learning process. The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017M%26PS...52..333B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017M%26PS...52..333B"><span>The variability of ruthenium in chromite from chassignite and olivine-phyric <span class="hlt">shergottite</span> meteorites: New insights into the behavior of PGE and sulfur in Martian magmatic systems</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Baumgartner, Raphael J.; Fiorentini, Marco L.; Baratoux, David; Ferrière, Ludovic; Locmelis, Marek; Tomkins, Andrew; Sener, Kerim A.</p> <p>2017-02-01</p> <p>The Martian meteorites comprise mantle-derived mafic to ultramafic rocks that formed in shallow intrusions and/or lava flows. This study reports the first in situ platinum-group element data on chromite and ulvöspinel from a series of dunitic chassignites and olivine-phyric <span class="hlt">shergottites</span>, determined using laser-ablation ICP-MS. As recent studies have shown that Ru has strongly contrasting affinities for coexisting sulfide and spinel phases, the precise in situ analysis of this element in spinel can provide important insights into the sulfide saturation history of Martian mantle-derived melts. The new data reveal distinctive differences between the two meteorite groups. Chromite from the chassignites Northwest Africa 2737 (NWA 2737) and Chassigny contained detectable concentrations of Ru (up to 160 ppb Ru) in solid solution, whereas chromite and ulvöspinel from the olivine-phyric <span class="hlt">shergottites</span> Yamato-980459 (Y-980459), Tissint, and Dhofar 019 displayed Ru concentrations consistently below detection limit (<42 ppb). The relatively elevated Ru signatures of chromite from the chassignites suggest a Ru-rich ( 1-4 ppb) parental melt for this meteorite group, which presumably did not experience segregation of immiscible sulfide liquids over the interval of mantle melting, melt ascent, and chromite crystallization. The relatively Ru-depleted signature of chromite and ulvöspinel from the olivine-phyric <span class="hlt">shergottites</span> may be the consequence of relatively lower Ru contents (<1 ppb) in the parental melts, and/or the presence of sulfides during the crystallization of the spinel phases. The results of this study illustrate the significance of platinum-group element in situ analysis on spinel phases to decipher the sulfide saturation history of magmatic systems.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19051087','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19051087"><span>Homicide death in <span class="hlt">Dar</span> es Salaam, Tanzania 2005.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Outwater, Anne H; Campbell, Jacquelyn C; Mgaya, Edward; Abraham, Alison G; Kinabo, Linna; Kazaura, Method; Kub, Joan</p> <p>2008-12-01</p> <p>Violence disproportionately affects low- and middle-income countries. Deeper understanding is needed in areas where little research has occurred. The objectives of the study were to: (a) ascertain rate of homicide death; (b) describe the victims and circumstances surrounding their deaths in <span class="hlt">Dar</span> es Salaam, Tanzania in 2005. This study was developed by adapting the WHO/CDC Injury Surveillance Guidelines (Holder et <span class="hlt">al</span>., 2001). Data on 12 variables were collected on all homicide deaths. Descriptive statistics and hypothesis tests were done when appropriate. Age standardised, age-specific and cause-specific mortality rates are presented. The overall homicide rate was 12.57 (males and females respectively: 22.26 and 2.64). Homicide deaths were 93.4% male, mostly unemployed, with a mean age of 28.2 years. Most deaths occurred in urban areas. Mob violence was the cause of 57% of deaths. The risk of homicide death for males was greater than the world average, but for females it was less. Most homicides were committed by community members policing against thieves.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_4");'>4</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li class="active"><span>6</span></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_6 --> <div id="page_7" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="121"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20080048128','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20080048128"><span>Processing Li<span class="hlt">DAR</span> Data to Predict Natural Hazards</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Fairweather, Ian; Crabtree, Robert; Hager, Stacey</p> <p>2008-01-01</p> <p>ELF-Base and ELF-Hazards (wherein 'ELF' signifies 'Extract Li<span class="hlt">DAR</span> Features' and 'Li<span class="hlt">DAR</span>' signifies 'light detection and ranging') are developmental software modules for processing remote-sensing Li<span class="hlt">DAR</span> data to identify past natural hazards (principally, landslides) and predict future ones. ELF-Base processes raw Li<span class="hlt">DAR</span> data, including Li<span class="hlt">DAR</span> intensity data that are often ignored in other software, to create digital terrain models (DTMs) and digital feature models (DFMs) with sub-meter accuracy. ELF-Hazards fuses raw Li<span class="hlt">DAR</span> data, data from multispectral and hyperspectral optical images, and DTMs and DFMs generated by ELF-Base to generate hazard risk maps. Advanced algorithms in these software modules include line-enhancement and edge-detection algorithms, surface-characterization algorithms, and algorithms that implement innovative data-fusion techniques. The line-extraction and edge-detection algorithms enable users to locate such features as faults and landslide headwall scarps. Also implemented in this software are improved methodologies for identification and mapping of past landslide events by use of (1) accurate, ELF-derived surface characterizations and (2) three Li<span class="hlt">DAR</span>/optical-data-fusion techniques: post-classification data fusion, maximum-likelihood estimation modeling, and hierarchical within-class discrimination. This software is expected to enable faster, more accurate forecasting of natural hazards than has previously been possible.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ISPAr49B3..283L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ISPAr49B3..283L"><span>Tensor Modeling Based for Airborne Li<span class="hlt">DAR</span> Data Classification</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, N.; Liu, C.; Pfeifer, N.; Yin, J. F.; Liao, Z. Y.; Zhou, Y.</p> <p>2016-06-01</p> <p>Feature selection and description is a key factor in classification of Earth observation data. In this paper a classification method based on tensor decomposition is proposed. First, multiple features are extracted from raw Li<span class="hlt">DAR</span> point cloud, and raster Li<span class="hlt">DAR</span> images are derived by accumulating features or the "raw" data attributes. Then, the feature rasters of Li<span class="hlt">DAR</span> data are stored as a tensor, and tensor decomposition is used to select component features. This tensor representation could keep the initial spatial structure and insure the consideration of the neighborhood. Based on a small number of component features a k nearest neighborhood classification is applied.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.B23B0557R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.B23B0557R"><span>Using Li<span class="hlt">DAR</span> to Estimate Total Aboveground Biomass of Redwood Stands in the Jackson Demonstration State Forest, Mendocino, California</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rao, M.; Vuong, H.</p> <p>2013-12-01</p> <p>The overall objective of this study is to develop a method for estimating total aboveground biomass of redwood stands in Jackson Demonstration State Forest, Mendocino, California using airborne Li<span class="hlt">DAR</span> data. Li<span class="hlt">DAR</span> data owing to its vertical and horizontal accuracy are increasingly being used to characterize landscape features including ground surface elevation and canopy height. These Li<span class="hlt">DAR</span>-derived metrics involving structural signatures at higher precision and accuracy can help better understand ecological processes at various spatial scales. Our study is focused on two major species of the forest: redwood (Sequoia semperirens [D.Don] Engl.) and Douglas-fir (Pseudotsuga mensiezii [Mirb.] Franco). Specifically, the objectives included linear regression models fitting tree diameter at breast height (dbh) to Li<span class="hlt">DAR</span> derived height for each species. From 23 random points on the study area, field measurement (dbh and tree coordinate) were collected for more than 500 trees of Redwood and Douglas-fir over 0.2 ha- plots. The USFS-FUSION application software along with its Li<span class="hlt">DAR</span> Data Viewer (LDV) were used to to extract Canopy Height Model (CHM) from which tree heights would be derived. Based on the Li<span class="hlt">DAR</span> derived height and ground based dbh, a linear regression model was developed to predict dbh. The predicted dbh was used to estimate the biomass at the single tree level using Jenkin's formula (Jenkin et <span class="hlt">al</span> 2003). The linear regression models were able to explain 65% of the variability associated with Redwood's dbh and 80% of that associated with Douglas-fir's dbh.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160003470','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160003470"><span>The Mineralogy, Geochemistry, and Redox State of Multivalent Cations During the Crystallization of Primitive <span class="hlt">Shergottitic</span> Liquids at Various (f)O2. Insights into the (f)O2 Fugacity of the Martian Mantle and Crustal Influences on Redox Conditions of Martian Magmas.</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shearer, C. K.; Bell, A. S.; Burger, P. V.; Papike, J. J.; Jones, J.; Le, L.; Muttik, N.</p> <p>2016-01-01</p> <p>The (f)O2 [oxygen fugacity] of crystallization for martian basalts has been estimated in various studies to range from IW-1 to QFM+4 [1-3]. A striking geochemical feature of the <span class="hlt">shergottites</span> is the large range in initial Sr isotopic ratios and initial epsilon(sup Nd) values. Studies by observed that within the <span class="hlt">shergottite</span> group the (f)O2 [oxygen fugacity] of crystallization is highly correlated with these chemical and isotopic characteristics with depleted <span class="hlt">shergottites</span> generally crystallizing at reduced conditions and enriched <span class="hlt">shergottites</span> crystallizing under more oxidizing conditions. More recent work has shown that (f)O2 [oxygen fugacity] changed during the crystallization of these magmas from one order of magnitude in Y980459 (Y98) to several orders of magnitude in Larkman Nunatak 06319. These real or apparent variations within single <span class="hlt">shergottitic</span> magmas have been attributed to mixing of a xenocrystic olivine component, volatile loss-water disassociation, auto-oxidation during crystallization of mafic phases, and assimilation of an oxidizing crustal component (e.g. sulfate). In contrast to the <span class="hlt">shergottites</span>, augite basalts such as NWA 8159 are highly depleted yet appear to be highly oxidized (e.g. QFM+4). As a first step in attempting to unravel petrologic complexities that influence (f)O2 [oxygen fugacity] in martian magmas, this study explores the effect of (f)O2 [oxygen fugacity] on the liquid line of descent (LLD) for a primitive <span class="hlt">shergottite</span> liquid composition (Y98). The results of this study will provide a fundamental basis for reconstructing the record of (f)O2 [oxygen fugacity] in <span class="hlt">shergottites</span> and other martian basalts, its effect on both mineral chemistries and valence state partitioning, and a means for examining the role of crystallization (and other more complex processes) on the petrologic linkages between olivine-phyric and pyroxene-plagioclase <span class="hlt">shergottites</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015OptEn..54a3108W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015OptEn..54a3108W"><span>Automatic registration method for mobile Li<span class="hlt">DAR</span> data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Ruisheng; Ferrie, Frank P.</p> <p>2015-01-01</p> <p>We present an automatic mutual information (MI) registration method for mobile Li<span class="hlt">DAR</span> and panoramas collected from a driving vehicle. The suitability of MI for registration of aerial Li<span class="hlt">DAR</span> and aerial oblique images has been demonstrated under an assumption that minimization of joint entropy (JE) is a sufficient approximation of maximization of MI. We show that this assumption is invalid for the ground-level data. The entropy of a Li<span class="hlt">DAR</span> image cannot be regarded as approximately constant for small perturbations. Instead of minimizing the JE, we directly maximize MI to estimate corrections of camera poses. Our method automatically registers mobile Li<span class="hlt">DAR</span> with spherical panoramas over an approximate 4-km drive, and is the first example we are aware of that tests MI registration in a large-scale context.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.5416K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.5416K"><span>Shipborne Li<span class="hlt">DAR</span> system for coastal change monitoring</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, chang hwan; Park, chang hong; Kim, hyun wook; hyuck Kim, won; Lee, myoung hoon; Park, hyeon yeong</p> <p>2016-04-01</p> <p>Coastal areas, used as human utilization areas like leisure space, medical care, ports and power plants, etc., are regions that are continuously changing and interconnected with oceans and land and the sea level has risen by about 8cm (1.9mm / yr) due to global warming from 1964 year to 2006 year in Korea. Coastal erosion due to sea-level rise has caused the problem of marine ecosystems and loss of tourism resources, etc. Regular monitoring of coastal erosion is essential at key locations with such volatility. But the survey method of land mobile Li<span class="hlt">DAR</span> (light detection and ranging) system has much time consuming and many restrictions. For effective monitoring beach erosion, KIOST (Korea Institute of Ocean Science & Technology) has constructed a shipborne mobile Li<span class="hlt">DAR</span> system. The shipborne mobile Li<span class="hlt">DAR</span> system comprised a land mobile Li<span class="hlt">DAR</span> (RIEGL LMS-420i), an INS (inertial navigation system, MAGUS Inertial+), a RTKGPS (LEICA GS15 GS25), and a fixed platform. The shipborne mobile Li<span class="hlt">DAR</span> system is much more effective than a land mobile Li<span class="hlt">DAR</span> system in the measuring of fore shore areas without shadow zone. Because the vessel with the shipborne mobile Li<span class="hlt">DAR</span> system is continuously moved along the shoreline, it is possible to efficiently survey a large area in a relatively short time. Effective monitoring of the changes using the constructed shipborne mobile Li<span class="hlt">DAR</span> system for seriously eroded coastal areas will be able to contribute to coastal erosion management and response.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70004894','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70004894"><span>Modelling rating curves using remotely sensed Li<span class="hlt">DAR</span> data</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Nathanson, Marcus; Kean, Jason W.; Grabs, Thomas J.; Seibert, Jan; Laudon, Hjalmar; Lyon, Steve W.</p> <p>2012-01-01</p> <p>Accurate stream discharge measurements are important for many hydrological studies. In remote locations, however, it is often difficult to obtain stream flow information because of the difficulty in making the discharge measurements necessary to define stage-discharge relationships (rating curves). This study investigates the feasibility of defining rating curves by using a fluid mechanics-based model constrained with topographic data from an airborne Li<span class="hlt">DAR</span> scanning. The study was carried out for an 8m-wide channel in the boreal landscape of northern Sweden. Li<span class="hlt">DAR</span> data were used to define channel geometry above a low flow water surface along the 90-m surveyed reach. The channel topography below the water surface was estimated using the simple assumption of a flat streambed. The roughness for the modelled reach was back calculated from a single measurment of discharge. The topographic and roughness information was then used to model a rating curve. To isolate the potential influence of the flat bed assumption, a 'hybrid model' rating curve was developed on the basis of data combined from the Li<span class="hlt">DAR</span> scan and a detailed ground survey. Whereas this hybrid model rating curve was in agreement with the direct measurements of discharge, the Li<span class="hlt">DAR</span> model rating curve was equally in agreement with the medium and high flow measurements based on confidence intervals calculated from the direct measurements. The discrepancy between the Li<span class="hlt">DAR</span> model rating curve and the low flow measurements was likely due to reduced roughness associated with unresolved submerged bed topography. Scanning during periods of low flow can help minimize this deficiency. These results suggest that combined ground surveys and Li<span class="hlt">DAR</span> scans or multifrequency Li<span class="hlt">DAR</span> scans that see 'below' the water surface (bathymetric Li<span class="hlt">DAR</span>) could be useful in generating data needed to run such a fluid mechanics-based model. This opens a realm of possibility to remotely sense and monitor stream flows in channels in remote</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20160003501','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20160003501"><span>Constraints on Mantle Plume Melting Conditions in the Martian Mantle Based on Improved Melting Phase Relationships of Olivine-Phyric <span class="hlt">Shergottite</span> Yamato 980459</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Kiefer, Walter S.; Rapp, Jennifer F.; Usui, Tomohiro; Draper, David S.; Filiberto, Justin</p> <p>2016-01-01</p> <p>Martian meteorite Yamato 980459 (hereafter Y98) is an olivine-phyric <span class="hlt">shergottite</span> that has been interpreted as closely approximating a martian mantle melt [1-4], making it an important constraint on adiabatic decompression melting models. It has long been recognized that low pressure melting of the Y98 composition occurs at extremely high temperatures relative to martian basalts (1430 degC at 1 bar), which caused great difficulties in a previous attempt to explain Y98 magma generation via a mantle plume model [2]. However, previous studies of the phase diagram were limited to pressures of 2 GPa and less [2, 5], whereas decompression melting in the present-day martian mantle occurs at pressures of 3-7 GPa, with the shallow boundary of the melt production zone occurring just below the base of the thermal lithosphere [6]. Recent experimental work has now extended our knowledge of the Y98 melting phase relationships to 8 GPa. In light of this improved petrological knowledge, we are therefore reassessing the constraints that Y98 imposes on melting conditions in martian mantle plumes. Two recently discovered olivine- phyric <span class="hlt">shergottites</span>, Northwest Africa (NWA) 5789 and NWA 6234, may also be primary melts from the martian mantle [7, 8]. However, these latter meteorites have not been the subject of detailed experimental petrology studies, so we focus here on Y98.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3231455','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3231455"><span>Georeferenced Li<span class="hlt">DAR</span> 3D Vine Plantation Map Generation</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Llorens, Jordi; Gil, Emilio; Llop, Jordi; Queraltó, Meritxell</p> <p>2011-01-01</p> <p>The use of electronic devices for canopy characterization has recently been widely discussed. Among such devices, Li<span class="hlt">DAR</span> sensors appear to be the most accurate and precise. Information obtained with Li<span class="hlt">DAR</span> sensors during reading while driving a tractor along a crop row can be managed and transformed into canopy density maps by evaluating the frequency of Li<span class="hlt">DAR</span> returns. This paper describes a proposed methodology to obtain a georeferenced canopy map by combining the information obtained with Li<span class="hlt">DAR</span> with that generated using a GPS receiver installed on top of a tractor. Data regarding the velocity of Li<span class="hlt">DAR</span> measurements and UTM coordinates of each measured point on the canopy were obtained by applying the proposed transformation process. The process allows overlap of the canopy density map generated with the image of the intended measured area using Google Earth®, providing accurate information about the canopy distribution and/or location of damage along the rows. This methodology was applied and tested on different vine varieties and crop stages in two important vine production areas in Spain. The results indicate that the georeferenced information obtained with Li<span class="hlt">DAR</span> sensors appears to be an interesting tool with the potential to improve crop management processes. PMID:22163952</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22163952','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22163952"><span>Georeferenced Li<span class="hlt">DAR</span> 3D vine plantation map generation.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Llorens, Jordi; Gil, Emilio; Llop, Jordi; Queraltó, Meritxell</p> <p>2011-01-01</p> <p>The use of electronic devices for canopy characterization has recently been widely discussed. Among such devices, Li<span class="hlt">DAR</span> sensors appear to be the most accurate and precise. Information obtained with Li<span class="hlt">DAR</span> sensors during reading while driving a tractor along a crop row can be managed and transformed into canopy density maps by evaluating the frequency of Li<span class="hlt">DAR</span> returns. This paper describes a proposed methodology to obtain a georeferenced canopy map by combining the information obtained with Li<span class="hlt">DAR</span> with that generated using a GPS receiver installed on top of a tractor. Data regarding the velocity of Li<span class="hlt">DAR</span> measurements and UTM coordinates of each measured point on the canopy were obtained by applying the proposed transformation process. The process allows overlap of the canopy density map generated with the image of the intended measured area using Google Earth(®), providing accurate information about the canopy distribution and/or location of damage along the rows. This methodology was applied and tested on different vine varieties and crop stages in two important vine production areas in Spain. The results indicate that the georeferenced information obtained with Li<span class="hlt">DAR</span> sensors appears to be an interesting tool with the potential to improve crop management processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016M%26PS...51..407W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016M%26PS...51..407W"><span>Noble gases in 18 Martian meteorites and angrite Northwest Africa 7812—Exposure ages, trapped gases, and a re-evaluation of the evidence for solar cosmic ray-produced neon in <span class="hlt">shergottites</span> and other achondrites</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wieler, R.; Huber, L.; Busemann, H.; Seiler, S.; Leya, I.; Maden, C.; Masarik, J.; Meier, M. M. M.; Nagao, K.; Trappitsch, R.; Irving, A. J.</p> <p>2016-02-01</p> <p>We present noble gas data for 16 <span class="hlt">shergottites</span>, 2 nakhlites (NWA 5790, NWA 10153), and 1 angrite (NWA 7812). Noble gas exposure ages of the <span class="hlt">shergottites</span> fall in the 1-6 Ma range found in previous studies. Three depleted olivine-phyric <span class="hlt">shergottites</span> (Tissint, NWA 6162, NWA 7635) have exposure ages of ~1 Ma, in agreement with published data for similar specimens. The exposure age of NWA 10153 (~12.2 Ma) falls in the range of 9-13 Ma reported for other nakhlites. Our preferred age of ~7.3 Ma for NWA 5790 is lower than this range, and it is possible that NWA 5790 represents a distinct ejection event. A Tissint glass sample contains Xe from the Martian atmosphere. Several samples show a remarkably low (21Ne/22Ne)cos ratio < 0.80, as previously observed in a many <span class="hlt">shergottites</span> and in various other rare achondrites. This was explained by solar cosmic ray-produced Ne (SCR Ne) in addition to the commonly found galactic cosmic ray-produced Ne, implying very low preatmospheric shielding and ablation loss. We revisit this by comparing measured (21Ne/22Ne)cos ratios with predictions by cosmogenic nuclide production models. Indeed, several <span class="hlt">shergottites</span>, acalpulcoites/lodranites, angrites (including NWA 7812), and the Brachina-like meteorite LEW 88763 likely contain SCR Ne, as previously postulated for many of them. The SCR contribution may influence the calculation of exposure ages. One likely reason that SCR nuclides are predominantly detected in meteorites from rare classes is because they usually are analyzed for cosmogenic nuclides even if they had a very small (preatmospheric) mass and hence low ablation loss.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.1537H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.1537H"><span>Li<span class="hlt">DAR</span> Vegetation Investigation and Signature Analysis System (LVISA)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Höfle, Bernhard; Koenig, Kristina; Griesbaum, Luisa; Kiefer, Andreas; Hämmerle, Martin; Eitel, Jan; Koma, Zsófia</p> <p>2015-04-01</p> <p>Our physical environment undergoes constant changes in space and time with strongly varying triggers, frequencies, and magnitudes. Monitoring these environmental changes is crucial to improve our scientific understanding of complex human-environmental interactions and helps us to respond to environmental change by adaptation or mitigation. The three-dimensional (3D) description of the Earth surface features and the detailed monitoring of surface processes using 3D spatial data have gained increasing attention within the last decades, such as in climate change research (e.g., glacier retreat), carbon sequestration (e.g., forest biomass monitoring), precision agriculture and natural hazard management. In all those areas, 3D data have helped to improve our process understanding by allowing quantifying the structural properties of earth surface features and their changes over time. This advancement has been fostered by technological developments and increased availability of 3D sensing systems. In particular, Li<span class="hlt">DAR</span> (light detection and ranging) technology, also referred to as laser scanning, has made significant progress and has evolved into an operational tool in environmental research and geosciences. The main result of Li<span class="hlt">DAR</span> measurements is a highly spatially resolved 3D point cloud. Each point within the Li<span class="hlt">DAR</span> point cloud has a XYZ coordinate associated with it and often additional information such as the strength of the returned backscatter. The point cloud provided by Li<span class="hlt">DAR</span> contains rich geospatial, structural, and potentially biochemical information about the surveyed objects. To deal with the inherently unorganized datasets and the large data volume (frequently millions of XYZ coordinates) of Li<span class="hlt">DAR</span> datasets, a multitude of algorithms for automatic 3D object detection (e.g., of single trees) and physical surface description (e.g., biomass) have been developed. However, so far the exchange of datasets and approaches (i.e., extraction algorithms) among Li<span class="hlt">DAR</span> users</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ISPAnIII1..201J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ISPAnIII1..201J"><span>Uas Topographic Mapping with Velodyne Li<span class="hlt">DAR</span> Sensor</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jozkow, G.; Toth, C.; Grejner-Brzezinska, D.</p> <p>2016-06-01</p> <p>Unmanned Aerial System (UAS) technology is nowadays willingly used in small area topographic mapping due to low costs and good quality of derived products. Since cameras typically used with UAS have some limitations, e.g. cannot penetrate the vegetation, Li<span class="hlt">DAR</span> sensors are increasingly getting attention in UAS mapping. Sensor developments reached the point when their costs and size suit the UAS platform, though, Li<span class="hlt">DAR</span> UAS is still an emerging technology. One issue related to using Li<span class="hlt">DAR</span> sensors on UAS is the limited performance of the navigation sensors used on UAS platforms. Therefore, various hardware and software solutions are investigated to increase the quality of UAS Li<span class="hlt">DAR</span> point clouds. This work analyses several aspects of the UAS Li<span class="hlt">DAR</span> point cloud generation performance based on UAS flights conducted with the Velodyne laser scanner and cameras. The attention was primarily paid to the trajectory reconstruction performance that is essential for accurate point cloud georeferencing. Since the navigation sensors, especially Inertial Measurement Units (IMUs), may not be of sufficient performance, the estimated camera poses could allow to increase the robustness of the estimated trajectory, and subsequently, the accuracy of the point cloud. The accuracy of the final UAS Li<span class="hlt">DAR</span> point cloud was evaluated on the basis of the generated DSM, including comparison with point clouds obtained from dense image matching. The results showed the need for more investigation on MEMS IMU sensors used for UAS trajectory reconstruction. The accuracy of the UAS Li<span class="hlt">DAR</span> point cloud, though lower than for point cloud obtained from images, may be still sufficient for certain mapping applications where the optical imagery is not useful.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFM.P51A0902D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFM.P51A0902D"><span>Assimilation of High 18O/16O Crust by <span class="hlt">Shergottite</span>-Nakhlite-Chassigny (SNC) Magmas on Mars</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Day, J. M.; Taylor, L. A.; Valley, J. W.; Spicuzza, M. J.</p> <p>2005-12-01</p> <p>There is significant geochemical evidence for assimilation of crustal material into sub-aerial, mantle-derived, terrestrial basaltic magmas. Some of the most powerful constraints on crustal assimilation come from oxygen isotope studies, because supracrustal rocks often have distinct 18O/16O ratios resulting from interaction with Earth's hydrosphere. From a planetary perspective, studies of carbonate concretions from meteorite ALH84001 have yielded evidence for low-temperature crustal interaction at or near the surface of its putative parent body, Mars. This finding raises the possibility that crustal assimilation processes may be tracked using oxygen isotopes in combination with geochemical data of other reputed martian (SNC) meteorites. The whole-rock oxygen isotope ratios (Laser fluorination δ18O = +4.21 to +5.85‰ VSMOW) of SNC meteorites, correlate with aspects of their incompatible element chemistry. Some of the oxygen isotope variability may be explained by post-magmatic alteration on Mars or Earth; however, it appears, based on petrographic and geochemical observations, that a number of SNC meteorites, especially <span class="hlt">Shergottites</span>, retain the original whole-rock oxygen isotope values of their magmas prior to crystallisation. Correlations between oxygen isotopes and incompatible element geochemistry are consistent with assimilation of a high-18O/16O, incompatible-element rich, oxidizing crustal component by hot, mantle-derived magmas (δ18O = ~~4.2‰). A crustal component has previously been recognized from Sr-Nd-Os isotope systematics and oxygen fugacity measurements of SNC meteorites. Oxygen isotope evidence from SNC meteorites suggests high-18O/16O crustal contaminants on Mars result from low temperature (< 300°C) interaction with martian hydrosphere. The extent of apparent crustal contamination tracked by oxygen isotopes in SNC meteorites implies that the majority of martian crust may have undergone such interactions. Evidence for assimilation of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMEP41B3539J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMEP41B3539J"><span>Automated Probabilistic Li<span class="hlt">DAR</span> Swath Registration</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jalobeanu, A.; Gonçalves, G. R.</p> <p>2014-12-01</p> <p>We recently developed a new point cloud registration algorithm. Compared to Iterated Closest Point (ICP) techniques, it is robust to noise and outliers, and easier to use, as it is less sensitive to initial conditions. It minimizes the entropy of the joint point cloud (including intensity attributes to help register areas with poor relief), uses a voxel space and B-Spline interpolation to accelerate computation. A natural application of registration is swath alignment in airborne light detection and ranging (Li<span class="hlt">DAR</span>). Indeed, due to uncertainty in the inertial navigation system (INS), attitude angles are subject to time-dependent errors. Such errors can be understood as a sum of three terms: 1) a global term, or boresight error, which can be addressed using several existing techniques; 2) a low-frequency term, which is modeled as a constant attitude error for regions several hundred meters along-track; 3) a high-frequency term, responsible for corduroy artifacts (not addressed here). We propose to use the new registration algorithm to correct the low-frequency attitude variations. Relative geometric errors are significantly reduced, as pairs of swaths are registered onto each other local corrections. Absolute geometric errors are reduced during a second step, by applying all the corrections together to the entire dataset. We used a test area of 200 km2 in Portugal, with a density of 3-4 pts/m2. The point clouds were derived from waveform data, and include predictive range uncertainties estimated within a Bayesian framework. The data collection was supported by FCT and FEDER as part of the AutoProbaDTM research project (2009-2012). Modeling and reducing geometric error helps build consistent uncertainty maps. After correction, residual errors are taken into account in the final 3D error budget. For gridded elevation models a vertical uncertainty map is computed. Finally, it is possible to use the inter-swath registration parameters to estimate the distribution of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.H54A..07H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.H54A..07H"><span>Wet Channel Network Extraction based on Li<span class="hlt">DAR</span> Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hooshyar, M.; Kim, S.; Wang, D.; Medeiros, S. C.</p> <p>2015-12-01</p> <p>The temporal dynamics of stream network is vitally important for understanding hydrologic processes including groundwater interactions and hydrograph recessions. However, observations are limited on flowing channel heads, which are usually located in headwater catchments and under canopy. Near infrared Li<span class="hlt">DAR</span> data provides an opportunity to map the flowing channel network owing to the fine spatial resolution, canopy penetration, and strong absorption of the light energy by the water surface. A systematic method is developed herein to map flowing channel networks based on the signal intensity of ground Li<span class="hlt">DAR</span> return, which is lower on water surfaces than on dry surfaces. Based on the selected sample sites where the wetness conditions are known, the signal intensities of ground returns are extracted from the Li<span class="hlt">DAR</span> point data. The frequency distributions of wet surface and dry surface returns are constructed. With the aid of Li<span class="hlt">DAR</span>-based ground elevation, the signal intensity thresholds are identified for mapping flowing channels. The developed method is applied to Lake Tahoe area based on eight Li<span class="hlt">DAR</span> snapshots during recession periods in five watersheds. A power-law relationship between streamflow and flowing channel length during the recession period is derived based on the result.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.B51C0422M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.B51C0422M"><span>Waveform Li<span class="hlt">DAR</span> across forest biomass gradients</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Montesano, P. M.; Nelson, R. F.; Dubayah, R.; Sun, G.; Ranson, J.</p> <p>2011-12-01</p> <p>Detailed information on the quantity and distribution of aboveground biomass (AGB) is needed to understand how it varies across space and changes over time. Waveform Li<span class="hlt">DAR</span> data is routinely used to derive the heights of scattering elements in each illuminated footprint, and the vertical structure of vegetation is related to AGB. Changes in Li<span class="hlt">DAR</span> waveforms across vegetation structure gradients can demonstrate instrument sensitivity to land cover transitions. A close examination of Li<span class="hlt">DAR</span> waveforms in footprints across a forest gradient can provide new insight into the relationship of vegetation structure and forest AGB. In this study we use field measurements of individual trees within Laser Vegetation Imaging Sensor (LVIS) footprints along transects crossing forest to non-forest gradients to examine changes in LVIS waveform characteristics at sites with low (< 50Mg/ha) AGB. We relate field AGB measurements to original and adjusted LVIS waveforms to detect the forest AGB interval along a forest - non-forest transition in which the LVIS waveform lose the ability to discern differences in AGB. Our results help identify the lower end the forest biomass range that a ~20m footprint waveform Li<span class="hlt">DAR</span> can detect, which can help infer accumulation of biomass after disturbances and during forest expansion, and which can guide the use of Li<span class="hlt">DAR</span> within a multi-sensor fusion biomass mapping approach.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18365761','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18365761"><span>Using Li<span class="hlt">DAR</span> technology in forestry activities.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Akay, Abdullah Emin; Oğuz, Hakan; Karas, Ismail Rakip; Aruga, Kazuhiro</p> <p>2009-04-01</p> <p>Managing natural resources in wide-scale areas can be highly time and resource consuming task which requires significant amount of data collection in the field and reduction of the data in the office to provide the necessary information. High performance Li<span class="hlt">DAR</span> remote sensing technology has recently become an effective tool for use in applications of natural resources. In the field of forestry, the Li<span class="hlt">DAR</span> measurements of the forested areas can provide high-quality data on three-dimensional characterizations of forest structures. Besides, Li<span class="hlt">DAR</span> data can be used to provide very high quality and accurate Digital Elevation Model (DEM) for the forested areas. This study presents the progress and opportunities of using Li<span class="hlt">DAR</span> remote sensing technology in various forestry applications. The results indicate that Li<span class="hlt">DAR</span> based forest structure data and high-resolution DEMs can be used in wide-scale forestry activities such as stand characterizations, forest inventory and management, fire behaviour modeling, and forest operations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AdWR...75..105M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AdWR...75..105M"><span>Urban flood modelling combining top-view Li<span class="hlt">DAR</span> data with ground-view SfM observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Meesuk, Vorawit; Vojinovic, Zoran; Mynett, Arthur E.; Abdullah, Ahmad F.</p> <p>2015-01-01</p> <p>Remote Sensing technologies are capable of providing high-resolution spatial data needed to set up advanced flood simulation models. Amongst them, aerial Light Detection and Ranging (Li<span class="hlt">DAR</span>) surveys or Airborne Laser Scanner (<span class="hlt">ALS</span>) systems have long been used to provide digital topographic maps. Nowadays, Remote Sensing data are commonly used to create Digital Terrain Models (DTMs) for detailed urban-flood modelling. However, the difficulty of relying on top-view Li<span class="hlt">DAR</span> data only is that it cannot detect whether passages for floodwaters are hidden underneath vegetated areas or beneath overarching structures such as roads, railroads, and bridges. Such (hidden) small urban features can play an important role in urban flood propagation. In this paper, a complex urban area of Kuala Lumpur, Malaysia was chosen as a study area to simulate the extreme flooding event that occurred in 2003. Three different DTMs were generated and used as input for a two-dimensional (2D) urban flood model. A top-view Li<span class="hlt">DAR</span> approach was used to create two DTMs: (i) a standard Li<span class="hlt">DAR</span>-DTM and (ii) a Filtered Li<span class="hlt">DAR</span>-DTM taking into account specific ground-view features. In addition, a Structure from Motion (SfM) approach was used to detect hidden urban features from a sequence of ground-view images; these ground-view SfM data were then combined with top-view Filtered Li<span class="hlt">DAR</span> data to create (iii) a novel Multidimensional Fusion of Views-Digital Terrain Model (MFV-DTM). These DTMs were then used as a basis for the 2D urban flood model. The resulting dynamic flood maps are compared with observations at six measurement locations. It was found that when applying only top-view DTMs as input data, the flood simulation results appear to have mismatches in both floodwater depths and flood propagation patterns. In contrast, when employing the top-ground-view fusion approach (MFV-DTM), the results not only show a good agreement in floodwater depth, but also simulate more correctly the floodwater dynamics around</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9901E..10D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9901E..10D"><span>Application of Li<span class="hlt">DAR</span>'s multiple attributes for wetland classification</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ding, Qiong; Ji, Shengyue; Chen, Wu</p> <p>2016-03-01</p> <p>Wetlands have received intensive interdisciplinary attention as a unique ecosystem and valuable resources. As a new technology, the airborne Li<span class="hlt">DAR</span> system has been applied in wetland research these years. However, most of the studies used only one or two Li<span class="hlt">DAR</span> observations to extract either terrain or vegetation in wetlands. This research aims at integrating Li<span class="hlt">DAR</span>'s multiple attributes (DSM, DTM, off-ground features, Slop map, multiple pulse returns, and normalized intensity) to improve mapping and classification of wetlands based on a multi-level object-oriented classification method. By using this method, we are able to classify the Yellow River Delta wetland into eight classes with overall classification accuracy of 92.5%</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_5");'>5</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li class="active"><span>7</span></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_7 --> <div id="page_8" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="141"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ISPAr.XL7...79E','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ISPAr.XL7...79E"><span>Raster Vs. Point Cloud Li<span class="hlt">DAR</span> Data Classification</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>El-Ashmawy, N.; Shaker, A.</p> <p>2014-09-01</p> <p>Airborne Laser Scanning systems with light detection and ranging (Li<span class="hlt">DAR</span>) technology is one of the fast and accurate 3D point data acquisition techniques. Generating accurate digital terrain and/or surface models (DTM/DSM) is the main application of collecting Li<span class="hlt">DAR</span> range data. Recently, Li<span class="hlt">DAR</span> range and intensity data have been used for land cover classification applications. Data range and Intensity, (strength of the backscattered signals measured by the Li<span class="hlt">DAR</span> systems), are affected by the flying height, the ground elevation, scanning angle and the physical characteristics of the objects surface. These effects may lead to uneven distribution of point cloud or some gaps that may affect the classification process. Researchers have investigated the conversion of Li<span class="hlt">DAR</span> range point data to raster image for terrain modelling. Interpolation techniques have been used to achieve the best representation of surfaces, and to fill the gaps between the Li<span class="hlt">DAR</span> footprints. Interpolation methods are also investigated to generate Li<span class="hlt">DAR</span> range and intensity image data for land cover classification applications. In this paper, different approach has been followed to classifying the Li<span class="hlt">DAR</span> data (range and intensity) for land cover mapping. The methodology relies on the classification of the point cloud data based on their range and intensity and then converted the classified points into raster image. The gaps in the data are filled based on the classes of the nearest neighbour. Land cover maps are produced using two approaches using: (a) the conventional raster image data based on point interpolation; and (b) the proposed point data classification. A study area covering an urban district in Burnaby, British Colombia, Canada, is selected to compare the results of the two approaches. Five different land cover classes can be distinguished in that area: buildings, roads and parking areas, trees, low vegetation (grass), and bare soil. The results show that an improvement of around 10 % in the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=264067','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=264067"><span>Modeling low-height vegetation with airborne Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>Low-height vegetation, common in semiarid regions, is difficult to characterize with Li<span class="hlt">DAR</span> (Light Detection and Ranging) due to similarities, in time and space, of the point returns of vegetation and ground. Other complications may occur due to the low-height vegetation structural characteristics a...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1210856S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1210856S"><span>Airborne Li<span class="hlt">DAR</span> based Mapping of Alpine Permafrost Distribution</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sailer, Rudolf; Bollmann, Erik; Briese, Christian; Fischer, Andrea; Krainer, Karl; Pfeifer, Norbert; Rieg, Lorenzo; Stötter, Johann</p> <p>2010-05-01</p> <p>Recent global climate change findings show an acceleration of melting of glaciers, ice-sheets and ice caps. Extended remote sensing and in-situ measurements demonstrate that glaciers are losing mass at an increasing rate. In contrast to glaciers with large mass losses (about 5 m per year at the lower parts of the glacier tongue of Hintereisferner, Ötztal Alps, Tyrol, Austria), moderate to small changing rates (centimetres to decimetres per year) characterize the surface variations caused by permafrost degradation in high mountain areas. For a reliable mapping of the spatial permafrost distribution advanced remote sensing techniques with a high degree of vertical accuracy have to be applied. Recent studies have shown that airborne Li<span class="hlt">DAR</span> survey in mountainous regions provide high-resolution spatial data with a vertical accuracy range of centimetre to decimetre. This prediction is based on a world wide unique dataset of 18 airborne Li<span class="hlt">DAR</span> campaigns covering the Hintereisferner region . Furthermore, the according multi-temporal dataset offers the opportunity to identify surface changes (altitudinal changes) outside glaciated areas, which have not been observed until now. Excluding gravitational induced processes these altitudinal changes have to be assigned to alpine permafrost degradations, although detailed information from prominent permafrost features like rock glaciers are missing. Beyond the detection of the climate induced permafrost degradation, based on the multi-temporal Li<span class="hlt">DAR</span> data set, the method (point based and avoiding point to raster conversions) will be applied to identify altitudinal changes and displacement rates of prominent rock glaciers in the Stubai and Ötztal Alps (Tyrol, Austria). In contrast to the multi-temporal approach, with at least one Li<span class="hlt">DAR</span> terrain model per ablation period (June to September), the analysis of the rock glacier features is based on a data set of only two Li<span class="hlt">DAR</span> campaigns, which were carried out with a time shift of four</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9145E..3JM','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9145E..3JM"><span>Optical turbulence profiling with Slo<span class="hlt">DAR</span> in the Canadian High Arctic</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Maire, Jérôme; Mieda, Etsuko; Steinbring, Eric; Murowinski, Richard; Graham, James R.; Carlberg, Raymond; Wright, Shelley A.; Law, Nicholas M.; Sivanandam, Suresh</p> <p>2014-07-01</p> <p>The Earth's polar regions offer unique advantages for ground-based astronomical observations with its cold and dry climate, long periods of darkness, and the potential for exquisite image quality. We present preliminary results from a site-testing campaign during nighttime from October to November 2012 at the Polar Environment Atmospheric Research Laboratory (PEARL), on a 610-m high ridge near the Eureka weatherstation on Ellesmere Island, Canada. A Shack-Hartmann wavefront sensor was employed, using the Slope Detection and Ranging (Slo<span class="hlt">DAR</span>) method. This instrument (Mieda et <span class="hlt">al</span>, this conference) was designed to measure the altitude, strength and variability of atmospheric turbulence, in particular for operation under Arctic conditions. First Slo<span class="hlt">DAR</span> optical turbulence profiles above PEARL show roughly half of the optical turbulence confined to the boundary layer, below about 1 km, with the majority of the remainder in one or two thin layers between 2 km and 5 km, or above. The median seeing during this campaign was measured to be 0.65 arcsec.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1510245K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1510245K"><span>Similarity and Complementarity of Airborne and Terrestrial Li<span class="hlt">DAR</span> Data in High Mountain Regions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kamp, Nicole; Glira, Philipp; Pfeifer, Norbert</p> <p>2013-04-01</p> <p> airborne to the terrestrial data (or vice versa) without introducing systematic errors caused by the above mentioned differences. A workflow for this analysis is established with command line processing of the point clouds using OPALS (Orientation and Processing of Airborne Laser Scanning data, Vienna University of Technology). For further processing of the data, it is necessary to adjust the different scans by using least squares matching of surfaces to improve the orientation of the <span class="hlt">ALS</span> and TLS data. Handling of the terrestrial Li<span class="hlt">DAR</span> data with its very high point density and the data filtering to minimize errors and artefacts turned out to be the biggest challenges. After a relative and absolute orientation of the TLS scans with the help of GNSS spheres (see P. Glira, ESSI1.5), the data are processed in order to make it comparable with the airborne Li<span class="hlt">DAR</span> scans. Different ranges and consequential different footprint sizes and a big variance of the point densities have to be considered. Therefore the application of different filter and interpolation methods is important to get the best results and in further consequence to calculate an ideal Digital Terrain Model (DTM), which provides a good input dataset for future modelling of the geomorphic processes in the PROSA study area around the Gepatschferner.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2010-title47-vol2/pdf/CFR-2010-title47-vol2-sec25-401.pdf','CFR'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2010-title47-vol2/pdf/CFR-2010-title47-vol2-sec25-401.pdf"><span>47 CFR 25.401 - Satellite <span class="hlt">DARS</span> applications subject to competitive bidding.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2010&page.go=Go">Code of Federal Regulations, 2010 CFR</a></p> <p></p> <p>2010-10-01</p> <p>... 47 Telecommunication 2 2010-10-01 2010-10-01 false Satellite <span class="hlt">DARS</span> applications subject to...) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Competitive Bidding Procedures for <span class="hlt">DARS</span> § 25.401 Satellite <span class="hlt">DARS</span> applications subject to competitive bidding. Mutually exclusive initial applications for...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2012-title47-vol2/pdf/CFR-2012-title47-vol2-sec25-401.pdf','CFR2012'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2012-title47-vol2/pdf/CFR-2012-title47-vol2-sec25-401.pdf"><span>47 CFR 25.401 - Satellite <span class="hlt">DARS</span> applications subject to competitive bidding.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2012&page.go=Go">Code of Federal Regulations, 2012 CFR</a></p> <p></p> <p>2012-10-01</p> <p>... 47 Telecommunication 2 2012-10-01 2012-10-01 false Satellite <span class="hlt">DARS</span> applications subject to...) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Competitive Bidding Procedures for <span class="hlt">DARS</span> § 25.401 Satellite <span class="hlt">DARS</span> applications subject to competitive bidding. Mutually exclusive initial applications for...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2014-title47-vol2/pdf/CFR-2014-title47-vol2-sec25-401.pdf','CFR2014'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2014-title47-vol2/pdf/CFR-2014-title47-vol2-sec25-401.pdf"><span>47 CFR 25.401 - Satellite <span class="hlt">DARS</span> applications subject to competitive bidding.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2014&page.go=Go">Code of Federal Regulations, 2014 CFR</a></p> <p></p> <p>2014-10-01</p> <p>... 47 Telecommunication 2 2014-10-01 2014-10-01 false Satellite <span class="hlt">DARS</span> applications subject to...) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Competitive Bidding Procedures for <span class="hlt">DARS</span> § 25.401 Satellite <span class="hlt">DARS</span> applications subject to competitive bidding. Mutually exclusive initial applications for...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2013-title47-vol2/pdf/CFR-2013-title47-vol2-sec25-401.pdf','CFR2013'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2013-title47-vol2/pdf/CFR-2013-title47-vol2-sec25-401.pdf"><span>47 CFR 25.401 - Satellite <span class="hlt">DARS</span> applications subject to competitive bidding.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2013&page.go=Go">Code of Federal Regulations, 2013 CFR</a></p> <p></p> <p>2013-10-01</p> <p>... 47 Telecommunication 2 2013-10-01 2013-10-01 false Satellite <span class="hlt">DARS</span> applications subject to...) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Competitive Bidding Procedures for <span class="hlt">DARS</span> § 25.401 Satellite <span class="hlt">DARS</span> applications subject to competitive bidding. Mutually exclusive initial applications for...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.gpo.gov/fdsys/pkg/CFR-2011-title47-vol2/pdf/CFR-2011-title47-vol2-sec25-401.pdf','CFR2011'); return false;" href="https://www.gpo.gov/fdsys/pkg/CFR-2011-title47-vol2/pdf/CFR-2011-title47-vol2-sec25-401.pdf"><span>47 CFR 25.401 - Satellite <span class="hlt">DARS</span> applications subject to competitive bidding.</span></a></p> <p><a target="_blank" href="http://www.gpo.gov/fdsys/browse/collectionCfr.action?selectedYearFrom=2011&page.go=Go">Code of Federal Regulations, 2011 CFR</a></p> <p></p> <p>2011-10-01</p> <p>... 47 Telecommunication 2 2011-10-01 2011-10-01 false Satellite <span class="hlt">DARS</span> applications subject to...) COMMON CARRIER SERVICES SATELLITE COMMUNICATIONS Competitive Bidding Procedures for <span class="hlt">DARS</span> § 25.401 Satellite <span class="hlt">DARS</span> applications subject to competitive bidding. Mutually exclusive initial applications for...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010JGE.....7..155L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010JGE.....7..155L"><span>On the Li<span class="hlt">DAR</span> contribution for the archaeological and geomorphological study of a deserted medieval village in Southern Italy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lasaponara, Rosa; Coluzzi, Rosa; Gizzi, Fabrizio T.; Masini, Nicola</p> <p>2010-06-01</p> <p>Airborne laser scanning (<span class="hlt">ALS</span>) is an optical measurement technique for obtaining high-precision information about the Earth's surface including basic terrain mapping (digital terrain model, bathymetry, corridor mapping), vegetation cover (forest assessment and inventory) and coastal and urban areas. Recent studies examined the possibility of using <span class="hlt">ALS</span> in archaeological investigations to identify earthworks, although the ability of <span class="hlt">ALS</span> measurements in this context has not yet been studied in detail. This paper focuses on the potential of the latest generation of airborne <span class="hlt">ALS</span> for the detection and the spatial characterization of micro-topographic relief linked to archaeological and geomorphological features. The investigations were carried out near Monteserico, an archaeological area in the Basilicata region (Southern Italy) which is characterized by complex topographical and morphological features. The study emphasizes that the DTM-Li<span class="hlt">DAR</span> data are a powerful instrument for detecting surface discontinuities relevant for investigating geomorphological processes and cultural features. The Li<span class="hlt">DAR</span> survey allowed us to identify the urban shape of a medieval village, by capturing the small differences in height produced by surface and shallow archaeological remains (the so-called shadow marks) which were not visible from ground or from optical dataset. In this way, surface reliefs and small elevation changes, linked to geomorphological and archaeological features, have been surveyed with great detail.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150012722','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150012722"><span>Features of Point Clouds Synthesized from Multi-View ALOS/PRISM Data and Comparisons with Li<span class="hlt">DAR</span> Data in Forested Areas</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Ni, Wenjian; Ranson, Kenneth Jon; Zhang, Zhiyu; Sun, Guoqing</p> <p>2014-01-01</p> <p>Li<span class="hlt">DAR</span> waveform data from airborne Li<span class="hlt">DAR</span> scanners (<span class="hlt">ALS</span>) e.g. the Land Vegetation and Ice Sensor (LVIS) havebeen successfully used for estimation of forest height and biomass at local scales and have become the preferredremote sensing dataset. However, regional and global applications are limited by the cost of the airborne LiDARdata acquisition and there are no available spaceborne Li<span class="hlt">DAR</span> systems. Some researchers have demonstrated thepotential for mapping forest height using aerial or spaceborne stereo imagery with very high spatial resolutions.For stereo imageswith global coverage but coarse resolution newanalysis methods need to be used. Unlike mostresearch based on digital surface models, this study concentrated on analyzing the features of point cloud datagenerated from stereo imagery. The synthesizing of point cloud data from multi-view stereo imagery increasedthe point density of the data. The point cloud data over forested areas were analyzed and compared to small footprintLi<span class="hlt">DAR</span> data and large-footprint Li<span class="hlt">DAR</span> waveform data. The results showed that the synthesized point clouddata from ALOSPRISM triplets produce vertical distributions similar to Li<span class="hlt">DAR</span> data and detected the verticalstructure of sparse and non-closed forests at 30mresolution. For dense forest canopies, the canopy could be capturedbut the ground surface could not be seen, so surface elevations from other sourceswould be needed to calculatethe height of the canopy. A canopy height map with 30 m pixels was produced by subtracting nationalelevation dataset (NED) fromthe averaged elevation of synthesized point clouds,which exhibited spatial featuresof roads, forest edges and patches. The linear regression showed that the canopy height map had a good correlationwith RH50 of LVIS data with a slope of 1.04 and R2 of 0.74 indicating that the canopy height derived fromPRISM triplets can be used to estimate forest biomass at 30 m resolution.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9477E..0FV','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9477E..0FV"><span>Volume component analysis for classification of Li<span class="hlt">DAR</span> data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Varney, Nina M.; Asari, Vijayan K.</p> <p>2015-03-01</p> <p>One of the most difficult challenges of working with Li<span class="hlt">DAR</span> data is the large amount of data points that are produced. Analysing these large data sets is an extremely time consuming process. For this reason, automatic perception of Li<span class="hlt">DAR</span> scenes is a growing area of research. Currently, most Li<span class="hlt">DAR</span> feature extraction relies on geometrical features specific to the point cloud of interest. These geometrical features are scene-specific, and often rely on the scale and orientation of the object for classification. This paper proposes a robust method for reduced dimensionality feature extraction of 3D objects using a volume component analysis (VCA) approach.1 This VCA approach is based on principal component analysis (PCA). PCA is a method of reduced feature extraction that computes a covariance matrix from the original input vector. The eigenvectors corresponding to the largest eigenvalues of the covariance matrix are used to describe an image. Block-based PCA is an adapted method for feature extraction in facial images because PCA, when performed in local areas of the image, can extract more significant features than can be extracted when the entire image is considered. The image space is split into several of these blocks, and PCA is computed individually for each block. This VCA proposes that a Li<span class="hlt">DAR</span> point cloud can be represented as a series of voxels whose values correspond to the point density within that relative location. From this voxelized space, block-based PCA is used to analyze sections of the space where the sections, when combined, will represent features of the entire 3-D object. These features are then used as the input to a support vector machine which is trained to identify four classes of objects, vegetation, vehicles, buildings and barriers with an overall accuracy of 93.8%</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016E%26PSL.444....1D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016E%26PSL.444....1D"><span>Variable microstructural response of baddeleyite to shock metamorphism in young basaltic <span class="hlt">shergottite</span> NWA 5298 and improved U-Pb dating of Solar System events</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Darling, James R.; Moser, Desmond E.; Barker, Ivan R.; Tait, Kim T.; Chamberlain, Kevin R.; Schmitt, Axel K.; Hyde, Brendt C.</p> <p>2016-06-01</p> <p>The accurate dating of igneous and impact events is vital for the understanding of Solar System evolution, but has been hampered by limited knowledge of how shock metamorphism affects mineral and whole-rock isotopic systems used for geochronology. Baddeleyite (monoclinic ZrO2) is a refractory mineral chronometer of great potential to date these processes due to its widespread occurrence in achondrites and robust U-Pb isotopic systematics, but there is little understanding of shock-effects on this phase. Here we present new nano-structural measurements of baddeleyite grains in a thin-section of the highly-shocked basaltic <span class="hlt">shergottite</span> Northwest Africa (NWA) 5298, using high-resolution electron backscattered diffraction (EBSD) and scanning transmission electron microscopy (STEM) techniques, to investigate shock-effects and their linkage with U-Pb isotopic disturbance that has previously been documented by in-situ U-Pb isotopic analyses. The shock-altered state of originally igneous baddeleyite grains is highly variable across the thin-section and often within single grains. Analyzed grains range from those that preserve primary (magmatic) twinning and trace-element zonation (baddeleyite shock Group 1), to quasi-amorphous ZrO2 (Group 2) and to recrystallized micro-granular domains of baddeleyite (Group 3). These groups correlate closely with measured U-Pb isotope compositions. Primary igneous features in Group 1 baddeleyites (n = 5) are retained in high shock impedance grain environments, and an average of these grains yields a revised late-Amazonian magmatic crystallization age of 175 ± 30 Ma for this <span class="hlt">shergottite</span>. The youngest U-Pb dates occur from Group 3 recrystallized nano- to micro-granular baddeleyite grains, indicating that it is post-shock heating and new mineral growth that drives much of the isotopic disturbance, rather than just shock deformation and phase transitions. Our data demonstrate that a systematic multi-stage microstructural evolution in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1714243W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1714243W"><span>Li<span class="hlt">DAR</span> observation of the flow structure in typhoons</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wu, Yu-Ting; Hsuan, Chung-Yao; Lin, Ta-Hui</p> <p>2015-04-01</p> <p>Taiwan is subject to 3.4 landfall typhoons each year in average, generally occurring in the third quarter of every year (July-September). Understanding of boundary-layer turbulence characteristics of a typhoon is needed to ensure the safety of both onshore and offshore wind turbines used for power generation. In this study, a floating Li<span class="hlt">DAR</span> (Light Detection and Ranging) was deployed in a harbor to collect data of wind turbulence, atmospheric pressure, and temperature in three typhoon events (Matmo typhoon, Soulik typhoon, Trami typhoon). Data collected from the floating Li<span class="hlt">DAR</span> and from meteorological stations located at Taipei, Taichung and Kaohsiung are adopted to analyse the wind turbulence characteristics in the three typhoon events. The measurement results show that the maximum 10-min average wind speed measured with the floating Li<span class="hlt">DAR</span> is up to 24 m/s at a height of 200 m. Compared with other normal days, the turbulence intensity is lower in the three typhoon events where the wind speed has a rapid increase. Changes of wind direction take place clearly as the typhoons cross Taiwan from East to West. Within the crossing intervals, the vertical momentum flux is observed to have a significant pattern with both upward and downward propagating waves which are relevant to the flow structure of the typhoons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017ITGRS..55..996X','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017ITGRS..55..996X"><span>Road Curb Extraction From Mobile Li<span class="hlt">DAR</span> Point Clouds</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Xu, Sheng; Wang, Ruisheng; Zheng, Han</p> <p>2017-02-01</p> <p>Automatic extraction of road curbs from uneven, unorganized, noisy and massive 3D point clouds is a challenging task. Existing methods often project 3D point clouds onto 2D planes to extract curbs. However, the projection causes loss of 3D information which degrades the performance of the detection. This paper presents a robust, accurate and efficient method to extract road curbs from 3D mobile Li<span class="hlt">DAR</span> point clouds. Our method consists of two steps: 1) extracting the candidate points of curbs based on the proposed novel energy function and 2) refining the candidate points using the proposed least cost path model. We evaluated our method on a large-scale of residential area (16.7GB, 300 million points) and an urban area (1.07GB, 20 million points) mobile Li<span class="hlt">DAR</span> point clouds. Results indicate that the proposed method is superior to the state-of-the-art methods in terms of robustness, accuracy and efficiency. The proposed curb extraction method achieved a completeness of 78.62% and a correctness of 83.29%. These experiments demonstrate that the proposed method is a promising solution to extract road curbs from mobile Li<span class="hlt">DAR</span> point clouds.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010Geomo.118..213L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010Geomo.118..213L"><span>Rockfall hazard analysis using Li<span class="hlt">DAR</span> and spatial modeling</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lan, Hengxing; Martin, C. Derek; Zhou, Chenghu; Lim, Chang Ho</p> <p>2010-05-01</p> <p>Rockfalls have been significant geohazards along the Canadian Class 1 Railways (CN Rail and CP Rail) since their construction in the late 1800s. These rockfalls cause damage to infrastructure, interruption of business, and environmental impacts, and their occurrence varies both spatially and temporally. The proactive management of these rockfall hazards requires enabling technologies. This paper discusses a hazard assessment strategy for rockfalls along a section of a Canadian railway using Li<span class="hlt">DAR</span> and spatial modeling. Li<span class="hlt">DAR</span> provides accurate topographical information of the source area of rockfalls and along their paths. Spatial modeling was conducted using Rockfall Analyst, a three dimensional extension to GIS, to determine the characteristics of the rockfalls in terms of travel distance, velocity and energy. Historical rockfall records were used to calibrate the physical characteristics of the rockfall processes. The results based on a high-resolution digital elevation model from a Li<span class="hlt">DAR</span> dataset were compared with those based on a coarse digital elevation model. A comprehensive methodology for rockfall hazard assessment is proposed which takes into account the characteristics of source areas, the physical processes of rockfalls and the spatial attribution of their frequency and energy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1817935S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1817935S"><span>Coastal and tidal landform detection from high resolution topobathymetric Li<span class="hlt">DAR</span> data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Skovgaard Andersen, Mikkel; Al-Hamdani, Zyad; Steinbacher, Frank; Rolighed Larsen, Laurids; Brandbyge Ernstsen, Verner</p> <p>2016-04-01</p> <p>Coastal and tidal environments are valuable ecosystems, which, however, are under pressure in many areas around the world due to globalisation and/or climate change. Detailed mapping of these environments is required in order to manage the coastal zone in a sustainable way. However, historically these transition zones between land and water are difficult or even impossible to map and investigate in high spatial resolution due to the challenging environmental conditions. The new generation of airborne topobathymetric light detection and ranging (Li<span class="hlt">DAR</span>) potentially enables full-coverage and high-resolution mapping of these land-water transition zones. We have carried out topobathymetric Li<span class="hlt">DAR</span> surveys in the Knudedyb tidal inlet system, a coastal environment in the Danish Wadden Sea which is part of the Wadden Sea National Park and UNESCO World Heritage. Detailed digital elevation models (DEMs) with a grid cell size of 0.5 m x 0.5 m were generated from the Li<span class="hlt">DAR</span> point cloud with a mean point density in the order of 20 points/m2. The DEM was analysed morphometrically using a modification of the tool Benthic Terrain Modeler (BTM) developed by Wright et <span class="hlt">al</span>. (2005). Initially, stage (the elevation in relation to tidal range) was used to divide the area of investigation into the different tidal zones, i.e. subtidal, intertidal and supratidal. Subsequently, morphometric units were identified and characterised by a combination of statistical neighbourhood analysis with varying window sizes (using the Bathymetric Positioning Index (BPI) from the BTM, moving average and standard deviation), slope parameters and area/perimeter ratios. Finally, these morphometric units were classified into six different types of landforms based on their stage and morphometric characteristics, i.e. either subtidal channel, intertidal flat, intertidal creek, linear bar, swash bar or beach dune. We hereby demonstrate the potential of using airborne topobathymetric Li<span class="hlt">DAR</span> for seamless mapping of land</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.B52A..07F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.B52A..07F"><span>Increasing the Efficiency of Li<span class="hlt">DAR</span> Based Forest Inventories: A Novel Approach for Integrating Variable Radius Inventory Plots with Li<span class="hlt">DAR</span> Data.</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Falkowski, M. J.; Fekety, P.; Silva, C. A.; Hudak, A. T.</p> <p>2015-12-01</p> <p>Li<span class="hlt">DAR</span> data are increasingly applied to support forest inventory and assessment across a variety of spatial scales. Typically this is achieved by integrating Li<span class="hlt">DAR</span> data with forest inventory collected at fixed radius forest inventory plots. A well-designed forest inventory, one that covers the full range of structural and compositional variation across the forest of interest, is costly especially when collecting fixed radius plot data. Variable radius plots offer an alternative inventory protocol that is more efficient in terms of both time and money. However, integrating variable radius plot data with Li<span class="hlt">DAR</span> data is problematic because the plots have unknown sizes that vary with variation in tree size. This leads to a spatial mismatch between Li<span class="hlt">DAR</span> metrics (e.g., mean height, canopy cover, density, etc.) and plot data, which ultimately translates into errors in Li<span class="hlt">DAR</span> derived forest inventory predictions. We propose and evaluate and novel approach for integrating variable radius plot data into a Li<span class="hlt">DAR</span> based forest inventories in two different forest systems, one in the inland northwest and another in the northern lakes states of the USA. The novel approach calculates Li<span class="hlt">DAR</span> metrics by weighting the point cloud proportional to return height, mimicking the way in which variable radius plot data weights tree measurements by tree size. This could increase inventory sampling efficiency, allowing for the collection of a greater number of inventory plots, and ultimately improve the performance of Li<span class="hlt">DAR</span> based inventories.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5173179','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5173179"><span>Immunogenicity and Protective Efficacy of the <span class="hlt">DAR</span>-901 Booster Vaccine in a Murine Model of Tuberculosis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Lahey, Timothy; Laddy, Dominick; Hill, Krystal; Schaeffer, Jacqueline; Hogg, Alison; Keeble, James; Dagg, Belinda; Ho, Mei Mei; Arbeit, Robert D.; von Reyn, C. Fordham</p> <p>2016-01-01</p> <p>Background The development of a novel tuberculosis vaccine is a leading global health priority. SRL172, an inactivated, whole-cell mycobacterial vaccine, was safe, immunogenic and reduced the incidence of culture-confirmed tuberculosis in a phase III trial in HIV-infected and BCG immunized adults in Tanzania. Here we describe the immunogenicity and protective efficacy of <span class="hlt">DAR</span>-901, a booster vaccine against tuberculosis manufactured from the same seed strain using a new scalable method. Methods We evaluated IFN-γ responses by ELISpot and antibody responses by enzyme linked immunosorbent assay in C57BL/6 and BALB/c mice after three doses of <span class="hlt">DAR</span>-901. In an aerosol challenge model, we evaluated the protective efficacy of the <span class="hlt">DAR</span>-901 booster in C57BL/6 mice primed with BCG and boosted with two doses of <span class="hlt">DAR</span>-901 at 4 dosage levels in comparison with homologous BCG boost. Results <span class="hlt">DAR</span>-901 vaccination elicited IFN-γ responses to mycobacterial antigen preparations derived from both <span class="hlt">DAR</span>-901 and Mycobacterium tuberculosis. <span class="hlt">DAR</span>-901 immunization enhanced antibody responses to <span class="hlt">DAR</span>-901 but not Mycobacterium tuberculosis lysate or purified protein derivative. Among animals primed with BCG, boosting with <span class="hlt">DAR</span>-901 at 1 mg provided greater protection against aerosol challenge than a homologous BCG boost (lungs P = 0.036, spleen P = 0.028). Conclusions <span class="hlt">DAR</span>-901 induces cellular and humoral immunity and boosts protection from M. tuberculosis compared to a homologous BCG boost. PMID:27997597</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_6");'>6</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li class="active"><span>8</span></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_8 --> <div id="page_9" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="161"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/19970019937','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/19970019937"><span>Constraints on Martian Differentiation Processes from Rb-Sr and Sm-Nd Isotopic Analyses of the Basaltic <span class="hlt">Shergottite</span> QUE 94201</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Borg, Lars E.; Nyquist, Larry E.; Taylor, Larry A.; Wiesmann, Henry; Shih, Chi-Y.</p> <p>1997-01-01</p> <p>Isotopic analyses of mineral, leachate, and whole rock fractions from the Martian <span class="hlt">shergottite</span> meteorite QUE 94201 yield Rb-Sr and Sm-Nd crystallization ages of 327 +/- 12 and 327 +/- 19 Ma, respectively. These ages are concordant, although the isochrons are defined by different fractions within the meteorite. Comparison of isotope dilution Sm and Nd data for the various QUE 94201 fractions with in situ ion microprobe data for QUE 94201 minerals from the literature demonstrate the presence of a leachable crustal component in the meteorite. This component is likely to have been added to QUE 94201 by secondary alteration processes on Mars, and can affect the isochrons by selectively altering the isotopic systematics of the leachates and some of the mineral fractions. The absence of crustal recycling processes on Mars may preserve the geochemical evidence for early differentiation and the decoupling of the Rb-Sr and Sm-Nd isotopic systems, underscoring one of the fundamental differences between geologic processes on Mars and the Earth.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1811609A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1811609A"><span>Surface expression of intraplate postglacial faults in Sweden: from Li<span class="hlt">DAR</span> data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Abduljabbar, Mawaheb; Ask, Maria; Bauer, Tobias; Lund, Björn; Smith, Colby; Mikko, Henrik; Munier, Raymond</p> <p>2016-04-01</p> <p>Large intraplate earthquakes, up to magnitude 8.0±0.3 (Lindblom et <span class="hlt">al</span>. 2015) are inferred to have occurred in northern Fennoscandia at the end of, or just after the Weichselian deglaciation. More than a dozen large so-called postglacial faults (PGF) have been found in the region. The present-day microseismic activity is rather high in north Sweden, and there is a correlation between microseismicity and mapped PGF scarps: 71% of the observed earthquakes north of 66°N locate within 30 km to the southeast and 10 km to the northwest of PGFs (Lindblom et <span class="hlt">al</span>., 2015). Surface expressions of PGFs in Sweden have mainly been mapped using aerial photogrammetry and trenching (e.g. Lagerbäck & Sundh 2008). Their detailed surface geometry may be investigated using the new high-resolution elevation model of Sweden (NNH) that has a vertical- and lateral resolution of 2 m and 0.25 m, respectively. With NNH data, known PGFs have been modified, and a number of new potential PGFs have been identified (Smith et <span class="hlt">al</span>. 2014; Mikko et <span class="hlt">al</span>. 2015). However, the detailed variation of their surface expression remains to be determined. Our main objective is to constrain the strike and surface offset (i.e., apparent vertical throw because of soil cover overlays the bedrock) across the PGF scarps. We anticipate using the results to constrain direction of fault motion and paleomagnitudes of PGFs, and in numerical analyzes to investigate the nature of PGFs. We have developed a methodology for analyzing PGF-geomorphology from Li<span class="hlt">DAR</span> data using two main software platforms (Ask et <span class="hlt">al</span>. 2015): (1) Move2015 by Midland Valley has been used for constructing 3D models of the surface traces of the PGFs to determine apparent vertical throw. The apparent hanging- and footwall cut off lines are digitized, and subsequent computation of coordinates is rather time efficient and provide continuous data of fault and soil geomorphology that can be statistically analyzed; and (2) ArcGIS 10.3 by Esri has mostly been</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.B33D0211G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.B33D0211G"><span>Estimating pre-fire biomass for the 2013 California Rim Fire using airborne Li<span class="hlt">DAR</span> and Landsat data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Garcia-Alonso, M.; Casas Planes, Á.; Koltunov, A.; Ustin, S.; Falk, M.; Ramirez, C.</p> <p>2014-12-01</p> <p>Accurate knowledge of the amount and distribution of fuels is critical for appropriate fire planning and management, but also to improve carbon emissions estimates resulting from both wildland and prescribed fires. Airborne Li<span class="hlt">DAR</span> (<span class="hlt">ALS</span>) data has shown great capability to determine the amount of biomass in different ecosystems. Nevertheless, for most incidents a pre-fire Li<span class="hlt">DAR</span> dataset that would enable the characterization of fuels before the incident is not available. Addressing this problem, we investigated the potential of combining a post-fire <span class="hlt">ALS</span> dataset and a pre-fire Landsat image to model the pre-fire biomass distribution for the third-largest wildfire in California history, the Rim fire. Very high density (≈ 20 points/m2) <span class="hlt">ALS</span> data was acquired covering the burned area plus a 2 km buffer. 500+ <span class="hlt">ALS</span>-plots were located throughout the buffer area using a stratified random sampling scheme, with the strata defined by species group (coniferous, hardwood, and mixed forests) and diametric classes (5-9.9"; 10-19.9"; 20-29.9" and >30"). In these plots, individual tree crowns were delineated by the Watershed algorithm. Crown delineation was visually refined to avoid over- and under-segmentation errors, and the tree biomass was determined based on species-specific allometric equations. The biomass estimates for correctly delineated trees were subsequently aggregated to the plot-level. The next step is to derive a model relating the plot-level biomass to plot-level <span class="hlt">ALS</span>-derived height and intensity metrics as explanatory variables. This model will be used to map pre-fire biomass in the buffer area outside the burn. To determine pre-fire biomass inside the fire perimeter, where <span class="hlt">ALS</span> data are not available, we will use a statistical approach based on spectral information provided by a pre-fire Landsat image and its relationships with the 2 km buffer Li<span class="hlt">DAR</span>-derived biomass estimates. We will validate our results with field measurements collected independently, before the fire.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPRS..110...66T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPRS..110...66T"><span>Segmenting tree crowns from terrestrial and mobile Li<span class="hlt">DAR</span> data by exploring ecological theories</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tao, Shengli; Wu, Fangfang; Guo, Qinghua; Wang, Yongcai; Li, Wenkai; Xue, Baolin; Hu, Xueyang; Li, Peng; Tian, Di; Li, Chao; Yao, Hui; Li, Yumei; Xu, Guangcai; Fang, Jingyun</p> <p>2015-12-01</p> <p>The rapid development of light detection and ranging (Li<span class="hlt">DAR</span>) techniques is advancing ecological and forest research. During the last decade, numerous single tree segmentation techniques have been developed using airborne Li<span class="hlt">DAR</span> data. However, accurate crown segmentation using terrestrial or mobile Li<span class="hlt">DAR</span> data, which is an essential prerequisite for extracting branch level forest characteristics, is still challenging mainly because of the difficulties posed by tree crown intersection and irregular crown shape. In the current work, we developed a comparative shortest-path algorithm (CSP) for segmenting tree crowns scanned using terrestrial (T)-Li<span class="hlt">DAR</span> and mobile Li<span class="hlt">DAR</span>. The algorithm consists of two steps, namely trunk detection and subsequent crown segmentation, with the latter inspired by the well-proved metabolic ecology theory and the ecological fact that vascular plants tend to minimize the transferring distance to the root. We tested the algorithm on mobile-Li<span class="hlt">DAR</span>-scanned roadside trees and T-Li<span class="hlt">DAR</span>-scanned broadleaved and coniferous forests in China. Point-level quantitative assessments of the segmentation results showed that for mobile-Li<span class="hlt">DAR</span>-scanned roadside trees, all the points were classified to their corresponding trees correctly, and for T-Li<span class="hlt">DAR</span>-scanned broadleaved and coniferous forests, kappa coefficients ranging from 0.83 to 0.93 were obtained. We believe that our algorithm will make a contribution to solving the problem of crown segmentation in T-Li<span class="hlt">DAR</span> scanned-forests, and might be of interest to researchers in Li<span class="hlt">DAR</span> data processing and to forest ecologists. In addition, our research highlights the advantages of using ecological theories as guidelines for processing Li<span class="hlt">DAR</span> data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008SPIE.7144E..2FZ','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008SPIE.7144E..2FZ"><span>Data management based on geocoding index and adaptive visualization for airborne Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhi, Xiaodong</p> <p>2008-10-01</p> <p>With more surveying practice and deeper application, data post-process for airborne Li<span class="hlt">DAR</span> system has been extracted lots of attention in data accuracy, post-process, fusion, modeling, automation and visualization. However, post-process and flexible visualization were found to be the bottle-neck which limits the Li<span class="hlt">DAR</span> data usage for industrial applications. The cause of above bottle-neck problems is great capacity for Li<span class="hlt">DAR</span> system. Thus in article a geocoding index based multivariate data management and adaptive visualization will be studied for based on the feature of airborne Li<span class="hlt">DAR</span>'s data to improve automatization of post-process and surveying efficiency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.C33B0649L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.C33B0649L"><span>Can we estimate precipitation rate during snowfall using a scanning terrestrial Li<span class="hlt">DAR</span>?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>LeWinter, A. L.; Bair, E. H.; Davis, R. E.; Finnegan, D. C.; Gutmann, E. D.; Dozier, J.</p> <p>2012-12-01</p> <p>Accurate snowfall measurements in windy areas have proven difficult. To examine a new approach, we have installed an automatic scanning terrestrial Li<span class="hlt">DAR</span> at Mammoth Mountain, CA. With this Li<span class="hlt">DAR</span>, we have demonstrated effective snow depth mapping over a small study area of several hundred m2. The Li<span class="hlt">DAR</span> also produces dense point clouds by detecting falling and blowing hydrometeors during storms. Daily counts of airborne detections from the Li<span class="hlt">DAR</span> show excellent agreement with automated and manual snow water equivalent measurements, suggesting that Li<span class="hlt">DAR</span> observations have the potential to directly estimate precipitation rate. Thus, we suggest Li<span class="hlt">DAR</span> scanners offer advantages over precipitation radars, which could lead to more accurate precipitation rate estimates. For instance, uncertainties in mass-diameter and mass-fall speed relationships used in precipitation radar, combined with low reflectivity of snow in the microwave spectrum, produce errors of up to 3X in snowfall rates measured by radar. Since snow has more backscatter in the near-infrared wavelengths used by Li<span class="hlt">DAR</span> compared to the wavelengths used by radar, and the Li<span class="hlt">DAR</span> detects individual hydrometeors, our approach has more potential for directly estimating precipitation rate. A key uncertainty is hydrometeor mass. At our study site, we have also installed a Multi Angle Snowflake Camera (MASC) to measure size, fallspeed, and mass of individual hydrometeors. By combining simultaneous MASC and Li<span class="hlt">DAR</span> measurements, we can estimate precipitation density and rate.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27828337','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27828337"><span>Weibull approximation of Li<span class="hlt">DAR</span> waveforms for estimating the beam attenuation coefficient.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Montes-Hugo, Martin A; Vuorenkoski, Anni K; Dalgleish, Fraser R; Ouyang, Bing</p> <p>2016-10-03</p> <p>Tank experiments were performed at different water turbidities to examine relationships between the beam attenuation coefficient (c) and Weibull shape parameters derived from Li<span class="hlt">DAR</span> waveforms measured with the Fine Structure Underwater Li<span class="hlt">DAR</span> (FSUIL). Optical inversions were made at 532 nm, within a c range of 0.045-1.52 m<sup>-1</sup>, and based on a Li<span class="hlt">DAR</span> system having two field-of-view (15 and 75.7 mrad) and two linear polarizations. Consistently, the Weibull scale parameter or P2 showed the strongest covariation with c and was a more accurate proxy with respect to the Li<span class="hlt">DAR</span> attenuation coefficient.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013CG.....54..122V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013CG.....54..122V"><span>Performance testing of Li<span class="hlt">DAR</span> exploitation software</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Varela-González, M.; González-Jorge, H.; Riveiro, B.; Arias, P.</p> <p>2013-04-01</p> <p>Mobile Li<span class="hlt">DAR</span> systems are being used widely in recent years for many applications in the field of geoscience. One of most important limitations of this technology is the large computational requirements involved in data processing. Several software solutions for data processing are available in the market, but users are often unknown about the methodologies to verify their performance accurately. In this work a methodology for Li<span class="hlt">DAR</span> software performance testing is presented and six different suites are studied: QT Modeler, AutoCAD Civil 3D, Mars 7, Fledermaus, Carlson and TopoDOT (all of them in x64). Results depict as QTModeler, TopoDOT and AutoCAD Civil 3D allow the loading of large datasets, while Fledermaus, Mars7 and Carlson do not achieve these powerful performance. AutoCAD Civil 3D needs large loading time in comparison with the most powerful softwares such as QTModeler and TopoDOT. Carlson suite depicts the poorest results among all the softwares under study, where point clouds larger than 5 million points cannot be loaded and loading time is very large in comparison with the other suites even for the smaller datasets. AutoCAD Civil 3D, Carlson and TopoDOT show more threads than other softwares like QTModeler, Mars7 and Fledermaus.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.B33A0392S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.B33A0392S"><span>Applying the Moment Distance Framework to Li<span class="hlt">DAR</span> Waveforms</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Salas, E. L.; Aguilar-Amuchastegui, N.; Henebry, G. M.</p> <p>2010-12-01</p> <p>In the past decade or so, there have only been limited approaches formulated for the analysis of waveform Li<span class="hlt">DAR</span> data. We illustrate how the Moment Distance (MD) framework can characterize the shape of the Li<span class="hlt">DAR</span> waveforms using simple, computationally fast, geometric operations. We assess the relationship of the MD metrics to some key waveform landmarks - such as locations of peaks, power of returns, and pseudo-heights - using LVIS datasets acquired over a tropical forest in La Selva, Costa Rica in 1998 and 2005. We also apply the MD framework to 2003 LVIS data from Howland Forest, Maine. We also explore the effects of noise on the MD Index (MDI). Our results reveal that the MDI can capture important dynamics in canopy structure. Movement in the location of the peaks is detected by shifts in the MDI. Because this new approach responds to waveform shape, it is more sensitive to changes of location of peak returns than to the power of the return. Results also suggest a positive relationship between the MDI and the canopy pseudo-height.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMNH41B1805K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMNH41B1805K"><span>Identifying Colluvial Slopes by Airborne Li<span class="hlt">DAR</span> Analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kasai, M.; Marutani, T.; Yoshida, H.</p> <p>2015-12-01</p> <p>Colluvial slopes are one of major sources of landslides. Identifying the locations of the slopes will help reduce the risk of disasters, by avoiding building infrastructure and properties nearby, or if they are already there, by applying appropriate counter measures before it suddenly moves. In this study, airborne Li<span class="hlt">DAR</span> data was analyzed to find their geomorphic characteristics to use for extracting their locations. The study site was set in the suburb of Sapporo City, Hokkaido in Japan. The area is underlain by Andesite and Tuff and prone to landslides. Slope angle and surface roughness were calculated from 5 m resolution DEM. These filters were chosen because colluvial materials deposit at around the angle of repose and accumulation of loose materials was considered to form a peculiar surface texture differentiable from other slope types. Field survey conducted together suggested that colluvial slopes could be identified by the filters with a probability of 80 percent. Repeat Li<span class="hlt">DAR</span> monitoring of the site by an unmanned helicopter indicated that those slopes detected as colluviums appeared to be moving at a slow rate. In comparison with a similar study from the crushed zone in Japan, the range of slope angle indicative of colluviums agreed with the Sapporo site, while the texture was rougher due to larger debris composing the slopes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20070003723','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20070003723"><span>Rb-Sr and Sm-Nd Isotopic Studies of Martian Depleted Shergottes SaU 094/005</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shih, C.-Y.; Nyquist, L. E.; Reese, Y.</p> <p>2007-01-01</p> <p>Sayh <span class="hlt">al</span> Uhaymir (SaU) 094 and SaU 005 are olivine-phyric <span class="hlt">shergottites</span> from the Oman desert and are considered as pairs. [e.g., 1]. They are very similar to the Libyan desert <span class="hlt">shergottite</span> <span class="hlt">Dar</span> <span class="hlt">al</span> Gani (DaG) 476 in petrology, chemistry and ejection age [2-6]. This group of <span class="hlt">shergottites</span>, also recognized as depleted <span class="hlt">shergottites</span> [e.g. 7] has been strongly shocked and contains very low abundances of light rare earth elements (REE). In addition, terrestrial contaminants are commonly present in meteorites found in desert environments. Age-dating these samples is very challenging, but lower calcite contents in the SaU meteorites suggest that they have been subjected to less severe desert weathering than their DaG counterparts [3-4]. In this report, we present Rb-Sr and Sm-Nd isotopic results for SaU 094 and SaU 005, discuss the correlation of their ages with those of other similar <span class="hlt">shergottites</span>, and discuss their petrogenesis.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..1110967K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..1110967K"><span>Analysis of airborne Li<span class="hlt">DAR</span> as a basis for digital soil mapping in Alpine areas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kringer, K.; Tusch, M.; Geitner, C.; Meißl, G.; Rutzinger, M.</p> <p>2009-04-01</p> <p>Especially in mountainous regions like the Alps the formation of soil is highly influenced by relief characteristics. Among all factors included in Jenny's (1941) model for soil development, relief is the one most commonly used in approaches to create digital soil maps and to derive soil properties from secondary data sources (McBratney et <span class="hlt">al</span>. 2003). Elevation data, first order (slope, aspect) and second order derivates (plan, profile and cross-sectional curvature) as well as complex morphometric parameters (various landform classifications, e.g., Wood 1996) and compound indices (e.g., topographic wetness indices, vertical distance to drainage network, insolation) can be calculated from digital elevation models (DEM). However, while being an important source of information for digital soil mapping on small map scales, "conventional" DEMs are of limited use for the design of large scale conceptual soil maps for small areas due to rather coarse raster resolutions with cell sizes ranging from 20 to 100 meters. Slight variations in elevation and small landform features might not be discernible even though they might have a significant effect to soil formation, e.g., regarding the influence of groundwater in alluvial soils or the extent of alluvial fans. Nowadays, Airborne Li<span class="hlt">DAR</span> (Light Detection And Ranging) provides highly accurate data for the elaboration of high-resolution digital terrain models (DTM) even in forested areas. In the project LASBO (Laserscanning in der Bodenkartierung) the applicability of digital terrain models derived from Li<span class="hlt">DAR</span> for the identification of soil-relevant geomorphometric parameter is investigated. Various algorithms which were initially designed for coarser raster data are applied on high-resolution DTMs. Test areas for LASBO are located in the region of Bruneck (Italy) and near the municipality of Kramsach in the Inn Valley (Austria). The freely available DTM for Bruneck has a raster resolution of 2.5 meters while in Kramsach a DTM with</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.6324H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.6324H"><span>Fusion of terrestrial Li<span class="hlt">DAR</span> and tomographic mapping data for 3D karst landform investigation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Höfle, B.; Forbriger, M.; Siart, C.; Nowaczinski, E.</p> <p>2012-04-01</p> <p>Highly detailed topographic information has gained in importance for studying Earth surface landforms and processes. Li<span class="hlt">DAR</span> has evolved into the state-of-the-art technology for 3D data acquisition on various scales. This multi-sensor system can be operated on several platforms such as airborne LS (<span class="hlt">ALS</span>), mobile LS (MLS) from moving vehicles or stationary on ground (terrestrial LS, TLS). In karst research the integral investigation of surface and subsurface components of solution depressions (e.g. sediment-filled dolines) is required to gather and quantify the linked geomorphic processes such as sediment flux and limestone dissolution. To acquire the depth of the different subsurface layers, a combination of seismic refraction tomography (SRT) and electrical resistivity tomography (ERT) is increasingly applied. This multi-method approach allows modeling the extension of different subsurface media (i.e. colluvial fill, epikarst zone and underlying basal bedrock). Subsequent fusion of the complementary techniques - Li<span class="hlt">DAR</span> surface and tomographic subsurface data - first-time enables 3D prospection and visualization as well as quantification of geomorphometric parameters (e.g. depth, volume, slope and aspect). This study introduces a novel GIS-based method for semi-automated fusion of TLS and geophysical data. The study area is located in the Dikti Mountains of East Crete and covers two adjacent dolines. The TLS data was acquired with a Riegl VZ-400 scanner from 12 scan positions located mainly at the doline divide. The scan positions were co-registered using the iterative closest point (ICP) algorithm of RiSCAN PRO. For the digital elevation rasters a resolution of 0.5 m was defined. The digital surface model (DSM) of the study was derived by moving plane interpolation of all laser points (including objects) using the OPALS software. The digital terrain model (DTM) was generated by iteratively "eroding" objects in the DSM by minimum filter, which additionally accounts for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4838101','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4838101"><span>The Daily Activity Report (<span class="hlt">DAR</span>) a Novel Measure of Functional Outcome for Serious Mental Illness</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Velligan, Dawn I.; Mintz, Jim; Sierra, Cynthia; Martin, Mona L.; Fredrick, Megan; Maglinte, Gregory A.; Corey-Lisle, Patricia K.</p> <p>2016-01-01</p> <p>The assessment of real-world functional outcomes in clinical trials for medications targeting negative symptoms and cognitive impairment is extremely important. We tested the psychometric properties of the Daily Activity Report (<span class="hlt">DAR</span>), a novel assessment of productive daily activity. We administered the <span class="hlt">DAR</span> and additional assessments of functional outcome, functional capacity, cognition and symptomatology to 50 individuals with schizophrenia at 2 time points, 1 month apart and to 25 healthy controls. The <span class="hlt">DAR</span> records a person’s daily activity for 7 consecutive days based upon phone calls made 3 times a day. A total score and scores in 3 domains; instrumental activities (ie, independent living), social and work or school related activities are generated for the <span class="hlt">DAR</span>. Inter-item consistency was high 0.89–0.94 for each domain and 0.88 overall. Test–retest reliability across 1 month for the total <span class="hlt">DAR</span> score was 0.67, P < .0001. The total <span class="hlt">DAR</span> score as well as scores for social activity and nondomestic work/school differed significantly between control and patient participants (P < .0001). <span class="hlt">DAR</span> domain scores were associated with negative symptoms and functional outcomes, but the primary score related to these measures was the work/school dimension of the <span class="hlt">DAR</span>. <span class="hlt">DAR</span> scores were only weakly and nonsignificantly related to positive symptoms. This study provides preliminary support for the reliability and validity of the <span class="hlt">DAR</span> using interviewer administration. The development of a patient reported version of the <span class="hlt">DAR</span> using smart phone technology with automatic scoring is the next step. PMID:26712856</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013M%26PS...48.1359B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013M%26PS...48.1359B"><span>Magmatic history and parental melt composition of olivine-phyric <span class="hlt">shergottite</span> LAR 06319: Importance of magmatic degassing and olivine antecrysts in Martian magmatism</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Balta, J. Brian; Sanborn, Matthew; McSween, Harry Y.; Wadhwa, Meenakshi</p> <p>2013-08-01</p> <p>Several olivine-phyric <span class="hlt">shergottites</span> contain enough olivine that they could conceivably represent the products of closed-system crystallization of primary melts derived from partial melting of the Martian mantle. Larkman Nunatak (LAR) 06319 has been suggested to represent a close approach to a Martian primary liquid composition based on approximate equilibrium between its olivine and groundmass. To better understand the olivine-melt relationship and the evolution of this meteorite, we report the results of new petrographic and chemical analyses. We find that olivine megacryst cores are generally not in equilibrium with the groundmass, but rather have been homogenized by diffusion to Mg# 72. We have identified two unique grain types: an olivine glomerocryst and an olivine grain preserving a primary magmatic boundary that constrains the time scale of eruption to be on the order of hours. We also report the presence of trace oxide phases and phosphate compositions that suggest that the melt contained approximately 1.1% H2O and lost volatiles during cooling, also associated with an increase in oxygen fugacity upon degassing. We additionally report in situ rare earth element measurements of the various mineral phases in LAR 06319. Based on these reported trace element abundances, we estimate the oxygen fugacity in the LAR 06319 parent melt early in its crystallization sequence (i.e., at the time of crystallization of the low-Ca and high-Ca pyroxenes), the rare earth element composition of the parent melt, and those of melts in equilibrium with later formed phases. We suggest that LAR 06319 represents the product of closed-system crystallization within a shallow magma chamber, with additional olivine accumulated from a cumulate pile. We infer that the olivine megacrysts are antecrysts, derived from a single magma chamber, but not directly related to the host magma, and suggest that mixing of antecrysts within magma chambers may be a common process in Martian magmatic</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPhCS.753e2019G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPhCS.753e2019G"><span>Nacelle Li<span class="hlt">DAR</span> online wind field reconstruction applied to feedforward pitch control</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>GUILLEMIN, F.; DOMENICO, D. DI; NGUYEN, N.; SABIRON, G.; BOQUET, M.; GIRARD, N.; COUPIAC, O.</p> <p>2016-09-01</p> <p>This paper presents innovative filtering and reconstruction techniques of nacelle Li<span class="hlt">DAR</span> data, and exploitation of obtained wind anticipation capabilities for wind turbine control strategy. The implemented algorithms are applied under industrial constraints, on a MAIA EOLIS wind turbine, equipped with a LEOSPHERE 5-beams pulsed Li<span class="hlt">DAR</span>, during experimental campaigns of SMARTEOLE collaborative project.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUSM.G31A..02L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUSM.G31A..02L"><span>Li<span class="hlt">DAR</span>, a great tool for archaeologists, but how do you interpret it?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Leisz, S.; Fisher, C.</p> <p>2013-05-01</p> <p>This paper focuses on the use of airborne Li<span class="hlt">DAR</span> to identify archaeological features below forest canopies in Mesoamerica and the challenges faced in interpreting the data. To illustrate the issues involved in interpreting Li<span class="hlt">DAR</span> point clouds and derived data sets for archaeological purposes, the case study of the use of airborne Li<span class="hlt">DAR</span> at the archaeological site of Angamuco in West-Central Mexico is discussed. The case study details the reason Li<span class="hlt">DAR</span> was collected, the challenges in interpreting it, methods and techniques that the authors are investigating to improve the interpretation of the Li<span class="hlt">DAR</span>, and discoveries that have so far been made through the use of Li<span class="hlt">DAR</span>. A key point discussed is the need to analyze the Li<span class="hlt">DAR</span> point cloud in conjunction with products developed from the point cloud. Analyzing the various data sets jointly allows the user to better identify archaeological features of interest. New ways of utilizing hillshades of DEMs, such as creating 360 degree hillshades of the derived DEMs, are also presented. Last the authors discuss their experience in using object-based classification of the products derived from the Li<span class="hlt">DAR</span> point cloud as an example of one possible technique for automating the delineation and classification of archaeological features.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70140317','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70140317"><span>Remote sensing of Sonoran Desert vegetation structure and phenology with ground-based Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Sankey, Joel B.; Munson, Seth M.; Webb, Robert H.; Wallace, Cynthia S.A.; Duran, Cesar M.</p> <p>2015-01-01</p> <p>Long-term vegetation monitoring efforts have become increasingly important for understanding ecosystem response to global change. Many traditional methods for monitoring can be infrequent and limited in scope. Ground-based Li<span class="hlt">DAR</span> is one remote sensing method that offers a clear advancement to monitor vegetation dynamics at high spatial and temporal resolution. We determined the effectiveness of Li<span class="hlt">DAR</span> to detect intra-annual variability in vegetation structure at a long-term Sonoran Desert monitoring plot dominated by cacti, deciduous and evergreen shrubs. Monthly repeat Li<span class="hlt">DAR</span> scans of perennial plant canopies over the course of one year had high precision. Li<span class="hlt">DAR</span> measurements of canopy height and area were accurate with respect to total station survey measurements of individual plants. We found an increase in the number of Li<span class="hlt">DAR</span> vegetation returns following the wet North American Monsoon season. This intra-annual variability in vegetation structure detected by Li<span class="hlt">DAR</span> was attributable to a drought deciduous shrub Ambrosia deltoidea, whereas the evergreen shrub Larrea tridentata and cactus Opuntia engelmannii had low variability. Benefits of using Li<span class="hlt">DAR</span> over traditional methods to census desert plants are more rapid, consistent, and cost-effective data acquisition in a high-resolution, 3-dimensional context. We conclude that repeat Li<span class="hlt">DAR</span> measurements can be an effective method for documenting ecosystem response to desert climatology and drought over short time intervals and at detailed-local spatial scale.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=299186','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=299186"><span>Wetland inundation mapping and change monitoring using landsat and airborne Li<span class="hlt">DAR</span> data</span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>This paper presents a new approach for mapping wetland inundation change using Landsat and Li<span class="hlt">DAR</span> intensity data. In this approach, Li<span class="hlt">DAR</span> data were used to derive highly accurate reference subpixel inundation percentage (SIP) maps at the 30-m resolution. The reference SIP maps were then used to est...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20020045649&hterms=learn+english&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dlearn%2Benglish','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20020045649&hterms=learn+english&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D20%26Ntt%3Dlearn%2Benglish"><span><span class="hlt">Dar</span> <span class="hlt">Al</span> Gani 872: Yet Another Eucrite, Yet Another Lesson to Learn?</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Patzer, A.; Hill, D. H.; Boynton, W. V.; Sipiera, P. P.; Jerman, G. A.</p> <p>2002-01-01</p> <p>We present chemical and mineralogical data on a new monomict basaltic eucrite recovered from Libya. In contrast to most other eucrites, it exhibits high shock features, unusually heterogeneous exsolution of pigeonite, and interesting melt pockets. Additional information is contained in the original extended abstract.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_7");'>7</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li class="active"><span>9</span></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_9 --> <div id="page_10" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="181"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMNH13G..05F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMNH13G..05F"><span>2011 Japan tsunami current and flow velocity measurements from survivor videos using Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fritz, H. M.; Phillips, D. A.; Okayasu, A.; Shimozono, T.; Liu, H.; Mohammed, F.; Skanavis, V.; Synolakis, C.; Takahashi, T.</p> <p>2011-12-01</p> <p>On March 11, 2011, a magnitude Mw 9.0 earthquake occurred off the coast of Japan's Tohoku region causing catastrophic damage and loss of life. Numerous tsunami reconnaissance trips were conducted in Japan (Tohoku Earthquake and Tsunami Joint Survey Group). This report focuses on the surveys at 9 tsunami eyewitness video recording locations in Yoriisohama, Kesennuma, Kamaishi and Miyako along Japan's Sanriku coast and the subsequent video image calibration, processing and tsunami flow velocity analysis. Selected tsunami video recording sites were visited, eyewitnesses interviewed and some ground control points recorded during the initial tsunami reconnaissance from April 9 to 25. A follow-up survey from June 9 to 15, 2011 focused on terrestrial laser scanning (TLS) at locations with previously identified high quality eyewitness videos. We acquired precise topographic data using TLS at nine video sites with multiple scans acquired from different instrument positions at each site. These ground-based Li<span class="hlt">DAR</span> measurements produce a 3-dimensional "point cloud" dataset. Digital photography from a scanner-mounted camera yields photorealistic 3D images. Integrated GPS measurements allow accurate georeferencing of the TLS data in an absolute reference frame such as WGS84. We deployed a Riegl VZ-400 scanner (1550 nm wavelength laser, 42,000 measurements/second, <600 meter max range) and peripheral equipment from the UNAVCO instrument pool. The original full length videos recordings were recovered from eyewitnesses and the Japanese Coast Guard (JCG). Multiple videos were synchronized and referenced in time (UTC). The analysis of the tsunami videos follows a four step procedure developed for the analysis of 2004 Indian Ocean tsunami videos at Banda Aceh, Indonesia (Fritz et <span class="hlt">al</span>., 2006). The first step requires the calibration of the sector of view present in the eyewitness video recording based on visually identifiable ground control points measured in the Li<span class="hlt">DAR</span> point cloud data</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..1413168F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..1413168F"><span>2011 Japan tsunami survivor video based hydrograph and flow velocity measurements using Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fritz, H. M.; Phillips, D. A.; Okayasu, A.; Shimozono, T.; Liu, H.; Mohammed, F.; Skanavis, V.; Synolakis, C. E.; Takahashi, T.</p> <p>2012-04-01</p> <p>On March 11, 2011, a magnitude Mw 9.0 earthquake occurred off the coast of Japan's Tohoku region causing catastrophic damage and loss of life. Numerous tsunami reconnaissance trips were conducted in Japan (Tohoku Earthquake and Tsunami Joint Survey Group). This report focuses on the surveys at 9 tsunami eyewitness video recording locations in Yoriisohama, Kesennuma, Kamaishi and Miyako along Japan's Sanriku coast and the subsequent video image calibration, processing, tsunami hydrograph and flow velocity analysis. Selected tsunami video recording sites were visited, eyewitnesses interviewed and some ground control points recorded during the initial tsunami reconnaissance from April 9 to 25. A follow-up survey from June 9 to 15, 2011 focused on terrestrial laser scanning (TLS) at locations with previously identified high quality eyewitness videos. We acquired precise topographic data using TLS at nine video sites with multiple scans acquired from different instrument positions at each site. These ground-based Li<span class="hlt">DAR</span> measurements produce a 3-dimensional "point cloud" dataset. Digital photography from a scanner-mounted camera yields photorealistic 3D images. Integrated GPS measurements allow accurate georeferencing of the TLS data in an absolute reference frame such as WGS84. We deployed a Riegl VZ-400 scanner (1550 nm wavelength laser, 42,000 measurements/second, <600 meter max range) and peripheral equipment from the UNAVCO instrument pool. The original full length videos recordings were recovered from eyewitnesses and the Japanese Coast Guard (JCG). Multiple videos were synchronized and referenced in time (UTC). The analysis of the tsunami videos follows a four step procedure developed for the analysis of 2004 Indian Ocean tsunami videos at Banda Aceh, Indonesia (Fritz et <span class="hlt">al</span>., 2006). The first step requires the calibration of the sector of view present in the eyewitness video recording based on visually identifiable ground control points measured in the Li<span class="hlt">DAR</span> point</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMEP43C0871C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMEP43C0871C"><span>Applicability of Aerial Green Li<span class="hlt">DAR</span> to a Large River in the Western United States</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Conner, J. T.; Welcker, C. W.; Cooper, C.; Faux, R.; Butler, M.; Nayegandhi, A.</p> <p>2013-12-01</p> <p>In October 2012, aerial green Li<span class="hlt">DAR</span> data were collected in the Snake River (within Idaho and Oregon) to test this emerging technology in a large river with poor water clarity. Six study areas (total of 30 river miles spread out over 250 river miles) were chosen to represent a variety of depths, channel types, and surface conditions to test the accuracy, depth penetration, data density of aerial green Li<span class="hlt">DAR</span>. These characteristics along with cost and speed of acquisition were compared to other bathymetric survey techniques including rod surveys (total station and RTK-GPS), single-beam sonar, and multibeam echosounder (MBES). The green Li<span class="hlt">DAR</span> system typically measured returns from the riverbed through 1-2 meters of water, which was less than one Secchi depth. However, in areas with steep banks or aquatic macrophytes, Li<span class="hlt">DAR</span> returns from the riverbed were less frequent or non-existent. In areas of good return density, depths measured from green Li<span class="hlt">DAR</span> data corresponded well with previously collected data sets from traditional bathymetric survey techniques. In such areas, the green Li<span class="hlt">DAR</span> point density was much higher than both rod and single beam sonar surveys, yet lower than MBES. The green Li<span class="hlt">DAR</span> survey was also collected more efficiently than all other methods. In the Snake River, green Li<span class="hlt">DAR</span> does not provide a method to map the entire riverbed as it only receives bottom returns in shallow water, typically at the channel margins. However, green Li<span class="hlt">DAR</span> does provide survey data that is an excellent complement to MBES, which is more effective at surveying the deeper portions of the channel. In some cases, the green Li<span class="hlt">DAR</span> was able to provide data in areas that the MBES could not, often due to issues with navigating the survey boat in shallow water. Even where both MBES and green Li<span class="hlt">DAR</span> mapped the river bottom, green Li<span class="hlt">DAR</span> often provides more accurate data through a better angle of incidence and less shadowing than the MBES survey. For one MBES survey in 2013, the green Li<span class="hlt">DAR</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100008620','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100008620"><span>SM-ND Age and REE Systematics of Larkman Nunatek 06319: Closed System Fractional Crystallization of a <span class="hlt">Shergottite</span> Magma</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Shafer, J. T.; Brandon, A. D.; Lapen T. J.; Righter, M.; Peslier, A. H.</p> <p>2010-01-01</p> <p>Sm-Nd isotopic data were collected on mineral separates and bulk rock powders of LAR 06319, yielding an age of 180+/-13 Ma (2(sigma)). This age is concordant with the Lu-Hf age (197+/-29 Ma, [1]) determined in conjunction with these data and the Sm-Nd age (190+/-26 Ma) of Shih et <span class="hlt">al</span>., 2009 [2]. The Sm-Nd data form at statistically significant isochron (Fig. 1) that is controlled largely by leachate-residue pairs (samples with the R suffix are residues after leaching in cold 2N HCl for 10 minutes).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23202177','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23202177"><span>Multipath estimation in urban environments from joint GNSS receivers and Li<span class="hlt">DAR</span> sensors.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Ali, Khurram; Chen, Xin; Dovis, Fabio; De Castro, David; Fernández, Antonio J</p> <p>2012-10-30</p> <p>In this paper, multipath error on Global Navigation Satellite System (GNSS) signals in urban environments is characterized with the help of Light Detection and Ranging (Li<span class="hlt">DAR</span>) measurements. For this purpose, Li<span class="hlt">DAR</span> equipment and Global Positioning System (GPS) receiver implementing a multipath estimating architecture were used to collect data in an urban environment. This paper demonstrates how GPS and Li<span class="hlt">DAR</span> measurements can be jointly used to model the environment and obtain robust receivers. Multipath amplitude and delay are estimated by means of Li<span class="hlt">DAR</span> feature extraction and multipath mitigation architecture. The results show the feasibility of integrating the information provided by Li<span class="hlt">DAR</span> sensors and GNSS receivers for multipath mitigation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3522930','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3522930"><span>Multipath Estimation in Urban Environments from Joint GNSS Receivers and Li<span class="hlt">DAR</span> Sensors</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ali, Khurram; Chen, Xin; Dovis, Fabio; De Castro, David; Fernández, Antonio J.</p> <p>2012-01-01</p> <p>In this paper, multipath error on Global Navigation Satellite System (GNSS) signals in urban environments is characterized with the help of Light Detection and Ranging (Li<span class="hlt">DAR</span>) measurements. For this purpose, Li<span class="hlt">DAR</span> equipment and Global Positioning System (GPS) receiver implementing a multipath estimating architecture were used to collect data in an urban environment. This paper demonstrates how GPS and Li<span class="hlt">DAR</span> measurements can be jointly used to model the environment and obtain robust receivers. Multipath amplitude and delay are estimated by means of Li<span class="hlt">DAR</span> feature extraction and multipath mitigation architecture. The results show the feasibility of integrating the information provided by Li<span class="hlt">DAR</span> sensors and GNSS receivers for multipath mitigation. PMID:23202177</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26560612','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26560612"><span>Using a multiwavelength Li<span class="hlt">DAR</span> for improved remote sensing of natural waters.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gray, Deric J; Anderson, John; Nelson, Jean; Edwards, Jarrod</p> <p>2015-11-01</p> <p>This paper describes research to characterize the benefits of a multiwavelength oceanographic Li<span class="hlt">DAR</span> for various water types. Field measurements were conducted to establish endmembers representative of both typical and extremely challenging natural conditions. Laboratory tests were performed using a prototype multiwavelength Li<span class="hlt">DAR</span> in water tanks with optical conditions simulating both sediment-laden and biologically rich water types. Li<span class="hlt">DAR</span> models were used to simulate the Li<span class="hlt">DAR</span> signal from both field and laboratory experiments. Our measurements and models show that using a laser wavelength of 470-490 nm in the open ocean leads to an improvement factor of 1.50-1.75 compared to a 532 nm system. In more turbid areas using a laser wavelength of 560-580 nm leads to an improvement factor of 1.25. We conclude by demonstrating how using multiple Li<span class="hlt">DAR</span> wavelengths can help detect and characterize constituents in the water column.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22453394','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22453394"><span>Full waveform hyperspectral Li<span class="hlt">DAR</span> for terrestrial laser scanning.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Hakala, Teemu; Suomalainen, Juha; Kaasalainen, Sanna; Chen, Yuwei</p> <p>2012-03-26</p> <p>We present the design of a full waveform hyperspectral light detection and ranging (Li<span class="hlt">DAR</span>) and the first demonstrations of its applications in remote sensing. The novel instrument produces a 3D point cloud with spectral backscattered reflectance data. This concept has a significant impact on remote sensing and other fields where target 3D detection and identification is crucial, such as civil engineering, cultural heritage, material processing, or geomorphological studies. As both the geometry and spectral information on the target are available from a single measurement, this technology will extend the scope of imaging spectroscopy into spectral 3D sensing. To demonstrate the potential of the instrument in the remote sensing of vegetation, 3D point clouds with backscattered reflectance and spectral indices are presented for a specimen of Norway spruce.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1714770R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1714770R"><span>Dynamic Li<span class="hlt">DAR</span>-NDVI classification of fluvial landscape units</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ramírez-Núñez, Carolina; Parrot, Jean-François</p> <p>2015-04-01</p> <p>The lower basin of the Coatzacoalcos River is a wide floodplain in which, during the wet season, local and major flooding are distinguished. Both types of floods, intermittent and regional, are important in terms of resources; the regional flood sediments enrich the soils of the plains and intermittent floods allow obtaining aquatic resources for subsistence during the heatwave. In the floodplain different abandoned meanders and intermittent streams are quickly colonized by aquatic vegetation. However, from the 1990s, the Coatzacoalcos River floodplain has important topographic changes due to mining, road and bridges construction; erosion and sedimentation requires continuous parcel boundaries along with the increasing demand of channel reparation, embankments, levees and bridges associated to tributaries. NDVI data, Li<span class="hlt">DAR</span> point cloud and various types of flood simulations taking into account the DTM are used to classify the dynamic landscape units. These units are associated to floods in relation with water resources, agriculture and livestock. In the study area, the first returns of the point cloud allow extracting vegetation strata. The last returns correspond to the bare earth surface, especially in this area with few human settlements. The surface that is not covered by trees or by aquatic vegetation, correspond to crops, pastures and bare soils. The classification is obtained by using the NDVI index coupled with vegetation strata and water bodies. The result shows that 47.96% of the area does not present active vegetation and it includes 31.53% of bare soils. Concerning the active vegetation, pastures, bushes and trees represent respectively 25.59%, 11.14% and 13.25%. The remaining 1.25% is distributed between water bodies with aquatic vegetation, trees and shrubs. Dynamic landscape units' classification represents a tool for monitoring water resources in a fluvial plain. This approach can be also applied to forest management, environmental services and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.B41E0351T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.B41E0351T"><span>Development of forest growth inputs from Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tinkham, W. T.; Falkowski, M. J.; Smith, A. M.; Hudak, A. T.; Crookston, N. L.</p> <p>2012-12-01</p> <p>Investigating the potential impacts of climate change on forest dynamics is a critical area of science, especially given the vast amount of ecosystems services forests provide. Critical understanding of these impacts is lacking, most visibly, at regional to local scales where on-the-ground management activities are implemented. To plan ahead and mitigate the impacts of climate change, land managers need of decision support tools that can be used to evaluate the future impacts of climate change on forest conditions, so that sustainable management practices that enhance ecosystem resilience can be defensibly developed, evaluated, and implemented. However, to be applicable to both regional forest planning and local operational forest management decisions, approaches must be capable of simulating forest dynamics across large spatial extents (required for regional planning) while maintaining a high-level of spatial detail (required for operational management). Numerous studies have demonstrated that Li<span class="hlt">DAR</span> remote sensing is an effective tool for accurately measuring forest structure at landscape scales, providing information with a level of detail appropriate for operational forest management. This study attempts to develop a system to spatially parameterize and supply critical initial conditions for Climate-FVS and other forest growth models across major ecoregions (in terms of forest structure and composition) in the Pacific Northwest (PNW) of the US, via an integration of airborne Li<span class="hlt">DAR</span>, spatial measures of productivity, and local climate. Integrating these inputs into forest growth models would be a big step towards planning and optimizing landscape level alterations to forest structure and productivity from climate change.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/19440962','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/19440962"><span>Urban agriculture and Anopheles habitats in <span class="hlt">Dar</span> es Salaam, Tanzania.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Dongus, Stefan; Nyika, Dickson; Kannady, Khadija; Mtasiwa, Deo; Mshinda, Hassan; Gosoniu, Laura; Drescher, Axel W; Fillinger, Ulrike; Tanner, Marcel; Killeen, Gerry F; Castro, Marcia C</p> <p>2009-05-01</p> <p>A cross-sectional survey of agricultural areas, combined with routinely monitored mosquito larval information, was conducted in urban <span class="hlt">Dar</span> es Salaam, Tanzania, to investigate how agricultural and geographical features may influence the presence of Anopheles larvae. Data were integrated into a geographical information systems framework, and predictors of the presence of Anopheles larvae in farming areas were assessed using multivariate logistic regression with independent random effects. It was found that more than 5% of the study area (total size 16.8 km2) was used for farming in backyard gardens and larger open spaces. The proportion of habitats containing Anopheles larvae was 1.7 times higher in agricultural areas compared to other areas (95% confidence interval = 1.56-1.92). Significant geographic predictors of the presence of Anopheles larvae in gardens included location in lowland areas, proximity to river, and relatively impermeable soils. Agriculture-related predictors comprised specific seedbed types, mid-sized gardens, irrigation by wells, as well as cultivation of sugar cane or leafy vegetables. Negative predictors included small garden size, irrigation by tap water, rainfed production and cultivation of leguminous crops or fruit trees. Although there was an increased chance of finding Anopheles larvae in agricultural sites, it was found that breeding sites originated by urban agriculture account for less than a fifth of all breeding sites of malaria vectors in <span class="hlt">Dar</span> es Salaam. It is suggested that strategies comprising an integrated malaria control effort in malaria-endemic African cities include participatory involvement of farmers by planting shade trees near larval habitats.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.B53I..08D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.B53I..08D"><span>Advances in animal ecology from 3D ecosystem mapping with Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Davies, A.; Asner, G. P.</p> <p>2015-12-01</p> <p>The advent and recent advances of Light Detection and Ranging (Li<span class="hlt">DAR</span>) have enabled accurate measurement of 3D ecosystem structure. Although the use of Li<span class="hlt">DAR</span> data is widespread in vegetation science, it has only recently (< 14 years) been applied to animal ecology. Despite such recent application, Li<span class="hlt">DAR</span> has enabled new insights in the field and revealed the fundamental importance of 3D ecosystem structure for animals. We reviewed the studies to date that have used Li<span class="hlt">DAR</span> in animal ecology, synthesising the insights gained. Structural heterogeneity is most conducive to increased animal richness and abundance, and increased complexity of vertical vegetation structure is more positively influential than traditionally measured canopy cover, which produces mixed results. However, different taxonomic groups interact with a variety of 3D canopy traits and some groups with 3D topography. Li<span class="hlt">DAR</span> technology can be applied to animal ecology studies in a wide variety of environments to answer an impressive array of questions. Drawing on case studies from vastly different groups, termites and lions, we further demonstrate the applicability of Li<span class="hlt">DAR</span> and highlight new understanding, ranging from habitat preference to predator-prey interactions, that would not have been possible from studies restricted to field based methods. We conclude with discussion of how future studies will benefit by using Li<span class="hlt">DAR</span> to consider 3D habitat effects in a wider variety of ecosystems and with more taxa to develop a better understanding of animal dynamics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120001831','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120001831"><span>Laboratory Shock Experiments on Basalt - Iron Sulfate Mixes at Approximately 40-50 GPa and Their Relevance to the Martian Regolith Component Present in <span class="hlt">Shergottites</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Rao, M. N.; Nyquist, L. E.; Ross, D. K.; Asimow, P. D.; See, T.; Sutton, S.; Cardernas, F.; Montes, R.; Cintala, M.</p> <p>2012-01-01</p> <p>Basaltic <span class="hlt">shergottites</span> such as Shergotty, Zagami and EET79001 contain impact melt glass pockets that are rich in Martian atmospheric gases [1] and are known as gas-rich impact-melt (GRIM) glasses. These glasses show evidence for the presence of a Martian regolith component based on Sm and Kr isotopic studies [2]. The GRIM glasses are sometimes embedded with clusters of innumerable micron-sized iron-sulfide blebs associated with minor amounts of iron sulfate particles [3, 4]. These sulfide blebs are secondary in origin and are not related to the primary igneous sulfides occurring in Martian meteorites. The material comprising these glasses arises from the highly oxidizing Martian surface and sulfur is unlikely to occur as sulfide in the Martian regoilith. Instead, sulfur is shown to occur as sulfate based on APXS and Mossbauer results obtained by the Opportunity and Spirit rovers at Meridiani and Gusev [5]. We have earlier suggested that the micron-sized iron sulfide globules in GRIM glasses were likely produced by shock-reduction of iron sulfate occurring in the regolith at the time when the GRIM glasses were produced by the meteoroid impact that launched the Martian meteorites into space [6]. As a result of high energy deposition by shock (approx. 40-60 GPa), the iron sulfate bearing phases are likely to melt along with other regolith components and will get reduced to immiscible sulfide fluid under reducing conditions. On quenching, this generates a dispersion of micron-scale sulfide blebs. The reducing agents in our case are likely to be H2 and CO which were shock-implanted from the Martian atmosphere into these glasses along with the noble gases. We conducted lab simulation experiments in the Lindhurst Laboratory of Experimental Geophysics at Caltech and the Experimental Impact Laboratory at JSC to test whether iron sulfide globules can be produced by impact-driven reduction of iron sulfate by subjecting Columbia River Basalt (CRB) and ferric sulfate mixtures to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5080361','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5080361"><span><span class="hlt">DAr</span>T Markers Effectively Target Gene Space in the Rye Genome</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Gawroński, Piotr; Pawełkowicz, Magdalena; Tofil, Katarzyna; Uszyński, Grzegorz; Sharifova, Saida; Ahluwalia, Shivaksh; Tyrka, Mirosław; Wędzony, Maria; Kilian, Andrzej; Bolibok-Brągoszewska, Hanna</p> <p>2016-01-01</p> <p>Large genome size and complexity hamper considerably the genomics research in relevant species. Rye (Secale cereale L.) has one of the largest genomes among cereal crops and repetitive sequences account for over 90% of its length. Diversity Arrays Technology is a high-throughput genotyping method, in which a preferential sampling of gene-rich regions is achieved through the use of methylation sensitive restriction enzymes. We obtained sequences of 6,177 rye <span class="hlt">DAr</span>T markers and following a redundancy analysis assembled them into 3,737 non-redundant sequences, which were then used in homology searches against five Pooideae sequence sets. In total 515 <span class="hlt">DAr</span>T sequences could be incorporated into publicly available rye genome zippers providing a starting point for the integration of <span class="hlt">DAr</span>T- and transcript-based genomics resources in rye. Using Blast2Go pipeline we attributed putative gene functions to 1101 (29.4%) of the non-redundant <span class="hlt">DAr</span>T marker sequences, including 132 sequences with putative disease resistance-related functions, which were found to be preferentially located in the 4RL and 6RL chromosomes. Comparative analysis based on the <span class="hlt">DAr</span>T sequences revealed obvious inconsistencies between two recently published high density consensus maps of rye. Furthermore we demonstrated that <span class="hlt">DAr</span>T marker sequences can be a source of SSR polymorphisms. Obtained data demonstrate that <span class="hlt">DAr</span>T markers effectively target gene space in the large, complex, and repetitive rye genome. Through the annotation of putative gene functions and the alignment of <span class="hlt">DAr</span>T sequences relative to reference genomes we obtained information, that will complement the results of the studies, where <span class="hlt">DAr</span>T genotyping was deployed, by simplifying the gene ontology and microcolinearity based identification of candidate genes. PMID:27833625</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPRS..101..262Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPRS..101..262Y"><span>Automatic registration of UAV-borne sequent images and Li<span class="hlt">DAR</span> data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, Bisheng; Chen, Chi</p> <p>2015-03-01</p> <p>Use of direct geo-referencing data leads to registration failure between sequent images and Li<span class="hlt">DAR</span> data captured by mini-UAV platforms because of low-cost sensors. This paper therefore proposes a novel automatic registration method for sequent images and Li<span class="hlt">DAR</span> data captured by mini-UAVs. First, the proposed method extracts building outlines from Li<span class="hlt">DAR</span> data and images and estimates the exterior orientation parameters (EoPs) of the images with building objects in the Li<span class="hlt">DAR</span> data coordinate framework based on corresponding corner points derived indirectly by using linear features. Second, the EoPs of the sequent images in the image coordinate framework are recovered using a structure from motion (SfM) technique, and the transformation matrices between the Li<span class="hlt">DAR</span> coordinate and image coordinate frameworks are calculated using corresponding EoPs, resulting in a coarse registration between the images and the Li<span class="hlt">DAR</span> data. Finally, 3D points are generated from sequent images by multi-view stereo (MVS) algorithms. Then the EoPs of the sequent images are further refined by registering the Li<span class="hlt">DAR</span> data and the 3D points using an iterative closest-point (ICP) algorithm with the initial results from coarse registration, resulting in a fine registration between sequent images and Li<span class="hlt">DAR</span> data. Experiments were performed to check the validity and effectiveness of the proposed method. The results show that the proposed method achieves high-precision robust co-registration of sequent images and Li<span class="hlt">DAR</span> data captured by mini-UAVs.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.B52A..04S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.B52A..04S"><span>Mapping Forest Carbon by Fusing Terrestrial and Airborne Li<span class="hlt">DAR</span> Datasets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stovall, A. E.</p> <p>2015-12-01</p> <p>The storage and flux of terrestrial carbon (C) is one of the largest and most uncertain components of the global C budget, the vast majority of which is held within the biomass of the world's forests. However, the spatial distribution and quantification of forest C remains difficult to measure on a large scale. Remote sensing of forests with airborne Li<span class="hlt">DAR</span> has proven to be an extremely effective method of bridging the gap between data from plot-level forestry mensuration and landscape-scale C storage estimates, but the standard method of assessing forest C is typically based on national or regional-scale allometric equations that are often not representative on the local-scale. Improvement of these measurements is necessary in order for collaborative multi-national carbon monitoring programs such as REDD implemented by the UNFCCC to be successful in areas, such as tropical forests, with tree species that have insufficiently documented allometric relationships. The primary goal of this study is to set forth a pipeline for precise non-destructive monitoring of C storage by: 1) determining C storage on 15 1/10th ha plots in a 25.6 ha Virginia temperate forest using the recently updated national allometric equations from Chojnacky et. <span class="hlt">al</span> 2014, 2) comparing these estimates to non-destructively determined individual tree biomass using several semi-automated approaches of three-dimensionally analyzing the point cloud from a high-precision Terrestrial Laser Scanner (TLS), and 3) creating a predictive model of forest C storage by fusing airborne Li<span class="hlt">DAR</span> data to the plot-level TLS measurements. Our findings align with several other studies, indicating a strong relationship between allometrically-derived C estimates and TLS-derived C measurements (R2=0.93, n=30) using relatively few individuals, suggesting the potential application of these methods to species that are understudied or are without allometric relationships. Voxel based C storage was estimated on the plot level and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1811295H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1811295H"><span>4D Near Real-Time Environmental Monitoring Using Highly Temporal Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Höfle, Bernhard; Canli, Ekrem; Schmitz, Evelyn; Crommelinck, Sophie; Hoffmeister, Dirk; Glade, Thomas</p> <p>2016-04-01</p> <p>The last decade has witnessed extensive applications of 3D environmental monitoring with the Li<span class="hlt">DAR</span> technology, also referred to as laser scanning. Although several automatic methods were developed to extract environmental parameters from Li<span class="hlt">DAR</span> point clouds, only little research has focused on highly multitemporal near real-time Li<span class="hlt">DAR</span> (4D-Li<span class="hlt">DAR</span>) for environmental monitoring. Large potential of applying 4D-Li<span class="hlt">DAR</span> is given for landscape objects with high and varying rates of change (e.g. plant growth) and also for phenomena with sudden unpredictable changes (e.g. geomorphological processes). In this presentation we will report on the most recent findings of the research projects 4DEMON (http://uni-heidelberg.de/4demon) and NoeSLIDE (https://geomorph.univie.ac.at/forschung/projekte/aktuell/noeslide/). The method development in both projects is based on two real-world use cases: i) Surface parameter derivation of agricultural crops (e.g. crop height) and ii) change detection of landslides. Both projects exploit the "full history" contained in the Li<span class="hlt">DAR</span> point cloud time series. One crucial initial step of 4D-Li<span class="hlt">DAR</span> analysis is the co-registration over time, 3D-georeferencing and time-dependent quality assessment of the Li<span class="hlt">DAR</span> point cloud time series. Due to the high amount of datasets (e.g. one full Li<span class="hlt">DAR</span> scan per day), the procedure needs to be performed fully automatically. Furthermore, the online near real-time 4D monitoring system requires to set triggers that can detect removal or moving of tie reflectors (used for co-registration) or the scanner itself. This guarantees long-term data acquisition with high quality. We will present results from a georeferencing experiment for 4D-Li<span class="hlt">DAR</span> monitoring, which performs benchmarking of co-registration, 3D-georeferencing and also fully automatic detection of events (e.g. removal/moving of reflectors or scanner). Secondly, we will show our empirical findings of an ongoing permanent Li<span class="hlt">DAR</span> observation of a landslide (Gresten</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014WRR....50.2749H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014WRR....50.2749H"><span>Li<span class="hlt">DAR</span>-derived snowpack data sets from mixed conifer forests across the Western United States</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Harpold, A. A.; Guo, Q.; Molotch, N.; Brooks, P. D.; Bales, R.; Fernandez-Diaz, J. C.; Musselman, K. N.; Swetnam, T. L.; Kirchner, P.; Meadows, M. W.; Flanagan, J.; Lucas, R.</p> <p>2014-03-01</p> <p>Airborne-based Light Detection and Ranging (Li<span class="hlt">DAR</span>) offers the potential to measure snow depth and vegetation structure at high spatial resolution over large extents and thereby increase our ability to quantify snow water resources. Here we present airborne Li<span class="hlt">DAR</span> data products at four Critical Zone Observatories (CZO) in the Western United States: Jemez River Basin, NM, Boulder Creek Watershed, CO, Kings River Experimental Watershed, CA, and Wolverton Basin, CA. We make publicly available snow depth data products (1 m2 resolution) derived from Li<span class="hlt">DAR</span> with an estimated accuracy of <30 cm compared to limited in situ snow depth observations.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPRS...99....1J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPRS...99....1J"><span>Compression strategies for Li<span class="hlt">DAR</span> waveform cube</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jóźków, Grzegorz; Toth, Charles; Quirk, Mihaela; Grejner-Brzezinska, Dorota</p> <p>2015-01-01</p> <p>Full-waveform Li<span class="hlt">DAR</span> data (FWD) provide a wealth of information about the shape and materials of the surveyed areas. Unlike discrete data that retains only a few strong returns, FWD generally keeps the whole signal, at all times, regardless of the signal intensity. Hence, FWD will have an increasingly well-deserved role in mapping and beyond, in the much desired classification in the raw data format. Full-waveform systems currently perform only the recording of the waveform data at the acquisition stage; the return extraction is mostly deferred to post-processing. Although the full waveform preserves most of the details of the real data, it presents a serious practical challenge for a wide use: much larger datasets compared to those from the classical discrete return systems. Atop the need for more storage space, the acquisition speed of the FWD may also limit the pulse rate on most systems that cannot store data fast enough, and thus, reduces the perceived system performance. This work introduces a waveform cube model to compress waveforms in selected subsets of the cube, aimed at achieving decreased storage while maintaining the maximum pulse rate of FWD systems. In our experiments, the waveform cube is compressed using classical methods for 2D imagery that are further tested to assess the feasibility of the proposed solution. The spatial distribution of airborne waveform data is irregular; however, the manner of the FWD acquisition allows the organization of the waveforms in a regular 3D structure similar to familiar multi-component imagery, as those of hyper-spectral cubes or 3D volumetric tomography scans. This study presents the performance analysis of several lossy compression methods applied to the Li<span class="hlt">DAR</span> waveform cube, including JPEG-1, JPEG-2000, and PCA-based techniques. Wide ranges of tests performed on real airborne datasets have demonstrated the benefits of the JPEG-2000 Standard where high compression rates incur fairly small data degradation. In</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhDT.......533S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhDT.......533S"><span>Frontiers in Using Li<span class="hlt">DAR</span> to Analyze Urban Landscape Heterogeneity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Singh, Kunwar Krishna Veer</p> <p></p> <p>Light Detection and Ranging (Li<span class="hlt">DAR</span>) technology has facilitated extraordinary advances in our ability to remotely sense precise details of both built and natural environments. The inherent complexity of urban landscapes and the massive data volumes produced by Li<span class="hlt">DAR</span> require unique methodological considerations for big data remote sensing over large metropolitan regions. The heterogeneous landscapes of the rapidly urbanizing Charlotte Metropolitan Region of North Carolina provided an ideal testing ground for developing methods of analysis for urban ecosystems over large regional extents, including: (1) fusion of Li<span class="hlt">DAR</span> digital surface models (DSMs) with Landsat TM imagery to balance spatial resolution, data volume, and mapping accuracy of urban land covers, (2) comparison of Li<span class="hlt">DAR</span>-derived metrics to fine grain optical imagery -- and their integration -- for detecting forest understory plant invaders, and (3) data reduction techniques for computationally efficient estimation of aboveground woody biomass in urban forests. In Chapter 1, I examined tradeoffs between potential gains in mapping accuracy and computational costs by integrating DSMs (structural and intensity) extracted from Li<span class="hlt">DAR</span> with TM imagery and evaluating the degree to which TM, Li<span class="hlt">DAR</span>, and Li<span class="hlt">DAR</span>-TM fusion data discriminated land covers. I used Maximum Likelihood and Classification Tree algorithms to classify TM data, Li<span class="hlt">DAR</span> data, and Li<span class="hlt">DAR</span>-TM fusions. I assessed the relative contributions of Li<span class="hlt">DAR</span> DSMs to map classification accuracy and identified an optimal spatial resolution of Li<span class="hlt">DAR</span> DSMs for large area assessments of urban land cover. In Chapter 2, I analyzed combinations of datasets developed from categorized Li<span class="hlt">DAR</span>-derived variables (Overstory, Understory, Topography, and Overall Vegetation Characteristics) and IKONOS imagery ( Optical) to detect and map the understory plant invader, Ligustrum sinense, using Random Forest (RF) and logistic regression (LR) algorithms, and I assessed the relative</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_8");'>8</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li class="active"><span>10</span></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_10 --> <div id="page_11" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="201"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFMEP31C..06P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFMEP31C..06P"><span>How Well Can We Predict Salmonid Spawning Habitat with Li<span class="hlt">DAR</span>?</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pfeiffer, A.; Finnegan, N. J.; Hayes, S.</p> <p>2013-12-01</p> <p>Suitable salmonid spawning habitat is, to a great extent, determined by physical, landscape driven characteristics such as channel morphology and grain size. Identifying reaches with high-quality spawning habitat is essential to restoration efforts in areas where salmonid species are endangered or threatened. While both predictions of suitable habitat and observations of utilized habitat are common in the literature, they are rarely combined. Here we exploit a unique combination of high-resolution Li<span class="hlt">DAR</span> data and seven years of 387 individually surveyed Coho and Steelhead redds in Scott Creek, a 77 km2 un-glaciated coastal California drainage in the Santa Cruz Mountains, to both make and test predictions of spawning habitat. Using a threshold channel assumption, we predict grain size throughout Scott Creek via a shear stress model that incorporates channel width, instead of height, using Manning's equation (Snyder et <span class="hlt">al</span>., 2013). Slope and drainage area are computed from a Li<span class="hlt">DAR</span>-derived DEM, and channel width is calculated via hydraulic modeling. Our results for median grain size predictions closely match median grain sizes (D50) measured in the field, with the majority of sites having predicted D50's within a factor of two of the observed values, especially for reaches with D50 > 0.02m. This success suggests that the threshold model used to predict grain size is appropriate for un-glaciated alluvial channel systems. However, it appears that grain size alone is not a strong predictor of salmon spawning. Reaches with a high (>0.1m) average predicted D50 do have lower redd densities, as expected based on spawning gravel sizes in the literature. However, reaches with lower (<0.1m) predicted D50 have a wide range of redd densities, suggesting that reach-average grain size alone cannot explain spawning site selection in the finer-grained reaches of Scott Creek. We turn to analysis of bedform morphology in order to explain the variation in redd density in the low</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.alsa.org/2015-non-responsive-pages/about-als/diagnosing-als.html','NIH-MEDLINEPLUS'); return false;" href="http://www.alsa.org/2015-non-responsive-pages/about-als/diagnosing-als.html"><span>Diagnosing <span class="hlt">ALS</span></span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a></p> <p></p> <p></p> <p>... that a person diagnosed with <span class="hlt">ALS</span> seek a second opinion from an <span class="hlt">ALS</span> "expert" - someone who diagnoses and treats many <span class="hlt">ALS</span> patients and has training in this medical specialty. The <span class="hlt">ALS</span> Association maintains a list of recognized experts in the field of <span class="hlt">ALS</span>. See <span class="hlt">ALS</span> Association Certified Centers of ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9998E..0TF','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9998E..0TF"><span>Validation points generation for Li<span class="hlt">DAR</span>-extracted hydrologic features</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Felicen, M. M.; De La Cruz, R. M.; Olfindo, N. T.; Borlongan, N. J. B.; Ebreo, D. J. R.; Perez, A. M. C.</p> <p>2016-10-01</p> <p>This paper discusses a novel way of generating sampling points of hydrologic features, specifically streams, irrigation network and inland wetlands, that could provide a promising measure of accuracy using combinations of traditional statistical sampling methods. Traditional statistical sampling techniques such as simple random sampling, systematic sampling, stratified sampling and disproportionate random sampling were all designed to generate points in an area where all the cells are classified and subjected to actual field validation. However, these sampling techniques are not applicable when generating points along linear features. This paper presents the Weighted Disproportionate Stratified Systematic Random Sampling (WDSSRS), a tool that combines the systematic and disproportionate stratified random sampling methods in generating points for accuracy computation. This tool makes use of a map series boundary shapefile covering around 27 by 27 kilometers at a scale of 1:50000, and the Li<span class="hlt">DAR</span>-extracted hydrologic features shapefiles (e.g. wetland polygons and linear features of stream and irrigation network). Using the map sheet shapefile, a 10 x 10 grid is generated, and grid cells with water and non-water features are tagged accordingly. Cells with water features are checked for the presence of intersecting linear features, and the intersections are given higher weights in the selection of validation points. The grid cells with non-intersecting linear features are then evaluated and the remaining points are generated randomly along these features. For grid cells with nonwater features, the sample points are generated randomly.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26192511','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26192511"><span>Surface characteristics modeling and performance evaluation of urban building materials using Li<span class="hlt">DAR</span> data.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Xiaolu; Liang, Yu</p> <p>2015-05-20</p> <p>Analysis of light detection and ranging (Li<span class="hlt">DAR</span>) intensity data to extract surface features is of great interest in remote sensing research. One potential application of Li<span class="hlt">DAR</span> intensity data is target classification. A new bidirectional reflectance distribution function (BRDF) model is derived for target characterization of rough and smooth surfaces. Based on the geometry of our coaxial full-waveform Li<span class="hlt">DAR</span> system, the integration method is improved through coordinate transformation to establish the relationship between the BRDF model and intensity data of Li<span class="hlt">DAR</span>. A series of experiments using typical urban building materials are implemented to validate the proposed BRDF model and integration method. The fitting results show that three parameters extracted from the proposed BRDF model can distinguish the urban building materials from perspectives of roughness, specular reflectance, and diffuse reflectance. A comprehensive analysis of these parameters will help characterize surface features in a physically rigorous manner.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2003EAEJA....11492G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2003EAEJA....11492G"><span>Sayh <span class="hlt">al</span> Uhaymir 094 a new martian meteorite from the Oman desert</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gnos, E.; Hofmann, B.; Franchi, I. A.; Al-Kathiri, A.; Hauser, M.; Moser, L.</p> <p>2003-04-01</p> <p>The new martian meteorite Sayh <span class="hlt">al</span> Uhaymir 094 was found in february 2001 during a joint meteorite search campaign of the University of Berne, the Natural History Museum Bern, and the Ministry of Commerce and Industry, Sultanate of Oman. The martian meteorite is a 223.3 g partially crusted, strongly to very strongly shocked melanocratic olivine-porphyric rock of the <span class="hlt">shergottite</span> group showing a microgabbroic texture. The rock consists of 52.0 58.2 vol% prismatic pigeonite (En60-68Fs20-27Wo7-9) and augite (En46-49Fs15-16Wo28-31), oxydized olivine (Fo65-69;22.1 31%), completely isotropic interstitial plagioclase glass (maskelynite; 8.6 13.0%), chromite and titanian magnesian chromite (0.9 1.0%), traces of ilmenite (ilm80-86), pyrrhotite (Fe92-100; 0.1 0.2%), merrillite, Ca9Na(Mg,Fe)(PO4)7, (<< 0.1%). Shock melt pockets (4.8 6.7%) consist of green basaltic to basaltic andesite glass that is devitrified into a brown to black product along the boundaries to the primary minerals. The average maximum dimensions of minerals are: olivine (1.5 mm), pyroxene (0.3 mm) and maskelynite (0.3 mm). Melt inclusions in olivine are common and account for 0.1 0.6% of the rock. X-ray tomography revealed that the specimen contains approximately 0.4 vol% of shock-melt associated vesicles, up to 3 mm in size, which show a preferred orientation. Fluidization of the maskelynite, melting and recrystallization of pyroxene, olivine and pyrrhotite indicate shock stage S6. Terrestrial weathering resulted in calcite-veining and minor oxidation of sulfides. The modal composition is similar to some basaltic <span class="hlt">shergottites</span>, with the exception that neither mesostasis nor titanomagnetite nor apatite are present and that all phases show little zonation. The restricted mineral composition, predominance of chromite among the oxides, and abundance of olivine indicate affinities to the ultramafic <span class="hlt">shergottites</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JPRS...93..171K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JPRS...93..171K"><span>Automatic representation and reconstruction of DBM from Li<span class="hlt">DAR</span> data using Recursive Minimum Bounding Rectangle</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kwak, Eunju; Habib, Ayman</p> <p>2014-07-01</p> <p>Three-dimensional building models are important for various applications, such as disaster management and urban planning. The development of laser scanning sensor technologies has resulted in many different approaches for efficient building model generation using Li<span class="hlt">DAR</span> data. Despite this effort, generation of these models lacks economical and reliable techniques that fully exploit the advantage of Li<span class="hlt">DAR</span> data. Therefore, this research aims to develop a framework for fully-automated building model generation by integrating data-driven and model-driven methods using Li<span class="hlt">DAR</span> datasets. The building model generation starts by employing Li<span class="hlt">DAR</span> data for building detection and approximate boundary determination. The generated building boundaries are then integrated into a model-based processing strategy because Li<span class="hlt">DAR</span> derived planes show irregular boundaries due to the nature of Li<span class="hlt">DAR</span> point acquisition. The focus of the research is generating models for the buildings with right-angled-corners, which can be described with a collection of rectangles under the assumption that the majority of the buildings in urban areas belong to this category. Therefore, by applying the Minimum Bounding Rectangle (MBR) algorithm recursively, the Li<span class="hlt">DAR</span> boundaries are decomposed into sets of rectangles for further processing. At the same time, the quality of the MBRs is examined to verify that the buildings, from which the boundaries are generated, are buildings with right-angled-corners. The parameters that define the model primitives are adjusted through a model-based boundary fitting procedure using Li<span class="hlt">DAR</span> boundaries. The level of details in the final Digital Building Model is based on the number of recursions during the MBR processing, which in turn are determined by the Li<span class="hlt">DAR</span> point density. The model-based boundary fitting improves the quality of the generated boundaries and as seen in experimental results, the quality depends on the average Li<span class="hlt">DAR</span> point spacing. This research thus develops an</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015IJAEO..38..267S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015IJAEO..38..267S"><span>Detecting understory plant invasion in urban forests using Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Singh, Kunwar K.; Davis, Amy J.; Meentemeyer, Ross K.</p> <p>2015-06-01</p> <p>Light detection and ranging (Li<span class="hlt">DAR</span>) data are increasingly used to measure structural characteristics of urban forests but are rarely used to detect the growing problem of exotic understory plant invaders. We explored the merits of using Li<span class="hlt">DAR</span>-derived metrics alone and through integration with spectral data to detect the spatial distribution of the exotic understory plant Ligustrum sinense, a rapidly spreading invader in the urbanizing region of Charlotte, North Carolina, USA. We analyzed regional-scale L. sinense occurrence data collected over the course of three years with Li<span class="hlt">DAR</span>-derived metrics of forest structure that were categorized into the following groups: overstory, understory, topography, and overall vegetation characteristics, and IKONOS spectral features - optical. Using random forest (RF) and logistic regression (LR) classifiers, we assessed the relative contributions of Li<span class="hlt">DAR</span> and IKONOS derived variables to the detection of L. sinense. We compared the top performing models developed for a smaller, nested experimental extent using RF and LR classifiers, and used the best overall model to produce a predictive map of the spatial distribution of L. sinense across our country-wide study extent. RF classification of Li<span class="hlt">DAR</span>-derived topography metrics produced the highest mapping accuracy estimates, outperforming IKONOS data by 17.5% and the integration of Li<span class="hlt">DAR</span> and IKONOS data by 5.3%. The top performing model from the RF classifier produced the highest kappa of 64.8%, improving on the parsimonious LR model kappa by 31.1% with a moderate gain of 6.2% over the county extent model. Our results demonstrate the superiority of Li<span class="hlt">DAR</span>-derived metrics over spectral data and fusion of Li<span class="hlt">DAR</span> and spectral data for accurately mapping the spatial distribution of the forest understory invader L. sinense.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.B43C0553S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.B43C0553S"><span>Aboveground Biomass Modeling from Field and Li<span class="hlt">DAR</span> Data in Brazilian Amazon Tropical Rain Forest</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Silva, C. A.; Hudak, A. T.; Vierling, L. A.; Keller, M. M.; Klauberg Silva, C. K.</p> <p>2015-12-01</p> <p>Tropical forests are an important component of global carbon stocks, but tropical forest responses to climate change are not sufficiently studied or understood. Among remote sensing technologies, airborne Li<span class="hlt">DAR</span> (Light Detection and Ranging) may be best suited for quantifying tropical forest carbon stocks. Our objective was to estimate aboveground biomass (AGB) using airborne Li<span class="hlt">DAR</span> and field plot data in Brazilian tropical rain forest. Forest attributes such as tree density, diameter at breast height, and heights were measured at a combination of square plots and linear transects (n=82) distributed across six different geographic zones in the Amazon. Using previously published allometric equations, tree AGB was computed and then summed to calculate total AGB at each sample plot. Li<span class="hlt">DAR</span>-derived canopy structure metrics were also computed at each sample plot, and random forest regression modelling was applied to predict AGB from selected Li<span class="hlt">DAR</span> metrics. The Li<span class="hlt">DAR</span>-derived AGB model was assessed using the random forest explained variation, adjusted coefficient of determination (Adj. R²), root mean square error (RMSE, both absolute and relative) and BIAS (both absolute and relative). Our findings showed that the 99th percentile of height and height skewness were the best Li<span class="hlt">DAR</span> metrics for AGB prediction. The AGB model using these two best predictors explained 59.59% of AGB variation, with an Adj. R² of 0.92, RMSE of 33.37 Mg/ha (20.28%), and bias of -0.69 (-0.42%). This study showed that Li<span class="hlt">DAR</span> canopy structure metrics can be used to predict AGC stocks in Tropical Forest with acceptable precision and accuracy. Therefore, we conclude that there is good potential to monitor carbon sequestration in Brazilian Tropical Rain Forest using airborne Li<span class="hlt">DAR</span> data, large field plots, and the random forest algorithm.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.G33A0969Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.G33A0969Z"><span>Change Detection from differential airborne Li<span class="hlt">DAR</span> using a weighted Anisotropic Iterative Closest Point Algorithm</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhang, X.; Kusari, A.; Glennie, C. L.; Oskin, M. E.; Hinojosa-Corona, A.; Borsa, A. A.; Arrowsmith, R.</p> <p>2013-12-01</p> <p>Differential Li<span class="hlt">DAR</span> (Light Detection and Ranging) from repeated surveys has recently emerged as an effective tool to measure three-dimensional (3D) change for applications such as quantifying slip and spatially distributed warping associated with earthquake ruptures, and examining the spatial distribution of beach erosion after hurricane impact. Currently, the primary method for determining 3D change is through the use of the iterative closest point (ICP) algorithm and its variants. However, all current studies using ICP have assumed that all Li<span class="hlt">DAR</span> points in the compared point clouds have uniform accuracy. This assumption is simplistic given that the error for each Li<span class="hlt">DAR</span> point is variable, and dependent upon highly variable factors such as target range, angle of incidence, and aircraft trajectory accuracy. Therefore, to rigorously determine spatial change, it would be ideal to model the random error for every Li<span class="hlt">DAR</span> observation in the differential point cloud, and use these error estimates as apriori weights in the ICP algorithm. To test this approach, we implemented a rigorous Li<span class="hlt">DAR</span> observation error propagation method to generate estimated random error for each point in a Li<span class="hlt">DAR</span> point cloud, and then determine 3D displacements between two point clouds using an anistropic weighted ICP algorithm. The algorithm was evaluated by qualitatively and quantitatively comparing post earthquake slip estimates from the 2010 El Mayor-Cucapah Earthquake between a uniform weight and anistropically weighted ICP algorithm, using pre-event Li<span class="hlt">DAR</span> collected in 2006 by Instituto Nacional de Estadística y Geografía (INEGI), and post-event Li<span class="hlt">DAR</span> collected by The National Center for Airborne Laser Mapping (NCALM).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20100028398','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20100028398"><span>Synergy of VSWIR and Li<span class="hlt">DAR</span> for Ecosystem Structure, Biomass, and Canopy Diversity</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cook, Bruce D.; Asner, Gregory P.</p> <p>2010-01-01</p> <p>This slide presentation reviews the use of Visible ShortWave InfraRed (VSWIR) Imaging Spectrometer and Li<span class="hlt">DAR</span> to study ecosystem structure, biomass and canopy diversity. It is shown that the biophysical data from Li<span class="hlt">DAR</span> and biochemical information from hyperspectral remote sensing provides complementary data for: (1) describing spatial patterns of vegetation and biodiversity, (2) characterizing relationships between ecosystem form and function, and (3) detecting natural and human induced change that affects the biogeochemical cycles.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70098139','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70098139"><span>Modeling marbled murrelet (Brachyramphus marmoratus) habitat using Li<span class="hlt">DAR</span>-derived canopy data</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hagar, Joan C.; Eskelson, Bianca N.I.; Haggerty, Patricia K.; Nelson, S. Kim; Vesely, David G.</p> <p>2014-01-01</p> <p>Li<span class="hlt">DAR</span> (Light Detection And Ranging) is an emerging remote-sensing tool that can provide fine-scale data describing vertical complexity of vegetation relevant to species that are responsive to forest structure. We used Li<span class="hlt">DAR</span> data to estimate occupancy probability for the federally threatened marbled murrelet (Brachyramphus marmoratus) in the Oregon Coast Range of the United States. Our goal was to address the need identified in the Recovery Plan for a more accurate estimate of the availability of nesting habitat by developing occupancy maps based on refined measures of nest-strand structure. We used murrelet occupancy data collected by the Bureau of Land Management Coos Bay District, and canopy metrics calculated from discrete return airborne Li<span class="hlt">DAR</span> data, to fit a logistic regression model predicting the probability of occupancy. Our final model for stand-level occupancy included distance to coast, and 5 Li<span class="hlt">DAR</span>-derived variables describing canopy structure. With an area under the curve value (AUC) of 0.74, this model had acceptable discrimination and fair agreement (Cohen's κ = 0.24), especially considering that all sites in our sample were regarded by managers as potential habitat. The Li<span class="hlt">DAR</span> model provided better discrimination between occupied and unoccupied sites than did a model using variables derived from Gradient Nearest Neighbor maps that were previously reported as important predictors of murrelet occupancy (AUC = 0.64, κ = 0.12). We also evaluated Li<span class="hlt">DAR</span> metrics at 11 known murrelet nest sites. Two Li<span class="hlt">DAR</span>-derived variables accurately discriminated nest sites from random sites (average AUC = 0.91). Li<span class="hlt">DAR</span> provided a means of quantifying 3-dimensional canopy structure with variables that are ecologically relevant to murrelet nesting habitat, and have not been as accurately quantified by other mensuration methods.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA567217','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA567217"><span>Urban Classification Techniques Using the Fusion of Li<span class="hlt">DAR</span> and Spectral Data</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>2012-09-01</p> <p>TECHNIQUES USING THE FUSION OF LIDAR AND SPECTRAL DATA by Justin E. Mesina September 2012 Thesis Advisor: Richard C. Olsen Second...TYPE AND DATES COVERED Master’s Thesis 4. TITLE AND SUBTITLE Urban Classification Techniques Using the Fusion of Li<span class="hlt">DAR</span> and Spectral Data 5...the potential to be more accurate than a single sensor. This research fused airborne Li<span class="hlt">DAR</span> data and WorldView-2 (WV-2) multispectral imagery (MSI) data</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA612636','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA612636"><span>Have I Been Here Before? A Method for Detecting Loop Closure With Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>2015-01-01</p> <p>JOHN G ROGERS III (1 HC, 1 PDF) JASON M GREGORY (1 HC, 1 PDF) STUART H YOUNG (1 PDF) 18 INTENTIONALLY LEFT BLANK. ...Have I Been Here Before? A Method for Detecting Loop Closure With Li<span class="hlt">DAR</span> by John G Rogers III and Jason M Gregory ARL-TR-7165 January...TR-7165 January 2015 Have I Been Here Before? A Method for Detecting Loop Closure With Li<span class="hlt">DAR</span> John G Rogers III and Jason M</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JAGeo..10..185B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JAGeo..10..185B"><span>On the impact of a refined stochastic model for airborne Li<span class="hlt">DAR</span> measurements</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bolkas, Dimitrios; Fotopoulos, Georgia; Glennie, Craig</p> <p>2016-09-01</p> <p>Accurate topographic information is critical for a number of applications in science and engineering. In recent years, airborne light detection and ranging (Li<span class="hlt">DAR</span>) has become a standard tool for acquiring high quality topographic information. The assessment of airborne Li<span class="hlt">DAR</span> derived DEMs is typically based on (i) independent ground control points and (ii) forward error propagation utilizing the Li<span class="hlt">DAR</span> geo-referencing equation. The latter approach is dependent on the stochastic model information of the Li<span class="hlt">DAR</span> observation components. In this paper, the well-known statistical tool of variance component estimation (VCE) is implemented for a dataset in Houston, Texas, in order to refine the initial stochastic information. Simulations demonstrate the impact of stochastic-model refinement for two practical applications, namely coastal inundation mapping and surface displacement estimation. Results highlight scenarios where erroneous stochastic information is detrimental. Furthermore, the refined stochastic information provides insights on the effect of each Li<span class="hlt">DAR</span> measurement in the airborne Li<span class="hlt">DAR</span> error budget. The latter is important for targeting future advancements in order to improve point cloud accuracy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1812855G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1812855G"><span>Intraday monitoring of granitic exfoliation sheets with Li<span class="hlt">DAR</span> and thermal imaging (Yosemite Valley, California, USA)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Guerin, Antoine; Derron, Marc-Henri; Jaboyedoff, Michel; Abellán, Antonio; Dubas, Olivier; Collins, Brian D.; Stock, Greg M.</p> <p>2016-04-01</p> <p>Rockfall activity in Yosemite Valley is often linked to the presence of exfoliation sheets associated with other structures such as faults, joints or geological contacts. Daily and seasonal temperature variations or freeze-thaw cycles may strongly promote crack propagation along discontinuities, ultimately leading to rockfalls (Stock et <span class="hlt">al</span>., 2013). However, little is known concerning the impact of thermal variations on rock face deformation, despite its occurrence at all times of year. To understand the influence of daily temperature fluctuations on the behavior of exfoliation joints (i.e., fractures separating exfoliation sheets), we carried out two different experiments in October 2015: (a) We first monitored a sub-vertical granodiorite flake (19 m by 4 m by 0.1 m ; Collins and Stock, 2014) for 24 consecutive hours using Li<span class="hlt">DAR</span> and infrared thermal sensors; (b) We monitored a rock cliff (60 m by 45 m) composed of tens of exfoliation sheets located on the southeast face of El Capitan (an ~1000-m-tall cliff located in western Yosemite Valley) for several hours (from 05:30 pm to 01:30 am) to investigate the diurnal cooling effect on rocks of different lithologies. To calibrate the raw apparent temperature measured by the thermal imager (FLIR T660 infrared camera), we fixed pieces of reflective paper (aluminum foil) and black duct tape on both monitored cliffs to measure the reflected temperature and the emissivity of the different rocks. In addition, ambient temperature and relative humidity readings were performed for each acquisition. We then compared the calibrated temperatures to the values registered by resistance temperature detectors (Pt100 sensors), also attached to the rock. Finally, we compared the millimeter scale deformations observed with Li<span class="hlt">DAR</span> to the values measured by manual crackmeters (standard analog comparators with springs) installed beforehand in the fractures. For the first experiment (24-hour monitoring), a series of measurements were carried</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016M%26PS...51..390S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016M%26PS...51..390S"><span>Determination of volatile concentrations in fluorapatite of Martian <span class="hlt">shergottite</span> NWA 2975 by combining synchrotron FTIR, Raman spectroscopy, EMPA, and TEM, and inferences on the volatile budget of the apatite host-magma</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>SłAby, Ewa; Koch-Müller, Monika; FöRster, Hans-Jürgen; Wirth, Richard; Rhede, Dieter; Schreiber, Anja; Schade, Ulrich</p> <p>2016-02-01</p> <p>We combined the focused ion beam sample preparation technique with polarized synchrotron-based FTIR (Fourier transform infrared) spectroscopy, laser-Raman spectroscopy, electron microprobe analysis (EMPA), and transmission electron microscope (TEM) analysis to identify and quantify structurally bound OH, F, Cl, and CO3 groups in fluorapatite from the Northwest Africa 2975 (NWA 2975) <span class="hlt">shergottite</span>. In this study, the first FTIR spectra of the OH-stretching region from a Martian apatite are presented that show characteristic OH-bands of a F-rich, hydroxyl-bearing apatite. Depending on the method of apatite-formula calculation and whether charge balance is assumed or not, the FTIR-based quantification of the incorporated OH, expressed as wt% H2O, is in variably good agreement with the H2O concentration calculated from electron microprobe data. EMP analyses yielded between 0.35 and 0.54 wt% H2O, and IR data yielded an average H2O content of 0.31 ± 0.03 wt%, consistent with the lower range determined from EMP analyses. The TEM observations implied that the volatiles budget of fluorapatite is magmatic. The water content and the relative volatile ratios calculated for the NWA 2975 magma are similar to those established for other enriched or intermediate <span class="hlt">shergottites</span>. It is difficult to define the source of enrichment: either Martian wet mantle or crustal assimilation. Comparing the environment of parental magma generation for NWA 2975 with the terrestrial mantle in terms of water content, it displays a composition intermediate between enriched and depleted MORB.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4164234','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4164234"><span>Homicide of children in <span class="hlt">Dar</span> es Salaam, Tanzania, 2005</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Outwater, Anne; Mgaya, Edward; Campbell, Jacquelyn C.; Becker, Stan; Kinabo, Linna; Menick, Daniel Mbassa</p> <p>2014-01-01</p> <p>Background Although data are sparse, it has been estimated that the highest rates of homicide death amongst children are in Africa. Little information is available on ages 0 -< 15 years. No reliable quantitative surveillance analysis of neonaticide (killed at less than one week) has been done. Methods A Violent Death Survey following WHO/CDC Guidelines was completed in <span class="hlt">Dar</span> es Salaam region, Tanzania (DSM) (population 2.845 million) in 2005. Qualitative and quantitative data were gathered and analyzed using mixed methods techniques. Results The overall age adjusted rate of discarded and killed children in DSM was 2.05. The rate of neonaticide was 27.7 per 100,000) while the rate of homicide incidence for children > one day was Discussion The overall estimated homicide rate for Africa of children under age 15 was 4.53 per 100,000, whereas. The estimated global rate is 1.7 per 100,000 closer to DSM‘s rate. The results in DSM show that broad age groupings such as ” <1 year” or “0–4 years” or “0 – <15 years” may mask a high incidence of neonaticide and an otherwise low incidence of murdered children. The print media provided good in-depth coverage for a few cases but it is not known if the reported cases are representative. Conclusion Eighty percent of homicides of children in DSM are neonaticides. Since it is believed that the forces behind neonaticide are fundamentally different than homicides of older children, it is suggested that data of future surveys be parsed to include neonates, until the phenomenon is more clearly understood and addressed. Further understanding of the mother and father of the deceased is needed. Continued surveillance data collection is important to expand the sample size. PMID:22066333</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.B53C0195S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.B53C0195S"><span>Quantifying Forest Carbon and Structure with Terrestrial Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Stovall, A. E.; Shugart, H. H., Jr.</p> <p>2014-12-01</p> <p>Current rising atmospheric CO2 concentrations are a major concern with significant global ramifications, however, of the carbon (C) fluxes that are known to occur on Earth, the terrestrial sink has the greatest amount of uncertainty. Improved monitoring of forest cover and change is required for reducing emissions from deforestation and forest degradation (REDD). We determine C storage from volume measurements with a high-precision Terrestrial Laser Scanner (TLS), substantially improving current standard ground validation techniques. This technology is utilized on several 30 m x 30 m plots in a Virginia temperate forest. Aboveground C is calculated on each of the study sites with commonly used allometric equations to offer a realistic comparison of field-based estimations to TLS-derived methods. The TLS and aerial Li<span class="hlt">DAR</span> point cloud data are compared via the development of canopy height models at the plot scale. The novel method of point cloud voxelization is applied to our TLS data in order to produce detailed volumetric calculations in these complex forest ecosystems. Statistical output from the TLS data allows us to resolve and compare forest structure on scales from the individual plot to the entire forest landscape. The estimates produced from this research will be used to inform more widely available remote sensing datasets provided by NASA's Landsat satellites, significantly reducing the uncertainty of the terrestrial C cycle in temperate forests. Preliminary findings corroborate previous research, suggesting the potential for highly detailed monitoring of forest C storage as defined by the REDD initiative and analysis of complex ecosystem structure.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ISPAr41B3..441Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ISPAr41B3..441Y"><span>Classification of Li<span class="hlt">DAR</span> Data with Point Based Classification Methods</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yastikli, N.; Cetin, Z.</p> <p>2016-06-01</p> <p>Li<span class="hlt">DAR</span> is one of the most effective systems for 3 dimensional (3D) data collection in wide areas. Nowadays, airborne Li<span class="hlt">DAR</span> data is used frequently in various applications such as object extraction, 3D modelling, change detection and revision of maps with increasing point density and accuracy. The classification of the Li<span class="hlt">DAR</span> points is the first step of Li<span class="hlt">DAR</span> data processing chain and should be handled in proper way since the 3D city modelling, building extraction, DEM generation, etc. applications directly use the classified point clouds. The different classification methods can be seen in recent researches and most of researches work with the gridded Li<span class="hlt">DAR</span> point cloud. In grid based data processing of the Li<span class="hlt">DAR</span> data, the characteristic point loss in the Li<span class="hlt">DAR</span> point cloud especially vegetation and buildings or losing height accuracy during the interpolation stage are inevitable. In this case, the possible solution is the use of the raw point cloud data for classification to avoid data and accuracy loss in gridding process. In this study, the point based classification possibilities of the Li<span class="hlt">DAR</span> point cloud is investigated to obtain more accurate classes. The automatic point based approaches, which are based on hierarchical rules, have been proposed to achieve ground, building and vegetation classes using the raw Li<span class="hlt">DAR</span> point cloud data. In proposed approaches, every single Li<span class="hlt">DAR</span> point is analyzed according to their features such as height, multi-return, etc. then automatically assigned to the class which they belong to. The use of un-gridded point cloud in proposed point based classification process helped the determination of more realistic rule sets. The detailed parameter analyses have been performed to obtain the most appropriate parameters in the rule sets to achieve accurate classes. The hierarchical rule sets were created for proposed Approach 1 (using selected spatial-based and echo-based features) and Approach 2 (using only selected spatial-based features</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.alsa.org/','NIH-MEDLINEPLUS'); return false;" href="http://www.alsa.org/"><span><span class="hlt">ALS</span> Association</span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a></p> <p></p> <p></p> <p>... toward a world without <span class="hlt">ALS</span>! Walk to Defeat ALS® Walk to Defeat ALS® draws people of all ... We need your help. I Will Advocate National <span class="hlt">ALS</span> Registry The National <span class="hlt">ALS</span> Registry is a congressionally ...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_9");'>9</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li class="active"><span>11</span></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_11 --> <div id="page_12" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="221"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.V13E2651R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.V13E2651R"><span>A Li<span class="hlt">DAR</span> Survey of an Exposed Magma Plumbing System in the San Rafael Desert, Utah</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Richardson, J. A.; Kinman, S.; Connor, L.; Connor, C.; Wetmore, P. H.</p> <p>2013-12-01</p> <p>Fields of dozens to hundreds of volcanoes are a common occurrence on Earth and are created due to distributed-style volcanism often referred to as "monogenetic." These volcanic fields represent a significant hazard on both local and regional scales. While it is important to understand the physical states of active volcanic fields, it is difficult or impossible to directly observe active magma emplacement. Because of this, observing an exposed magmatic plumbing system may enable further efforts to describe active volcanic fields. The magmatic plumbing system of a Pliocene-aged monogenetic volcanic field is currently exposed as a sill and dike swarm in the San Rafael Desert of Central Utah. Alkali diabase and shonkinitic sills and dikes in this region intruded into Mesozoic sedimentary units of the Colorado Plateau and now make up the most erosion resistant units, forming mesas, ridges, and small peaks associated with sills, dikes, and plug-like bodies respectively. Diez et <span class="hlt">al</span>. (Lithosphere, 2009) and Kiyosugi et <span class="hlt">al</span>. (Geology, 2012) provide evidence that each cylindrical plug-like body represents a conduit that once fed one volcano. The approximate original depth of the currently exposed swarm is estimated to be 0.8 km. Volcanic and sedimentary materials may be discriminated at very high resolution with the use of Light Detection and Ranging (Li<span class="hlt">DAR</span>). Li<span class="hlt">DAR</span> produces a three dimensional point cloud, where each point has an associated return intensity. High resolution, bare earth digital elevation models (DEMs) can be produced after vegetation is identified and removed from the dataset. The return intensity at each point can enable classification as either sedimentary or volcanic rock. A Terrestrial Li<span class="hlt">DAR</span> Survey (TLS) has been carried out to map a large hill with at least one volcanic conduit at its core. This survey implements a RIEGL VZ-400 3D Laser Scanner, which successfully maps solid objects in line-of-sight and within 600 meters. The laser used has a near</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.B31A0356M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.B31A0356M"><span>Li<span class="hlt">DAR</span> Applications in Resource Geology and Benefits for Land Management</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mikulovsky, R. P.; De La Fuente, J. A.</p> <p>2013-12-01</p> <p>The US Forest Service (US Department of Agriculture) manages a broad range of geologic resources and hazards on National Forests and Grass Lands throughout the United States. Resources include rock and earth materials, groundwater, caves and paleontological resources, minerals, energy resources, and unique geologic areas. Hazards include landslides, floods, earthquakes, volcanic eruptions, and naturally hazardous materials (e.g., asbestos, radon). Forest Service Geologists who address these issues are Resource Geologists. They have been exploring Li<span class="hlt">DAR</span> as a revolutionary tool to efficiently manage all of these hazards and resources. However, most Li<span class="hlt">DAR</span> applications for management have focused on timber and fuels management, rather than landforms. This study shows the applications and preliminary results of using Li<span class="hlt">DAR</span> for managing geologic resources and hazards on public lands. Applications shown include calculating sediment budgets, mapping and monitoring landslides, mapping and characterizing borrow pits or mines, determining landslide potential, mapping faults, and characterizing groundwater dependent ecosystems. Li<span class="hlt">DAR</span> can be used to model potential locations of groundwater dependent ecosystems with threatened or endangered plant species such as Howellia aquatilis. This difficult to locate species typically exists on the Mendocino National Forest within sag ponds on landslide benches. Li<span class="hlt">DAR</span> metrics of known sites are used to model potential habitat. Thus Li<span class="hlt">DAR</span> can link the disciplines of geology, hydrology, botany, archaeology and others for enhanced land management. As Li<span class="hlt">DAR</span> acquisition costs decrease and it becomes more accessible, land management organizations will find a wealth of applications with potential far-reaching benefits for managing geologic resources and hazards.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPRS..101..310S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPRS..101..310S"><span>Effects of Li<span class="hlt">DAR</span> point density and landscape context on estimates of urban forest biomass</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Singh, Kunwar K.; Chen, Gang; McCarter, James B.; Meentemeyer, Ross K.</p> <p>2015-03-01</p> <p>Light Detection and Ranging (Li<span class="hlt">DAR</span>) data is being increasingly used as an effective alternative to conventional optical remote sensing to accurately estimate aboveground forest biomass ranging from individual tree to stand levels. Recent advancements in Li<span class="hlt">DAR</span> technology have resulted in higher point densities and improved data accuracies accompanied by challenges for procuring and processing voluminous Li<span class="hlt">DAR</span> data for large-area assessments. Reducing point density lowers data acquisition costs and overcomes computational challenges for large-area forest assessments. However, how does lower point density impact the accuracy of biomass estimation in forests containing a great level of anthropogenic disturbance? We evaluate the effects of Li<span class="hlt">DAR</span> point density on the biomass estimation of remnant forests in the rapidly urbanizing region of Charlotte, North Carolina, USA. We used multiple linear regression to establish a statistical relationship between field-measured biomass and predictor variables derived from Li<span class="hlt">DAR</span> data with varying densities. We compared the estimation accuracies between a general Urban Forest type and three Forest Type models (evergreen, deciduous, and mixed) and quantified the degree to which landscape context influenced biomass estimation. The explained biomass variance of the Urban Forest model, using adjusted R2, was consistent across the reduced point densities, with the highest difference of 11.5% between the 100% and 1% point densities. The combined estimates of Forest Type biomass models outperformed the Urban Forest models at the representative point densities (100% and 40%). The Urban Forest biomass model with development density of 125 m radius produced the highest adjusted R2 (0.83 and 0.82 at 100% and 40% Li<span class="hlt">DAR</span> point densities, respectively) and the lowest RMSE values, highlighting a distance impact of development on biomass estimation. Our evaluation suggests that reducing Li<span class="hlt">DAR</span> point density is a viable solution to regional</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.B34B..03H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.B34B..03H"><span>Elements of systemic sensitivity and propagated uncertainty in Li<span class="hlt">DAR</span>-based forest attribute maps (Invited)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hopkinson, C.; Chasmer, L.; Kljun, N.; van Gorsel, E.</p> <p>2013-12-01</p> <p>The application of airborne Li<span class="hlt">DAR</span> to vegetation and forest attribute extraction and modeling is now common place. Direct estimates of tree-, plot- or stand-level height and canopy cover are frequently made as pre-cursors to more complex and indirect attribute derivations such as leaf area, biomass, basal area, fuel, even species. Frequently, the faith placed in Li<span class="hlt">DAR</span> to produce these spatial variables appears so complete that raw data properties or the methods employed in the modeling of direct or indirect attributes are glossed over. The assumption being that if basic variables and derivatives can be easily predicted across a few studies, then it follows this will always be the case. Few studies address explicitly the range of sensitivity in direct and indirect forest attribute estimations: a) derived from Li<span class="hlt">DAR</span> data of differing fundamental acquisition or point cloud properties; or b) produced using different data extraction, filtering or raster interpolation approaches. The paper will illustrate some of the critical acquisition and point cloud attributes (such as pulse power, flight line configuration, timing and point density) that strongly influence mapped and modeled forest attributes at a range of case study sites in North America and Australia. Further, the influence of multiple seemingly defensible canopy height model generation criteria will be compared to illustrate the high sensitivity in even the most basic of Li<span class="hlt">DAR</span>-based forest attribute maps. We conclude that not all Li<span class="hlt">DAR</span> are created equal and that both raw data properties and all data manipulation steps must be communicated when utilising such data. Finally, we believe that as with more standard products like Li<span class="hlt">DAR</span> point cloud formats and digital terrain models (DTMs), an international committee is needed to provide guidance on airborne Li<span class="hlt">DAR</span> vegetation products so that uncertainties can be mitigated when data are shared or compared across sites and through time.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20697878','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20697878"><span>Estimation of effective plant area index for South Korean forests using Li<span class="hlt">DAR</span> system.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kwak, Doo-Ahn; Lee, Woo-Kyun; Kafatos, Menas; Son, Yowhan; Cho, Hyun-Kook; Lee, Seung-Ho</p> <p>2010-07-01</p> <p>Light Detection and Ranging (Li<span class="hlt">DAR</span>) systems can be used to estimate both vertical and horizontal forest structure. Woody components, the leaves of trees and the understory can be described with high precision, using geo-registered 3D-points. Based on this concept, the Effective Plant Area Indices (PAI(e)) for areas of Korean Pine (Pinus koraiensis), Japanese Larch (Larix leptolepis) and Oak (Quercus spp.) were estimated by calculating the ratio of intercepted and incident LIDAR laser rays for the canopies of the three forest types. Initially, the canopy gap fraction (G ( Li<span class="hlt">DAR</span> )) was generated by extracting the Li<span class="hlt">DAR</span> data reflected from the canopy surface, or inner canopy area, using k-means statistics. The Li<span class="hlt">DAR</span>-derived PAI(e) was then estimated by using G ( LIDAR ) with the Beer-Lambert law. A comparison of the Li<span class="hlt">DAR</span>-derived and field-derived PAI(e) revealed the coefficients of determination for Korean Pine, Japanese Larch and Oak to be 0.82, 0.64 and 0.59, respectively. These differences between field-based and LIDAR-based PAI(e) for the different forest types were attributed to the amount of leaves and branches in the forest stands. The absence of leaves, in the case of both Larch and Oak, meant that the Li<span class="hlt">DAR</span> pulses were only reflected from branches. The probability that the Li<span class="hlt">DAR</span> pulses are reflected from bare branches is low as compared to the reflection from branches with a high leaf density. This is because the size of the branch is smaller than the resolution across and along the 1 meter LIDAR laser track. Therefore, a better predictive accuracy would be expected for the model if the study would be repeated in late spring when the shoots and leaves of the deciduous trees begin to appear.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24663850','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24663850"><span>Estimating FPAR of maize canopy using airborne discrete-return Li<span class="hlt">DAR</span> data.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Luo, Shezhou; Wang, Cheng; Xi, Xiaohuan; Pan, Feifei</p> <p>2014-03-10</p> <p>The fraction of absorbed photosynthetically active radiation (FPAR) is a key parameter for ecosystem modeling, crop growth monitoring and yield prediction. Ground-based FPAR measurements are time consuming and labor intensive. Remote sensing provides an alternative method to obtain repeated, rapid and inexpensive estimates of FPAR over large areas. Li<span class="hlt">DAR</span> is an active remote sensing technology and can be used to extract accurate canopy structure parameters. A method to estimating FPAR of maize from airborne discrete-return Li<span class="hlt">DAR</span> data was developed and tested in this study. The raw Li<span class="hlt">DAR</span> point clouds were processed to separate ground returns from vegetation returns using a filter method over a maize field in the Heihe River Basin, northwest China. The fractional cover (fCover) of maize canopy was computed using the ratio of canopy return counts or intensity sums to the total of returns or intensities. FPAR estimation models were established based on linear regression analysis between the Li<span class="hlt">DAR</span>-derived fCover and the field-measured FPAR (R(2) = 0.90, RMSE = 0.032, p < 0.001). The reliability of the constructed regression model was assessed using the leave-one-out cross-validation procedure and results show that the regression model is not overfitting the data and has a good generalization capability. Finally, 15 independent field-measured FPARs were used to evaluate accuracy of the Li<span class="hlt">DAR</span>-predicted FPARs and results show that the Li<span class="hlt">DAR</span>-predicted FPAR has a high accuracy (R(2) = 0.89, RMSE = 0.034). In summary, this study suggests that the airborne discrete-return Li<span class="hlt">DAR</span> data could be adopted to accurately estimate FPAR of maize.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24324655','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24324655"><span>Using satellite and airborne Li<span class="hlt">DAR</span> to model woodpecker habitat occupancy at the landscape scale.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vierling, Lee A; Vierling, Kerri T; Adam, Patrick; Hudak, Andrew T</p> <p>2013-01-01</p> <p>Incorporating vertical vegetation structure into models of animal distributions can improve understanding of the patterns and processes governing habitat selection. Li<span class="hlt">DAR</span> can provide such structural information, but these data are typically collected via aircraft and thus are limited in spatial extent. Our objective was to explore the utility of satellite-based Li<span class="hlt">DAR</span> data from the Geoscience Laser Altimeter System (GLAS) relative to airborne-based Li<span class="hlt">DAR</span> to model the north Idaho breeding distribution of a forest-dependent ecosystem engineer, the Red-naped sapsucker (Sphyrapicus nuchalis). GLAS data occurred within ca. 64 m diameter ellipses spaced a minimum of 172 m apart, and all occupancy analyses were confined to this grain scale. Using a hierarchical approach, we modeled Red-naped sapsucker occupancy as a function of Li<span class="hlt">DAR</span> metrics derived from both platforms. Occupancy models based on satellite data were weak, possibly because the data within the GLAS ellipse did not fully represent habitat characteristics important for this species. The most important structural variables influencing Red-naped Sapsucker breeding site selection based on airborne Li<span class="hlt">DAR</span> data included foliage height diversity, the distance between major strata in the canopy vertical profile, and the vegetation density near the ground. These characteristics are consistent with the diversity of foraging activities exhibited by this species. To our knowledge, this study represents the first to examine the utility of satellite-based Li<span class="hlt">DAR</span> to model animal distributions. The large area of each GLAS ellipse and the non-contiguous nature of GLAS data may pose significant challenges for wildlife distribution modeling; nevertheless these data can provide useful information on ecosystem vertical structure, particularly in areas of gentle terrain. Additional work is thus warranted to utilize Li<span class="hlt">DAR</span> datasets collected from both airborne and past and future satellite platforms (e.g. GLAS, and the planned IceSAT2</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1511160C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1511160C"><span>Inside and around the roman town of Grumentum: the contribution of Li<span class="hlt">DAR</span> and historical air photography</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cianciarulo, Dario; Guariglia, Annibale; Lasaponara, Rosa; Masini, Nicola</p> <p>2013-04-01</p> <p>The papers deals with the integration of aerial laser scanning, multitemporal satellite and aerial dataset to provide information on the 'forma urbis' of the Grumentum roman town, to detect new archaeological features in its close surrounding and to analyze changes of the landscape over the time. Grumentum is an ancient town, 50 km south of Potenza (Southern Italy), located near the 'Via Herculea' connecting Venusia, in the north est of Basilicata, with Heraclea in the Ionian coast. The first settlement date back to the 6th century BC. Then, it was resettled by the Romans in the 3rd century BC. The town, which evidences a long history from the Republican age to late Antiquity (III BC-V AD), is characterized by the typical urban pattern of 'cardi' and 'decumani'. Its excavated ruins include a large amphitheatre, a theatre, the thermae, the Forum and some temples. Li<span class="hlt">DAR</span> data, adequately filtered, classified and post processed by using geostatistics methods(Lasaponara et <span class="hlt">al</span>. 2012), enabled to detect features linked to tombs under a dense vegetation located close to the urban perimeter. The analysis of historical air photos, draped over the ground surface obtained from the Li<span class="hlt">DAR</span> survey, put in evidence some unknown crop-marks linked to roman urban fabric. Finally, the same photos along with the satellite multitemporal dataset allowed us to reconstruct the recent history of the landscape from the Agrarian Reform, in the 50s, up today. Reference Lasaponara R., Masini N., Holmgren R., Backe Forsberg Y., Integration of aerial and satellite remote sensing for archaeological investigations: a case study of the Etruscan site San Giovenale, Journal of Geophysics and Engineering, vol. 9, S26-S39, doi:10.1088/1742-2132/9/4/S26</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016IJAEO..50..150L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016IJAEO..50..150L"><span>Retrieval of effective leaf area index (LAIe) and leaf area density (LAD) profile at individual tree level using high density multi-return airborne Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lin, Yi; West, Geoff</p> <p>2016-08-01</p> <p>As an important canopy structure indicator, leaf area index (LAI) proved to be of considerable implications for forest ecosystem and ecological studies, and efficient techniques for accurate LAI acquisitions have long been highlighted. Airborne light detection and ranging (Li<span class="hlt">DAR</span>), often termed as airborne laser scanning (<span class="hlt">ALS</span>), once was extensively investigated for this task but showed limited performance due to its low sampling density. Now, <span class="hlt">ALS</span> systems exhibit more competing capacities such as high density and multi-return sampling, and hence, people began to ask the questions like-"can <span class="hlt">ALS</span> now work better on the task of LAI prediction?" As a re-examination, this study investigated the feasibility of LAI retrievals at the individual tree level based on high density and multi-return <span class="hlt">ALS</span>, by directly considering the vertical distributions of laser points lying within each tree crown instead of by proposing feature variables such as quantiles involving laser point distribution modes at the plot level. The examination was operated in the case of four tree species (i.e. Picea abies, Pinus sylvestris, Populus tremula and Quercus robur) in a mixed forest, with their LAI-related reference data collected by using static terrestrial laser scanning (TLS). In light of the differences between <span class="hlt">ALS</span>- and TLS-based LAI characterizations, the methods of voxelization of 3D scattered laser points, effective LAI (LAIe) that does not distinguish branches from canopies and unified cumulative LAI (ucLAI) that is often used to characterize the vertical profiles of crown leaf area densities (LADs) was used; then, the relationships between the <span class="hlt">ALS</span>- and TLS-derived LAIes were determined, and so did ucLAIs. Tests indicated that the tree-level LAIes for the four tree species can be estimated based on the used airborne Li<span class="hlt">DAR</span> (R2 = 0.07, 0.26, 0.43 and 0.21, respectively) and their ucLAIs can also be derived. Overall, this study has validated the usage of the contemporary high density multi</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3703277','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3703277"><span>Challenges in diagnosing paediatric malaria in <span class="hlt">Dar</span> es Salaam, Tanzania</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2013-01-01</p> <p>Background Malaria is a major cause of paediatric morbidity and mortality. As no clinical features clearly differentiate malaria from other febrile illnesses, and malaria diagnosis is challenged by often lacking laboratory equipment and expertise, overdiagnosis and overtreatment is common. Methods Children admitted with fever at the general paediatric wards at Muhimbili National Hospital (MNH), <span class="hlt">Dar</span> es Salaam, Tanzania from January to June 2009 were recruited consecutively and prospectively. Demographic and clinical features were registered. Routine thick blood smear microscopy at MNH was compared to results of subsequent thin blood smear microscopy, and rapid diagnostics tests (RDTs). Genus-specific PCR of Plasmodium mitochondrial DNA was performed on DNA extracted from whole blood and species-specific PCR was done on positive samples. Results Among 304 included children, 62.6% had received anti-malarials during the last four weeks prior to admission and 65.1% during the hospital stay. Routine thick blood smears, research blood smears, PCR and RDT detected malaria in 13.2%, 6.6%, 25.0% and 13.5%, respectively. Positive routine microscopy was confirmed in only 43% (17/40), 45% (18/40) and 53% (21/40), by research microscopy, RDTs and PCR, respectively. Eighteen percent (56/304) had positive PCR but negative research microscopy. Reported low parasitaemia on routine microscopy was associated with negative research blood slide and PCR. RDT-positive cases were associated with signs of severe malaria. Palmar pallor, low haemoglobin and low platelet count were significantly associated with positive PCR, research microscopy and RDT. Conclusions The true morbidity attributable to malaria in the study population remains uncertain due to the discrepancies in results among the diagnostic methods. The current routine microscopy appears to result in overdiagnosis of malaria and, consequently, overuse of anti-malarials. Conversely, children with a false positive malaria diagnosis</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA495570','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA495570"><span>Demonstration of Li<span class="hlt">DAR</span> and Orthophotography for Wide Area Assessment at Pueblo Precision Bombing Range #2, Colorado</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>2008-01-01</p> <p>for classification of Li<span class="hlt">DAR</span> points into vegetation, ground, and “other,” creating bare earth and surface model digital terrain models ( DTM ...for rectification of the photography to the DTM . 2.1.6 Data Analysis Once processed, the Li<span class="hlt">DAR</span> /orthophotography datasets are analyzed to...creation: Triangulation results were loaded into ortho-processing software, along with a Li<span class="hlt">DAR</span> -derived DTM and aerial photography. Aerial photographs</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21563587','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21563587"><span>Spinning a laser web: predicting spider distributions using Li<span class="hlt">DAR</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vierling, K T; Bässler, C; Brandl, R; Vierling, L A; Weiss, I; Müller, J</p> <p>2011-03-01</p> <p>Li<span class="hlt">DAR</span> remote sensing has been used to examine relationships between vertebrate diversity and environmental characteristics, but its application to invertebrates has been limited. Our objectives were to determine whether Li<span class="hlt">DAR</span>-derived variables could be used to accurately describe single-species distributions and community characteristics of spiders in remote forested and mountainous terrain. We collected over 5300 spiders across multiple transects in the Bavarian National Park (Germany) using pitfall traps. We examined spider community characteristics (species richness, the Shannon index, the Simpson index, community composition, mean body size, and abundance) and single-species distribution and abundance with Li<span class="hlt">DAR</span> variables and ground-based measurements. We used the R2 and partial R2 provided by variance partitioning to evaluate the predictive power of Li<span class="hlt">DAR</span>-derived variables compared to ground measurements for each of the community characteristics. The total adjusted R2 for species richness, the Shannon index, community species composition, and body size had a range of 25-57%. Li<span class="hlt">DAR</span> variables and ground measurements both contributed >80% to the total predictive power. For species composition, the explained variance was approximately 32%, which was significantly greater than expected by chance. The predictive power of Li<span class="hlt">DAR</span>-derived variables was comparable or superior to that of the ground-based variables for examinations of single-species distributions, and it explained up to 55% of the variance. The predictability of species distributions was higher for species that had strong associations with shade in open-forest habitats, and this niche position has been well documented across the European continent for spider species. The similar statistical performance between Li<span class="hlt">DAR</span> and ground-based measures at our field sites indicated that deriving spider community and species distribution information using Li<span class="hlt">DAR</span> data can provide not only high predictive power at</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1213613D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1213613D"><span>Automated Detection of Geomorphic Features in Li<span class="hlt">DAR</span> Point Clouds of Various Spatial Density</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dorninger, Peter; Székely, Balázs; Zámolyi, András.; Nothegger, Clemens</p> <p>2010-05-01</p> <p> relevant results. Consequently, it could be verified that a topographic surface can be properly represented by a set of distinct planar structures. Therefore, the subsequent interpretation of those planes with respect to geomorphic characteristics is acceptable. The additional in situ geological measurements verified some of our findings in the sense that similar primary directions could be found that were derived from the Li<span class="hlt">DAR</span> data set and (Zámolyi et <span class="hlt">al</span>., 2010, this volume). References: P. Dorninger, N. Pfeifer: "A Comprehensive Automated 3D Approach for Building Extraction, Reconstruction, and Regularization from Airborne Laser Scanning Point Clouds"; Sensors, 8 (2008), 11; 7323 - 7343. C. Nothegger, P. Dorninger: "3D Filtering of High-Resolution Terrestrial Laser Scanner Point Clouds for Cultural Heritage Documentation"; Photogrammetrie, Fernerkundung, Geoinformation, 1 (2009), 53 - 63. A. Zámolyi, B. Székely, G. Molnár, A. Roncat, P. Dorninger, A. Pocsai, M. Wyszyski, P. Drexel: "Comparison of Li<span class="hlt">DAR</span> derived directional topographic features with geologic field evidence: a case study of Doren landslide (Vorarlberg, Austria)"; EGU General Assembly 2010, Vienna, Austria</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008E%26ES....1a2063R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008E%26ES....1a2063R"><span>Development of Li<span class="hlt">DAR</span> measurements for the German offshore test site</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rettenmeier, A.; Kühn, M.; Wächter, M.; Rahm, S.; Mellinghoff, H.; Siegmeier, B.; Reeder, L.</p> <p>2008-05-01</p> <p>The paper introduces the content of the recently started joint research project 'Development of Li<span class="hlt">DAR</span> measurements for the German Offshore Test Site' which has the objective to support other research projects at the German offshore test site 'alpha ventus'. The project has started before the erection of the offshore wind farm and one aim is to give recommendations concerning Li<span class="hlt">DAR</span> technology useable for offshore measurement campaigns and data analysis. The work is organized in four work packages. The work package Li<span class="hlt">DAR</span> technology deals with the specification, acquisition and calibration of a commercial Li<span class="hlt">DAR</span> system for the measurement campaigns. Power curve measurements are dedicated to power curve assessment with ground-based Li<span class="hlt">DAR</span> using standard statistical methods. Additionally, it deals with the development of new methods for the measurement of non-steady short-term power curves. Wind field research aims at the development of wake loading simulation methods of wind turbines and the exploration of loading control strategies and nacelle-based wind field measurement techniques. Finally, dissemination of results to the industry takes place in work package Technology transfer.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AdG....24..125C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AdG....24..125C"><span>On the Li<span class="hlt">DAR</span> contribution for landscape archaeology and palaeoenvironmental studies: the case study of Bosco dell'Incoronata (Southern Italy)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Coluzzi, R.; Lanorte, A.; Lasaponara, R.</p> <p>2010-06-01</p> <p>This paper focuses on the potential of the latest generation of Airborne laser scanning (<span class="hlt">ALS</span>) for the detection and the spatial characterization of microtopographic relief linked to ancient landscapes and palaeoenvironmental features. <span class="hlt">ALS</span> is an optical measurement technique for obtaining high-precision information about the Earth's surface including basic terrain mapping (Digital terrain model, bathymetry, corridor mapping), vegetation cover (forest assessment and inventory), coastal, and urban areas. Recent studies examined the possibility of using <span class="hlt">ALS</span> in archaeological investigations to identify earthworks, although the ability of <span class="hlt">ALS</span> measurements in this context has not yet been studied in detail. In this study, the investigations based on <span class="hlt">ALS</span> survey and aerial photos were carried out for the natural protected area, Bosco dell'Incoronata in the Apulia Region (Southern Italy). The investigated area is an important site from the naturalistic, historic and archaeological point of view. It is an ancient lowland forest, still present in the medieval time, which has been characterized by a long and intensive human activity from Neolithic to Middle Ages. The Li<span class="hlt">DAR</span> based analysis allowed us to identify features not visible from ground or from optical data set because hidden by forest canopy and dense understory. The DTM enabled us to identify some microtopographic relief linked to traces of past landscapes, as in the case of the Cervaro paleaoriverbed. It is quite interesting to note that the river changed many times from North to South side compared to the present stream, and traces of past human activities can be still evident close to the diverse paleaoriverbeds. Nevertheless, intensive and systematic study of the ancient landscapes of the Bosco dell'Incoronata is just beginning and so far questions tend to be raised rather than answered. The current study emphasizes the potential of aerial Li<span class="hlt">DAR</span> (Light Detection And Ranging) survey for detecting surface</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPRS..113...59S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPRS..113...59S"><span>Octree-based segmentation for terrestrial Li<span class="hlt">DAR</span> point cloud data in industrial applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Su, Yun-Ting; Bethel, James; Hu, Shuowen</p> <p>2016-03-01</p> <p>Automated and efficient algorithms to perform segmentation of terrestrial Li<span class="hlt">DAR</span> data is critical for exploitation of 3D point clouds, where the ultimate goal is CAD modeling of the segmented data. In this work, a novel segmentation technique is proposed, starting with octree decomposition to recursively divide the scene into octants or voxels, followed by a novel split and merge framework that uses graph theory and a series of connectivity analyses to intelligently merge components into larger connected components. The connectivity analysis, based on a combination of proximity, orientation, and curvature connectivity criteria, is designed for the segmentation of pipes, vessels, and walls from terrestrial Li<span class="hlt">DAR</span> data of piping systems at industrial sites, such as oil refineries, chemical plants, and steel mills. The proposed segmentation method is exercised on two terrestrial Li<span class="hlt">DAR</span> datasets of a steel mill and a chemical plant, demonstrating its ability to correctly reassemble and segregate features of interest.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010SPIE.7649E..1KL','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010SPIE.7649E..1KL"><span>The role of terrestrial 3D Li<span class="hlt">DAR</span> scan in bridge health monitoring</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Liu, Wanqiu; Chen, Shen-En; Sajedi, Allen; Hauser, Edd</p> <p>2010-04-01</p> <p>This paper addresses the potential applications of terrestrial 3D Li<span class="hlt">DAR</span> scanning technologies for bridge monitoring. High resolution ground-based optical-photonic images from Li<span class="hlt">DAR</span> scans can provide detailed geometric information about a bridge. Applications of simple algorithms can retrieve damage information from the geometric point cloud data, which can be correlated to possible damage quantification including concrete mass loss due to vehicle collisions, large permanent steel deformations, and surface erosions. However, any proposed damage detection technologies should provide information that is relevant and useful to bridge managers for their decision making process. This paper summaries bridge issues that can be detected from the 3D Li<span class="hlt">DAR</span> technologies, establishes the general approach in using 3D point clouds for damage evaluation and suggests possible bridge state ratings that can be used as supplements to existing bridge management systems (BMS).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JInst..1010003A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JInst..1010003A"><span>The Iso<span class="hlt">DAR</span> high intensity H2+ transport and injection tests</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alonso, J.; Axani, S.; Calabretta, L.; Campo, D.; Celona, L.; Conrad, J. M.; Day, A.; Castro, G.; Labrecque, F.; Winklehner, D.</p> <p>2015-10-01</p> <p>This technical report reviews the tests performed at the Best Cyclotron Systems, Inc. facility in regards to developing a cost effective ion source, beam line transport system, and acceleration system capable of high H2+ current output for the Iso<span class="hlt">DAR</span> (Isotope Decay At Rest) experiment. We begin by outlining the requirements for the Iso<span class="hlt">DAR</span> experiment then provide overviews of the Versatile Ion Source (VIS), Low Energy Beam Transport (LEBT) system, spiral inflector, and cyclotron. The experimental measurements are then discussed and the results are compared with a thorough set of simulation studies. Of particular importance we note that the VIS proved to be a reliable ion source capable of generating a large amount of H2+ current. The results suggest that with further upgrades, the VIS could potentially be a suitable candidate for Iso<span class="hlt">DAR</span>. The conclusion outlines the key results from our tests and introduces the forthcoming work this technical report has motivated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26164889','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26164889"><span>[Analysis of an Air Pollution Process Using Li<span class="hlt">DAR</span> in Nanjing, Spring of 2014].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Bao, Qing; He, Jun-liang; Zha, Yong; Cheng, Feng; Li, Qian-nan</p> <p>2015-04-01</p> <p>Based on environmental monitoring data, meteorological data and the results of numerical simulation, a typical air pollution process in Nanjing, from 26th May to 1st June, 2014 was deeply analyzed combining aerosol extinction coefficient derived from Li<span class="hlt">DAR</span> system. Experimental results showed that the entire pollution process was affected by both local pollution and exogenous inputs including dust and smoke. Meteorological factors played a significant role in the generation and elimination of pollutants. Low pressure and temperature inversion also hindered the diffusion of pollutants, while strong rainfall terminated the pollution process. During the pollution, the height of atmospheric boundary layer was lower than normal situation and changed little during the pollution period, which provided a poor diffusion condition for pollutants. Li<span class="hlt">DAR</span> could accurately detect aerosol vertical structure which was able to capture the temporal and spatial variation of pollutant distributions. Therefore, Li<span class="hlt">DAR</span> can be of great significance for the atmospheric pollution monitoring.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFMNH31A1588K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFMNH31A1588K"><span>Study of Ground Subsidence in North West Houston using GPS, Li<span class="hlt">DAR</span> and InSAR techniques</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Karacay, A.; Khan, S. D.</p> <p>2012-12-01</p> <p>Land subsidence can be caused by natural or human activities, such as carbonate dissolution, extraction of material from mines, soil compaction and fluid withdrawal. This phenomenon affects many cities around the world, such as Nagoya-Japan, Venice-Italy, San Joaquin Valley and Long Beach in California. Recent work by Engelkemeir et <span class="hlt">al</span>, (2010), suggested that subsidence occurred as high as 5.6 cm/year in northwest Houston. The processes that may contribute to land subsidence in the Houston-Galveston area includes faulting, soil compaction, salt tectonic, water pumping and hydrocarbon extraction. This study aims to assess the possible role of water pumping on subsidence. Northwest Houston has two aquifer systems, the Evangeline and Chicot aquifers that dip in the southeast direction. The effect of water pumping on subsidence from these two aquifers was monitored using InSAR, GPS and Li<span class="hlt">DAR</span> data. The data from eleven GPS stations were processed using Online Positioning User Service (OPUS) of National Geodetic Survey (NGS). Three of these GPS stations are Continuously Operating Reference Stations (CORS) and eight are Port-A-Measure (PAM) sites. All the GPS data were obtained from Harris-Galveston Subsidence District (HGSD). CORS sites were used as reference stations for processing GPS data from the PAM stations. GPS data show that subsidence rate in northwest Houston decreased to approximately 2 cm/year. In addition, the surface deformation is also estimated using Light Detection and Ranging (Li<span class="hlt">DAR</span>) technique. For this purpose, raw Li<span class="hlt">DAR</span> (LAS-Long ASCII Standart) files of 2001 and 2008 were processed. The subsidence rate near the Hockley Fault was calculated by applying zonal statistics method on Li<span class="hlt">DAR</span> data which shows about 10 cm of subsidence in nine years. This result is supported by processed GPS data from PAM site 48 that show subsidence rate of 1.3 cm/yr. For the InSAR (Interferometric Synthetic Aperture Radar) technique, an image pair of PALSAR (The Phased Array</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_10");'>10</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li class="active"><span>12</span></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_12 --> <div id="page_13" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="241"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.B43C0522R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.B43C0522R"><span>Li<span class="hlt">DAR</span> remote sensing observations for forest assessment and recovery responses following disturbance</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rosette, J.; Suárez, J.; Fonweben, J.; North, P.</p> <p>2013-12-01</p> <p>Li<span class="hlt">DAR</span> data covering 400 km2 in the Cowal and Trossacs Forest District, Scotland, U.K., were used to provide a low cost solution to update the database of public forests and to produce multi-scale cartographic products for supporting management decisions in the event of forest disturbance such as infestation or wind damage. All parameter estimates were directly obtained from the Li<span class="hlt">DAR</span> data without the necessity of field calibration. This was achieved using a hybrid approach integrating current stand models for Sitka spruce (Picea sitchensis bong. Carr) and Li<span class="hlt">DAR</span> analysis. More conventional field methods offer percentage sampling, permitting only a proportion of stands to be surveyed each year and aiming to represent stand-level conditions. The use of Li<span class="hlt">DAR</span> is advantageous in allowing a complete observation-based assessment throughout the forest and greatly-improved spatial representation of important forest parameters. Time-series analysis was performed using Li<span class="hlt">DAR</span> data collected in the past 10 years. This analysis allowed us to establish growth trajectories in the forest stands, automatically discriminating areas of growth, those whose growth had been affected by disease and the occurrence of windthrow gaps. The results were compared to the cartography produced by the Forest District after a severe wind storm that affected the area in 2012. This analysis showed the ability of Li<span class="hlt">DAR</span> to create a more precise location and extent of catastrophic damage and windthrow gaps. In addition, once windthrow has occurred, progression of further damage in existing canopy gaps can be observed. This approach additionally allows the impact of disease on forest growth and subsequent recovery response to be monitored.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20182905','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20182905"><span>Estimating stem volume and biomass of Pinus koraiensis using Li<span class="hlt">DAR</span> data.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Kwak, Doo-Ahn; Lee, Woo-Kyun; Cho, Hyun-Kook; Lee, Seung-Ho; Son, Yowhan; Kafatos, Menas; Kim, So-Ra</p> <p>2010-07-01</p> <p>The objective of this study was to estimate the stem volume and biomass of individual trees using the crown geometric volume (CGV), which was extracted from small-footprint light detection and ranging (Li<span class="hlt">DAR</span>) data. Attempts were made to analyze the stem volume and biomass of Korean Pine stands (Pinus koraiensis Sieb. et Zucc.) for three classes of tree density: low (240 N/ha), medium (370 N/ha), and high (1,340 N/ha). To delineate individual trees, extended maxima transformation and watershed segmentation of image processing methods were applied, as in one of our previous studies. As the next step, the crown base height (CBH) of individual trees has to be determined; information for this was found in the Li<span class="hlt">DAR</span> point cloud data using k-means clustering. The Li<span class="hlt">DAR</span>-derived CGV and stem volume can be estimated on the basis of the proportional relationship between the CGV and stem volume. As a result, low tree-density plots had the best performance for Li<span class="hlt">DAR</span>-derived CBH, CGV, and stem volume (R (2) = 0.67, 0.57, and 0.68, respectively) and accuracy was lowest for high tree-density plots (R (2) = 0.48, 0.36, and 0.44, respectively). In the case of medium tree-density plots accuracy was R (2) = 0.51, 0.52, and 0.62, respectively. The Li<span class="hlt">DAR</span>-derived stem biomass can be predicted from the stem volume using the wood basic density of coniferous trees (0.48 g/cm(3)), and the Li<span class="hlt">DAR</span>-derived above-ground biomass can then be estimated from the stem volume using the biomass conversion and expansion factors (BCEF, 1.29) proposed by the Korea Forest Research Institute (KFRI).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3189831','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3189831"><span>Reconstruction and analysis of a deciduous sapling using digital photographs or terrestrial-Li<span class="hlt">DAR</span> technology</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Delagrange, Sylvain; Rochon, Pascal</p> <p>2011-01-01</p> <p>Background and Aims To meet the increasing need for rapid and non-destructive extraction of canopy traits, two methods were used and compared with regard to their accuracy in estimatating 2-D and 3-D parameters of a hybrid poplar sapling. Methods The first method consisted of the analysis of high definition photographs in Tree Analyser (TA) software (PIAF-INRA/Kasetsart University). TA allowed the extraction of individual traits using a space carving approach. The second method utilized 3-D point clouds acquired from terrestrial light detection and ranging (T-Li<span class="hlt">DAR</span>) scans. T-Li<span class="hlt">DAR</span> scans were performed on trees without leaves to reconstruct the lignified structure of the sapling. From this skeleton, foliage was added using simple modelling rules extrapolated from field measurements. Validation of the estimated dimension and the accuracy of reconstruction was then achieved by comparison with an empirical data set. Key Results TA was found to be slightly less precise than T-Li<span class="hlt">DAR</span> for estimating tree height, canopy height and mean canopy diameter, but for 2-D traits both methods were, however, fully satisfactory. TA tended to over-estimate total leaf area (error up to 50 %), but better estimates were obtained by reducing the size of the voxels used for calculations. In contrast, T-Li<span class="hlt">DAR</span> estimated total leaf area with an error of <6 %. Finally, both methods led to an over-estimation of canopy volume. With respect to this trait, T-Li<span class="hlt">DAR</span> (14·5 % deviation) greatly surpassed the accuracy of TA (up to 50 % deviation), even if the voxels used were reduced in size. Conclusions Taking into account their magnitude of data acquisition and analysis and their accuracy in trait estimations, both methods showed contrasting potential future uses. Specifically, T-Li<span class="hlt">DAR</span> is a particularly promising tool for investigating the development of large perennial plants, by itself or in association with plant modelling. PMID:21515607</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1054709','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1054709"><span>Detailed Hydrographic Feature Extraction from High-Resolution Li<span class="hlt">DAR</span> Data</span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Danny L. Anderson</p> <p>2012-05-01</p> <p>Detailed hydrographic feature extraction from high-resolution light detection and ranging (Li<span class="hlt">DAR</span>) data is investigated. Methods for quantitatively evaluating and comparing such extractions are presented, including the use of sinuosity and longitudinal root-mean-square-error (LRMSE). These metrics are then used to quantitatively compare stream networks in two studies. The first study examines the effect of raster cell size on watershed boundaries and stream networks delineated from Li<span class="hlt">DAR</span>-derived digital elevation models (DEMs). The study confirmed that, with the greatly increased resolution of Li<span class="hlt">DAR</span> data, smaller cell sizes generally yielded better stream network delineations, based on sinuosity and LRMSE. The second study demonstrates a new method of delineating a stream directly from Li<span class="hlt">DAR</span> point clouds, without the intermediate step of deriving a DEM. Direct use of Li<span class="hlt">DAR</span> point clouds could improve efficiency and accuracy of hydrographic feature extractions. The direct delineation method developed herein and termed “mDn”, is an extension of the D8 method that has been used for several decades with gridded raster data. The method divides the region around a starting point into sectors, using the Li<span class="hlt">DAR</span> data points within each sector to determine an average slope, and selecting the sector with the greatest downward slope to determine the direction of flow. An mDn delineation was compared with a traditional grid-based delineation, using TauDEM, and other readily available, common stream data sets. Although, the TauDEM delineation yielded a sinuosity that more closely matches the reference, the mDn delineation yielded a sinuosity that was higher than either the TauDEM method or the existing published stream delineations. Furthermore, stream delineation using the mDn method yielded the smallest LRMSE.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2006SPIE.6209E..0IM','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2006SPIE.6209E..0IM"><span>Parallel algorithm for linear feature detection from airborne Li<span class="hlt">DAR</span> data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mareboyana, Manohar; Chi, Paul</p> <p>2006-05-01</p> <p>Linear features from airport images correspond to runways, taxiways and roads. Detecting runways helps pilots to focus on runway incursions in poor visibility conditions. In this work, we attempt to detect linear features from Li<span class="hlt">DAR</span> swath in near real time using parallel implementation on G5-based apple cluster called Xseed. Data from Li<span class="hlt">DAR</span> swath is converted into a uniform grid with nearest neighbor interpolation. The edges and gradient directions are computed using standard edge detection algorithms such as Canny's detector. Edge linking and detecting straight-line features are described. Preliminary results on Reno, Nevada airport data are included.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://medlineplus.gov/ency/article/002189.htm','NIH-MEDLINEPLUS'); return false;" href="https://medlineplus.gov/ency/article/002189.htm"><span><span class="hlt">ALS</span> - resources</span></a></p> <p><a target="_blank" href="http://medlineplus.gov/">MedlinePlus</a></p> <p></p> <p></p> <p>Resources - <span class="hlt">ALS</span> ... The following organizations are good resources for information on amyotrophic lateral sclerosis : Muscular Dystrophy Association -- www.mda.org/disease/amyotrophic-lateral-sclerosis National Amyotrophic Lateral Sclerosis (<span class="hlt">ALS</span>) ...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.V53F..07B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.V53F..07B"><span>4D Micro-Piston Motion of Halemaumau Lava Lake Surface Measured with Ground-Based Tripod Li<span class="hlt">DAR</span>, Kilauea, Hawaii</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bawden, G. W.; Patrick, M. R.; Orr, T. R.; Howle, J.; Bond, S.; Thelen, W. A.; Kauahikaua, J. P.; Angeli, K.; Pelkie, A.; Molnia, B. F.</p> <p>2013-12-01</p> <p>We measured decimeter-scale oscillations in the elevation of the Halemaumau lava lake (HLL) surface at Kilauea Volcano, Hawaii, during a sequence of ground-based Tripod-Li<span class="hlt">DAR</span> (T-Li<span class="hlt">DAR</span>) laser scans September 13-14, 2012. Geodetically measuring elevational changes of a dynamic lava lake surface has inherent risks and technical challenges, including the ability to see the lake surface through the volcanic gases. We successfully penetrated most of the dense volcanic gases from the rim of the HLL using the Optech LR laser scanner 1-micron (1064 nm) laser (a wavelength that is not attenuated by water) to measure elevation changes of the surface of the active lava lake 164 meters below the scanner. We found that the average elevation of the entire lava lake surface oscillated with an average 10-cm amplitude across the HLL with increased amplitude (2-3 times larger) proximal to the downwelling portion of the lake. A temporal power-spectrum analysis of the T-Li<span class="hlt">DAR</span> point cloud resolved an 8.4-second primary oscillation frequency with secondary frequencies at 3.3-second intervals from the primary (1.8, 5.1, 8.4, 11.7 seconds). Preliminary analysis of the seismic spectra shows a peak in the seismic signal at 7.8 seconds (0.13 hz) for the same time period. Qualitative assessment of time-lapse video of the lava lake surface visually confirms that the lava lake rises and falls about every 8 seconds with superimposed smaller-amplitude elevation changes approximately every 3 seconds. We suggest the term micro-pistoning to distinguish this behavior from the larger-scale gas pistoning events at Kilauea that take place over several minutes (Patrick, M. et <span class="hlt">al</span>, Bull Volcanol, V73(9)pp 1179-1186, 2011).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMIN33A1034C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMIN33A1034C"><span>Visualization of High-Resolution Li<span class="hlt">DAR</span> Topography in Google Earth</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Crosby, C. J.; Nandigam, V.; Arrowsmith, R.; Blair, J. L.</p> <p>2009-12-01</p> <p>The growing availability of high-resolution Li<span class="hlt">DAR</span> (Light Detection And Ranging) topographic data has proven to be revolutionary for Earth science research. These data allow scientists to study the processes acting on the Earth’s surfaces at resolutions not previously possible yet essential for their appropriate representation. In addition to their utility for research, the data have also been recognized as powerful tools for communicating earth science concepts for education and outreach purposes. Unfortunately, the massive volume of data produced by Li<span class="hlt">DAR</span> mapping technology can be a barrier to their use. To facilitate access to these powerful data for research and educational purposes, we have been exploring the use of Keyhole Markup Language (KML) and Google Earth to deliver Li<span class="hlt">DAR</span>-derived visualizations. The OpenTopography Portal (http://www.opentopography.org/) is a National Science Foundation-funded facility designed to provide access to Earth science-oriented Li<span class="hlt">DAR</span> data. OpenTopography hosts a growing collection of Li<span class="hlt">DAR</span> data for a variety of geologic domains, including many of the active faults in the western United States. We have found that the wide spectrum of Li<span class="hlt">DAR</span> users have variable scientific applications, computing resources, and technical experience and thus require a data distribution system that provides various levels of access to the data. For users seeking a synoptic view of the data, and for education and outreach purposes, delivering full-resolution images derived from Li<span class="hlt">DAR</span> topography into the Google Earth virtual globe is powerful. The virtual globe environment provides a freely available and easily navigated viewer and enables quick integration of the Li<span class="hlt">DAR</span> visualizations with imagery, geographic layers, and other relevant data available in KML format. Through region-dependant network linked KML, OpenTopography currently delivers over 20 GB of Li<span class="hlt">DAR</span>-derived imagery to users via simple, easily downloaded KMZ files hosted at the Portal</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMEP41A0601C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMEP41A0601C"><span>Investigation of the Hector Mine Earthquake Surface Rupture with Airborne Li<span class="hlt">DAR</span> data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, T.; Zhang, D.; Akciz, S. O.; Hudnut, K. W.</p> <p>2011-12-01</p> <p>The 16 October 1999 Hector Mine earthquake (Mw7.1) generated significant surface rupture along the Lavic Lake Fault through almost 60 kilometers of sparsely vegetated, relatively barren desert terrain. It was the first large earthquake for which post-earthquake airborne Li<span class="hlt">DAR</span>, collected to image the fault surface rupture, exists. Despite the lack of pre-earthquake high-resolution topographic data, we were able to make both horizontal and vertical displacement measurements, which complement published field investigation results that include ~254 data points (164 of which are within Li<span class="hlt">DAR</span> coverage area). We made 255 new horizontal and 83 vertical displacement measurements using a 0.5 m DEM generated from the Li<span class="hlt">DAR</span> dataset. The maximum horizontal offset value is 6.6 ± 1.1 m, and is located approximately ~700 m south of the maximum horizontal offset observed during the field work. The average horizontal offset value from Li<span class="hlt">DAR</span> measurements is ~2.27 m, whereas the average calculated from field data is ~2.5 m. The maximum vertical displacement is ~1.2 m, and the average vertical offset value is less than 1 m. No consistent trends are apparent in the sense of the vertical component, except in the north of the mountainous section, which is predominated by east-side-down measurements. Compared to field data, Li<span class="hlt">DAR</span>-based measurements (a) have larger measurement uncertainties, (b) have slightly higher values, (c) do not include many measurements of offsets <1 m due to the DEM resolution, and (d) are spatially denser. The field investigation produced measurements of higher quality in alluvial deposits (e.g. tire tracks, offset rock or pebble lineaments) which are not typically visible with 0.5 m resolution DEMs unless a piercing feature has a very large or clear offset. Li<span class="hlt">DAR</span> measurements included more geomorphic features with larger measurement uncertainties, which may not have been measured in the field due to their proximity to higher quality measurements. However, along</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.3366C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.3366C"><span>Climate change induced heat wave hazard in eastern Africa: <span class="hlt">Dar</span> Es Salaam (Tanzania) and Addis Ababa (Ethiopia) case study</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Capuano, Paolo; Sellerino, Mariangela; Di Ruocco, Angela; Kombe, Wilbard; Yeshitela, Kumelachew</p> <p>2013-04-01</p> <p>Last decades, new records were set in the world for tornadoes, drought, wind, floods, wildfires and hot temperatures, testifying unusual weather and climate patterns with increasing frequency and intensity of extreme weather events. Extreme heat events are natural hazards affecting many regions in the world, nevertheless limited work has been done on the analysis and effects of extreme heat events in Africa, that is considered a continent particularly vulnerable to the effects of climate change. In fact, the increase of temperature expected in the African continent during the 21st century is larger than the global mean warming, being about 3° to 4° C, about 1.5 times the global temperature increase (Christensen et <span class="hlt">al</span>., 2007; Gualdi et <span class="hlt">al</span>., 2012), with the subtropical regions projected to warm more than the tropical regions. Observations and downscaled model simulations (RCP4.5 and RCP8.5 IPCC scenarios) are analyzed to describe heat wave characteristics in <span class="hlt">Dar</span> es Salaam (Tanzania) and Addis Ababa (Ethiopia), spanning the last five decades as well as that projected for the 21st century. Observed data are daily maximum and minimum temperature collected in the period 1961-2011; downscaled model simulations span up to 2050. Heat waves are defined following a peak over threshold approach by statistical comparison to historical meteorological baselines (site dependent), using a fixed absolute threshold. Projected future warming in the <span class="hlt">Dar</span> es Salaam and Addis Ababa shows a further increase in the heat waves parameters. Heat wave duration and hot days number are strictly correlated showing that the temperature rise could generate not only an increase of heat waves number but mainly a longer average duration, that can strongly affect the resilience capacity of the population, particularly the elder people. In fact, the impacts of heat waves on the society are determined also by temporal duration (Stephenson, 2008), in addition to their frequency, in fact the capacity of</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.H12E..06G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.H12E..06G"><span>Estimating Evapotranspiration over Heterogeneously Vegetated Surfaces using Large Aperture Scintillometer, Li<span class="hlt">DAR</span>, and Airborne Multispectral Imagery</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Geli, H. M.; Neale, C. M.; Pack, R. T.; Watts, D. R.; Osterberg, J.</p> <p>2011-12-01</p> <p>Estimates of evapotranspiration (ET) over heterogeneous areas is challenging especially in water-limited sparsely vegetated environments. New techniques such as airborne full-waveform Li<span class="hlt">DAR</span> (Light Detection and Ranging) and high resolution multispectral and thermal imagery can provide enough detail of sparse canopies to improve energy balance model estimations as well as footprint analysis of scintillometer data. The objectives of this study were to estimate ET over such areas and develop methodologies for the use of these airborne data technologies. Because of the associated heterogeneity, this study was conducted over the Cibola National wildlife refuge, southern California on an area dominated with tamarisk (salt cedar) forest (90%) interspersed with arrowweed and bare soil (10%). A set of two large aperture scintillometers (LASs) were deployed over the area to provide estimates of sensible heat flux (HLAS). The LASs were distributed over the area in a way that allowed capturing different surface spatial heterogeneity. Bowen ratio systems were used to provide hydrometeorological variables and surface energy balance fluxes (SEBF) (i.e. Rn, G, H, and LE) measurements. Scintillometer-based estimates of HLAS were improved by considering the effect of the corresponding 3D footprint and the associated displacement height (d) and the roughness length (z0) following Geli et <span class="hlt">al</span>. (2011). The Li<span class="hlt">DAR</span> data were acquired using the LASSI Lidar developed at Utah State University (USU). The data was used to obtain 1-m spatial resolution DEM's and vegetation canopy height to improve the HLAS estimates. The BR measurements of Rn and G were combined with LAS estimates, HLAS, to provide estimates of LELASas a residual of the energy balance equation. A thermal remote sensing model namely the two source energy balance (TSEB) of Norman et <span class="hlt">al</span>. (1995) was applied to provide spatial estimates of SEBF. Four airborne images at 1-4 meter spatial resolution acquired using the USU airborne</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3086283','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3086283"><span>Differential regulation of dendritic and axonal development by the novel Krüppel-like factor <span class="hlt">Dar</span>1</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Ye, Bing; Kim, Jung Hwan; Yang, Limin; McLachlan, Ian; Younger, Susan; Jan, Lily Yeh; Jan, Yuh Nung</p> <p>2011-01-01</p> <p>Dendrites and axons are two major neuronal compartments with differences that are critical for neuronal functions. To learn about the differential regulation of dendritic and axonal development, we conducted a genetic screen in Drosophila and isolated the dendritic arbor reduction 1 (<span class="hlt">dar</span>1) mutants, which display defects in dendritic but not axonal growth. The <span class="hlt">dar</span>1 gene encodes a novel transcription regulator in the Krüppel-like factor family. Neurons lacking <span class="hlt">dar</span>1 function have severely reduced growth of microtubule- but not F-actin-based dendritic branches. In contrast, overexpression of <span class="hlt">Dar</span>1 dramatically increased the growth of microtubule-based dendritic branches. Our results suggest that <span class="hlt">Dar</span>1 promotes dendrite growth in part by suppressing the expression of the microtubule severing protein Spastin. Our study thus uncovers a novel transcriptional program for microtubule regulation that preferentially controls dendrite growth. PMID:21368042</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=education+AND+system+AND+tanzania&pg=4&id=EJ953006','ERIC'); return false;" href="http://eric.ed.gov/?q=education+AND+system+AND+tanzania&pg=4&id=EJ953006"><span>Integrating ICT into Teaching and Learning at the University of <span class="hlt">Dar</span> es Salaam</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Mtebe, Joel S.; Dachi, Hilary; Raphael, Christina</p> <p>2011-01-01</p> <p>Since 1985, Tanzania has been undergoing significant political and economic changes from a centralized to a more market-oriented and globally connected economy. The University of <span class="hlt">Dar</span> es Salaam (UDSM) has responded to these changes by reviewing its legal status, vision, and functions, particularly those related to research, teaching, and public…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/EJ1071342.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/EJ1071342.pdf"><span>Students' Experiences and Challenges of Blended Learning at the University of <span class="hlt">Dar</span> Es Salaam, Tanzania</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Mtebe, Joel S.; Raphael, Christina</p> <p>2013-01-01</p> <p>Recent developments in Information and Communication Technologies (ICTs), especially eLearning, have heightened the need for University of <span class="hlt">Dar</span> es Salaam (UDSM) to supplement on-campus face-to-face delivery as well as meeting increased students' enrolments through blended distance learning. Since 2008, the University has been offering three…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=231779','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=231779"><span>Biomass estimation of Douglas fir stands using airborne Li<span class="hlt">DAR</span> data</span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>Biomass is an important parameter not only for carbon cycle modeling, but also for supporting land management operations (e.g. land use policy, forest fire management). Various remote sensing data have been utilized for biomass estimation, especially in forested areas. Li<span class="hlt">DAR</span> (Light Detection And Ran...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016E%26ES...37a2068H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016E%26ES...37a2068H"><span>Mapping of post-event earthquake induced landslides in Sg. Mesilou using Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hanan Mat Yusoff, Habibah; Azahari Razak, Khamarrul; Yuen, Florence; Harun, Afifi; Talib, Jasmi; Mohamad, Zakaria; Ramli, Zamri; Abd Razab, Razain</p> <p>2016-06-01</p> <p>Earthquake is a common natural disaster in active tectonic regions. The disaster can induce cascading disasters such as debris flow, mudflow and reactivated old landslides. M 6.0 Ranau earthquake dated on June 05, 2015 coupling with intense and prolonged rainfall caused several mass movements such as debris flow, deep-seated and shallow landslides in Mesilou, Sabah. This study aims at providing a better insight into the use of advanced Li<span class="hlt">DAR</span> mapping technology for recognizing landslide induced by earthquakes particularly in a vegetated terrain, assessing post event hazard and analyzing its distribution for hazard zonation. We developed the landslide inventory using Li<span class="hlt">DAR</span>-derived visual analysis method and validated in the field. A landslide inventory map improved with the support of Li<span class="hlt">DAR</span> derivative data. Finally, landslide inventory was analysed by emphasizing its distribution and density in such a way that it provides clues of risky zone as a result of debris flow. We recommend that mitigation action and risk reduction should be taken place at a transport zone of the channel compared to other zones. This study indicates that modern airborne Li<span class="hlt">DAR</span> can be a good complementary tool for improving landslide inventory in a complex environment, and an effective tool for rapid regional hazard and risk assessment in the tropics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3420181','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3420181"><span>Geospatial revolution and remote sensing Li<span class="hlt">DAR</span> in Mesoamerican archaeology</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chase, Arlen F.; Fisher, Christopher T.; Leisz, Stephen J.; Weishampel, John F.</p> <p>2012-01-01</p> <p>The application of light detection and ranging (Li<span class="hlt">DAR</span>), a laser-based remote-sensing technology that is capable of penetrating overlying vegetation and forest canopies, is generating a fundamental shift in Mesoamerican archaeology and has the potential to transform research in forested areas world-wide. Much as radiocarbon dating that half a century ago moved archaeology forward by grounding archaeological remains in time, Li<span class="hlt">DAR</span> is proving to be a catalyst for an improved spatial understanding of the past. With Li<span class="hlt">DAR</span>, ancient societies can be contextualized within a fully defined landscape. Interpretations about the scale and organization of densely forested sites no longer are constrained by sample size, as they were when mapping required laborious on-ground survey. The ability to articulate ancient landscapes fully permits a better understanding of the complexity of ancient Mesoamerican urbanism and also aids in modern conservation efforts. The importance of this geospatial innovation is demonstrated with newly acquired Li<span class="hlt">DAR</span> data from the archaeological sites of Caracol, Cayo, Belize and Angamuco, Michoacán, Mexico. These data illustrate the potential of technology to act as a catalytic enabler of rapid transformational change in archaeological research and interpretation and also underscore the value of on-the-ground archaeological investigation in validating and contextualizing results. PMID:22802623</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4861515','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4861515"><span>Clinical, Virologic, and Epidemiologic Characteristics of Dengue Outbreak, <span class="hlt">Dar</span> es Salaam, Tanzania, 2014</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mboera, Leonard E.G.; De Nardo, Pasquale; Oriyo, Ndekya M.; Meschi, Silvia; Rumisha, Susan F.; Colavita, Francesca; Mhina, Athanas; Carletti, Fabrizio; Mwakapeje, Elibariki; Capobianchi, Maria Rosaria; Castilletti, Concetta; Di Caro, Antonino; Nicastri, Emanuele; Malecela, Mwelecele N.; Ippolito, Giuseppe</p> <p>2016-01-01</p> <p>We investigated a dengue outbreak in <span class="hlt">Dar</span> es Salaam, Tanzania, in 2014, that was caused by dengue virus (DENV) serotype 2. DENV infection was present in 101 (20.9%) of 483 patients. Patient age and location of residence were associated with infection. Seven (4.0%) of 176 patients were co-infected with malaria and DENV. PMID:27088845</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA615027','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA615027"><span>Terrain Referenced Navigation Using SIFT Features in Li<span class="hlt">DAR</span> Range-Based Data</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>2014-12-26</p> <p>Geomorphology , 182:147– 156, 2013. [39] Jiaping Zhao, Suya You. “Road Network Extraction from Airbone Li<span class="hlt">DAR</span> Data using Scene Context”. International...New Opportunities from High Resolution DTMs”. Geomorphology , 113(1):47–56, 2009. [106] The National Coordination Office. “GPS Applications”, September</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5298643','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5298643"><span>Line-Based Registration of Panoramic Images and Li<span class="hlt">DAR</span> Point Clouds for Mobile Mapping</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Cui, Tingting; Ji, Shunping; Shan, Jie; Gong, Jianya; Liu, Kejian</p> <p>2016-01-01</p> <p>For multi-sensor integrated systems, such as the mobile mapping system (MMS), data fusion at sensor-level, i.e., the 2D-3D registration between an optical camera and Li<span class="hlt">DAR</span>, is a prerequisite for higher level fusion and further applications. This paper proposes a line-based registration method for panoramic images and a Li<span class="hlt">DAR</span> point cloud collected by a MMS. We first introduce the system configuration and specification, including the coordinate systems of the MMS, the 3D Li<span class="hlt">DAR</span> scanners, and the two panoramic camera models. We then establish the line-based transformation model for the panoramic camera. Finally, the proposed registration method is evaluated for two types of camera models by visual inspection and quantitative comparison. The results demonstrate that the line-based registration method can significantly improve the alignment of the panoramic image and the Li<span class="hlt">DAR</span> datasets under either the ideal spherical or the rigorous panoramic camera model, with the latter being more reliable. PMID:28042855</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_11");'>11</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li class="active"><span>13</span></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_13 --> <div id="page_14" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="261"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25837107','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25837107"><span>Registration of optical imagery and Li<span class="hlt">DAR</span> data using an inherent geometrical constraint.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Zhang, Wuming; Zhao, Jing; Chen, Mei; Chen, Yiming; Yan, Kai; Li, Linyuan; Qi, Jianbo; Wang, Xiaoyan; Luo, Jinghui; Chu, Qing</p> <p>2015-03-23</p> <p>A novel method for registering imagery with Light Detection And Ranging (Li<span class="hlt">DAR</span>) data is proposed. It is based on the phenomenon that the back-projection of Li<span class="hlt">DAR</span> point cloud of an object should be located within the object boundary in the image. Using this inherent geometrical constraint, the registration parameters computation of both data sets only requires Li<span class="hlt">DAR</span> point clouds of several objects and their corresponding boundaries in the image. The proposed registration method comprises of four steps: point clouds extraction, boundary extraction, back-projection computation and registration parameters computation. There are not any limitations on the geometrical and spectral properties of the object. So it is suitable not only for structured scenes with man-made objects but also for natural scenes. Moreover, the proposed method based on the inherent geometrical constraint can register two data sets derived from different parts of an object. It can be used to co-register TLS (Terrestrial Laser Scanning) Li<span class="hlt">DAR</span> point cloud and UAV (Unmanned aerial vehicle) image, which are obtaining more attention in the forest survey application. Using initial registration parameters comparable to POS (position and orientation system) accuracy, the performed experiments validated the feasibility of the proposed registration method.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27088845','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27088845"><span>Clinical, Virologic, and Epidemiologic Characteristics of Dengue Outbreak, <span class="hlt">Dar</span> es Salaam, Tanzania, 2014.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vairo, Francesco; Mboera, Leonard E G; De Nardo, Pasquale; Oriyo, Ndekya M; Meschi, Silvia; Rumisha, Susan F; Colavita, Francesca; Mhina, Athanas; Carletti, Fabrizio; Mwakapeje, Elibariki; Capobianchi, Maria Rosaria; Castilletti, Concetta; Di Caro, Antonino; Nicastri, Emanuele; Malecela, Mwelecele N; Ippolito, Giuseppe</p> <p>2016-05-01</p> <p>We investigated a dengue outbreak in <span class="hlt">Dar</span> es Salaam, Tanzania, in 2014, that was caused by dengue virus (DENV) serotype 2. DENV infection was present in 101 (20.9%) of 483 patients. Patient age and location of residence were associated with infection. Seven (4.0%) of 176 patients were co-infected with malaria and DENV.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/ED535262.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/ED535262.pdf"><span>An Analysis of Student Reading as Measured on the Diagnostic Assessment of Reading (<span class="hlt">DAR</span>)</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Baca, Jo-Ann M.; Shepperson, Barbara A.</p> <p>2006-01-01</p> <p>As part of the reporting of Delaware's State Improvement Grant (DelaSIG), the Delaware Education Research and Development Center (R&D Center) completed a study on the Diagnostic Assessment of Reading (<span class="hlt">DAR</span>) scores of students whose teachers attended a professional development program designed to help focus teacher instruction of struggling …</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.B43C0560J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.B43C0560J"><span>Spatial Patterns of Trees from Airborne Li<span class="hlt">DAR</span> Using a Simple Tree Segmentation Algorithm</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jeronimo, S.; Kane, V. R.; McGaughey, R. J.; Franklin, J. F.</p> <p>2015-12-01</p> <p>Objectives for management of forest ecosystems on public land incorporate a focus on maintenance and restoration of ecological functions through silvicultural manipulation of forest structure. The spatial pattern of residual trees - the horizontal element of structure - is a key component of ecological restoration prescriptions. We tested the ability of a simple Li<span class="hlt">DAR</span> individual tree segmentation method - the watershed transform - to generate spatial pattern metrics similar to those obtained by the traditional method - ground-based stem mapping - on forested plots representing the structural diversity of a large wilderness area (Yosemite NP) and a large managed area (Sierra NF) in the Sierra Nevada, Calif. Most understory and intermediate-canopy trees were not detected by the Li<span class="hlt">DAR</span> segmentation; however, Li<span class="hlt">DAR</span>- and field-based assessments of spatial pattern in terms of tree clump size distributions largely agreed. This suggests that (1) even when individual tree segmentation is not effective for tree density estimates, it can provide a good measurement of tree spatial pattern, and (2) a simple segmentation method is adequate to measure spatial pattern of large areas with a diversity of structural characteristics. These results lay the groundwork for a Li<span class="hlt">DAR</span> tool to assess clumping patterns across forest landscapes in support of restoration silviculture. This tool could describe spatial patterns of functionally intact reference ecosystems, measure departure from reference targets in treatment areas, and, with successive acquisitions, monitor treatment efficacy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014ISPAr.XL2..225S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014ISPAr.XL2..225S"><span>a Data Driven Method for Building Reconstruction from Li<span class="hlt">DAR</span> Point Clouds</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sajadian, M.; Arefi, H.</p> <p>2014-10-01</p> <p>Airborne laser scanning, commonly referred to as Li<span class="hlt">DAR</span>, is a superior technology for three-dimensional data acquisition from Earth's surface with high speed and density. Building reconstruction is one of the main applications of Li<span class="hlt">DAR</span> system which is considered in this study. For a 3D reconstruction of the buildings, the buildings points should be first separated from the other points such as; ground and vegetation. In this paper, a multi-agent strategy has been proposed for simultaneous extraction and segmentation of buildings from Li<span class="hlt">DAR</span> point clouds. Height values, number of returned pulse, length of triangles, direction of normal vectors, and area are five criteria which have been utilized in this step. Next, the building edge points are detected using a new method named "Grid Erosion". A RANSAC based technique has been employed for edge line extraction. Regularization constraints are performed to achieve the final lines. Finally, by modelling of the roofs and walls, 3D building model is reconstructed. The results indicate that the proposed method could successfully extract the building from Li<span class="hlt">DAR</span> data and generate the building models automatically. A qualitative and quantitative assessment of the proposed method is then provided.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MSSP...82..339K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MSSP...82..339K"><span>Dynamic displacement estimation by fusing LDV and Li<span class="hlt">DAR</span> measurements via smoothing based Kalman filtering</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kim, Kiyoung; Sohn, Hoon</p> <p>2017-01-01</p> <p>This paper presents a smoothing based Kalman filter to estimate dynamic displacement in real-time by fusing the velocity measured from a laser Doppler vibrometer (LDV) and the displacement from a light detection and ranging (Li<span class="hlt">DAR</span>). Li<span class="hlt">DAR</span> can measure displacement based on the time-of-flight information or the phase-shift of the laser beam reflected off form a target surface, but it typically has a high noise level and a low sampling rate. On the other hand, LDV primarily measures out-of-plane velocity of a moving target, and displacement is estimated by numerical integration of the measured velocity. Here, the displacement estimated by LDV suffers from integration error although LDV can achieve a lower noise level and a much higher sampling rate than Li<span class="hlt">DAR</span>. The proposed data fusion technique estimates high-precision and high-sampling rate displacement by taking advantage of both Li<span class="hlt">DAR</span> and LDV measurements and overcomes their limitations by adopting a real-time smoothing based Kalman filter. To verify the performance of the proposed dynamic displacement estimation technique, a series of lab-scale tests are conducted under various loading conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA581853','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA581853"><span>An Algorithm to Identify and Localize Suitable Dock Locations from 3-D Li<span class="hlt">DAR</span> Scans</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>2013-05-10</p> <p>3-D) Li<span class="hlt">DARs</span> have proved themselves very useful on many autonomous ground vehicles, such as the Google Driverless Car Project, the DARPA, Defense...appear in a typical point cloud data set, relative to other clusters such as cars , trees, boulders, etc. In this algorithm, these values were</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=288819','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=288819"><span>Diversity Arrays Technology (<span class="hlt">DAr</span>T) platform for genotyping and mapping in carrot (Daucus carota L.)</span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>Carrot is one of the most important root vegetable crops grown worldwide on more than one million hectares. Its progenitor, wild Daucus carota, is a weed commonly occurring across continents in the temperate climatic zone. Diversity Array Technology (<span class="hlt">DAr</span>T) is a microarray-based molecular marker syst...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4377920','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4377920"><span>Pit Latrine Emptying Behavior and Demand for Sanitation Services in <span class="hlt">Dar</span> Es Salaam, Tanzania</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jenkins, Marion W.; Cumming, Oliver; Cairncross, Sandy</p> <p>2015-01-01</p> <p>Pit latrines are the main form of sanitation in unplanned areas in many rapidly growing developing cities. Understanding demand for pit latrine fecal sludge management (FSM) services in these communities is important for designing demand-responsive sanitation services and policies to improve public health. We examine latrine emptying knowledge, attitudes, behavior, trends and rates of safe/unsafe emptying, and measure demand for a new hygienic latrine emptying service in unplanned communities in <span class="hlt">Dar</span> Es Salaam (<span class="hlt">Dar</span>), Tanzania, using data from a cross-sectional survey at 662 residential properties in 35 unplanned sub-wards across <span class="hlt">Dar</span>, where 97% had pit latrines. A picture emerges of expensive and poor FSM service options for latrine owners, resulting in widespread fecal sludge exposure that is likely to increase unless addressed. Households delay emptying as long as possible, use full pits beyond what is safe, face high costs even for unhygienic emptying, and resort to unsafe practices like ‘flooding out’. We measured strong interest in and willingness to pay (WTP) for the new pit emptying service at 96% of residences; 57% were WTP ≥U.S. $17 to remove ≥200 L of sludge. Emerging policy recommendations for safe FSM in unplanned urban communities in <span class="hlt">Dar</span> and elsewhere are discussed. PMID:25734790</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=intelligence+AND+studies+AND+higher+AND+education&pg=2&id=EJ1097023','ERIC'); return false;" href="http://eric.ed.gov/?q=intelligence+AND+studies+AND+higher+AND+education&pg=2&id=EJ1097023"><span>How Children Living in Poor Areas of <span class="hlt">Dar</span> Es Salaam, Tanzania Perceive Their Own Multiple Intelligences</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Dixon, Pauline; Humble, Steve; Chan, David W.</p> <p>2016-01-01</p> <p>This study was carried out with 1,857 poor children from 17 schools, living in low-income areas of <span class="hlt">Dar</span> Es Salaam, Tanzania. All children took the "Student Multiple Intelligences Profile" (SMIP) questionnaire as part of a bigger project that gathered data around concepts and beliefs of talent. This paper sets out two aims, first to…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=260894','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=260894"><span>High-throughput genotyping of hop (Humulus lupulus L.) utilising diversity arrays technology (<span class="hlt">DAr</span>T)</span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>Implementation of molecular methods in hop breeding is dependent on the availability of sizeable numbers of polymorphic markers and a comprehensive understanding of genetic variation. Diversity Arrays Technology (<span class="hlt">DAr</span>T) is a high-throughput cost-effective method for the discovery of large numbers of...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21243330','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21243330"><span>High-throughput genotyping of hop (Humulus lupulus L.) utilising diversity arrays technology (<span class="hlt">DAr</span>T).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Howard, E L; Whittock, S P; Jakše, J; Carling, J; Matthews, P D; Probasco, G; Henning, J A; Darby, P; Cerenak, A; Javornik, B; Kilian, A; Koutoulis, A</p> <p>2011-05-01</p> <p>Implementation of molecular methods in hop (Humulus lupulus L.) breeding is dependent on the availability of sizeable numbers of polymorphic markers and a comprehensive understanding of genetic variation. However, use of molecular marker technology is limited due to expense, time inefficiency, laborious methodology and dependence on DNA sequence information. Diversity arrays technology (<span class="hlt">DAr</span>T) is a high-throughput cost-effective method for the discovery of large numbers of quality polymorphic markers without reliance on DNA sequence information. This study is the first to utilise <span class="hlt">DAr</span>T for hop genotyping, identifying 730 polymorphic markers from 92 hop accessions. The marker quality was high and similar to the quality of <span class="hlt">DAr</span>T markers previously generated for other species; although percentage polymorphism and polymorphism information content (PIC) were lower than in previous studies deploying other marker systems in hop. Genetic relationships in hop illustrated by <span class="hlt">DAr</span>T in this study coincide with knowledge generated using alternate methods. Several statistical analyses separated the hop accessions into genetically differentiated North American and European groupings, with hybrids between the two groups clearly distinguishable. Levels of genetic diversity were similar in the North American and European groups, but higher in the hybrid group. The markers produced from this time and cost-efficient genotyping tool will be a valuable resource for numerous applications in hop breeding and genetics studies, such as mapping, marker-assisted selection, genetic identity testing, guidance in the maintenance of genetic diversity and the directed breeding of superior cultivars.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.V43B2895A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.V43B2895A"><span>The Effect of Lava Texture on Li<span class="hlt">DAR</span> Attributes and Full Waveform</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Anderson, S. W.; Finnegan, D. C.; LeWinter, A.</p> <p>2013-12-01</p> <p>The distribution of glassy, vesicular, and crystalline textures on lava flow and dome surfaces provides insights regarding the physical and chemical processes occurring during emplacement. For silicic flows, these textures may reflect variations in the volatile content of lava upon eruption. To assess the efficacy of texture detection with our terrestrial full waveform Li<span class="hlt">DAR</span> system capable of measuring ~125,000 topographic points/second, we analyzed attribute and full waveform data from a variety of lava textures displayed on recent rhyolitic obsidian flows of the Inyo Dome chain (California) and pahoehoe and aa flows at Kilauea volcano (Hawaii). We find that attributes such as intensity, amplitude and deviation of the returned 1550nm laser pulse fall into discrete ranges associated with glassy, pumiceous and crystalline textures on both the rhyolitic and basaltic surfaces. This enables detection of vesicularity at ranges in excess of 500 m, making Li<span class="hlt">DAR</span> a useful tool for remotely determining lava texture. Scan times using our Riegl VZ1000 and VZ400 systems require only minutes, allowing for repeated scans over a short time period, and processing times are <1 hour. We have also analyzed the full digitized waveforms of Li<span class="hlt">DAR</span> pulses returned from these surfaces, and find that they also have unique signatures related to texture. We therefore suggest that Li<span class="hlt">DAR</span> can provide reliable information on lava texture during eruption, aiding in the interpretation of eruption hazards from increasing volatile contents.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1612562T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1612562T"><span>Airborne hyperspectral and Li<span class="hlt">DAR</span> data integration for weed detection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tamás, János; Lehoczky, Éva; Fehér, János; Fórián, Tünde; Nagy, Attila; Bozsik, Éva; Gálya, Bernadett; Riczu, Péter</p> <p>2014-05-01</p> <p>Agriculture uses 70% of global available fresh water. However, ca. 50-70% of water used by cultivated plants, the rest of water transpirated by the weeds. Thus, to define the distribution of weeds is very important in precision agriculture and horticulture as well. To survey weeds on larger fields by traditional methods is often time consuming. Remote sensing instruments are useful to detect weeds in larger area. In our investigation a 3D airborne laser scanner (RIEGL LMS-Q680i) was used in agricultural field near Sopron to scouting weeds. Beside the airborne Li<span class="hlt">DAR</span>, hyperspectral imaging system (AISA DUAL) and air photos helped to investigate weed coverage. The Li<span class="hlt">DAR</span> survey was carried out at early April, 2012, before sprouting of cultivated plants. Thus, there could be detected emerging of weeds and direction of cultivation. However airborne Li<span class="hlt">DAR</span> system was ideal to detect weeds, identification of weeds at species level was infeasible. Higher point density Li<span class="hlt">DAR</span> - Terrestrial laser scanning - systems are appropriate to distinguish weed species. Based on the results, laser scanner is an effective tool to scouting of weeds. Appropriate weed detection and mapping systems could contribute to elaborate water and herbicide saving management technique. This publication was supported by the OTKA project K 105789.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28042855','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28042855"><span>Line-Based Registration of Panoramic Images and Li<span class="hlt">DAR</span> Point Clouds for Mobile Mapping.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Cui, Tingting; Ji, Shunping; Shan, Jie; Gong, Jianya; Liu, Kejian</p> <p>2016-12-31</p> <p>For multi-sensor integrated systems, such as the mobile mapping system (MMS), data fusion at sensor-level, i.e., the 2D-3D registration between an optical camera and Li<span class="hlt">DAR</span>, is a prerequisite for higher level fusion and further applications. This paper proposes a line-based registration method for panoramic images and a Li<span class="hlt">DAR</span> point cloud collected by a MMS. We first introduce the system configuration and specification, including the coordinate systems of the MMS, the 3D Li<span class="hlt">DAR</span> scanners, and the two panoramic camera models. We then establish the line-based transformation model for the panoramic camera. Finally, the proposed registration method is evaluated for two types of camera models by visual inspection and quantitative comparison. The results demonstrate that the line-based registration method can significantly improve the alignment of the panoramic image and the Li<span class="hlt">DAR</span> datasets under either the ideal spherical or the rigorous panoramic camera model, with the latter being more reliable.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=255950','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=255950"><span>Errors in Li<span class="hlt">DAR</span>-derived shrub height and crown area on sloped terrain</span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>This study developed and tested four methodologies for determining shrub height measurements with Li<span class="hlt">DAR</span> data in a semiarid shrub-steppe in southwestern Idaho, USA. Unique to this study was the focus of sagebrush height measurements on sloped terrain. The study also developed one of the first metho...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28113588','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28113588"><span>Shape Detection from Raw Li<span class="hlt">DAR</span> Data with Subspace Modeling.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Jun; Xu, Kevin Kai</p> <p>2016-08-31</p> <p>Li<span class="hlt">DAR</span> scanning has become a prevalent technique for digitalizing large-scale outdoor scenes. However, the raw Li<span class="hlt">DAR</span> data often contain imperfections, e.g., missing large regions, anisotropy of sampling density, and contamination of noise and outliers, which are the major obstacles that hinder its more ambitious and higher level applications in digital city modeling. Observing that 3D urban scenes can be locally described with several low dimensional subspaces, we propose to locally classify the neighborhoods of the scans to model the substructures of the scenes. The key enabler is the adaptive kernel-scale scoring, filtering and clustering of substructures, making it possible to recover the local structures at all points simultaneously, even in the presence of severe data imperfections. Integrating the local analyses leads to robust shape detection from raw Li<span class="hlt">DAR</span> data. On this basis, we develop several urban scene applications and verify them on a number of Li<span class="hlt">DAR</span> scans with various complexities and styles, which demonstrates the effectiveness and robustness of our methods.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=271443','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=271443"><span>A comparison of two open source Li<span class="hlt">DAR</span> surface classification algorithms</span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>With the progression of Li<span class="hlt">DAR</span> (Light Detection and Ranging) towards a mainstream resource management tool, it has become necessary to understand how best to process and analyze the data. While most ground surface identification algorithms remain proprietary and have high purchase costs; a few are op...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22802623','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22802623"><span>Geospatial revolution and remote sensing Li<span class="hlt">DAR</span> in Mesoamerican archaeology.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chase, Arlen F; Chase, Diane Z; Fisher, Christopher T; Leisz, Stephen J; Weishampel, John F</p> <p>2012-08-07</p> <p>The application of light detection and ranging (Li<span class="hlt">DAR</span>), a laser-based remote-sensing technology that is capable of penetrating overlying vegetation and forest canopies, is generating a fundamental shift in Mesoamerican archaeology and has the potential to transform research in forested areas world-wide. Much as radiocarbon dating that half a century ago moved archaeology forward by grounding archaeological remains in time, Li<span class="hlt">DAR</span> is proving to be a catalyst for an improved spatial understanding of the past. With Li<span class="hlt">DAR</span>, ancient societies can be contextualized within a fully defined landscape. Interpretations about the scale and organization of densely forested sites no longer are constrained by sample size, as they were when mapping required laborious on-ground survey. The ability to articulate ancient landscapes fully permits a better understanding of the complexity of ancient Mesoamerican urbanism and also aids in modern conservation efforts. The importance of this geospatial innovation is demonstrated with newly acquired Li<span class="hlt">DAR</span> data from the archaeological sites of Caracol, Cayo, Belize and Angamuco, Michoacán, Mexico. These data illustrate the potential of technology to act as a catalytic enabler of rapid transformational change in archaeological research and interpretation and also underscore the value of on-the-ground archaeological investigation in validating and contextualizing results.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=Genetics&pg=3&id=EJ936928','ERIC'); return false;" href="http://eric.ed.gov/?q=Genetics&pg=3&id=EJ936928"><span>Genetics and Human Agency: Comment on <span class="hlt">Dar</span>-Nimrod and Heine (2011)</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Turkheimer, Eric</p> <p>2011-01-01</p> <p><span class="hlt">Dar</span>-Nimrod and Heine (2011) decried genetic essentialism without denying the importance of genetics in the genesis of human behavior, and although I agree on both counts, a deeper issue remains unaddressed: how should we adjust our cognitions about our own behavior in light of genetic influence, or is it perhaps not necessary to take genetics into…</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_12");'>12</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li class="active"><span>14</span></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_14 --> <div id="page_15" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="281"> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23516227','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23516227"><span>Draft genome sequence of Bacillus thuringiensis strain <span class="hlt">DAR</span> 81934, which exhibits molluscicidal activity.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Wang, Aisuo; Pattemore, Julie; Ash, Gavin; Williams, Angela; Hane, James</p> <p>2013-03-21</p> <p>Bacillus thuringiensis has been widely used as a biopesticide for a long time. Its molluscicidal activity, however, is rarely realized. Here, we report the genome sequence of B. thuringiensis strain <span class="hlt">DAR</span> 81934, a strain with molluscicidal activity against the pest snail Cernuella virgata.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/18488621','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/18488621"><span>Hyperspectral and Li<span class="hlt">DAR</span> remote sensing of fire fuels in Hawaii Volcanoes National Park.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Varga, Timothy A; Asner, Gregory P</p> <p>2008-04-01</p> <p>Alien invasive grasses threaten to transform Hawaiian ecosystems through the alteration of ecosystem dynamics, especially the creation or intensification of a fire cycle. Across sub-montane ecosystems of Hawaii Volcanoes National Park on Hawaii Island, we quantified fine fuels and fire spread potential of invasive grasses using a combination of airborne hyperspectral and light detection and ranging (Li<span class="hlt">DAR</span>) measurements. Across a gradient from forest to savanna to shrubland, automated mixture analysis of hyperspectral data provided spatially explicit fractional cover estimates of photosynthetic vegetation, non-photosynthetic vegetation, and bare substrate and shade. Small-footprint Li<span class="hlt">DAR</span> provided measurements of vegetation height along this gradient of ecosystems. Through the fusion of hyperspectral and Li<span class="hlt">DAR</span> data, a new fire fuel index (FFI) was developed to model the three-dimensional volume of grass fuels. Regionally, savanna ecosystems had the highest volumes of fire fuels, averaging 20% across the ecosystem and frequently filling all of the three-dimensional space represented by each image pixel. The forest and shrubland ecosystems had lower FFI values, averaging 4.4% and 8.4%, respectively. The results indicate that the fusion of hyperspectral and Li<span class="hlt">DAR</span> remote sensing can provide unique information on the three-dimensional properties of ecosystems, their flammability, and the potential for fire spread.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=urban+AND+agriculture&pg=3&id=EJ509044','ERIC'); return false;" href="http://eric.ed.gov/?q=urban+AND+agriculture&pg=3&id=EJ509044"><span>Child Labour in Urban Agriculture: The Case of <span class="hlt">Dar</span> es Salaam, Tanzania.</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Mlozi, Malongo R. S.</p> <p>1995-01-01</p> <p>Urban agriculture in <span class="hlt">Dar</span> es Salaam was found to use child labor of both children with parents of higher and lower socioeconomic status (SES). Discusses policy implications and calls for the education of parents of lower SES not to expect an economic contribution from their children's labor, and the education of children about their rights. (LZ)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=genetic+AND+disorders&pg=3&id=EJ936968','ERIC'); return false;" href="http://eric.ed.gov/?q=genetic+AND+disorders&pg=3&id=EJ936968"><span>Genetic Essentialism, Neuroessentialism, and Stigma: Commentary on <span class="hlt">Dar</span>-Nimrod and Heine (2011)</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Haslam, Nick</p> <p>2011-01-01</p> <p><span class="hlt">Dar</span>-Nimrod and Heine (2011) presented a masterfully broad review of the implications of genetic essentialism for understandings of human diversity. This commentary clarifies the reasons that essentialist thinking has problematic social consequences and links genetic forms of essentialism to those invoking neural essences. The mounting evidence…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.4799S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.4799S"><span>Multitemporal Error Analysis of Li<span class="hlt">DAR</span> Data for Geomorphological Feature Detection</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sailer, R.; Höfle, B.; Bollmann, E.; Vetter, M.; Stötter, J.; Pfeifer, N.; Rutzinger, M.; Geist, T.</p> <p>2009-04-01</p> <p>Since 2001 airborne Li<span class="hlt">DAR</span> measurements have been carried out regularly at the Hintereisferner region (Ötztal, Tyrol, Austria). This results in a worldwide unique data set, which is primarily used for multitemporal glacial and periglacial analyses. Several methods and tools i) to delineate the glacier boundary, ii) to derive standard glaciological mass balance parameters (e.g. volume changes), iii) to excerpt crevasse zones or iv) to classify glacier surface features (e.g. snow, firn, glacier ice, debris covered glacier ice) have been developed as yet. Furthermore, the available multitemporal Li<span class="hlt">DAR</span> data set offers the opportunity to identify surface changes occurring outside the glacier boundary, which have not been recognized until now. The respective areas are characterized by small variations of the surface topography from year to year. These changes of the surface topography are primarily caused by periglacial processes further initiating secondary gravitative mass movements. The present study aims at quantifying the error range of Li<span class="hlt">DAR</span> measurements. The error analysis, which is based on (at least) 66 cross-combinations of the single Li<span class="hlt">DAR</span> measurement campaigns, excluding areas which are obviously related to glacial surface changes, results in statistically derived error margins. Hence, surface changes which exceed these error margins have to be assigned to periglacial or gravitative process activities. The study further aims at identifying areas which are explicitly related to those periglacial and gravitative processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25734790','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25734790"><span>Pit latrine emptying behavior and demand for sanitation services in <span class="hlt">Dar</span> Es Salaam, Tanzania.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Jenkins, Marion W; Cumming, Oliver; Cairncross, Sandy</p> <p>2015-02-27</p> <p>Pit latrines are the main form of sanitation in unplanned areas in many rapidly growing developing cities. Understanding demand for pit latrine fecal sludge management (FSM) services in these communities is important for designing demand-responsive sanitation services and policies to improve public health. We examine latrine emptying knowledge, attitudes, behavior, trends and rates of safe/unsafe emptying, and measure demand for a new hygienic latrine emptying service in unplanned communities in <span class="hlt">Dar</span> Es Salaam (<span class="hlt">Dar</span>), Tanzania, using data from a cross-sectional survey at 662 residential properties in 35 unplanned sub-wards across <span class="hlt">Dar</span>, where 97% had pit latrines. A picture emerges of expensive and poor FSM service options for latrine owners, resulting in widespread fecal sludge exposure that is likely to increase unless addressed. Households delay emptying as long as possible, use full pits beyond what is safe, face high costs even for unhygienic emptying, and resort to unsafe practices like 'flooding out'. We measured strong interest in and willingness to pay (WTP) for the new pit emptying service at 96% of residences; 57% were WTP≥U.S. $17 to remove ≥200 L of sludge. Emerging policy recommendations for safe FSM in unplanned urban communities in <span class="hlt">Dar</span> and elsewhere are discussed.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..16.5939T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..16.5939T"><span>Erosion in vineyards and Li<span class="hlt">DAR</span>: new opportunities for anthropogenic terraced landscapes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tarolli, Paolo; Sofia, Giulia; Calligaro, Simone; Prosdocimi, Massimo; Preti, Federico; Dalla Fontana, Giancarlo</p> <p>2014-05-01</p> <p>Vineyard landscapes are a relevant part of the European cultivated land, and several authors concluded that they are the agricultural practice that causes the highest soil loss. Since grape quality depends on the availability of water for the vineyards, and since soil erosion is an important parameter dictating the sustainability of vineyards, soil and water conservation are often implemented. The most widely used measure for soil conservation for vineyards in hilly/mountainous landscapes is terracing. However, while improving vineyards stability, the same changes in hillslope hydrology caused by these anthropogenic structures to favor agricultural activities, often result in situations that may lead to local instabilities. Terraces, in fact, when not properly maintained can create hazards for people and settlements, but also for cultivations and for the related economy. Agricultural roads also serve terraced lands, and the construction of these types of anthropogenic features can have deep effects on water flows, in a way similar to the one already registered for forest roads. The goal of this research is to use Li<span class="hlt">DAR</span> data for the high-resolution hydro-geomorphological analysis of vineyards, underlining the capability of high-resolution topography to provide new tools for a correct management of vineyards terraced landscapes. The work focus on terraced- and road-induced erosion, and it considers a methodology successfully applied to a different environmental context (the RPII index, Tarolli et <span class="hlt">al</span>. 2013). The index is applied to two study areas, located in the center of Italy, where soil erosion and terrace failures represent a critical issue. The results highlight the effectiveness of high-resolution topography in the analysis of surface erosion, thus providing useful tool to schedule a suitable environmental planning for a sustainable development, and so, to mitigate the consequences of the anthropogenic alterations induced by the terraces structures and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1611679V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1611679V"><span>Effects of atmospheric stability on the evolution of wind turbine wakes: Volumetric Li<span class="hlt">DAR</span> scans</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Valerio Iungo, Giacomo; Porté-Agel, Fernando</p> <p>2014-05-01</p> <p>Aerodynamic optimization of wind farm layout is a fundamental task to reduce wake effects on downstream wind turbines, thus to maximize wind power harvesting. However, downstream evolution and recovery of wind turbine wakes are strongly affected by the characteristics of the incoming atmospheric boundary layer (ABL) flow, like the vertical profiles of the mean wind velocity and the turbulence intensity, which are in turn affected by the ABL stability regime. Therefore, the characterization of the variability of wind turbine wakes under different ABL stability regimes becomes fundamental to better predict wind power harvesting and improve wind farm efficiency. To this aim, wind velocity measurements of the wake produced by a 2 MW Enercon E-70 wind turbine were performed with three scanning Doppler wind Light Detection and Ranging (Li<span class="hlt">DAR</span>) instruments. One Li<span class="hlt">DAR</span> was typically devoted to the characterization of the incoming wind, in particular wind velocity, shear and turbulence intensity at the height of the rotor disc. The other two Li<span class="hlt">DARs</span> performed scans in order to characterize the wake velocity field produced by the tested wind turbine. The main challenge in performing field measurements of wind turbine wakes is represented by the varying wind conditions, and by the consequent adjustments of the turbine yaw angle needed to maximize power production. Consequently, taking into account possible variations of the relative position between Li<span class="hlt">DAR</span> measurement volume and wake location, different Li<span class="hlt">DAR</span> measurement procedures were carried out in order to perform 2-D and 3-D characterizations of the mean wake velocity field. However, larger measurement volumes and higher spatial resolution require longer sampling periods; thus, to investigate wake turbulence tests were also performed by staring the Li<span class="hlt">DAR</span> laser beam over fixed directions and with the maximum sampling frequency. Furthermore, volumetric scans of the wind turbine wake were performed under different wind</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3855685','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3855685"><span>Using Satellite and Airborne Li<span class="hlt">DAR</span> to Model Woodpecker Habitat Occupancy at the Landscape Scale</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Vierling, Lee A.; Vierling, Kerri T.; Adam, Patrick; Hudak, Andrew T.</p> <p>2013-01-01</p> <p>Incorporating vertical vegetation structure into models of animal distributions can improve understanding of the patterns and processes governing habitat selection. Li<span class="hlt">DAR</span> can provide such structural information, but these data are typically collected via aircraft and thus are limited in spatial extent. Our objective was to explore the utility of satellite-based Li<span class="hlt">DAR</span> data from the Geoscience Laser Altimeter System (GLAS) relative to airborne-based Li<span class="hlt">DAR</span> to model the north Idaho breeding distribution of a forest-dependent ecosystem engineer, the Red-naped sapsucker (Sphyrapicus nuchalis). GLAS data occurred within ca. 64 m diameter ellipses spaced a minimum of 172 m apart, and all occupancy analyses were confined to this grain scale. Using a hierarchical approach, we modeled Red-naped sapsucker occupancy as a function of Li<span class="hlt">DAR</span> metrics derived from both platforms. Occupancy models based on satellite data were weak, possibly because the data within the GLAS ellipse did not fully represent habitat characteristics important for this species. The most important structural variables influencing Red-naped Sapsucker breeding site selection based on airborne Li<span class="hlt">DAR</span> data included foliage height diversity, the distance between major strata in the canopy vertical profile, and the vegetation density near the ground. These characteristics are consistent with the diversity of foraging activities exhibited by this species. To our knowledge, this study represents the first to examine the utility of satellite-based Li<span class="hlt">DAR</span> to model animal distributions. The large area of each GLAS ellipse and the non-contiguous nature of GLAS data may pose significant challenges for wildlife distribution modeling; nevertheless these data can provide useful information on ecosystem vertical structure, particularly in areas of gentle terrain. Additional work is thus warranted to utilize Li<span class="hlt">DAR</span> datasets collected from both airborne and past and future satellite platforms (e.g. GLAS, and the planned IceSAT2</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1512086C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1512086C"><span>Urban morphological determinants of temperature regulating ecosystem services in African cities: the case of <span class="hlt">Dar</span> es Salaam, Tanzania</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cavan, Gina; Lindley, Sarah; Kibassa, Deusdedit; Shemdoe, Riziki; Capuano, Paolo; De Paola, Francesco; Renner, Florian; Pauleit, Stephan</p> <p>2013-04-01</p> <p>Urban green structure provides important regulating ecosystem services, such as temperature and flood regulation, and thus, has the potential to increase the resilience of African cities to climate change. Green structures within urban areas are not only limited to discrete units associated with recreational parks, agricultural areas and open spaces: they also exist within zones which have other primary functions, such as church yards, along transport routes, and within residential areas. Differing characteristics of urban areas can be conceptualised and subsequently mapped through the idea of urban morphology types. Urban morphology types are classifications which combine facets of urban form and function. When mapped, UMT units provide biophysically relevant meso-scale geographical zones which can be used as the basis for understanding climate-related impacts and adaptations. For example, they support the assessment of urban temperature patterns and the temperature regulating services provided by urban green structures. There are some examples of the use of UMTs for assessing regulating ecosystem services in European cities but little similar knowledge is available in an African context. This paper outlines the concept of urban morphology types (UMTs) and how they were applied to African case study cities (Cavan et <span class="hlt">al</span>., 2012). It then presents the methods used to understand temperature regulating ecosystem services across an example African case study city, including (i) a GIS-based assessment of urban green structures, and (ii) applying an energy balance model to estimate current and future surface temperatures under climate change projections. The assessment is carried out for <span class="hlt">Dar</span> es Salaam, Tanzania. Existing evidence suggests increases in both mean and extreme temperatures in the city. Historical analysis of the number of hot days per year suggests a rise from a maximum of 47 days per year in the period 1961-87 to 72 days per year in 2003-2011 (Giugni et <span class="hlt">al</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMEP51E..05P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMEP51E..05P"><span>Distinguishing grass from ground using Li<span class="hlt">DAR</span>: Techniques and applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pelletier, J. D.; Swetnam, T.; Papuga, S. A.; Nelson, K.; Brooks, P. D.; Harpold, A. A.; Chorover, J.</p> <p>2011-12-01</p> <p>Standard protocols exist for extracting bare-earth Digital Elevation Models (DEMs) from Li<span class="hlt">DAR</span> point clouds that include trees and other large woody vegetation. Grasses and other herbaceous plants can also obscure the ground surface, yet methods for optimally distinguishing grass from ground to generate accurate Li<span class="hlt">DAR</span>-based raster products for geomorphic and ecological applications are still under development. Developing such methods is important because Li<span class="hlt">DAR</span>-based difference products (e.g. snow thickness) require accurate representations of the ground surface and because raster data for grass height and density have important applications in ecology. In this study, we developed and tested methods for constructing optimal bare-earth and grass height raster layers from Li<span class="hlt">DAR</span> point clouds and compared the results to high-quality field-based measurements of grass height, density, and species type for nearly 1000 precisely geo-referenced locations collected during the acquisition of a >200 km^2 airborne Li<span class="hlt">DAR</span> flight of the Valles Caldera National Preserve (New Mexico). In cases of partially bare ground (where the skewness of return heights above a plane fit to the lowest first returns is sufficiently large), a planar fit to the lowest first returns provides a good method of producing an accurate bare-earth DEM and the statistics of the first returns above that planar fit provide good estimates of the mean and variance of grass height. In areas of relatively thick grass cover, however, a fit to the lowest first returns yields a bare-earth DEM that may be a meter or more above the actual ground surface. Here we propose a method to solve this problem using field-measured correlations among the mean, variance, and skewness of grass heights. In this method, the variance and skewness of the differences between Li<span class="hlt">DAR</span> first returns and a 10m^2 planar fit to the lowest first returns is used, together with field-based correlations of grass height statistics, to estimate the mean</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ISPArXL15..595R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ISPArXL15..595R"><span>Building Damage Assessment after Earthquake Using Post-Event Li<span class="hlt">DAR</span> Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rastiveis, H.; Eslamizade, F.; Hosseini-Zirdoo, E.</p> <p>2015-12-01</p> <p>After an earthquake, damage assessment plays an important role in leading rescue team to help people and decrease the number of mortality. Damage map is a map that demonstrates collapsed buildings with their degree of damage. With this map, finding destructive buildings can be quickly possible. In this paper, we propose an algorithm for automatic damage map generation after an earthquake using post-event Li<span class="hlt">DAR</span> Data and pre-event vector map. The framework of the proposed approach has four main steps. To find the location of all buildings on Li<span class="hlt">DAR</span> data, in the first step, Li<span class="hlt">DAR</span> data and vector map are registered by using a few number of ground control points. Then, building layer, selected from vector map, are mapped on the Li<span class="hlt">DAR</span> data and all pixels which belong to the buildings are extracted. After that, through a powerful classifier all the extracted pixels are classified into three classes of "debris", "intact building" and "unclassified". Since textural information make better difference between "debris" and "intact building" classes, different textural features are applied during the classification. After that, damage degree for each candidate building is estimated based on the relation between the numbers of pixels labelled as "debris" class to the whole building area. Calculating the damage degree for each candidate building, finally, building damage map is generated. To evaluate the ability proposed method in generating damage map, a data set from Port-au-Prince, Haiti's capital after the 2010 Haiti earthquake was used. In this case, after calculating of all buildings in the test area using the proposed method, the results were compared to the damage degree which estimated through visual interpretation of post-event satellite image. Obtained results were proved the reliability of the proposed method in damage map generation using Li<span class="hlt">DAR</span> data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015ISPAr.XL3..189S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015ISPAr.XL3..189S"><span>Mapping the Risk of Forest Wind Damage Using Airborne Scanning Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Saarinen, N.; Vastaranta, M.; Honkavaara, E.; Wulder, M. A.; White, J. C.; Litkey, P.; Holopainen, M.; Hyyppä, J.</p> <p>2015-03-01</p> <p>Wind damage is known for causing threats to sustainable forest management and yield value in boreal forests. Information about wind damage risk can aid forest managers in understanding and possibly mitigating damage impacts. The objective of this research was to better understand and quantify drivers of wind damage, and to map the probability of wind damage. To accomplish this, we used open-access airborne scanning light detection and ranging (Li<span class="hlt">DAR</span>) data. The probability of wind-induced forest damage (PDAM) in southern Finland (61°N, 23°E) was modelled for a 173 km2 study area of mainly managed boreal forests (dominated by Norway spruce and Scots pine) and agricultural fields. Wind damage occurred in the study area in December 2011. Li<span class="hlt">DAR</span> data were acquired prior to the damage in 2008. High spatial resolution aerial imagery, acquired after the damage event (January, 2012) provided a source of model calibration via expert interpretation. A systematic grid (16 m x 16 m) was established and 430 sample grid cells were identified systematically and classified as damaged or undamaged based on visual interpretation using the aerial images. Potential drivers associated with PDAM were examined using a multivariate logistic regression model. Risk model predictors were extracted from the Li<span class="hlt">DAR</span>-derived surface models. Geographic information systems (GIS) supported spatial mapping and identification of areas of high PDAM across the study area. The risk model based on Li<span class="hlt">DAR</span> data provided good agreement with detected risk areas (73 % with kappa-value 0,47). The strongest predictors in the risk model were mean canopy height and mean elevation. Our results indicate that open-access Li<span class="hlt">DAR</span> data sets can be used to map the probability of wind damage risk without field data, providing valuable information for forest management planning.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2007AGUFM.B21A0035A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2007AGUFM.B21A0035A"><span>Object-Based Land Use Classification using Airborne Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Antonarakis, A. S.; Richards, K. S.; Brasington, J.</p> <p>2007-12-01</p> <p>Better information on roughness of various types of vegetation is needed for use in resistance equations and eventually in flood modelling. These types include woody riparian species with different structural characteristics. Remote Sensing information such as 3D point cloud data from Li<span class="hlt">DAR</span> can be used as a tool for extracting simple roughness information relevant for the condition of below canopy flow, as well as roughness relevant for more complex tree morphology that affects the flow when it enters the canopy levels. A strategy for extracting roughness parameters from remote sensing techniques is to use a data fusion object classification model. This means that multiple datasets such as Li<span class="hlt">DAR</span>, digital aerial photography, ground data and satellite data can be combined to produce roughness parameters estimated for different vegetative patches, which can subsequently be mapped spatially using a classification methodology. Airborne Li<span class="hlt">DAR</span> is used in this study in order to classify forest and ground types quickly and efficiently without the need for manipulating multispectral image files. Li<span class="hlt">DAR</span> has the advantage of being able to create elevation surfaces that are in 3D, while also having information on Li<span class="hlt">DAR</span> intensity values, thus it is a spatial and spectral segmentation tool. This classification method also uses point distribution frequency criteria to differentiate between land cover types. The classification of three meanders of the Garonne and Allier rivers in France has demonstrated overall classification accuracies of 95%. Five types of riparian forest were classified with accuracies between 66-98%. These forest types included planted and natural forest stands of different ages. Classifications of short vegetation and bare earth also produced high accuracies averaging above 90%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMEP44B..07Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMEP44B..07Y"><span>Effects of Li<span class="hlt">DAR</span> Derived DEM Resolution on Hydrographic Feature Extraction</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, P.; Ames, D. P.; Glenn, N. F.; Anderson, D.</p> <p>2010-12-01</p> <p>This paper examines the effect of Li<span class="hlt">DAR</span>-derived digital elevation model (DEM) resolution on digitally extracted stream networks with respect to known stream channel locations. Two study sites, Reynolds Creek Experimental Watershed (RCEW) and Dry Creek Experimental Watershed (DCEW), which represent terrain characteristics for lower and intermediate elevation mountainous watersheds in the Intermountain West, were selected as study areas for this research. DEMs reflecting bare earth ground were created from the Li<span class="hlt">DAR</span> observations at a series of raster cell sizes (from 1 m to 60 m) using spatial interpolation techniques. The effect of DEM resolution on resulting hydrographic feature (specifically stream channel) derivation was studied. Stream length, watershed area, and sinuosity were explored at each of the raster cell sizes. Also, variation from known channel location as estimated by root mean square error (RMSE) between surveyed channel location and extracted channel was computed for each of the DEMs and extracted stream networks. As expected, the results indicate that the DEM based hydrographic extraction process provides more detailed hydrographic features at a finer resolution. RMSE between the known channel location and modeled locations generally increased with larger cell size DEM with a greater effect in the larger RCEW. Sensitivity analyses on sinuosity demonstrated that the resulting shape of streams obtained from Li<span class="hlt">DAR</span> data matched best with the reference data at an intermediate cell size instead of highest resolution, which is at a range of cell size from 5 to 10 m likely due to original point spacing, terrain characteristics, and Li<span class="hlt">DAR</span> noise influence. More importantly, the absolute sinuosity deviation displayed a smallest value at the cell size of 10 m in both experimental watersheds, which suggests that optimal cell size for Li<span class="hlt">DAR</span>-derived DEMs used for hydrographic feature extraction is 10 m.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015IJAEO..37...56R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015IJAEO..37...56R"><span>Combined use of Li<span class="hlt">DAR</span> data and multispectral earth observation imagery for wetland habitat mapping</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rapinel, Sébastien; Hubert-Moy, Laurence; Clément, Bernard</p> <p>2015-05-01</p> <p>Although wetlands play a key role in controlling flooding and nonpoint source pollution, sequestering carbon and providing an abundance of ecological services, the inventory and characterization of wetland habitats are most often limited to small areas. This explains why the understanding of their ecological functioning is still insufficient for a reliable functional assessment on areas larger than a few hectares. While Li<span class="hlt">DAR</span> data and multispectral Earth Observation (EO) images are often used separately to map wetland habitats, their combined use is currently being assessed for different habitat types. The aim of this study is to evaluate the combination of multispectral and multiseasonal imagery and Li<span class="hlt">DAR</span> data to precisely map the distribution of wetland habitats. The image classification was performed combining an object-based approach and decision-tree modeling. Four multispectral images with high (SPOT-5) and very high spatial resolution (Quickbird, KOMPSAT-2, aerial photographs) were classified separately. Another classification was then applied integrating summer and winter multispectral image data and three layers derived from Li<span class="hlt">DAR</span> data: vegetation height, microtopography and intensity return. The comparison of classification results shows that some habitats are better identified on the winter image and others on the summer image (overall accuracies = 58.5 and 57.6%). They also point out that classification accuracy is highly improved (overall accuracy = 86.5%) when combining Li<span class="hlt">DAR</span> data and multispectral images. Moreover, this study highlights the advantage of integrating vegetation height, microtopography and intensity parameters in the classification process. This article demonstrates that information provided by the synergetic use of multispectral images and Li<span class="hlt">DAR</span> data can help in wetland functional assessment</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/22033763','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/22033763"><span>A universal airborne Li<span class="hlt">DAR</span> approach for tropical forest carbon mapping.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Asner, Gregory P; Mascaro, Joseph; Muller-Landau, Helene C; Vieilledent, Ghislain; Vaudry, Romuald; Rasamoelina, Maminiaina; Hall, Jefferson S; van Breugel, Michiel</p> <p>2012-04-01</p> <p>Airborne light detection and ranging (Li<span class="hlt">DAR</span>) is fast turning the corner from demonstration technology to a key tool for assessing carbon stocks in tropical forests. With its ability to penetrate tropical forest canopies and detect three-dimensional forest structure, Li<span class="hlt">DAR</span> may prove to be a major component of international strategies to measure and account for carbon emissions from and uptake by tropical forests. To date, however, basic ecological information such as height-diameter allometry and stand-level wood density have not been mechanistically incorporated into methods for mapping forest carbon at regional and global scales. A better incorporation of these structural patterns in forests may reduce the considerable time needed to calibrate airborne data with ground-based forest inventory plots, which presently necessitate exhaustive measurements of tree diameters and heights, as well as tree identifications for wood density estimation. Here, we develop a new approach that can facilitate rapid Li<span class="hlt">DAR</span> calibration with minimal field data. Throughout four tropical regions (Panama, Peru, Madagascar, and Hawaii), we were able to predict aboveground carbon density estimated in field inventory plots using a single universal Li<span class="hlt">DAR</span> model (r ( 2 ) = 0.80, RMSE = 27.6 Mg C ha(-1)). This model is comparable in predictive power to locally calibrated models, but relies on limited inputs of basal area and wood density information for a given region, rather than on traditional plot inventories. With this approach, we propose to radically decrease the time required to calibrate airborne Li<span class="hlt">DAR</span> data and thus increase the output of high-resolution carbon maps, supporting tropical forest conservation and climate mitigation policy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.H41E1379P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.H41E1379P"><span>Water turbidity estimation from airborne hyperspectral imagery and full waveform bathymetric Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pan, Z.; Glennie, C. L.; Fernandez-Diaz, J. C.</p> <p>2015-12-01</p> <p>The spatial and temporal variations in water turbidity are of great interest for the study of fluvial and coastal environments; and for predicting the performance of remote sensing systems that are used to map these. Conventional water turbidity estimates from remote sensing observations have normally been derived using near infrared reflectance. We have investigated the potential of determining water turbidity from additional remote sensing sources, namely airborne hyperspectral imagery and single wavelength bathymetric Li<span class="hlt">DAR</span> (Light Detection and Ranging). The confluence area of the Blue and Colorado River, CO was utilized as a study area to investigate the capabilities of both airborne bathymetric Li<span class="hlt">DAR</span> and hyperspectral imagery for water turbidity estimation. Discrete and full waveform bathymetric data were collected using Optech's Gemini (1064 nm) and Aquarius (532 nm) Li<span class="hlt">DAR</span> sensors. Hyperspectral imagery (1.2 m pixel resolution and 72 spectral bands) was acquired using an ITRES CASI-1500 imaging system. As an independent reference, measurements of turbidity were collected concurrent with the airborne remote sensing acquisitions, using a WET Labs EcoTriplet deployed from a kayak and turbidity was then derived from the measured backscatter. The bathymetric full waveform dataset contains a discretized sample of the full backscatter of water column and benthic layer. Therefore, the full waveform records encapsulate the water column characteristics of turbidity. A nonparametric support vector regression method is utilized to estimate water turbidity from both hyperspectral imagery and voxelized full waveform Li<span class="hlt">DAR</span> returns, both individually and as a fused dataset. Results of all the evaluations will be presented, showing an initial turbidity prediction accuracy of approximately 1.0 NTU. We will also discuss our future strategy for enhanced fusion of the full waveform Li<span class="hlt">DAR</span> and hyperspectral imagery for improved turbidity estimation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFM.B33A0395R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFM.B33A0395R"><span>Estimating Above Ground Biomass using Li<span class="hlt">DAR</span> in the Northcoast Redwood Forests</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Rao, M.; Stewart, E.</p> <p>2010-12-01</p> <p>In recent years, Li<span class="hlt">DAR</span> (Light Intensity Detection Amplification and Ranging) is increasingly being used in estimating biophysical parameters related to forested environments. The main goal of the project is to estimate long-term biomass accumulation and carbon sequestration potential of the redwoods ecosystem. The project objectives are aimed at providing an assessment of carbon pools within the redwood ecosystem. Specifically, we intend to develop a relational model based on Li<span class="hlt">DAR</span>-based canopy estimates and extensive ground-based measurements available for the old-growth redwood forest located within the Prairie Creek Redwoods State Park, CA. Our preliminary analysis involved developing a geospatial database, including Li<span class="hlt">DAR</span> data collected in 2007 for the study site, and analyzing the data using USFS Fusion software. The study area comprised of a 12-acres section of coastal redwood (Sequoia sempervirens) in the Prairie Creek Redwoods State Park, located in Orick, CA. A series of analytical steps were executed using the USFS FUSION software to produce some intermediate data such as bare earth model, canopy height model, canopy coverage model, and canopy maxima treelist. Canopy maxima tree tops were compared to ground layer to determine height of tree tops. A total of over 1000 trees were estimated, and then with thinning (to eliminate errors due to low vegetation > 3 meters tall), a total of 950 trees were delineated. Ground measurements were imported as a point based shapefile and then compared to the treetop heights created from Li<span class="hlt">DAR</span> data to the actual ground referenced data. The results were promising as most estimated treetops were within 1-3 meters of the ground measurements and generally within 3-5m of the actual tree height. Finally, we are in the process of applying some allometric equations to estimate above ground biomass using some of the Li<span class="hlt">DAR</span>-derived canopy metrics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFM.B41A0351M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFM.B41A0351M"><span>Characterizing Wildlife Habitat With Li<span class="hlt">DAR</span> Data: Distribution Mapping Of Snags And Understory Shrubs</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Martinuzzi, S.; Vierling, L.; Gould, W.; Falkowski, M.; Evans, J.; Hudak, A.; Vierling, K.</p> <p>2008-12-01</p> <p>Spatial data about the distribution of snags and understory shrubs is a major need for managing wildlife habitat in forests. We are evaluating the use of discrete return Li<span class="hlt">DAR</span> data for predicting the distribution (presence/absence) of understory shrubs and different classes (i.e. diameters) of snags, in a managed, mixed-conifer forest in Northern Idaho, US. We are using a variety of ground and vegetation metrics derived from Li<span class="hlt">DAR</span> data and the Random Forest algorithm to build our distribution models, and have obtained overall accuracies >80%. These preliminary results indicate that Li<span class="hlt">DAR</span> data are valuable for predicting the distribution of understory shrubs and common snag diameter classes in the study area. In particular, Li<span class="hlt">DAR</span>-derived metrics allow us to 1) quantify a variety of ecological factors (e.g. canopy structure, topography) that are known to influence the distribution and abundance of understory vegetation and snags in temperate, mountainous forests, and 2) quantify structural characteristics that are known to directly or indirectly indicate the presence of our classes of interest, such as the percent of vegetation returns in the lower strata of the canopy (for the shrubs), and the structural heterogeneity of the forest canopy (for the snags). Finally, and in order to further evaluate the use of Li<span class="hlt">DAR</span> data for characterizing wildlife habitat, we integrate our maps of snags and shrubs distribution into models of habitat suitability, using four avian species (i.e. three woodpeckers and a flycatcher) as a case study.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_13");'>13</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li class="active"><span>15</span></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_15 --> <div id="page_16" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="301"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JHyd..533..343Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JHyd..533..343Z"><span>Applying a weighted random forests method to extract karst sinkholes from Li<span class="hlt">DAR</span> data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhu, Junfeng; Pierskalla, William P.</p> <p>2016-02-01</p> <p>Detailed mapping of sinkholes provides critical information for mitigating sinkhole hazards and understanding groundwater and surface water interactions in karst terrains. Li<span class="hlt">DAR</span> (Light Detection and Ranging) measures the earth's surface in high-resolution and high-density and has shown great potentials to drastically improve locating and delineating sinkholes. However, processing Li<span class="hlt">DAR</span> data to extract sinkholes requires separating sinkholes from other depressions, which can be laborious because of the sheer number of the depressions commonly generated from Li<span class="hlt">DAR</span> data. In this study, we applied the random forests, a machine learning method, to automatically separate sinkholes from other depressions in a karst region in central Kentucky. The sinkhole-extraction random forest was grown on a training dataset built from an area where Li<span class="hlt">DAR</span>-derived depressions were manually classified through a visual inspection and field verification process. Based on the geometry of depressions, as well as natural and human factors related to sinkholes, 11 parameters were selected as predictive variables to form the dataset. Because the training dataset was imbalanced with the majority of depressions being non-sinkholes, a weighted random forests method was used to improve the accuracy of predicting sinkholes. The weighted random forest achieved an average accuracy of 89.95% for the training dataset, demonstrating that the random forest can be an effective sinkhole classifier. Testing of the random forest in another area, however, resulted in moderate success with an average accuracy rate of 73.96%. This study suggests that an automatic sinkhole extraction procedure like the random forest classifier can significantly reduce time and labor costs and makes its more tractable to map sinkholes using Li<span class="hlt">DAR</span> data for large areas. However, the random forests method cannot totally replace manual procedures, such as visual inspection and field verification.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28282897','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28282897"><span>Li<span class="hlt">DAR</span>-IMU Time Delay Calibration Based on Iterative Closest Point and Iterated Sigma Point Kalman Filter.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Wanli</p> <p>2017-03-08</p> <p>The time delay calibration between Light Detection and Ranging (Li<span class="hlt">DAR</span>) and Inertial Measurement Units (IMUs) is an essential prerequisite for its applications. However, the correspondences between Li<span class="hlt">DAR</span> and IMU measurements are usually unknown, and thus cannot be computed directly for the time delay calibration. In order to solve the problem of Li<span class="hlt">DAR</span>-IMU time delay calibration, this paper presents a fusion method based on iterative closest point (ICP) and iterated sigma point Kalman filter (ISPKF), which combines the advantages of ICP and ISPKF. The ICP algorithm can precisely determine the unknown transformation between Li<span class="hlt">DAR</span>-IMU; and the ISPKF algorithm can optimally estimate the time delay calibration parameters. First of all, the coordinate transformation from the Li<span class="hlt">DAR</span> frame to the IMU frame is realized. Second, the measurement model and time delay error model of Li<span class="hlt">DAR</span> and IMU are established. Third, the methodology of the ICP and ISPKF procedure is presented for Li<span class="hlt">DAR</span>-IMU time delay calibration. Experimental results are presented that validate the proposed method and demonstrate the time delay error can be accurately calibrated.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5375825','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5375825"><span>Li<span class="hlt">DAR</span>-IMU Time Delay Calibration Based on Iterative Closest Point and Iterated Sigma Point Kalman Filter</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Liu, Wanli</p> <p>2017-01-01</p> <p>The time delay calibration between Light Detection and Ranging (Li<span class="hlt">DAR</span>) and Inertial Measurement Units (IMUs) is an essential prerequisite for its applications. However, the correspondences between Li<span class="hlt">DAR</span> and IMU measurements are usually unknown, and thus cannot be computed directly for the time delay calibration. In order to solve the problem of Li<span class="hlt">DAR</span>-IMU time delay calibration, this paper presents a fusion method based on iterative closest point (ICP) and iterated sigma point Kalman filter (ISPKF), which combines the advantages of ICP and ISPKF. The ICP algorithm can precisely determine the unknown transformation between Li<span class="hlt">DAR</span>-IMU; and the ISPKF algorithm can optimally estimate the time delay calibration parameters. First of all, the coordinate transformation from the Li<span class="hlt">DAR</span> frame to the IMU frame is realized. Second, the measurement model and time delay error model of Li<span class="hlt">DAR</span> and IMU are established. Third, the methodology of the ICP and ISPKF procedure is presented for Li<span class="hlt">DAR</span>-IMU time delay calibration. Experimental results are presented that validate the proposed method and demonstrate the time delay error can be accurately calibrated. PMID:28282897</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26250147','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26250147"><span>Development and validation of the Dimensional Anhedonia Rating Scale (<span class="hlt">DARS</span>) in a community sample and individuals with major depression.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Rizvi, Sakina J; Quilty, Lena C; Sproule, Beth A; Cyriac, Anna; Michael Bagby, R; Kennedy, Sidney H</p> <p>2015-09-30</p> <p>Anhedonia, a core symptom of Major Depressive Disorder (MDD), is predictive of antidepressant non-response. In contrast to the definition of anhedonia as a "loss of pleasure", neuropsychological studies provide evidence for multiple facets of hedonic function. The aim of the current study was to develop and validate the Dimensional Anhedonia Rating Scale (<span class="hlt">DARS</span>), a dynamic scale that measures desire, motivation, effort and consummatory pleasure across hedonic domains. Following item selection procedures and reliability testing using data from community participants (N=229) (Study 1), the 17-item scale was validated in an online study with community participants (N=150) (Study 2). The <span class="hlt">DARS</span> was also validated in unipolar or bipolar depressed patients (n=52) and controls (n=50) (Study 3). Principal components analysis of the 17-item <span class="hlt">DARS</span> revealed a 4-component structure mapping onto the domains of anhedonia: hobbies, food/drink, social activities, and sensory experience. Reliability of the <span class="hlt">DARS</span> subscales was high across studies (Cronbach's α=0.75-0.92). The <span class="hlt">DARS</span> also demonstrated good convergent and divergent validity. Hierarchical regression analysis revealed the <span class="hlt">DARS</span> showed additional utility over the Snaith-Hamilton Pleasure Scale (SHAPS) in predicting reward function and distinguishing MDD subgroups. These studies provide support for the reliability and validity of the <span class="hlt">DARS</span>.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMEP23A0775Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMEP23A0775Q"><span>An application of vessel-based Li<span class="hlt">DAR</span> to quantify coastal retreat in Southern Monterey Bay, CA during the 2008-2009 year and the 2009-2010 El Nino</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Quan, S.; Kvitek, R. G.; Smith, D. P.</p> <p>2010-12-01</p> <p>Coastal erosion has become a prominent issue in Monterey Bay, California. Areas at high risk include native coastal dunes, private and public beachfront properties, municipal sewage lines, and areas of the highway 1 corridor. Traditional airborne Li<span class="hlt">DAR</span> has been an effective but costly method for measuring coastal topography by providing high resolution and broad coverage. In 1997 and 1998, NASA, USGS, and NOAA collaborated to conduct pre-and post-El Niño airborne Li<span class="hlt">DAR</span> surveys of the California coastline. The anticipation of this ENSO event coupled with Li<span class="hlt">DAR</span> technology resulted in high resolution snapshots of the coastline pre-post El Niño, with analyses yielding erosion rates on the order of nearly seven times the historical annual dune erosion average (Thornton et <span class="hlt">al</span> 2006). Since then, there have been no further, publicly available Li<span class="hlt">DAR</span> surveys of the Monterey Bay shoreline. The goal of this project is to apply a vessel-based Li<span class="hlt">DAR</span> system to measure coastal geomorphology, determine the efficacy of vessel-based topographic Li<span class="hlt">DAR</span> for mapping coastal geomorphology, and quantify the spatial distribution of coastal retreat for Southern Monterey Bay, California during the 2009-10 El Niño and the 2008-2009 normal (non- El Niño) year. The area of study was the Monterey Bay coastline from Monterey harbor, CA north to Marina State Beach at Reservation Road. Sea cliff morphology data were measured on Dec 9th and 10th, 2008, Nov 4th 2009, and on July 15, 16, and 17th 2010 through the use of a terrestrial Li<span class="hlt">DAR</span> system mounted atop the CSUMB Seafloor Mapping Lab’s R/V VenTresca. These vessel based Li<span class="hlt">DAR</span> data were compared using mapping and spatial analysis tools in ArcGIS to quantify the spatial distribution of coastal retreat and calculate erosion rates for the Monterey Bay shoreline during the 2009-2010 El Niño and the 2008-2009 normal year. In keeping with previous published work based on other methods, preliminary results show numerous erosional hotspots which</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.H23E1318M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.H23E1318M"><span>Importance of High-Resolution Li<span class="hlt">DAR</span> Data in Modeling Runoff Levels Over Impervious Surfaces</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Melosh, C.; Rao, M.</p> <p>2013-12-01</p> <p>Directly connected impervious areas collect and deliver unfiltered runoff to modified and impacted waterways. Modeling water flow over the landscape is an effective method of observing drainage patterns and predicting pollutant and sediment loadings. Improved models applying high-resolution elevation data can identify key areas with high pollutant output. This is a crucial issue in the Lake Tahoe Basin where lakeshore urban development has increased and lake clarity has been declining for years. This study aims to evaluate an integrated Li<span class="hlt">DAR</span> and GIS-based modeling approach that uses a fine-scaled ground surface and impervious surface connectivity to predict the pollutant load in the Lake Tahoe Basin This study produced a fine-scaled surface model of nine subset catchments in the South Tahoe basin, including areas of low (below 20%), medium (30% to 50%) and high (above 50%) impervious surface cover. Our method integrated Li<span class="hlt">DAR</span>, multispectral imagery, and GIS data to develop accurate terrain models, hydrologic routing, and directly connected impervious area layers for the Lake Tahoe basin. The high-density ground and object elevation data collected using Light Detection and Ranging (Li<span class="hlt">DAR</span>) creates an accurate picture of water flow over the land, and obstacles to the flow such as buildings. High-resolution Li<span class="hlt">DAR</span> data was obtained from the Round 10 Lake Tahoe Southern Nevada Public Land Management capital program from the year 2010. This data was processed to create a digital elevation model of the ground surface. Land use classification used object height information from the Li<span class="hlt">DAR</span> cloud, NAIP 4-band images with 1-meter resolution and a normalized difference vegetation index image derived from the NAIP imagery. The US Army Core of Engineers hydrologic modeling system (HEC-HMS) will be used to model runoff. Based on long-term simulations the effect of directly connected impervious area on rainfall-runoff characteristics for the South Lake Tahoe catchments will be</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70034405','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70034405"><span>Investigating the spatial distribution of water levels in the Mackenzie Delta using airborne Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hopkinson, C.; Crasto, N.; Marsh, P.; Forbes, D.; Lesack, L.</p> <p>2011-01-01</p> <p>Airborne light detection and ranging (Li<span class="hlt">DAR</span>) data were used to map water level (WL) and hydraulic gradients (??H/??x) in the Mackenzie Delta. The Li<span class="hlt">DAR</span> WL data were validated against eight independent hydrometric gauge measurements and demonstrated mean offsets from - 0??22 to + 0??04 m (??< 0??11). Li<span class="hlt">DAR</span>-based WL gradients could be estimated with confidence over channel lengths exceeding 5-10 km where the WL change exceeded local noise levels in the Li<span class="hlt">DAR</span> data. For the entire Delta, the Li<span class="hlt">DAR</span> sample coverage indicated a rate of change in longitudinal gradient (??2H/??x) of 5??5 ?? 10-10 m m-2; therefore offering a potential means to estimate average flood stage hydraulic gradient for areas of the Delta not sampled or monitored. In the Outer Delta, within-channel and terrain gradient measurements all returned a consistent estimate of - 1 ?? 10-5 m m-1, suggesting that this is a typical hydraulic gradient for the downstream end of the Delta. For short reaches (<10 km) of the Peel and Middle Channels in the middle of the Delta, significant and consistent hydraulic gradient estimates of - 5 ?? 10-5 m m-1 were observed. Evidence that hydraulic gradients can vary over short distances, however, was observed in the Peel Channel immediately upstream of Aklavik. A positive elevation anomaly (bulge) of > 0??1 m was observed at a channel constriction entering a meander bend, suggesting a localized modification of the channel hydraulics. Furthermore, water levels in the anabranch channels of the Peel River were almost 1 m higher than in Middle Channel of the Mackenzie River. This suggests: (i) the channels are elevated and have shallower bank heights in this part of the delta, leading to increased cross-delta and along-channel hydraulic gradients; and/or (ii) a proportion of the Peel River flow is lost to Middle Channel due to drainage across the delta through anastamosing channels. This study has demonstrated that airborne Li<span class="hlt">DAR</span> data contain valuable information describing</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2764732','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=2764732"><span><span class="hlt">DAr</span>T markers: diversity analyses, genomes comparison, mapping and integration with SSR markers in Triticum monococcum</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Jing, Hai-Chun; Bayon, Carlos; Kanyuka, Kostya; Berry, Simon; Wenzl, Peter; Huttner, Eric; Kilian, Andrzej; E Hammond-Kosack, Kim</p> <p>2009-01-01</p> <p>Background Triticum monococcum (2n = 2x = 14) is an ancient diploid wheat with many useful traits and is used as a model for wheat gene discovery. <span class="hlt">DAr</span>T (Diversity Arrays Technology) employs a hybridisation-based approach to type thousands of genomic loci in parallel. <span class="hlt">DAr</span>T markers were developed for T. monococcum to assess genetic diversity, compare relationships with hexaploid genomes, and construct a genetic linkage map integrating <span class="hlt">DAr</span>T and microsatellite markers. Results A <span class="hlt">DAr</span>T array, consisting of 2304 hexaploid wheat, 1536 tetraploid wheat, 1536 T. monococcum as well as 1536 T. boeoticum representative genomic clones, was used to fingerprint 16 T. monococcum accessions of diverse geographical origins. In total, 846 polymorphic <span class="hlt">DAr</span>T markers were identified, of which 317 were of T. monococcum origin, 246 of hexaploid, 157 of tetraploid, and 126 of T. boeoticum genomes. The fingerprinting data indicated that the geographic origin of T. monococcum accessions was partially correlated with their genetic variation. <span class="hlt">DAr</span>T markers could also well distinguish the genetic differences amongst a panel of 23 hexaploid wheat and nine T. monococcum genomes. For the first time, 274 <span class="hlt">DAr</span>T markers were integrated with 82 simple sequence repeat (SSR) and two morphological trait loci in a genetic map spanning 1062.72 cM in T. monococcum. Six chromosomes were represented by single linkage groups, and chromosome 4Am was formed by three linkage groups. The <span class="hlt">DAr</span>T and SSR genetic loci tended to form independent clusters along the chromosomes. Segregation distortion was observed for one third of the <span class="hlt">DAr</span>T loci. The Ba (black awn) locus was refined to a 23.2 cM region between the <span class="hlt">DAr</span>T marker locus wPt-2584 and the microsatellite locus Xgwmd33 on 1Am; and the Hl (hairy leaf) locus to a 4.0 cM region between <span class="hlt">DAr</span>T loci 376589 and 469591 on 5Am. Conclusion <span class="hlt">DAr</span>T is a rapid and efficient approach to develop many new molecular markers for genetic studies in T. monococcum. The constructed genetic</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017NatSR...740362S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017NatSR...740362S"><span>Evaluation of hyperspectral Li<span class="hlt">DAR</span> for monitoring rice leaf nitrogen by comparison with multispectral Li<span class="hlt">DAR</span> and passive spectrometer</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sun, Jia; Shi, Shuo; Gong, Wei; Yang, Jian; Du, Lin; Song, Shalei; Chen, Biwu; Zhang, Zhenbing</p> <p>2017-01-01</p> <p>Fast and nondestructive assessment of leaf nitrogen concentration (LNC) is critical for crop growth diagnosis and nitrogen management guidance. In the last decade, multispectral Li<span class="hlt">DAR</span> (MSL) systems have promoted developments in the earth and ecological sciences with the additional spectral information. With more wavelengths than MSL, the hyperspectral Li<span class="hlt">DAR</span> (HSL) system provides greater possibilities for remote sensing crop physiological conditions. This study compared the performance of ASD FieldSpec Pro FR, MSL, and HSL for estimating rice (Oryza sativa) LNC. Spectral reflectance and biochemical composition were determined in rice leaves of different cultivars (Yongyou 4949 and Yangliangyou 6) throughout two growing seasons (2014–2015). Results demonstrated that HSL provided the best indicator for predicting rice LNC, yielding a coefficient of determination (R2) of 0.74 and a root mean square error of 2.80 mg/g with a support vector machine, similar to the performance of ASD (R2 = 0.73). Estimation of rice LNC could be significantly improved with the finer spectral resolution of HSL compared with MSL (R2 = 0.56).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5238418','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5238418"><span>Evaluation of hyperspectral Li<span class="hlt">DAR</span> for monitoring rice leaf nitrogen by comparison with multispectral Li<span class="hlt">DAR</span> and passive spectrometer</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Sun, Jia; Shi, Shuo; Gong, Wei; Yang, Jian; Du, Lin; Song, Shalei; Chen, Biwu; Zhang, Zhenbing</p> <p>2017-01-01</p> <p>Fast and nondestructive assessment of leaf nitrogen concentration (LNC) is critical for crop growth diagnosis and nitrogen management guidance. In the last decade, multispectral Li<span class="hlt">DAR</span> (MSL) systems have promoted developments in the earth and ecological sciences with the additional spectral information. With more wavelengths than MSL, the hyperspectral Li<span class="hlt">DAR</span> (HSL) system provides greater possibilities for remote sensing crop physiological conditions. This study compared the performance of ASD FieldSpec Pro FR, MSL, and HSL for estimating rice (Oryza sativa) LNC. Spectral reflectance and biochemical composition were determined in rice leaves of different cultivars (Yongyou 4949 and Yangliangyou 6) throughout two growing seasons (2014–2015). Results demonstrated that HSL provided the best indicator for predicting rice LNC, yielding a coefficient of determination (R2) of 0.74 and a root mean square error of 2.80 mg/g with a support vector machine, similar to the performance of ASD (R2 = 0.73). Estimation of rice LNC could be significantly improved with the finer spectral resolution of HSL compared with MSL (R2 = 0.56). PMID:28091610</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/28091610','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/28091610"><span>Evaluation of hyperspectral Li<span class="hlt">DAR</span> for monitoring rice leaf nitrogen by comparison with multispectral Li<span class="hlt">DAR</span> and passive spectrometer.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sun, Jia; Shi, Shuo; Gong, Wei; Yang, Jian; Du, Lin; Song, Shalei; Chen, Biwu; Zhang, Zhenbing</p> <p>2017-01-16</p> <p>Fast and nondestructive assessment of leaf nitrogen concentration (LNC) is critical for crop growth diagnosis and nitrogen management guidance. In the last decade, multispectral Li<span class="hlt">DAR</span> (MSL) systems have promoted developments in the earth and ecological sciences with the additional spectral information. With more wavelengths than MSL, the hyperspectral Li<span class="hlt">DAR</span> (HSL) system provides greater possibilities for remote sensing crop physiological conditions. This study compared the performance of ASD FieldSpec Pro FR, MSL, and HSL for estimating rice (Oryza sativa) LNC. Spectral reflectance and biochemical composition were determined in rice leaves of different cultivars (Yongyou 4949 and Yangliangyou 6) throughout two growing seasons (2014-2015). Results demonstrated that HSL provided the best indicator for predicting rice LNC, yielding a coefficient of determination (R(2)) of 0.74 and a root mean square error of 2.80 mg/g with a support vector machine, similar to the performance of ASD (R(2) = 0.73). Estimation of rice LNC could be significantly improved with the finer spectral resolution of HSL compared with MSL (R(2) = 0.56).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA589768','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA589768"><span>Li<span class="hlt">DAR</span> Point Cloud and Stereo Image Point Cloud Fusion</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>2013-09-01</p> <p>Photogrammetry , Fusion, Accuracy 15. NUMBER OF PAGES 81 16. PRICE CODE 17. SECURITY CLASSIFICATION OF REPORT Unclassified 18. SECURITY CLASSIFICATION...similar to those of Photogrammetry . In Photogrammetry , the objective is to extract precision three-dimensional representations of the earth’s surface...knowledge problems. 4 The history of Li<span class="hlt">DAR</span> and photogrammetry fusion shows that many individuals with diverse interests are studying this problem</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA601990','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA601990"><span>Use of Li<span class="hlt">DAR</span> to Assist in Delineating Waters of the United States, Including Wetlands</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>2014-03-01</p> <p>position in the land- scape. Wetness indices are often calculated using the general formula WI = ln(A/tanβ) where A is the catchment area (m2/m...delineations of an Ordinary High Water Mark (OHWM) boundary, Li<span class="hlt">DAR</span> data or products may be used to view the OHWM signature across a project area ...view vegeta- tive, topographic, and hydrologic patterns across a project area and to focus the investigation on transitional areas . They cannot</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20090027836&hterms=Norway&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DNorway','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20090027836&hterms=Norway&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D10%26Ntt%3DNorway"><span>Estimating Volume, Biomass, and Carbon in Hedmark County, Norway Using a Profiling Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nelson, Ross; Naesset, Erik; Gobakken, T.; Gregoire, T.; Stahl, G.</p> <p>2009-01-01</p> <p>A profiling airborne Li<span class="hlt">DAR</span> is used to estimate the forest resources of Hedmark County, Norway, a 27390 square kilometer area in southeastern Norway on the Swedish border. One hundred five profiling flight lines totaling 9166 km were flown over the entire county; east-west. The lines, spaced 3 km apart north-south, duplicate the systematic pattern of the Norwegian Forest Inventory (NFI) ground plot arrangement, enabling the profiler to transit 1290 circular, 250 square meter fixed-area NFI ground plots while collecting the systematic Li<span class="hlt">DAR</span> sample. Seven hundred sixty-three plots of the 1290 plots were overflown within 17.8 m of plot center. Laser measurements of canopy height and crown density are extracted along fixed-length, 17.8 m segments closest to the center of the ground plot and related to basal area, timber volume and above- and belowground dry biomass. Linear, nonstratified equations that estimate ground-measured total aboveground dry biomass report an R(sup 2) = 0.63, with an regression RMSE = 35.2 t/ha. Nonstratified model results for the other biomass components, volume, and basal area are similar, with R(sup 2) values for all models ranging from 0.58 (belowground biomass, RMSE = 8.6 t/ha) to 0.63. Consistently, the most useful single profiling Li<span class="hlt">DAR</span> variable is quadratic mean canopy height, h (sup bar)(sub qa). Two-variable models typically include h (sup bar)(sub qa) or mean canopy height, h(sup bar)(sub a), with a canopy density or a canopy height standard deviation measure. Stratification by productivity class did not improve the nonstratified models, nor did stratification by pine/spruce/hardwood. County-wide profiling Li<span class="hlt">DAR</span> estimates are reported, by land cover type, and compared to NFI estimates.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.B43C0549W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.B43C0549W"><span>Mapping Vegetation Canopy Structure and Distribution for Great Smoky Mountains National Park Using Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Weiner, J.; Kumar, J.; Norman, S. P.</p> <p>2015-12-01</p> <p>A major challenge in forest management is the inaccessibility of large swaths of land, which makes accurate monitoring of forest change difficult. Remote sensing methods can help address this issue by allowing investigators to monitor remote or inaccessible regions using aerial or satellite-based platforms. However, most remote sensing methods do not provide a full three-dimensional (3D) description of the area. Rather, they return only a single elevation point or landcover description. Multiple-return Li<span class="hlt">DAR</span> (Light Detection and Ranging) gathers data in a 3D point cloud, which allows forest managers to more accurately characterize and monitor changes in canopy structure and vegetation-type distribution. Our project used high-resolution aerial multiple-return Li<span class="hlt">DAR</span> data to determine vegetation canopy structures and their spatial distribution in Great Smoky Mountains National Park. To ensure sufficient data density and to match LANDSAT resolution, we gridded the data into 30m x 30m cells. The Li<span class="hlt">DAR</span> data points within each cell were then used to generate the vertical canopy structure for that cell. After vertical profiles had been created, we used a k-means cluster analysis algorithm to classify the landscape based on the canopy structure. The spatial distribution of distinct and unique canopy structures was mapped across the park and compared to a vegetation-type map to determine the correlation of canopy structure to vegetation types. Preliminary analysis conducted at a number of phenology sites maintained by the Great Smoky Mountains Institute at Tremont shows strong correspondence between canopy structure and vegetation type. However, more validation is needed in other regions of the park to establish this method as a reliable tool. Li<span class="hlt">DAR</span> data has a unique ability to map full 3D structures of vegetation and the methods developed in this project offer an extensible tool for forest mapping and monitoring.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/20048314','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/20048314"><span>Combining Li<span class="hlt">DAR</span> and IKONOS data for eco-hydrological classification of an ombrotrophic peatland.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Anderson, K; Bennie, J J; Milton, E J; Hughes, P D M; Lindsay, R; Meade, R</p> <p>2010-01-01</p> <p>Remote sensing techniques have potential for peatland monitoring, but most previous work has focused on spectral approaches that often result in poor discrimination of cover types and neglect structural information. Peatlands contain structural "microtopes" (e.g., hummocks and hollows) which are linked to hydrology, biodiversity and carbon sequestration, and information on surface structure is thus a useful proxy for peatland condition. The objective of this work was to develop and test a new eco-hydrological mapping technique for ombrotrophic (rain-fed) peatlands using a combined spectral-structural remote sensing approach. The study site was Wedholme Flow, Cumbria, UK. Airborne light dectection and ranging (Li<span class="hlt">DAR</span>) data were used with IKONOS data in a combined multispectral-structural approach for mapping peatland condition classes. Li<span class="hlt">DAR</span> data were preprocessed so that spatial estimates of minimum and maximum land surface height, variance and semi-variance (from semi-variogram analysis) were extracted. These were assimilated alongside IKONOS data into a maximum likelihood classification procedure, and thematic outputs were compared. Ecological survey data were used to validate the results. Considerable improvements in thematic separation of peatland classes were achieved when spatially-distributed measurements of Li<span class="hlt">DAR</span> variance or semi-variance were included. Specifically, the classification accuracy improved from 71.8% (IKONOS data only) to 88.0% when a Li<span class="hlt">DAR</span> semi-variance product was used. Of note was the improved delineation of management classes (including Eriophorum bog, active raised bog and degraded raised bog). The application of a combined textural-optical approach can improve land cover mapping in areas where reliance on purely spectral discrimination approaches would otherwise result in considerable thematic uncertainty.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.B43C0584S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.B43C0584S"><span>Flying Under the Li<span class="hlt">DAR</span>: Relating Forest Structure to Bat Community Diversity</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Swanson, A. C.; Weishampel, J. F.</p> <p>2015-12-01</p> <p>Bats are important to many ecological processes such as pollination, insect (and by proxy, disease) control, and seed dispersal and can be used to monitor ecosystem health. However, they are facing unprecedented extinction risks from habitat degradation as well as pressures from pathogens (e.g., white-nose syndrome) and wind turbines. Li<span class="hlt">DAR</span> allows ecologists to measure structural variables of forested landscapes with increased precision and accuracy at broader spatial scales than previously possible. This study used airborne Li<span class="hlt">DAR</span> to classify forest habitat/canopy structure at the Ordway-Swisher Biological Station (OSBS) in north central Florida. Li<span class="hlt">DAR</span> data were acquired by the NEON airborne observation platform in summer 2014. OSBS consists of open-canopy pine savannas, closed-canopy hardwood hammocks, and seasonally wet prairies. Multiple forest structural parameters (e.g., mean, maximum, and standard deviation of height returns) were derived from Li<span class="hlt">DAR</span> point clouds using the USDA software program FUSION. K-means clustering was used to segregate each 5x5 m raster across the ~3765 ha OSBS area into six different clusters based on the derived canopy metrics. Cluster averages for maximum, mean, and standard deviation of return heights ranged from 0 to 19.4 m, 0 to 15.3 m, and 0 to 3.0 m, respectively. To determine the relationships among these landscape-canopy features and bat species diversity and abundances, AnaBat II bat detectors were deployed from May to September in 2015 stratified by these distinct clusters. Bat calls were recorded from sunset to sunrise during each sampling period. Species were identified using AnalookW. A statistical regression model selection approach was performed in order to evaluate how forest attributes such as understory clutter, open regions, open and closed canopy, etc. influence bat communities. This knowledge provides a deeper understanding of habitat-species interactions to better manage survival of these species.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPRS..118...22H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPRS..118...22H"><span>Road centerline extraction from airborne Li<span class="hlt">DAR</span> point cloud based on hierarchical fusion and optimization</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hui, Zhenyang; Hu, Youjian; Jin, Shuanggen; Yevenyo, Yao Ziggah</p> <p>2016-08-01</p> <p>Road information acquisition is an important part of city informatization construction. Airborne Li<span class="hlt">DAR</span> provides a new means of acquiring road information. However, the existing road extraction methods using Li<span class="hlt">DAR</span> point clouds always decide the road intensity threshold based on experience, which cannot obtain the optimal threshold to extract a road point cloud. Moreover, these existing methods are deficient in removing the interference of narrow roads and several attached areas (e.g., parking lot and bare ground) to main roads extraction, thereby imparting low completeness and correctness to the city road network extraction result. Aiming at resolving the key technical issues of road extraction from airborne Li<span class="hlt">DAR</span> point clouds, this paper proposes a novel method to extract road centerlines from airborne Li<span class="hlt">DAR</span> point clouds. The proposed approach is mainly composed of three key algorithms, namely, Skewness balancing, Rotating neighborhood, and Hierarchical fusion and optimization (SRH). The skewness balancing algorithm used for the filtering was adopted as a new method for obtaining an optimal intensity threshold such that the "pure" road point cloud can be obtained. The rotating neighborhood algorithm on the other hand was developed to remove narrow roads (corridors leading to parking lots or sidewalks), which are not the main roads to be extracted. The proposed hierarchical fusion and optimization algorithm caused the road centerlines to be unaffected by certain attached areas and ensured the road integrity as much as possible. The proposed method was tested using the Vaihingen dataset. The results demonstrated that the proposed method can effectively extract road centerlines in a complex urban environment with 91.4% correctness and 80.4% completeness.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA538884','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA538884"><span>Fast Surface Reconstruction and Segmentation with Terrestrial Li<span class="hlt">DAR</span> Range Data</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>2009-05-18</p> <p>SUPPLEMENTARY NOTES 14. ABSTRACT Recent advances in range measurement devices have opened up new opportunities and challenges for fast 3D modeling of...which are composed of partially ordered terrestrial range data. Our algorithms can be applied to a large class of Li<span class="hlt">DAR</span> data acquisition systems, where...obtained by two different terrestrial acquisition systems. The first dataset contains 94 million points obtained by a vehicle-borne acquisition system</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.3829A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.3829A"><span>Abu Dhabi Basemap Update Using the Li<span class="hlt">DAR</span> Mobile Mapping Technology</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Alshaiba, Omar; Amparo Núñez-Andrés, M.; Lantada, Nieves</p> <p>2016-04-01</p> <p>Mobile Li<span class="hlt">DAR</span> system provides a new technology which can be used to update geospatial information by direct and rapid data collection. This technology is faster than the traditional survey ways and has lower cost. Abu Dhabi Municipal System aims to update its geospatial system frequently as the government entities have invested heavily in GIS technology and geospatial data to meet the repaid growth in the infrastructure and construction projects in recent years. The Emirate of Abu Dhabi has witnessed a huge growth in infrastructure and construction projects in recent years. Therefore, it is necessary to develop and update its basemap system frequently to meet their own organizational needs. Currently, the traditional ways are used to update basemap system such as human surveyors, GPS receivers and controller (GPS assigned computer). Then the surveyed data are downloaded, edited and reviewed manually before it is merged to the basemap system. Traditional surveying ways may not be applicable in some conditions such as; bad weather, difficult topographic area and boundary area. This paper presents a proposed methodology which uses the Mobile Li<span class="hlt">DAR</span> system to update basemap in Abu Dhabi by using daily transactions services. It aims to use and integrate the mobile Li<span class="hlt">DAR</span> technology into the municipality's daily workflow such that it becomes the new standard cost efficiency operating procedure for updating the base-map in Abu Dhabi Municipal System. On another note, the paper will demonstrate the results of the innovated workflow for the base-map update using the mobile Li<span class="hlt">DAR</span> point cloud and few processing algorithms.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_14");'>14</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li class="active"><span>16</span></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_16 --> <div id="page_17" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="321"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1610352C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1610352C"><span>3D turbulence measurements in inhomogeneous boundary layers with three wind Li<span class="hlt">DARs</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carbajo Fuertes, Fernando; Valerio Iungo, Giacomo; Porté-Agel, Fernando</p> <p>2014-05-01</p> <p>One of the most challenging tasks in atmospheric anemometry is obtaining reliable turbulence measurements of inhomogeneous boundary layers at heights or in locations where is not possible or convenient to install tower-based measurement systems, e.g. mountainous terrain, cities, wind farms, etc. Wind Li<span class="hlt">DARs</span> are being extensively used for the measurement of averaged vertical wind profiles, but they can only successfully accomplish this task under the limiting conditions of flat terrain and horizontally homogeneous flow. Moreover, it has been shown that common scanning strategies introduce large systematic errors in turbulence measurements, regardless of the characteristics of the flow addressed. From the point of view of research, there exist a variety of techniques and scanning strategies to estimate different turbulence quantities but most of them rely in the combination of raw measurements with atmospheric models. Most of those models are only valid under the assumption of horizontal homogeneity. The limitations stated above can be overcome by a new triple Li<span class="hlt">DAR</span> technique which uses simultaneous measurements from three intersecting Doppler wind Li<span class="hlt">DARs</span>. It allows for the reconstruction of the three-dimensional velocity vector in time as well as local velocity gradients without the need of any turbulence model and with minimal assumptions [EGU2013-9670]. The triple Li<span class="hlt">DAR</span> technique has been applied to the study of the flow over the campus of EPFL in Lausanne (Switzerland). The results show the potential of the technique for the measurement of turbulence in highly complex boundary layer flows. The technique is particularly useful for micrometeorology and wind engineering studies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014Geomo.214..307L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014Geomo.214..307L"><span>Step by step error assessment in braided river sediment budget using airborne Li<span class="hlt">DAR</span> data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lallias-Tacon, S.; Liébault, F.; Piégay, H.</p> <p>2014-06-01</p> <p>Sequential airborne Li<span class="hlt">DAR</span> surveys were used to reconstruct the sediment budget of a 7-km-long braided river channel in southeastern France following a 14-year return period flood and to improve its accuracy step by step. Data processing involved (i) surface matching of the sequential point clouds, (ii) spatially distributed propagation of uncertainty based on surface conditions of the channel, and (iii) water depth subtraction from the digital elevation models based on water depths measured in the field. The respective influence of each processing step on sediment budget computation was systematically documented. This showed that surface matching and water depth subtraction both have a considerable effect on the net sediment budget. Although DEM of difference thresholding based on uncertainty analysis on absolute elevation values had a smaller effect on the sediment budget, this step is crucial for the production of a comprehensive map of channel deformations. A large independent data set of RTK-GPS checkpoints was used to control the quality of the Li<span class="hlt">DAR</span> altimetry. The results showed that high density (7-9 points/m2) airborne Li<span class="hlt">DAR</span> surveys can provide a very high level of detection of elevation changes on the exposed surfaces of the channel, with a 95% confidence interval level of detection between 19 and 30 cm. Change detection from Li<span class="hlt">DAR</span> data revealed that 54% of the pre-flood active channel was reworked by the flood. The braided channel pattern was highly disturbed by the flood owing to the occurrence of several channel avulsions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFMNH41B3785M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFMNH41B3785M"><span>Evaluation of Landslide Mapping Techniques and Li<span class="hlt">DAR</span>-based Conditioning Factors</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mahalingam, R.; Olsen, M. J.</p> <p>2014-12-01</p> <p>Landslides are a major geohazard, which result in significant human, infrastructure, and economic losses. Landslide susceptibility mapping can help communities to plan and prepare for these damaging events. Mapping landslide susceptible locations using GIS and remote sensing techniques is gaining popularity in the past three decades. These efforts use a wide variety of procedures and consider a wide range of factors. Unfortunately, each study is often completed differently and independently of others. Further, the quality of the datasets used varies in terms of source, data collection, and generation, which can propagate errors or inconsistencies into the resulting output maps. Light detection and ranging (Li<span class="hlt">DAR</span>) has proved to have higher accuracy in representing the continuous topographic surface, which can help minimize this uncertainty. The primary objectives of this paper are to investigate the applicability and performance of terrain factors in landslide hazard mapping, determine if Li<span class="hlt">DAR</span>-derived datasets (slope, slope roughness, terrain roughness, stream power index and compound topographic index) can be used for predictive mapping without data representing other common landslide conditioning factors, and evaluate the differences in landslide susceptibility mapping using widely-used statistical approaches. The aforementioned factors were used to produce landslide susceptibility maps for a 140 km2 study area in northwest Oregon using six representative techniques: frequency ratio, weights of evidence, logistic regression, discriminant analysis, artificial neural network, and support vector machine. Most notably, the research showed an advantage in selecting fewer critical conditioning factors. The most reliable factors all could be derived from a single Li<span class="hlt">DAR</span> DEM, reducing the need for laborious and costly data gathering. Most of the six techniques showed similar statistical results; however, ANN showed less accuracy for predictive mapping. Keywords : Li<span class="hlt">DAR</span></p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.C33G..07F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.C33G..07F"><span>Multispectral Airborne Mapping Li<span class="hlt">DAR</span> Observations of the McMurdo Dry Valleys</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fernandez Diaz, J. C.; Fountain, A. G.; Morin, P. J.; Singhania, A.; Hauser, D.; Obryk, M.; Shrestha, R. L.; Carter, W. E.; Sartori, M. P.</p> <p>2015-12-01</p> <p>Field observations have documented dramatic changes over the past decade in the McMurdo Dry Valleys of Antarctica: extreme river incisions, significant glacier loss, and the appearance of numerous thermokarst slumps. To date these observations have been sporadic and localized, and have not been able to capture change on a valley-wide scale. During the 2014-2015 Antarctic summer season, specifically between December 4th, 2014 and January 19th, 2015, we undertook a widescale airborne laser mapping campaign to collect a baseline digital elevation model for 3500 km2 area of the Dry Valleys and other areas of interest. The airborne Li<span class="hlt">DAR</span> observations were acquired with a novel multi-spectral Li<span class="hlt">DAR</span> sensor with active laser observations at three light wavelengths (532 nm, 1064 nm, and 1550 nm) simultaneously; which not only allowed the generation of a high resolution elevation model of the area, but also provides multispectral signatures for observed terrain features. In addition to the Li<span class="hlt">DAR</span> data, high resolution (5-15 cm pixels) digital color images were collected. During the six week survey campaign of the Dry Valleys a total of 30 flights were performed, in which about 20 billion Li<span class="hlt">DAR</span> returns and 21,000 60-Mpixels images were collected. The primary objective of this project is to perform a topographic change detection analysis by comparing the recently acquired dataset to a lower resolution dataset collected by NASA in the 2001-2002 season. This presentation will describe the processing and analysis of this significant mapping dataset and will provide some initial observations from the high resolution topography acquired.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20150023286','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20150023286"><span>NASA Goddards Li<span class="hlt">DAR</span>, Hyperspectral and Thermal (G-LiHT) Airborne Imager</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cook, Bruce D.; Corp, Lawrence A.; Nelson, Ross F.; Middleton, Elizabeth M.; Morton, Douglas C.; McCorkel, Joel T.; Masek, Jeffrey G.; Ranson, Kenneth J.; Ly, Vuong; Montesano, Paul M.</p> <p>2013-01-01</p> <p>The combination of Li<span class="hlt">DAR</span> and optical remotely sensed data provides unique information about ecosystem structure and function. Here, we describe the development, validation and application of a new airborne system that integrates commercial off the shelf Li<span class="hlt">DAR</span> hyperspectral and thermal components in a compact, lightweight and portable system. Goddard's Li<span class="hlt">DAR</span>, Hyperspectral and Thermal (G-LiHT) airborne imager is a unique system that permits simultaneous measurements of vegetation structure, foliar spectra and surface temperatures at very high spatial resolution (approximately 1 m) on a wide range of airborne platforms. The complementary nature of Li<span class="hlt">DAR</span>, optical and thermal data provide an analytical framework for the development of new algorithms to map plant species composition, plant functional types, biodiversity, biomass and carbon stocks, and plant growth. In addition, G-LiHT data enhance our ability to validate data from existing satellite missions and support NASA Earth Science research. G-LiHT's data processing and distribution system is designed to give scientists open access to both low- and high-level data products (http://gliht.gsfc.nasa.gov), which will stimulate the community development of synergistic data fusion algorithms. G-LiHT has been used to collect more than 6,500 km2 of data for NASA-sponsored studies across a broad range of ecoregions in the USA and Mexico. In this paper, we document G-LiHT design considerations, physical specifications, instrument performance and calibration and acquisition parameters. In addition, we describe the data processing system and higher-level data products that are freely distributed under NASA's Data and Information policy.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012SPIE.8537E..0MW','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012SPIE.8537E..0MW"><span>Reduction of training costs using active classification in fused hyperspectral and Li<span class="hlt">DAR</span> data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wuttke, Sebastian; Schilling, Hendrik; Middelmann, Wolfgang</p> <p>2012-11-01</p> <p>This paper presents a novel approach for the reduction of training costs in classification with co-registered hyperspectral (HS) and Light Detection and Ranging (Li<span class="hlt">DAR</span>) data using an active classification framework. Fully automatic classification can be achieved by unsupervised learning, which is not suited for adjustment to specific classes. On the other hand, supervised classification with predefined classes needs a lot of training examples, which need to be labeled with the ground truth, usually at a significant cost. The concept of active classification alleviates these problems by the use of a selection strategy: only selected samples are ground truth labeled and used as training data. One common selection strategy is to incorporate in a first step the current state of the classification algorithm and choose only the examples for which the expected information gain is maximized. In the second step a conventional classification algorithm is trained using this data. By alternating between these two steps the algorithm reaches high classification accuracy results with less training samples and therefore lower training costs. The approach presented in this paper involves the user in the active selection strategy and the k-NN algorithm is chosen for classification. The results further benefit from fusing the heterogeneous information of HS and Li<span class="hlt">DAR</span> data within the classification algorithm. For this purpose, several HS features, such as vegetation indices, and Li<span class="hlt">DAR</span> features, such as relative height and roughness, are extracted. This increases the separability between different classes and reduces the dimensionality of the HS data. The practicability and performance of this framework is shown for the detection and separation of different kinds of vegetation, e.g. trees and grass in an urban area of Berlin. The HS data was obtained by the SPECIM AISA Eagle 2 sensor, Li<span class="hlt">DAR</span> data by Riegl LMS Q560.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70042983','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70042983"><span>Strategies for minimizing sample size for use in airborne Li<span class="hlt">DAR</span>-based forest inventory</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Junttila, Virpi; Finley, Andrew O.; Bradford, John B.; Kauranne, Tuomo</p> <p>2013-01-01</p> <p>Recently airborne Light Detection And Ranging (Li<span class="hlt">DAR</span>) has emerged as a highly accurate remote sensing modality to be used in operational scale forest inventories. Inventories conducted with the help of Li<span class="hlt">DAR</span> are most often model-based, i.e. they use variables derived from Li<span class="hlt">DAR</span> point clouds as the predictive variables that are to be calibrated using field plots. The measurement of the necessary field plots is a time-consuming and statistically sensitive process. Because of this, current practice often presumes hundreds of plots to be collected. But since these plots are only used to calibrate regression models, it should be possible to minimize the number of plots needed by carefully selecting the plots to be measured. In the current study, we compare several systematic and random methods for calibration plot selection, with the specific aim that they be used in Li<span class="hlt">DAR</span> based regression models for forest parameters, especially above-ground biomass. The primary criteria compared are based on both spatial representativity as well as on their coverage of the variability of the forest features measured. In the former case, it is important also to take into account spatial auto-correlation between the plots. The results indicate that choosing the plots in a way that ensures ample coverage of both spatial and feature space variability improves the performance of the corresponding models, and that adequate coverage of the variability in the feature space is the most important condition that should be met by the set of plots collected.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.B51B0022M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.B51B0022M"><span>Single Pass Li<span class="hlt">DAR</span>-derived Estimate of Site Productivity in Western Oregon</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>McAdam, E.; Hilker, T.; Waring, R. H.; Sousa, C. H. R. D.; Moura, Y. M.</p> <p>2014-12-01</p> <p>Accurate estimates of forest growth at different ages are essential to evaluate the effect of a changing climate and to adjust management practices accordingly. Most current approaches are spatially discrete and therefore unable to predict forest growth accurately across landscapes. While airborne Li<span class="hlt">DAR</span> has been widely used in forestry, it can only estimate growth rates with repeated passes. In contrast, Landsat imagery records disturbances (at 30 m resolution) but is unable to measure changes in growth rates. Historical archives of Landsat imagery provided us a way of knowing when and where even-aged stands of Pseudotsuga menziesii (Douglas-fir) were cut and replanted. Since early growth rates are nearly linear with age, the height of dominant trees recorded in one pass by Li<span class="hlt">DAR</span> yields a direct measure of growth and likely changes as stands age under recent climatic conditions. Process-based growth models are available to assess possible shifts in the growth rates of stands under a changing climate; the accuracy of such model predictions can be evaluated with additional Li<span class="hlt">DAR</span> coverage. In this study we use the Physiological Principles Predicting Growth Model (3-PG) to estimate site index at the landscape level to predict site productivity based on the year of stand establishment obtained from Landsat, and one-pass airborne Li<span class="hlt">DAR</span> measurement of forest height. We are monitoring forest plantations of known ages and with data on their current age we will calculate site index for 60 separate sites across western Oregon. The results of this study will allow us to create updated site index maps for the state of Oregon under varying climate scenarios.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70175910','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70175910"><span>Quantitative study of tectonic geomorphology along Haiyuan fault based on airborne Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Chen, Tao; Zhang, Pei Zhen; Liu, Jing; Li, Chuan You; Ren, Zhi Kun; Hudnut, Kenneth W.</p> <p>2014-01-01</p> <p>High-precision and high-resolution topography are the fundamental data for active fault research. Light detection and ranging (Li<span class="hlt">DAR</span>) presents a new approach to build detailed digital elevation models effectively. We take the Haiyuan fault in Gansu Province as an example of how Li<span class="hlt">DAR</span> data may be used to improve the study of active faults and the risk assessment of related hazards. In the eastern segment of the Haiyuan fault, the Shaomayin site has been comprehensively investigated in previous research because of its exemplary tectonic topographic features. Based on unprecedented Li<span class="hlt">DAR</span> data, the horizontal and vertical coseismic offsets at the Shaomayin site are described. The measured horizontal value is about 8.6 m, and the vertical value is about 0.8 m. Using prior dating ages sampled from the same location, we estimate the horizontal slip rate as 4.0 ± 1.0 mm/a with high confidence and define that the lower bound of the vertical slip rate is 0.4 ± 0.1 mm/a since the Holocene. Li<span class="hlt">DAR</span> data can repeat the measurements of field work on quantifying offsets of tectonic landform features quite well. The offset landforms are visualized on an office computer workstation easily, and specialized software may be used to obtain displacement quantitatively. By combining precious chronological results, the fundamental link between fault activity and large earthquakes is better recognized, as well as the potential risk for future earthquake hazards.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20050156907','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20050156907"><span>Mapping and Monitoring Delmarva Fox Squirrel Habitat Using an Airborne Li<span class="hlt">DAR</span> Profiler</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Nelson, Ross; Ratnaswamy, Mary; Keller, Cherry</p> <p>2004-01-01</p> <p>Twenty five hundred thirty nine kilometers of airborne laser profiling and videography data were acquired over the state of Delaware during the summer of 2000. The laser ranging measurements and video from approximately one-half of that data set (1304 km) were analyzed to identify and locate forested sites that might potentially support populations of Delmarva fox squirrel (DFS, Sciurus niger cinereus). The DFS is an endangered species previously endemic to tall, dense, mature forests with open understories on the Eastern Shore of the Chesapeake Bay. The airborne Li<span class="hlt">DAR</span> employed in this study can measure forest canopy height and canopy closure, but cannot measure or infer understory canopy conditions. Hence the Li<span class="hlt">DAR</span> must be viewed as a tool to map potential, not actual, habitat. Fifty-three potentially suitable DFS sites were identified in the 1304 km of flight transect data. Each of the 53 sites met the following criteria according to the Li<span class="hlt">DAR</span> and video record: (1 ) at least 120m of contiguous forest; (2) an average canopy height greater than 20m; (3) an average canopy closure of >80%; and (4) no roofs, impervious surface (e.g., asphalt, concrete), and/or open water anywhere along the 120m length of the laser segment. Thirty-two of the 53 sites were visited on the ground and measurements taken for a DFS habitat suitability model. Seventy eight percent of the sites (25 of 32) were judged by the model to be suited to supporting a DFS population. Twenty-eight of the 32 sites visited in the field were in forest cover types (hardwood, mixed wood, conifer, wetlands) according to a land cover GIS map. Of these, 23 (82%) were suited to support DFS. The remaining 4 sites were located in nonforest cover types - agricultural or residential areas. Two of the four, or 50% were suited to the DFS. All of the Li<span class="hlt">DAR</span> flight data, 2539 km, were analyzed to</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JARS....8.3529S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JARS....8.3529S"><span>Evaluation of the contribution of Li<span class="hlt">DAR</span> data and postclassification procedures to object-based classification accuracy</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Styers, Diane M.; Moskal, L. Monika; Richardson, Jeffrey J.; Halabisky, Meghan A.</p> <p>2014-01-01</p> <p>Object-based image analysis (OBIA) is becoming an increasingly common method for producing land use/land cover (LULC) classifications in urban areas. In order to produce the most accurate LULC map, Li<span class="hlt">DAR</span> data and postclassification procedures are often employed, but their relative contributions to accuracy are unclear. We examined the contribution of Li<span class="hlt">DAR</span> data and postclassification procedures to increase classification accuracies over using imagery alone and assessed sources of error along an ecologically complex urban-to-rural gradient in Olympia, Washington. Overall classification accuracy and user's and producer's accuracies for individual classes were evaluated. The addition of Li<span class="hlt">DAR</span> data to the OBIA classification resulted in an 8.34% increase in overall accuracy, while manual postclassification to the imagery+Li<span class="hlt">DAR</span> classification improved accuracy only an additional 1%. Sources of error in this classification were largely due to edge effects, from which multiple different types of errors result.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.H31D1436N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.H31D1436N"><span>Analyzing Hydro-Geomorphic Responses in Post-Fire Stream Channels with Terrestrial Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nourbakhshbeidokhti, S.; Kinoshita, A. M.; Chin, A.</p> <p>2015-12-01</p> <p>Wildfires have potential to significantly alter soil properties and vegetation within watersheds. These alterations often contribute to accelerated erosion, runoff, and sediment transport in stream channels and hillslopes. This research applies repeated Terrestrial Laser Scanning (TLS) Light Detection and Ranging (Li<span class="hlt">DAR</span>) to stream reaches within the Pike National Forest in Colorado following the 2012 Waldo Canyon Fire. These scans allow investigation of the relationship between sediment delivery and environmental characteristics such as precipitation, soil burn severity, and vegetation. Post-fire Li<span class="hlt">DAR</span> images provide high resolution information of stream channel changes in eight reaches for three years (2012-2014). All images are processed with RiSCAN PRO to remove vegetation and triangulated and smoothed to create a Digital Elevation Model (DEM) with 0.1 m resolution. Study reaches with two or more successive DEM images are compared using a differencing method to estimate the volume of sediment erosion and deposition. Preliminary analysis of four channel reaches within Williams Canyon and Camp Creek yielded erosion estimates between 0.035 and 0.618 m3 per unit area. Deposition was estimated as 0.365 to 1.67 m3 per unit area. Reaches that experienced higher soil burn severity or larger rainfall events produced the greatest geomorphic changes. Results from Li<span class="hlt">DAR</span> analyses can be incorporated into post-fire hydrologic models to improve estimates of runoff and sediment yield. These models will, in turn, provide guidance for water resources management and downstream hazards mitigation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9988E..03H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9988E..03H"><span>Automated object detection and tracking with a flash Li<span class="hlt">DAR</span> system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hammer, Marcus; Hebel, Marcus; Arens, Michael</p> <p>2016-10-01</p> <p>The detection of objects, or persons, is a common task in the fields of environment surveillance, object observation or danger defense. There are several approaches for automated detection with conventional imaging sensors as well as with Li<span class="hlt">DAR</span> sensors, but for the latter the real-time detection is hampered by the scanning character and therefore by the data distortion of most Li<span class="hlt">DAR</span> systems. The paper presents a solution for real-time data acquisition of a flash Li<span class="hlt">DAR</span> sensor with synchronous raw data analysis, point cloud calculation, object detection, calculation of the next best view and steering of the pan-tilt head of the sensor. As a result the attention is always focused on the object, independent of the behavior of the object. Even for highly volatile and rapid changes in the direction of motion the object is kept in the field of view. The experimental setup used in this paper is realized with an elementary person detection algorithm in medium distances (20 m to 60 m) to show the efficiency of the system for objects with a high angular speed. It is easy to replace the detection part by any other object detection algorithm and thus it is easy to track nearly any object, for example a car or a boat or an UAV in various distances.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23828665','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23828665"><span>Geodetic imaging with airborne Li<span class="hlt">DAR</span>: the Earth's surface revealed.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Glennie, C L; Carter, W E; Shrestha, R L; Dietrich, W E</p> <p>2013-08-01</p> <p>The past decade has seen an explosive increase in the number of peer reviewed papers reporting new scientific findings in geomorphology (including fans, channels, floodplains and landscape evolution), geologic mapping, tectonics and faulting, coastal processes, lava flows, hydrology (especially snow and runoff routing), glaciers and geo-archaeology. A common genesis of such findings is often newly available decimeter resolution 'bare Earth' geodetic images, derived from airborne laser swath mapping, a.k.a. airborne Li<span class="hlt">DAR</span>, observations. In this paper we trace nearly a half century of advances in geodetic science made possible by space age technology, such as the invention of short-pulse-length high-pulse-rate lasers, solid state inertial measurement units, chip-based high speed electronics and the GPS satellite navigation system, that today make it possible to map hundreds of square kilometers of terrain in hours, even in areas covered with dense vegetation or shallow water. To illustrate the impact of the Li<span class="hlt">DAR</span> observations we present examples of geodetic images that are not only stunning to the eye, but help researchers to develop quantitative models explaining how terrain evolved to its present form, and how it will likely change with time. Airborne Li<span class="hlt">DAR</span> technology continues to develop quickly, promising ever more scientific discoveries in the years ahead.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/23187409','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/23187409"><span>Range determination for generating point clouds from airborne small footprint Li<span class="hlt">DAR</span> waveforms.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Qin, Yuchu; Vu, Tuong Thuy; Ban, Yifang; Niu, Zheng</p> <p>2012-11-05</p> <p>This paper presents a range determination approach for generating point clouds from small footprint Li<span class="hlt">DAR</span> waveforms. Waveform deformation over complex terrain area is simulated using convolution. Drift of the peak center position is analyzed to identify the first echo returned by the illuminated objects in the Li<span class="hlt">DAR</span> footprint. An approximate start point of peak in the waveform is estimated and adopted as the indicator of range calculation; range correction method is proposed to correct pulse widening over complex terrain surface. The experiment was carried out on small footprint Li<span class="hlt">DAR</span> waveform data acquired by RIEGL LMS-Q560. The results suggest that the proposed approach generates more points than standard commercial products; based on field measurements, a comparative analysis between the point clouds generated by the proposed approach and the commercial software GeocodeWF indicates that: 1). the proposed approach obtained more accurate tree heights; 2). smooth surface can be achieved with low standard deviation. In summary, the proposed approach provides a satisfactory solution for range determination in estimating 3D coordinate values of point clouds, especially for correcting range information of waveforms containing deformed peaks.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFMGC13I..06H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFMGC13I..06H"><span>Supporting Indonesia's National Forest Monitoring System with Li<span class="hlt">DAR</span> Observations</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hagen, S. C.</p> <p>2015-12-01</p> <p>Scientists at Applied GeoSolutions, Jet Propulsion Laboratory, Winrock International, and the University of New Hampshire are working with the government of Indonesia to enhance the National Forest Monitoring System in Kalimantan, Indonesia. The establishment of a reliable, transparent, and comprehensive NFMS has been limited by a dearth of relevant data that are accurate, low-cost, and spatially resolved at subnational scales. In this NASA funded project, we are developing, evaluating, and validating several critical components of a NFMS in Kalimantan, Indonesia, focusing on the use of Li<span class="hlt">DAR</span> and radar imagery for improved carbon stock and forest degradation information. Applied GeoSolutions and the University of New Hampshire have developed an Open Source Software package to process large amounts Li<span class="hlt">DAR</span> data quickly, easily, and accurately. The Open Source project is called lidar2dems and includes the classification of raw LAS point clouds and the creation of Digital Terrain Models (DTMs), Digital Surface Models (DSMs), and Canopy Height Models (CHMs). Preliminary estimates of forest structure and forest damage from logging from these data sets support the idea that comprehensive, well documented, freely available software for processing Li<span class="hlt">DAR</span> data can enable countries such as Indonesia to cost effectively monitor their forests with high precision.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25207868','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25207868"><span>Motion field estimation for a dynamic scene using a 3D Li<span class="hlt">DAR</span>.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Li, Qingquan; Zhang, Liang; Mao, Qingzhou; Zou, Qin; Zhang, Pin; Feng, Shaojun; Ochieng, Washington</p> <p>2014-09-09</p> <p>This paper proposes a novel motion field estimation method based on a 3D light detection and ranging (Li<span class="hlt">DAR</span>) sensor for motion sensing for intelligent driverless vehicles and active collision avoidance systems. Unlike multiple target tracking methods, which estimate the motion state of detected targets, such as cars and pedestrians, motion field estimation regards the whole scene as a motion field in which each little element has its own motion state. Compared to multiple target tracking, segmentation errors and data association errors have much less significance in motion field estimation, making it more accurate and robust. This paper presents an intact 3D Li<span class="hlt">DAR</span>-based motion field estimation method, including pre-processing, a theoretical framework for the motion field estimation problem and practical solutions. The 3D Li<span class="hlt">DAR</span> measurements are first projected to small-scale polar grids, and then, after data association and Kalman filtering, the motion state of every moving grid is estimated. To reduce computing time, a fast data association algorithm is proposed. Furthermore, considering the spatial correlation of motion among neighboring grids, a novel spatial-smoothing algorithm is also presented to optimize the motion field. The experimental results using several data sets captured in different cities indicate that the proposed motion field estimation is able to run in real-time and performs robustly and effectively.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4208193','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4208193"><span>Motion Field Estimation for a Dynamic Scene Using a 3D Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Li, Qingquan; Zhang, Liang; Mao, Qingzhou; Zou, Qin; Zhang, Pin; Feng, Shaojun; Ochieng, Washington</p> <p>2014-01-01</p> <p>This paper proposes a novel motion field estimation method based on a 3D light detection and ranging (Li<span class="hlt">DAR</span>) sensor for motion sensing for intelligent driverless vehicles and active collision avoidance systems. Unlike multiple target tracking methods, which estimate the motion state of detected targets, such as cars and pedestrians, motion field estimation regards the whole scene as a motion field in which each little element has its own motion state. Compared to multiple target tracking, segmentation errors and data association errors have much less significance in motion field estimation, making it more accurate and robust. This paper presents an intact 3D Li<span class="hlt">DAR</span>-based motion field estimation method, including pre-processing, a theoretical framework for the motion field estimation problem and practical solutions. The 3D Li<span class="hlt">DAR</span> measurements are first projected to small-scale polar grids, and then, after data association and Kalman filtering, the motion state of every moving grid is estimated. To reduce computing time, a fast data association algorithm is proposed. Furthermore, considering the spatial correlation of motion among neighboring grids, a novel spatial-smoothing algorithm is also presented to optimize the motion field. The experimental results using several data sets captured in different cities indicate that the proposed motion field estimation is able to run in real-time and performs robustly and effectively. PMID:25207868</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ISPAn.II5b..31A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ISPAn.II5b..31A"><span>A signal denoising method for full-waveform Li<span class="hlt">DAR</span> data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Azadbakht, M.; Fraser, C. S.; Zhang, C.; Leach, J.</p> <p>2013-10-01</p> <p>The lack of noise reduction methods resistant to waveform distortion can hamper correct and accurate decomposition in the processing of full-waveform Li<span class="hlt">DAR</span> data. This paper evaluates a time-domain method for smoothing and reducing the noise level in such data. The Savitzky-Golay (S-G) approach approximates and smooths data by taking advantage of fitting a polynomial of degree d, using local least-squares. As a consequence of the integration of this method with the Singular Value Decomposition (SVD) approach, and applying this filter on the singular vectors of the SVD, satisfactory denoising results can be obtained. The results of this SVD-based S-G approach have been evaluated using two different Li<span class="hlt">DAR</span> datasets and also compared with those of other popular methods in terms of the degree of preservation of the moments of the signal and closeness to the noisy signal. The results indicate that the SVD-based S-G approach has superior performance in denoising full-waveform Li<span class="hlt">DAR</span> data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ISPAr49B3..289L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ISPAr49B3..289L"><span>An Efficient Method for Automatic Road Extraction Based on Multiple Features from Li<span class="hlt">DAR</span> Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Y.; Hu, X.; Guan, H.; Liu, P.</p> <p>2016-06-01</p> <p>The road extraction in urban areas is difficult task due to the complicated patterns and many contextual objects. Li<span class="hlt">DAR</span> data directly provides three dimensional (3D) points with less occlusions and smaller shadows. The elevation information and surface roughness are distinguishing features to separate roads. However, Li<span class="hlt">DAR</span> data has some disadvantages are not beneficial to object extraction, such as the irregular distribution of point clouds and lack of clear edges of roads. For these problems, this paper proposes an automatic road centerlines extraction method which has three major steps: (1) road center point detection based on multiple feature spatial clustering for separating road points from ground points, (2) local principal component analysis with least squares fitting for extracting the primitives of road centerlines, and (3) hierarchical grouping for connecting primitives into complete roads network. Compared with MTH (consist of Mean shift algorithm, Tensor voting, and Hough transform) proposed in our previous article, this method greatly reduced the computational cost. To evaluate the proposed method, the Vaihingen data set, a benchmark testing data provided by ISPRS for "Urban Classification and 3D Building Reconstruction" project, was selected. The experimental results show that our method achieve the same performance by less time in road extraction using Li<span class="hlt">DAR</span> data.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_15");'>15</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li class="active"><span>17</span></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_17 --> <div id="page_18" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="341"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016IJAEO..53...64R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016IJAEO..53...64R"><span>Extracting cross sections and water levels of vegetated ditches from Li<span class="hlt">DAR</span> point clouds</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Roelens, Jennifer; Dondeyne, Stefaan; Van Orshoven, Jos; Diels, Jan</p> <p>2016-12-01</p> <p>The hydrologic response of a catchment is sensitive to the morphology of the drainage network. Dimensions of bigger channels are usually well known, however, geometrical data for man-made ditches is often missing as there are many and small. Aerial Li<span class="hlt">DAR</span> data offers the possibility to extract these small geometrical features. Analysing the three-dimensional point clouds directly will maintain the highest degree of information. A longitudinal and cross-sectional buffer were used to extract the cross-sectional profile points from the Li<span class="hlt">DAR</span> point cloud. The profile was represented by spline functions fitted through the minimum envelop of the extracted points. The cross-sectional ditch profiles were classified for the presence of water and vegetation based on the normalized difference water index and the spatial characteristics of the points along the profile. The normalized difference water index was created using the RGB and intensity data coupled to the Li<span class="hlt">DAR</span> points. The mean vertical deviation of 0.14 m found between the extracted and reference cross sections could mainly be attributed to the occurrence of water and partly to vegetation on the banks. In contrast to the cross-sectional area, the extracted width was not influenced by the environment (coefficient of determination R2 = 0.87). Water and vegetation influenced the extracted ditch characteristics, but the proposed method is still robust and therefore facilitates input data acquisition and improves accuracy of spatially explicit hydrological models.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013RPPh...76h6801G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013RPPh...76h6801G"><span>Geodetic imaging with airborne Li<span class="hlt">DAR</span>: the Earth's surface revealed</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Glennie, C. L.; Carter, W. E.; Shrestha, R. L.; Dietrich, W. E.</p> <p>2013-08-01</p> <p>The past decade has seen an explosive increase in the number of peer reviewed papers reporting new scientific findings in geomorphology (including fans, channels, floodplains and landscape evolution), geologic mapping, tectonics and faulting, coastal processes, lava flows, hydrology (especially snow and runoff routing), glaciers and geo-archaeology. A common genesis of such findings is often newly available decimeter resolution ‘bare Earth’ geodetic images, derived from airborne laser swath mapping, a.k.a. airborne Li<span class="hlt">DAR</span>, observations. In this paper we trace nearly a half century of advances in geodetic science made possible by space age technology, such as the invention of short-pulse-length high-pulse-rate lasers, solid state inertial measurement units, chip-based high speed electronics and the GPS satellite navigation system, that today make it possible to map hundreds of square kilometers of terrain in hours, even in areas covered with dense vegetation or shallow water. To illustrate the impact of the Li<span class="hlt">DAR</span> observations we present examples of geodetic images that are not only stunning to the eye, but help researchers to develop quantitative models explaining how terrain evolved to its present form, and how it will likely change with time. Airborne Li<span class="hlt">DAR</span> technology continues to develop quickly, promising ever more scientific discoveries in the years ahead.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24336112','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24336112"><span>Phylogenetic relationships between four Salix L. species based on <span class="hlt">DAr</span>T markers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Przyborowski, Jerzy A; Sulima, Paweł; Kuszewska, Anna; Załuski, Dariusz; Kilian, Andrzej</p> <p>2013-12-11</p> <p>The objectives of this study were to evaluate the usefulness of <span class="hlt">DAr</span>T markers in genotypic identification of willow species and describe genetic relationships between four willow species: Salix viminalis, S. purpurea, S. alba and S. triandra. The experimental plant material comprised 53 willow genotypes of these four species, which are popularly grown in Poland. <span class="hlt">DAr</span>T markers seem to identify Salix species with a high degree of accuracy. As a result, the examined species were divided into four distinct groups which corresponded to the four analyzed species. In our study, we observed that S. triandra was very different genetically from the other species, including S. alba which is generally classified into the same subgenus of Salix. The above corroborates the findings of other authors who relied on molecular methods to reveal that the classification of S. triandra to the subgenus Salix was erroneous. The Principal Coordinate Analysis (PCoA) and the neighbor-joining dendrogram also confirmed the clear division of the studied willow genotypes into four clusters corresponding to individual species. This confirmed the usefulness of <span class="hlt">DAr</span>T markers in taxonomic analyses and identification of willow species.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015Geomo.250..236S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015Geomo.250..236S"><span>Downstream hydraulic geometry relationships: Gathering reference reach-scale width values from Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sofia, G.; Tarolli, P.; Cazorzi, F.; Dalla Fontana, G.</p> <p>2015-12-01</p> <p>This paper examines the ability of Li<span class="hlt">DAR</span> topography to provide reach-scale width values for the analysis of downstream hydraulic geometry relationships along some streams in the Dolomites (northern Italy). Multiple reach-scale dimensions can provide representative geometries and statistics characterising the longitudinal variability in the channel, improving the understanding of geomorphic processes across networks. Starting from the minimum curvature derived from a Li<span class="hlt">DAR</span> DTM, the proposed algorithm uses a statistical approach for the identification of the scale of analysis, and for the automatic characterisation of reach-scale bankfull widths. The downstream adjustment in channel morphology is then related to flow parameters (drainage area and stream power). With the correct planning of a Li<span class="hlt">DAR</span> survey, uncertainties in the procedure are principally due to the resolution of the DTM. The outputs are in general comparable in quality to field survey measurements, and the procedure allows the quick comparison among different watersheds. The proposed automatic approach could improve knowledge about river systems with highly variable widths, and about systems in areas covered by vegetation or inaccessible to field surveys. With proven effectiveness, this research could offer an interesting starting point for the analysis of differences between watersheds, and to improve knowledge about downstream channel adjustment in relation, for example, to scale and landscape forcing (e.g. sediment transport, tectonics, lithology, climate, geomorphology, and anthropic pressure).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017IJBm...61...69N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017IJBm...61...69N"><span>Assessment of human thermal perception in the hot-humid climate of <span class="hlt">Dar</span> es Salaam, Tanzania</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ndetto, Emmanuel L.; Matzarakis, Andreas</p> <p>2017-01-01</p> <p><span class="hlt">Dar</span> es Salaam, Tanzania, is a typical African city along the Indian Ocean coast, and therefore an important urban area to examine human thermal perception in the hot-humid tropical climate. Earlier research on human bioclimate at <span class="hlt">Dar</span> es Salaam indicated that heat stress prevails during the hot season from October to March, peaking between December and February, particularly the early afternoons. In order to assess the human thermal perception and adaptation, two popular places, one at an urban park and another at a beach environment, were selected and questionnaire surveys were conducted in August-September 2013 and January 2014, concurrently with local micro-meteorological measurements at survey locations. The thermal conditions were quantified in terms of the thermal index of the physiologically equivalent temperature (PET) using the micro-scale climate model RayMan. The thermal comfort range of human thermal comfort and the local thermal adaptive capacity were determined in respect to the thermal index by binning thermal sensation votes. The thermal comfort range was found to be well above that in temperate climates at about 23-31 °C of PET. The study could significantly contribute to urban planning in <span class="hlt">Dar</span> es Salaam and other coastal cities in the tropics.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27410085','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27410085"><span>Effects of Li<span class="hlt">DAR</span> point density, sampling size and height threshold on estimation accuracy of crop biophysical parameters.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Luo, Shezhou; Chen, Jing M; Wang, Cheng; Xi, Xiaohuan; Zeng, Hongcheng; Peng, Dailiang; Li, Dong</p> <p>2016-05-30</p> <p>Vegetation leaf area index (LAI), height, and aboveground biomass are key biophysical parameters. Corn is an important and globally distributed crop, and reliable estimations of these parameters are essential for corn yield forecasting, health monitoring and ecosystem modeling. Light Detection and Ranging (Li<span class="hlt">DAR</span>) is considered an effective technology for estimating vegetation biophysical parameters. However, the estimation accuracies of these parameters are affected by multiple factors. In this study, we first estimated corn LAI, height and biomass (R<sup>2</sup> = 0.80, 0.874 and 0.838, respectively) using the original Li<span class="hlt">DAR</span> data (7.32 points/m<sup>2</sup>), and the results showed that Li<span class="hlt">DAR</span> data could accurately estimate these biophysical parameters. Second, comprehensive research was conducted on the effects of Li<span class="hlt">DAR</span> point density, sampling size and height threshold on the estimation accuracy of LAI, height and biomass. Our findings indicated that Li<span class="hlt">DAR</span> point density had an important effect on the estimation accuracy for vegetation biophysical parameters, however, high point density did not always produce highly accurate estimates, and reduced point density could deliver reasonable estimation results. Furthermore, the results showed that sampling size and height threshold were additional key factors that affect the estimation accuracy of biophysical parameters. Therefore, the optimal sampling size and the height threshold should be determined to improve the estimation accuracy of biophysical parameters. Our results also implied that a higher Li<span class="hlt">DAR</span> point density, larger sampling size and height threshold were required to obtain accurate corn LAI estimation when compared with height and biomass estimations. In general, our results provide valuable guidance for Li<span class="hlt">DAR</span> data acquisition and estimation of vegetation biophysical parameters using Li<span class="hlt">DAR</span> data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMEP41A0582Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMEP41A0582Y"><span>Spatiotemporal analysis of stream network structure based on snow-on and snow-off Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, P.; Ames, D. P.; Shrestha, R.</p> <p>2011-12-01</p> <p>The spatio-temporal analysis of ephemeral and intermittent stream structure provides valuable information for streamflow or discharge estimation, which can be important for snow pack volume and vegetation biomass calculation. Airborne Li<span class="hlt">DAR</span> data collected under snow-on and snow-off conditions from Dry Creek Experimental Watershed (DCEW), a semi-arid region in southern Idaho, USA, were used to create a vegetation and snow height model based on the intensity information from the Li<span class="hlt">DAR</span> point cloud. Stream networks under two conditions were delineated based on Li<span class="hlt">DAR</span>-generated DEMs from snow and vegetation filtered point clouds. Ephemeral streams and perennial streams were identified through a difference analysis between snow-on and snow-off Li<span class="hlt">DAR</span> derivatives, together with remote sensing imagery integration. A spatiotemporal analysis of stream network structure was carried out using a newly developed open source GIS software, HydroLi<span class="hlt">DAR</span>, designed for accessing both point cloud and interpolated raster of Li<span class="hlt">DAR</span> data. Field surveys are being conducted for validating and assessment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/25898621','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/25898621"><span>[Estimating individual tree aboveground biomass of the mid-subtropical forest using airborne Li<span class="hlt">DAR</span> technology].</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Liu, Feng; Tan, Chang; Lei, Pi-Feng</p> <p>2014-11-01</p> <p>Taking Wugang forest farm in Xuefeng Mountain as the research object, using the airborne light detection and ranging (Li<span class="hlt">DAR</span>) data under leaf-on condition and field data of concomitant plots, this paper assessed the ability of using Li<span class="hlt">DAR</span> technology to estimate aboveground biomass of the mid-subtropical forest. A semi-automated individual tree Li<span class="hlt">DAR</span> cloud point segmentation was obtained by using condition random fields and optimization methods. Spatial structure, waveform characteristics and topography were calculated as Li<span class="hlt">DAR</span> metrics from the segmented objects. Then statistical models between aboveground biomass from field data and these Li<span class="hlt">DAR</span> metrics were built. The individual tree recognition rates were 93%, 86% and 60% for coniferous, broadleaf and mixed forests, respectively. The adjusted coefficients of determination (R(2)adj) and the root mean squared errors (RMSE) for the three types of forest were 0.83, 0.81 and 0.74, and 28.22, 29.79 and 32.31 t · hm(-2), respectively. The estimation capability of model based on canopy geometric volume, tree percentile height, slope and waveform characteristics was much better than that of traditional regression model based on tree height. Therefore, Li<span class="hlt">DAR</span> metrics from individual tree could facilitate better performance in biomass estimation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://ntrs.nasa.gov/search.jsp?R=20040059920&hterms=Stone+Age&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DStone%2BAge','NASA-TRS'); return false;" href="https://ntrs.nasa.gov/search.jsp?R=20040059920&hterms=Stone+Age&qs=Ntx%3Dmode%2Bmatchall%26Ntk%3DAll%26N%3D0%26No%3D30%26Ntt%3DStone%2BAge"><span>Rb-Sr and Sm-Nd Isotope Systematics of <span class="hlt">Shergottite</span> NWA 856: Crystallization Age and Implications for Alteration of Hot Desert SNC Meteorites</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Brandon, A. D.; Nyquist, L. E.; Shih, C.-Y.; Wiesmann, H.</p> <p>2004-01-01</p> <p>Nakhlite NWA 998 was discovered in Algeria in 2001, and is unique among the six known members of this group of Martian meteorites in containing significant modal orthopyroxene. Initial petrologic and isotopic data were reported by Irving et <span class="hlt">al</span>. This 456 gram stone consists mainly of sub-calcic augite with subordinate olivine and minor orthopyroxene, titanomagnetite, pyrrhotite, chlorapatite, and intercumulus An(sub 35) plagioclase. We report here preliminary results of radiogenic isotopic analyses conducted on fragmental material from the main mass.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.9073V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.9073V"><span>Multiple-Li<span class="hlt">DAR</span> measurements of wind turbine wakes: effect of the atmospheric stability</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Valerio Iungo, Giacomo; Porté-Agel, Fernando</p> <p>2013-04-01</p> <p>Aerodynamic design and optimization of a wind farm layout are mainly based on the evaluation of wind turbine wake recovery by moving downstream, and on the characterization of wake interactions within a wind farm. Indeed, the power production of downstream wind turbine rows is strictly affected by the cumulative wake produced by the turbines deployed upstream. Wind turbine wakes are dependent on their aerodynamic features, and being immersed in the atmospheric boundary layer (ABL), they are also affected by surface heterogeneity, e.g. site topography and surface coverage, and atmospheric stability. The ABL stability is typically classified as neutral, convective or stable. In a neutral ABL the mechanical turbulent production is the dominating phenomenon. Conversely, for a convective ABL the turbulent kinetic energy and vertical transport phenomena are enhanced by positive buoyancy. Finally, for a stable ABL, a lower turbulence level is typically observed with an increased wind shear. For the present campaign convective ABL was typically observed during day-time, and neutral ABL for early morning and sunset periods. The aim of the present work is the evaluation of the influence of the ABL stability on downstream evolution of wind turbine wakes, which is mainly controlled by different ABL turbulence characteristics. Field measurements of the wake produced from a 2 MW Enercon E-70 wind turbine were performed with three scanning Doppler wind Li<span class="hlt">DARs</span>. The wind and atmospheric conditions were characterized through a sonic anemometer deployed in proximity of the wind turbine. One Li<span class="hlt">DAR</span> was placed at a distance about 12 rotor diameters upstream of the turbine in order to characterize the incoming wind. Two additional Li<span class="hlt">DARs</span> were typically used to perform wake measurements. Tests were performed over the wake vertical symmetry plane in order to characterize wake recovery. Measurements were also carried out over conical surfaces in order to investigate the wind turbine wake</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1811161Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1811161Q"><span>Mobile Li<span class="hlt">DAR</span> Measurement for Aerosol Investigation in South-Central Hebei, China</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>qin, kai; Wu, Lixin; Zheng, Yunhui; Wong Man, Sing; Wang, Runfeng; Hu, Mingyu; Lang, Hongmei; Wang, Luyao; Bai, Yang; Rao, Lanlan</p> <p>2016-04-01</p> <p>With the rapid industrialization and urbanization in China during the last decades, the increasing anthropogenic pollutant emissions have significantly caused serious air pollution problems which are adversely influencing public health. Hebei is one of the most air polluted provinces in China. In January 2013, an extremely severe and persistent haze episode with record-breaking PM2.5 outbreak affecting hundreds of millions of people occurred over eastern and northern China. During that haze episode, 7 of the top 10 most polluted cities in China were located in the Hebei Province according to the report of China's Ministry of Environmental Protection. To investigate and the spatial difference and to characterize the vertical distribution of aerosol in different regions of south-central Hebei, mobile measurements were carried out using a mini micro pulse Li<span class="hlt">DAR</span> system (model: MiniMPL) in March 2014. The mobile Li<span class="hlt">DAR</span> kit consisting of a MiniMPL, a vibration reduction mount, a power inverter, a Windows surface tablet and a GPS receiver were mounted in a car watching though the sunroof opening. For comparison, a fixed measurement using a traditional micro pulse Li<span class="hlt">DAR</span> system (model: MPL-4B) was conducted simultaneously in Shijiazhuang, the capital of Hebei Province. The equipped car was driven from downtown Shijiazhuang by way of suburban and rural area to downtown Cangzhou, Handan, and Baoding respectively at almost stable speed around 100Km per hour along different routes which counted in total more than 1000Km. The results can be summarized as: 1) the spatial distribution of total aerosol optical depth along the measurement routes in south-central Hebei was controlled by local terrain and population in general, with high values in downtown and suburban in the plain areas, and low values in rural areas along Taihang mountain to the west and Yan mountain to the north; 2) obviously high AODs were obtained at roads crossing points, inside densely populated area and nearby</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.4665H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.4665H"><span>Glacier surface feature detection and classification from airborne Li<span class="hlt">DAR</span> data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Höfle, B.; Sailer, R.; Vetter, M.; Rutzinger, M.; Pfeifer, N.</p> <p>2009-04-01</p> <p>In recent years airborne Li<span class="hlt">DAR</span> evolved to the state-of-the-art technology for topographic data acquisition. Up to now mainly the derived elevation information has been used in glaciology (e.g. roughness determination, multitemporal elevation and volume changes). Few studies have already shown the potential of using Li<span class="hlt">DAR</span> signal intensities for glacier surface differentiation, primarily based on visual interpretation of signal intensity images. This contribution brings together the spatial and radiometric information provided by airborne Li<span class="hlt">DAR</span>, in order to make an automatic glacier surface feature detection and classification possible. The automation of the processing workflow and the standardization of the used input data become important particularly for multitemporal analysis where surface changes and feature tracking are of major interest. This study is carried out at the Hintereisferner, Ötztal Alps/Austria, where 16 airborne Li<span class="hlt">DAR</span> acquisitions have taken place since 2001. We aim at detecting the main glacier surface classes as defined by crevasses, snow, firn, ice and debris covered ice areas. Prior to the glacier facies differentiation, an automated glacier delineation based on roughness constraints is performed. It is assumed that the glacier surface, except the crevasse zone, tends to a smoother surface than the adjacent slopes and represents one large connected spatial unit. The developed method combines raster and point cloud based processing steps in an object-based segmentation and classification procedure where elevation and calibrated signal intensity are used as complementary input. The calibration of the recorded signal intensity removes known effects originating from the atmosphere, topography and scan geometry (e.g. distance to target) and hence provides a value proportional to surface reflectance in the wavelength of the laser system. Since the Bidirectional Reflectance Distribution Function (BRDF) of the scanned surface is not known beforehand</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010EGUGA..1214005B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010EGUGA..1214005B"><span>Calculation and Evaluation of the Mass Balance of Hintereisferner using Airborne Li<span class="hlt">DAR</span> Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bollmann, Erik; Fischer, Andrea; Fritzmann, Patrick; Sailer, Rudolf; Stötter, Hans</p> <p>2010-05-01</p> <p>Since 2001 airborne Li<span class="hlt">DAR</span> measurements have been carried out regularly at the Hintereisferner region (Ötztal, Tyrol, Austria). This results in a worldwide unique data set of 18 airborne Li<span class="hlt">DAR</span> flight campaigns, which is primarily used for multitemporal glacial and periglacial surface analyses. The potential of this data set for the quantification of glacier surface elevation changes with high spatial and temporal resolution has already been shown in several studies. In this study we go beyond this stage and calculate the net mass balance of Hintereisferner by applying the geodetic method on regular raster digital elevation models (DEMs) with 1 m spatial resolution. The total geodetic net mass balance of the glacier is determined on an interannual time-scale as well as over the whole investigation period from 2001 - 2008. The accuracy of the geodetic net mass balance mainly depends on the accuracy of the input airborne Li<span class="hlt">DAR</span> data and on density assumptions which have to be made to convert surface elevation changes to mass changes. To determine the accuracy of the Li<span class="hlt">DAR</span> data and the derived DEMs, an accuracy assessment was computed comprising i) deviations between dGPS- and Li<span class="hlt">DAR</span>-points, ii) errors resulting from point to raster conversion and iii) accuracy dependence of the DEMs on terrain slope angles. The calculated geodetic net mass balances of Hintereisferner are compared to results from the direct glaciological method. Mass balance calculations using the direct glaciological method already started in glaciological year 1952/53 and are continued up to the present day. Thus, a wide experience and well-founded knowledge on the application of the method at Hintereisferner was obtained and its accuracy is determined to be ± 100 mm water equivalent a-1 for the mean specific mass balance. Comparing the results of the geodetic method to direct measurements on the total net mass balance on an interannual time-scale, some stronger deviations between the two methods</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..1511886T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..1511886T"><span>Buildings classification from airborne Li<span class="hlt">DAR</span> point clouds through OBIA and ontology driven approach</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tomljenovic, Ivan; Belgiu, Mariana; Lampoltshammer, Thomas J.</p> <p>2013-04-01</p> <p>In the last years, airborne Light Detection and Ranging (Li<span class="hlt">DAR</span>) data proved to be a valuable information resource for a vast number of applications ranging from land cover mapping to individual surface feature extraction from complex urban environments. To extract information from Li<span class="hlt">DAR</span> data, users apply prior knowledge. Unfortunately, there is no consistent initiative for structuring this knowledge into data models that can be shared and reused across different applications and domains. The absence of such models poses great challenges to data interpretation, data fusion and integration as well as information transferability. The intention of this work is to describe the design, development and deployment of an ontology-based system to classify buildings from airborne Li<span class="hlt">DAR</span> data. The novelty of this approach consists of the development of a domain ontology that specifies explicitly the knowledge used to extract features from airborne Li<span class="hlt">DAR</span> data. The overall goal of this approach is to investigate the possibility for classification of features of interest from Li<span class="hlt">DAR</span> data by means of domain ontology. The proposed workflow is applied to the building extraction process for the region of "Biberach an der Riss" in South Germany. Strip-adjusted and georeferenced airborne Li<span class="hlt">DAR</span> data is processed based on geometrical and radiometric signatures stored within the point cloud. Region-growing segmentation algorithms are applied and segmented regions are exported to the GeoJSON format. Subsequently, the data is imported into the ontology-based reasoning process used to automatically classify exported features of interest. Based on the ontology it becomes possible to define domain concepts, associated properties and relations. As a consequence, the resulting specific body of knowledge restricts possible interpretation variants. Moreover, ontologies are machinable and thus it is possible to run reasoning on top of them. Available reasoners (FACT++, JESS, Pellet) are used to check</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.H13G1441P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.H13G1441P"><span>Seagrass Identification Using High-Resolution 532nm Bathymetric Li<span class="hlt">DAR</span> and Hyperspectral Imagery</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pan, Z.; Prasad, S.; Starek, M. J.; Fernandez Diaz, J. C.; Glennie, C. L.; Carter, W. E.; Shrestha, R. L.; Singhania, A.; Gibeaut, J. C.</p> <p>2013-12-01</p> <p>Seagrass provides vital habitat for marine fisheries and is a key indicator species of coastal ecosystem vitality. Monitoring seagrass is therefore an important environmental initiative, but measuring details of seagrass distribution over large areas via remote sensing has proved challenging. Developments in airborne bathymetric light detection and ranging (Li<span class="hlt">DAR</span>) provide great potential in this regard. Traditional bathymetric Li<span class="hlt">DAR</span> systems have been limited in their ability to map within the shallow water zone (< 1 m) where seagrass is typically present due to limitations in receiver response and laser pulse length. Emergent short-pulse width bathymetric Li<span class="hlt">DAR</span> sensors and waveform processing algorithms enable depth measurements in shallow water environments previously inaccessible. This 3D information of the benthic layer can be applied to detect seagrass and characterize its distribution. Researchers with the National Center for Airborne Laser Mapping (NCALM) at the University of Houston (UH) and the Coastal and Marine Geospatial Sciences Lab (CMGL) of the Harte Research Institute at Texas A&M University-Corpus Christi conducted a coordinated airborne and boat-based survey of the Redfish Bay State Scientific Area as part of a collaborative study to investigate the capabilities of bathymetric Li<span class="hlt">DAR</span> and hyperspectral imaging for seagrass mapping. Redfish Bay, located along the middle Texas coast of the Gulf of Mexico, is a state scientific area designated for the purpose of protecting and studying native seagrasses. Redfish Bay is part of the broader Coastal Bend Bays estuary system recognized by the US Environmental Protection Agency (EPA) as a national estuary of significance. For this survey, UH acquired high-resolution discrete-return and full-waveform bathymetric data using their Optech Aquarius 532 nm green Li<span class="hlt">DAR</span>. In a separate flight, UH collected 2 sets of hyperspectral imaging data (1.2-m pixel resolution and 72 bands, and 0.6m pixel resolution and 36</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2005AGUFM.H31E1349C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2005AGUFM.H31E1349C"><span>A Geoinformatics Approach to Li<span class="hlt">DAR</span> / ALSM Data Distribution, Interpolation, and Analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Crosby, C. J.; Conner, J.; Frank, E.; Arrowsmith, J. R.; Memon, A.; Nandigam, V.; Wurman, G.; Baru, C.</p> <p>2005-12-01</p> <p>Distribution, interpolation and analysis of large Li<span class="hlt">DAR</span> (Light Distance And Ranging, also known as ALSM (Airborne Laser Swath Mapping)) datasets pushes the computational limits of typical data distribution and processing systems. The high point-density of Li<span class="hlt">DAR</span> datasets makes grid interpolation difficult for geoscience users who lack the computing and software resources necessary to handle these massive data volumes. We are using a geoinformatics approach to the distribution, interpolation and analysis of Li<span class="hlt">DAR</span> data that capitalizes on cyberinfrastructure being developed as part of the GEON project (http://www.geongrid.org). Our approach utilizes a comprehensive workflow-based solution that begins with user-defined selection of a subset of raw data and ends with download and visualization of interpolated surfaces and derived products. The workflow environment allows us to modularize and generalize the procedure. It provides the freedom to easily plug-in new processes, to utilize existing sub workflows within an analysis, and easily extend or modify the analysis using drag-and-drop functionality through the Kepler workflow management system. In this GEON-based workflow, the billions of points within a Li<span class="hlt">DAR</span> dataset point cloud are hosted in an IBM DB2 spatial database running on the DataStar terascale computer at San Diego Supercomputer Center; a machine designed specifically for data intensive computations. Data selection is performed via an ArcIMS-based interface that allows users to execute spatial and attribute subset queries on the larger dataset. The subset of data is then passed to a GRASS Open Source GIS-based web service, "lservice", that handles interpolation to grid and analysis of the data. Lservice was developed entirely within the open source domain and offers spline and inverse distance weighted (IDW) interpolation to grid with user-defined resolution and parameters. We also compute geomorphic metrics such as slope, curvature, and aspect. Users may</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1711254F','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1711254F"><span>LESTO: an Open Source GIS-based toolbox for Li<span class="hlt">DAR</span> analysis</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Franceschi, Silvia; Antonello, Andrea; Tonon, Giustino</p> <p>2015-04-01</p> <p>During the last five years different research institutes and private companies stared to implement new algorithms to analyze and extract features from Li<span class="hlt">DAR</span> data but only a few of them also created a public available software. In the field of forestry there are different examples of software that can be used to extract the vegetation parameters from Li<span class="hlt">DAR</span> data, unfortunately most of them are closed source (even if free), which means that the source code is not shared with the public for anyone to look at or make changes to. In 2014 we started the development of the library LESTO (Li<span class="hlt">DAR</span> Empowered Sciences Toolbox Opensource): a set of modules for the analysis of Li<span class="hlt">DAR</span> point cloud with an Open Source approach with the aim of improving the performance of the extraction of the volume of biomass and other vegetation parameters on large areas for mixed forest structures. LESTO contains a set of modules for data handling and analysis implemented within the JGrassTools spatial processing library. The main subsections are dedicated to 1) preprocessing of Li<span class="hlt">DAR</span> raw data mainly in LAS format (utilities and filtering); 2) creation of raster derived products; 3) flight-lines identification and normalization of the intensity values; 4) tools for extraction of vegetation and buildings. The core of the LESTO library is the extraction of the vegetation parameters. We decided to follow the single tree based approach starting with the implementation of some of the most used algorithms in literature. These have been tweaked and applied on Li<span class="hlt">DAR</span> derived raster datasets (DTM, DSM) as well as point clouds of raw data. The methods range between the simple extraction of tops and crowns from local maxima, the region growing method, the watershed method and individual tree segmentation on point clouds. The validation procedure consists in finding the matching between field and Li<span class="hlt">DAR</span>-derived measurements at individual tree and plot level. An automatic validation procedure has been developed</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMEP43A0638Q','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMEP43A0638Q"><span>An application of vessel-based Li<span class="hlt">DAR</span> to quantify coastal retreat in Southern Monterey Bay, CA</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Quan, S.; Kvitek, R.; Smith, D. P.</p> <p>2009-12-01</p> <p>Coastal erosion has become a prominent issue in Monterey Bay, California. Areas at high risk include native coastal dunes, private and public beachfront properties, municipal sewage lines, and areas of the highway 1 corridor. Traditional airborne Li<span class="hlt">DAR</span> has been an effective method in measuring coastal topography by providing high resolution and great coverage, but it remains costly. In 1997 and 1998, NASA, USGS, and NOAA collaborated to conduct pre- and post- El Niño airborne Li<span class="hlt">DAR</span> surveys of the California coastline. Since then, there have been no further, publically available Li<span class="hlt">DAR</span> surveys of the Monterey Bay shoreline. The goal of this project is to apply a vessel-based Li<span class="hlt">DAR</span> system to measure coastal geomorphology, determine the efficiency of vessel-based topographic Li<span class="hlt">DAR</span> for mapping coastal geomorphology, and quantify the spatial distribution of coastal retreat for Monterey Bay, California. The area of study was the Monterey Bay coastline from the Monterey Bay Commercial Wharf II to Marina State Beach at Reservation Rd. Sea cliff morphology data were measured on Dec 9th and 10th, 2008 through the use of a terrestrial Li<span class="hlt">DAR</span> system mounted atop the CSUMB Seafloor Mapping Lab’s R/V VenTresca. These vessel based Li<span class="hlt">DAR</span> data were compared with 1998 NOAA Airborne Topographic Mapper Li<span class="hlt">DAR</span> data using mapping, modeling and spatial analysis tools in ArcGIS to quantify the spatial distribution of coastal retreat and calculate annualized rates of erosion for the Monterey Bay shoreline over the past decade. Preliminary results show a slight correlation between volumetric change and distance along the coast from Wharf II, in keeping with previous published results. On the other hand, average sand dune apron retreat rate is 0.92 m/yr with a significant relationship between sand dune apron retreat rate and distance along the coast. The utilization of vessel based Li<span class="hlt">DAR</span> is an effective and cost efficient method to frequently measure sea cliff geomorphology with very high</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.7405V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.7405V"><span>The Hintereisferner - eight years of experience in method development for glacier monitoring with airborne Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vetter, M.; Höfle, B.; Pfeifer, N.; Rutzinger, M.; Sailer, R.; Stötter, J.; Geist, T.</p> <p>2009-04-01</p> <p>Topographic data acquisition with Li<span class="hlt">DAR</span> technology, airborne or terrestrial, has become the state-of-the-art procedure for Earth surface surveying. For glacier monitoring different remote sensing technologies are used for many years. With the advent of airborne Li<span class="hlt">DAR</span> a paradigm shift in glacier monitoring has taken place. Eight years ago pioneer work within glacier surface surveying and monitoring has been carried out at the Institute of Geography (Innsbruck) within the OMEGA (Development of Operational Monitoring System for European Glacial Areas) project by using airborne Li<span class="hlt">DAR</span>. Since 2001, 16 single airborne Li<span class="hlt">DAR</span> campaigns have been carried out by collecting data of Hintereisferner, Kesselwandferner and adjacent small glaciers as well as their surrounding areas (Ötztal Alps, Tyrol, Austria). We present the main results of this period of glacier monitoring based on Li<span class="hlt">DAR</span> data. One major task was to set up a geo-database system to manage the huge amount of Li<span class="hlt">DAR</span> data, offering the opportunity to compute various point features and different rasterized data sets using this Li<span class="hlt">DAR</span> data management and analysis system. In this context some basic routines were developed (e.g. a tool for intensity calibration, for derive intensity and point density images, and for modeling the locations of laser shot dropouts). In addition, tools for the analysis of the glacier surface have been developed: (a) a glacier delineation tool, using intensity and roughness information, (b) tools to compute and visualize the volume and elevation changes using multitemporal data, (c) a tool to calculate the ice flow velocity at the glacier surface, (d) a classification tool to detect crevasses, snow, firn, ice and debris covered ice areas, using calibrated intensity data, roughness information and modeled laser shot dropouts. For the analysis of glacial geomorphologic processes (i) a routine for the delineation of moraine ridges and rock glaciers works on the basis of break lines, (ii) a</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70159835','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70159835"><span>Quantifying soil carbon loss and uncertainty from a peatland wildfire using multi-temporal Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Reddy, Ashwan D.; Hawbaker, Todd J.; Wurster, F.; Zhu, Zhiliang; Ward, S.; Newcomb, Doug; Murray, R.</p> <p>2015-01-01</p> <p>Peatlands are a major reservoir of global soil carbon, yet account for just 3% of global land cover. Human impacts like draining can hinder the ability of peatlands to sequester carbon and expose their soils to fire under dry conditions. Estimating soil carbon loss from peat fires can be challenging due to uncertainty about pre-fire surface elevations. This study uses multi-temporal Li<span class="hlt">DAR</span> to obtain pre- and post-fire elevations and estimate soil carbon loss caused by the 2011 Lateral West fire in the Great Dismal Swamp National Wildlife Refuge, VA, USA. We also determine how Li<span class="hlt">DAR</span> elevation error affects uncertainty in our carbon loss estimate by randomly perturbing the Li<span class="hlt">DAR</span> point elevations and recalculating elevation change and carbon loss, iterating this process 1000 times. We calculated a total loss using Li<span class="hlt">DAR</span> of 1.10 Tg C across the 25 km2 burned area. The fire burned an average of 47 cm deep, equivalent to 44 kg C/m2, a value larger than the 1997 Indonesian peat fires (29 kg C/m2). Carbon loss via the First-Order Fire Effects Model (FOFEM) was estimated to be 0.06 Tg C. Propagating the Li<span class="hlt">DAR</span> elevation error to the carbon loss estimates, we calculated a standard deviation of 0.00009 Tg C, equivalent to 0.008% of total carbon loss. We conclude that Li<span class="hlt">DAR</span> elevation error is not a significant contributor to uncertainty in soil carbon loss under severe fire conditions with substantial peat consumption. However, uncertainties may be more substantial when soil elevation loss is of a similar or smaller magnitude than the reported Li<span class="hlt">DAR</span> error.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_16");'>16</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li class="active"><span>18</span></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_18 --> <div id="page_19" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="361"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70037559','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70037559"><span>Analysis of elevation changes detected from multi-temporal Li<span class="hlt">DAR</span> surveys in forested landslide terrain in western Oregon</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Burns, W.J.; Coe, J.A.; Kaya, B.S.; Ma, L.</p> <p>2010-01-01</p> <p>We examined elevation changes detected from two successive sets of Light Detection and Ranging (Li<span class="hlt">DAR</span>) data in the northern Coast Range of Oregon. The first set of Li<span class="hlt">DAR</span> data was acquired during leafon conditions and the second set during leaf-off conditions. We were able to successfully identify and map active landslides using a differential digital elevation model (DEM) created from the two Li<span class="hlt">DAR</span> data sets, but this required the use of thresholds (0.50 and 0.75 m) to remove noise from the differential elevation data, visual pattern recognition of landslideinduced elevation changes, and supplemental QuickBird satellite imagery. After mapping, we field-verified 88 percent of the landslides that we had mapped with high confidence, but we could not detect active landslides with elevation changes of less than 0.50 m. Volumetric calculations showed that a total of about 18,100 m3 of material was missing from landslide areas, probably as a result of systematic negative elevation errors in the differential DEM and as a result of removal of material by erosion and transport. We also examined the accuracies of 285 leaf-off Li<span class="hlt">DAR</span> elevations at four landslide sites using Global Positioning System and total station surveys. A comparison of Li<span class="hlt">DAR</span> and survey data indicated an overall root mean square error of 0.50 m, a maximum error of 2.21 m, and a systematic error of 0.09 m. Li<span class="hlt">DAR</span> ground-point densities were lowest in areas with young conifer forests and deciduous vegetation, which resulted in extensive interpolations of elevations in the leaf-on, bare-earth DEM. For optimal use of multi-temporal Li<span class="hlt">DAR</span> data in forested areas, we recommend that all data sets be flown during leaf-off seasons.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9974E..0NF','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9974E..0NF"><span>Modeling of a sensitive time-of-flight flash Li<span class="hlt">DAR</span> system</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Fathipour, V.; Wheaton, S.; Johnson, W. E.; Mohseni, H.</p> <p>2016-09-01</p> <p>used for monitoring and profiling structures, range, velocity, vibration, and air turbulence. Remote sensing in the IR region has several advantages over the visible region, including higher transmitter energy while maintaining eye-safety requirements. Electron-injection detectors are a new class of detectors with high internal avalanche-free amplification together with an excess-noise-factor of unity. They have a cutoff wavelength of 1700 nm. Furthermore, they have an extremely low jitter. The detector operates in linear-mode and requires only bias voltage of a few volts. This together with the feedback stabilized gain mechanism, makes formation of large-format high pixel density electron-injection FPAs less challenging compared to other detector technologies such as avalanche photodetectors. These characteristics make electron-injection detectors an ideal choice for flash Li<span class="hlt">DAR</span> application with mm scale resolution at longer ranges. Based on our experimentally measured device characteristics, a detailed theoretical Li<span class="hlt">DAR</span> model was developed. In this model we compare the performance of the electron-injection detector with commercially available linear-mode InGaAs APD from (Hamamatsu G8931-20) as well as a p-i-n diode (Hamamatsu 11193 p-i-n). Flash Li<span class="hlt">DAR</span> images obtained by our model, show the electron-injection detector array (of 100 x 100 element) achieves better resolution with higher signal-to-noise compared with both the InGaAs APD and the p-i-n array (of 100 x 100 element).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5134582','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5134582"><span>3D Scene Reconstruction Using Omnidirectional Vision and Li<span class="hlt">DAR</span>: A Hybrid Approach</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Vlaminck, Michiel; Luong, Hiep; Goeman, Werner; Philips, Wilfried</p> <p>2016-01-01</p> <p>In this paper, we propose a novel approach to obtain accurate 3D reconstructions of large-scale environments by means of a mobile acquisition platform. The system incorporates a Velodyne Li<span class="hlt">DAR</span> scanner, as well as a Point Grey Ladybug panoramic camera system. It was designed with genericity in mind, and hence, it does not make any assumption about the scene or about the sensor set-up. The main novelty of this work is that the proposed Li<span class="hlt">DAR</span> mapping approach deals explicitly with the inhomogeneous density of point clouds produced by Li<span class="hlt">DAR</span> scanners. To this end, we keep track of a global 3D map of the environment, which is continuously improved and refined by means of a surface reconstruction technique. Moreover, we perform surface analysis on consecutive generated point clouds in order to assure a perfect alignment with the global 3D map. In order to cope with drift, the system incorporates loop closure by determining the pose error and propagating it back in the pose graph. Our algorithm was exhaustively tested on data captured at a conference building, a university campus and an industrial site of a chemical company. Experiments demonstrate that it is capable of generating highly accurate 3D maps in very challenging environments. We can state that the average distance of corresponding point pairs between the ground truth and estimated point cloud approximates one centimeter for an area covering approximately 4000 m2. To prove the genericity of the system, it was tested on the well-known Kitti vision benchmark. The results show that our approach competes with state of the art methods without making any additional assumptions. PMID:27854315</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1715254H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1715254H"><span>The offshore wind resources assessment application of floating Li<span class="hlt">DAR</span> in the Taiwan Strait</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hsuan, Chung-Yao; Wu, Yu-Ting; Lin, Ta-Hui</p> <p>2015-04-01</p> <p>Wind and wave measurements of a Floating Li<span class="hlt">DAR</span> (Light Detection And Ranging) Device (FLD) are performed on the site of Fuhai Offshore Wind Farm in the Taiwan Strait. The location of the deployment is situated 10 kilometers off-coast of Changhua County, and the anchored water depth is 25 meters. It is the very first time in Asia Pacific Region to use such device for tasks of offshore wind and wave measurement. Six range gate heights were set at 55m, 71m, 90m, 110m, 150m and 200m from the FLD sensor lens. Wind speeds and wind directions were measured by a remote sensing technology. Wave heights and periods were also measured by the buoy wave sensor. A validation campaign of NCKU WindSentinel has performed by a portable Li<span class="hlt">DAR</span> (WINDCUBE v2) at Hsing-Da Harbor in the south of Taiwan from October 16th to 26th, 2013. The results showed good agreements with 10 minute averaged data of the wind speed and wind direction measured by the two Li<span class="hlt">DARs</span>. NCKU WindSentinel data are planning comparisons with Fuhai's offshore fixed mast data when the meteorological mast is completed. The goal is to convince the wind energy community that FLD are a reliable and cost effective way of obtaining data for resource assessment. Until this moment, The FLD are observing and measuring the offshore wind farm's meteorological and oceanographic data. In September of 2014, a mild typhoon (Fung-Wong) passed through from east of Taiwan. NCKU WindSentinel continuously measured during typhoon period in the sea. The present preliminary measurements campaign presented the convenient and more cost effective option of the FLD, which may be a key tool for assessment of offshore wind resources in the near-future offshore wind farm developments.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015PhDT.......100J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015PhDT.......100J"><span>Li<span class="hlt">DAR</span> Individual Tree Detection for Assessing Structurally Diverse Forest Landscapes</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jeronimo, Sean</p> <p></p> <p>Contemporary forest management on public land incorporates a focus on restoration and maintenance of ecological functions through silvicultural manipulation of forest structure on a landscape scale. Incorporating reference conditions into restoration treatment planning and monitoring can improve treatment efficacy, but the typical ground-based methods of quantifying reference condition data---and comparing it to pre- and post-treatment stands---are expensive, time-consuming, and limited in scale. Airborne Li<span class="hlt">DAR</span> may be part of the solution to this problem, since Li<span class="hlt">DAR</span> acquisitions have both broad coverage and high resolution. I evaluated the ability of Li<span class="hlt">DAR</span> Individual Tree Detection (ITD) to describe forest structure across a structurally variable landscape in support of large-scale forest restoration. I installed nineteen 0.25 ha stem map plots across a range of structural conditions in potential reference areas (Yosemite National Park) and potential restoration treatment areas (Sierra National Forest) in the Sierra Nevada of California. I used the plots to evaluate a common ITD algorithm, the watershed transform, compare it to past uses of ITD, and determine which aspects of forest structure contributed to errors in ITD. I found that ITD across this structurally diverse landscape was generally less accurate than across the smaller and less diverse areas over which it has previously been studied. However, the pattern of tree recognition is consistent: regardless of forest structure, canopy dominants are almost always detected and relatively shorter trees are almost never detected. Correspondingly, metrics dominated by large trees, such as biomass, basal area, and spatial heterogeneity, can be measured using ITD, while metrics dominated by smaller trees, such as stand density, cannot. Bearing these limitations in mind, ITD can be a powerful tool for describing forest structure across heterogeneous landscape restoration project areas.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.B11B0419K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.B11B0419K"><span>Fusing Hyperspectral and Li<span class="hlt">DAR</span> data from CAO-VSWIR for Increased Data Dimensionality</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Knapp, D. E.; Asner, G. P.; Boardman, J. W.; Kennedy-Bowdoin, T.; Eastwood, M.; Anderson, C.; Martin, R. E.; Green, R. O.</p> <p>2012-12-01</p> <p>The use of multi-sensor platforms for scientific data collection requires precise co-location in order to gain maximum data dimensionality for Earth system research. The different types of collection mechanisms of the sensors (e.g., scanning and pushbroom) can make it difficult to precisely match data from multiple sensors, even when the sensors are flown on the same aircraft at the same time. To overcome these problems, the Carnegie Airborne Observatory (CAO) AToMS sensor suite uses a method that maximizes the match between the Light Detection and Ranging (Li<span class="hlt">DAR</span>), Visible-to-Near Infrared (VNIR), and Visible-to-Shortwave Infrared (VSWIR) sensors. This is done by generating an intensity image from the Li<span class="hlt">DAR</span> data that serves as a base on which the spectrometers (VNIR and VSWIR) are matched using ground control points (GCPs). To do so, we employ the use of automated tie point matching in the overlap regions of the spectrometers to improve the co-location between flightlines. The combination of the GCPs and tie points produce data that is used to build camera models for the VNIR and VSWIR spectrometers such that they will match the Li<span class="hlt">DAR</span> data. The result produces a matched hyper-dimensional data set with great scientific information content. We compare the data dimensionality of two contrasting scenes - a built environment at Stanford University and a lowland tropical forest in Amazonia. Principal components analysis revealed 336 dimensions (degrees of freedom) in the Stanford case, and 218 dimensions in the Amazon. The Amazon case presents what could be the highest level of remotely sensed data dimensionality ever reported for a forested ecosystem. Simulated misalignment of data streams reduced the effective information content by up to 48%, highlighting the critical role of achieving high precision when undertaking multi-sensor fusion. The instrumentation and methods described here are a pathfinder for future airborne applications undertaken by the National</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1816427L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1816427L"><span>Numerical simulation of groundwater flow in <span class="hlt">Dar</span> es Salaam Coastal Plain (Tanzania)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Luciani, Giulia; Sappa, Giuseppe; Cella, Antonella</p> <p>2016-04-01</p> <p>They are presented the results of a groundwater modeling study on the Coastal Aquifer of <span class="hlt">Dar</span> es Salaam (Tanzania). <span class="hlt">Dar</span> es Salaam is one of the fastest-growing coastal cities in Sub-Saharan Africa, with with more than 4 million of inhabitants and a population growth rate of about 8 per cent per year. The city faces periodic water shortages, due to the lack of an adequate water supply network. These two factors have determined, in the last ten years, an increasing demand of groundwater exploitation, carried on by quite a number of private wells, which have been drilled to satisfy human demand. A steady-state three dimensional groundwater model has been set up by the MODFLOW code, and calibrated with the UCODE code for inverse modeling. The aim of the model was to carry out a characterization of groundwater flow system in the <span class="hlt">Dar</span> es Salaam Coastal Plain. The inputs applied to the model included net recharge rate, calculated from time series of precipitation data (1961-2012), estimations of average groundwater extraction, and estimations of groundwater recharge, coming from zones, outside the area under study. Parametrization of the hydraulic conductivities was realized referring to the main geological features of the study area, based on available literature data and information. Boundary conditions were assigned based on hydrogeological boundaries. The conceptual model was defined in subsequent steps, which added some hydrogeological features and excluded other ones. Calibration was performed with UCODE 2014, using 76 measures of hydraulic head, taken in 2012 referred to the same season. Data were weighted on the basis of the expected errors. Sensitivity analysis of data was performed during calibration, and permitted to identify which parameters were possible to be estimated, and which data could support parameters estimation. Calibration was evaluated based on statistical index, maps of error distribution and test of independence of residuals. Further model</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015AGUFM.B53B0552H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015AGUFM.B53B0552H"><span>Regional forest biomass estimation using ICESat/GLAS spaceborne Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hayashi, M.; Saigusa, N.; Habura, B.; Sawada, Y.; Yamagata, Y.; Hirano, T.; Ichii, K.</p> <p>2015-12-01</p> <p>Spaceborne Li<span class="hlt">DAR</span> can observe vertical structure of forests and provide a means for accurate forest monitoring, therefore, it may meet the growing demand of forest resources monitoring on a large scale. This study aims to clarify the potential of ICESat/GLAS, which had been the only spaceborne Li<span class="hlt">DAR</span> up to now, for forest resources monitoring on a regional scale. The study areas were three regions: Hokkaido Island in Japan (cool-temperate forest), Borneo Island (tropical forest) and Siberia (boreal forest). Firstly, we conducted field measurements at 106 points in Hokkaido and 37 points in Borneo to measure the average canopy height (Lorey's height) and the above-ground biomass (AGB) for each GLAS-footprint, then, we developed some models to estimate canopy height and AGB from the GLAS waveform parameters. Next, we applied the developed models to the GLAS data which were 14,000 points in Hokkaido, and 130,000 points in Borneo, to estimate canopy height and AGB on a regional scale. As a result, we clarified the forest condition concerning canopy height and AGB for each region, namely, the average value, the comparison between the average of each forest type, and the spatial distribution. Furthermore, we detected the AGB change over the years (forest degradation) and estimated the forest loss rate of 1.6% yr-1 in Borneo. Next, we applied the developed models in Hokkaido to the 1,600,000 points GLAS data observed in Siberia. As a result, we clarified that the average AGB in Siberia was a remarkable low value as compared with those in Hokkaido and Borneo, and that the AGB change over the years (forest degradation) was significant in the southern region of western Siberia. This study showed that spaceborne Li<span class="hlt">DAR</span> had an ability of forest resources monitoring on a regional scale for various forests over the world.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27854315','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27854315"><span>3D Scene Reconstruction Using Omnidirectional Vision and Li<span class="hlt">DAR</span>: A Hybrid Approach.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Vlaminck, Michiel; Luong, Hiep; Goeman, Werner; Philips, Wilfried</p> <p>2016-11-16</p> <p>In this paper, we propose a novel approach to obtain accurate 3D reconstructions of large-scale environments by means of a mobile acquisition platform. The system incorporates a Velodyne Li<span class="hlt">DAR</span> scanner, as well as a Point Grey Ladybug panoramic camera system. It was designed with genericity in mind, and hence, it does not make any assumption about the scene or about the sensor set-up. The main novelty of this work is that the proposed Li<span class="hlt">DAR</span> mapping approach deals explicitly with the inhomogeneous density of point clouds produced by Li<span class="hlt">DAR</span> scanners. To this end, we keep track of a global 3D map of the environment, which is continuously improved and refined by means of a surface reconstruction technique. Moreover, we perform surface analysis on consecutive generated point clouds in order to assure a perfect alignment with the global 3D map. In order to cope with drift, the system incorporates loop closure by determining the pose error and propagating it back in the pose graph. Our algorithm was exhaustively tested on data captured at a conference building, a university campus and an industrial site of a chemical company. Experiments demonstrate that it is capable of generating highly accurate 3D maps in very challenging environments. We can state that the average distance of corresponding point pairs between the ground truth and estimated point cloud approximates one centimeter for an area covering approximately 4000 m 2 . To prove the genericity of the system, it was tested on the well-known Kitti vision benchmark. The results show that our approach competes with state of the art methods without making any additional assumptions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015SPIE.9526E..0GB','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015SPIE.9526E..0GB"><span>Horizontal geometrical reaction time model for two-beam nacelle Li<span class="hlt">DARs</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Beuth, Thorsten; Fox, Maik; Stork, Wilhelm</p> <p>2015-06-01</p> <p>Wind energy is one of the leading sustainable energies. To attract further private and state investment in this technology, a broad scaled drop of the cost of energy has to be enforced. There is a trend towards using Laser Doppler Velocimetry Li<span class="hlt">DAR</span> systems for enhancing power output and minimizing downtimes, fatigue and extreme forces. Since most used Li<span class="hlt">DARs</span> are horizontally setup on a nacelle and work with two beams, it is important to understand the geometrical configuration which is crucial to estimate reaction times for the actuators to compensate wind gusts. In the beginning of this article, the basic operating modes of wind turbines are explained and the literature on wind behavior is analyzed to derive specific wind speed and wind angle conditions in relation to the yaw angle of the hub. A short introduction to the requirements for the reconstruction of the wind vector length and wind angle leads to the problem of wind shear detection of angled but horizontal homogeneous wind fronts due to the spatial separation of the measuring points. A distance is defined in which the wind shear of such homogeneous wind fronts is not present which is used as a base to estimate further distance calculations. The reaction time of the controller and the actuators are having a negative effect on the effective overall reaction time for wind regulation as well. In the end, exemplary calculations estimate benefits and disadvantages of system parameters for wind gust regulating Li<span class="hlt">DARs</span> for a wind turbine of typical size. An outlook shows possible future improvements concerning the vertical wind behavior.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SedG..338...72S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SedG..338...72S"><span>Li<span class="hlt">DAR</span>-based volume assessment of the origin of the Wadena drumlin field, Minnesota, USA</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sookhan, Shane; Eyles, Nick; Putkinen, Niko</p> <p>2016-06-01</p> <p>The Wadena drumlin field (WDF; ~ 7500 km2) in west-central Minnesota, USA, is bordered along its outer extremity by the till-cored Alexandria moraine marking the furthest extent of the southwesterly-flowing Wadena ice lobe at c. 15,000 kyr BP. Newly available high-resolution Light Detection and Ranging (Li<span class="hlt">DAR</span>) data reveal new information regarding the number, morphology and extent of streamlined bedforms in the WDF. In addition, a newly-developed quantitative methodology based on relief curvature analysis of Li<span class="hlt">DAR</span> elevation-based raster data is used to evaluate sediment volumes represented by the WDF and its bounding end moraine. These data are used to evaluate models for the origin of drumlins. High-resolution Li<span class="hlt">DAR</span>-based mapping doubles the streamlined footprint of the Wadena Lobe to ~ 16,500 km2 increases the number of bedforms from ~ 2000 to ~ 6000, and most significantly, reclassifies large numbers of bedforms mapped previously as 'drumlins' as 'mega-scale glacial lineations' (MSGLs), indicating that the Wadena ice lobe experienced fast ice flow. The total volume of sediment in the Alexandria moraine is ~ 71-110 km3, that in the drumlins and MSGLs is ~ 2.83 km3, and the volume of swales between these bedforms is ~ 74.51 km3. The moraine volume is equivalent to a till layer 6.8 m thick across the entire bed of the Wadena lobe, suggesting drumlinization and moraine formation were accompanied by widespread lowering of the bed. This supports the hypothesis that drumlins and MSGLs are residual erosional features carved from a pre-existing till; swales represent 'missing sediment' that was eroded subglacially and advected downglacier to build the Alexandria Moraine during fast ice flow. Alternatively, the relatively small volume of sediment represented by subglacial bedforms indicates they could have formed rapidly by depositional processes.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.dtic.mil/docs/citations/ADA607122','DTIC-ST'); return false;" href="http://www.dtic.mil/docs/citations/ADA607122"><span>Demonstration of Li<span class="hlt">DAR</span> and Orthophotography for Wide Area Assessment at Pueblo Precision Bombing Range #2 Colorado and Borrego Military Wash Area, California</span></a></p> <p><a target="_blank" href="https://publicaccess.dtic.mil/psm/api/service/search/search">DTIC Science & Technology</a></p> <p></p> <p>2008-12-01</p> <p>software for rectification of the photography to the DTM . 2.2.3 Data Analysis Once processed, the Li<span class="hlt">DAR</span> /orthophotography data sets are analyzed to...ESTCP Cost and Performance Report ENVIRONMENTAL SECURITY TECHNOLOGY CERTIFICATION PROGRAM U.S. Department of Defense (MM-0535) Demonstration of Li<span class="hlt">DAR</span> ...DEC 2008 2. REPORT TYPE 3. DATES COVERED 00-00-2008 to 00-00-2008 4. TITLE AND SUBTITLE Demonstration of Li<span class="hlt">DAR</span> and Orthophotography for Wide</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009PhDT.......342S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009PhDT.......342S"><span>Unsupervised building detection from irregularly spaced Li<span class="hlt">DAR</span> and aerial imagery</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Shorter, Nicholas Sven</p> <p></p> <p>As more data sources containing 3-D information are becoming available, an increased interest in 3-D imaging has emerged. Among these is the 3-D reconstruction of buildings and other man-made structures. A necessary preprocessing step is the detection and isolation of individual buildings that subsequently can be reconstructed in 3-D using various methodologies. Applications for both building detection and reconstruction have commercial use for urban planning, network planning for mobile communication (cell phone tower placement), spatial analysis of air pollution and noise nuisances, microclimate investigations, geographical information systems, security services and change detection from areas affected by natural disasters. Building detection and reconstruction are also used in the military for automatic target recognition and in entertainment for virtual tourism. Previously proposed building detection and reconstruction algorithms solely utilized aerial imagery. With the advent of Light Detection and Ranging (Li<span class="hlt">DAR</span>) systems providing elevation data, current algorithms explore using captured Li<span class="hlt">DAR</span> data as an additional feasible source of information. Additional sources of information can lead to automating techniques (alleviating their need for manual user intervention) as well as increasing their capabilities and accuracy. Several building detection approaches surveyed in the open literature have fundamental weaknesses that hinder their use; such as requiring multiple data sets from different sensors, mandating certain operations to be carried out manually, and limited functionality to only being able to detect certain types of buildings. In this work, a building detection system is proposed and implemented which strives to overcome the limitations seen in existing techniques. The developed framework is flexible in that it can perform building detection from just Li<span class="hlt">DAR</span> data (first or last return), or just nadir, color aerial imagery. If data from both Li<span class="hlt">DAR</span> and</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMIN14A..07M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMIN14A..07M"><span>Interoperable Data Systems for Satellite, Airborne, and Terrestrial Li<span class="hlt">DAR</span> Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Meertens, C. M.; Baru, C.; Blair, B.; Crosby, C. J.; Haran, T. M.; Harding, D. J.; Hofton, M. A.; Khalsa, S. S.; McWhirter, J.</p> <p>2010-12-01</p> <p>Li<span class="hlt">DAR</span> (Light Detection and Ranging) technology is being widely applied to scientific problems on global to local scales using a range of laser technologies mounted on satellite, low- and high-altitude airborne and terrestrial platforms. Modern laser ranging instruments are increasingly capable of providing full waveform data, multiple detectors, higher sample rates and longer ranges. Accompanying these improvements, however, are rapidly growing data volumes and ever more complex data formats and processing algorithms. This presents significant challenges for existing Earth science data systems serving these data and creates barriers to the efficient use of these data by a growing and diverse community of scientific and other users who are studying deformation of the solid Earth, the cryosphere, vegetation structure, and land form evolution. To address these challenges, a group of data centers is collaborating under a project funded by the NASA ROSES ACCESS Program to develop interoperable Li<span class="hlt">DAR</span> data access systems to provide integrated access to data and derived products in common data formats via simple-to-navigate web interfaces. The web service-based systems created by this project, called NLAS, will enhance access to existing laser data sources hosted at the National Snow and Ice Data Center DAAC, Goddard Space Flight Center LVIS Data Center, UNAVCO, and the OpenTopography Facility at the San Diego Supercomputer Center (SDSC). Through the OpenTopography portal, NLAS systems will provide access to satellite laser altimetry data from ICESat and high altitude airborne laser scanning data from LVIS, as well as low altitude airborne Li<span class="hlt">DAR</span> and terrestrial laser scanning data hosted at OpenTopography and UNAVCO. NLAS will develop new web service interfaces for NASA data archives at GSFC/LVIS and NSIDC in an effort to improve and streamline access to these data archives. The OpenTopography portal will act as a client to the NLAS services and will provide integrated</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4934329','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4934329"><span>Scan Line Based Road Marking Extraction from Mobile Li<span class="hlt">DAR</span> Point Clouds†</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Yan, Li; Liu, Hua; Tan, Junxiang; Li, Zan; Xie, Hong; Chen, Changjun</p> <p>2016-01-01</p> <p>Mobile Mapping Technology (MMT) is one of the most important 3D spatial data acquisition technologies. The state-of-the-art mobile mapping systems, equipped with laser scanners and named Mobile Li<span class="hlt">DAR</span> Scanning (MLS) systems, have been widely used in a variety of areas, especially in road mapping and road inventory. With the commercialization of Advanced Driving Assistance Systems (ADASs) and self-driving technology, there will be a great demand for lane-level detailed 3D maps, and MLS is the most promising technology to generate such lane-level detailed 3D maps. Road markings and road edges are necessary information in creating such lane-level detailed 3D maps. This paper proposes a scan line based method to extract road markings from mobile Li<span class="hlt">DAR</span> point clouds in three steps: (1) preprocessing; (2) road points extraction; (3) road markings extraction and refinement. In preprocessing step, the isolated Li<span class="hlt">DAR</span> points in the air are removed from the Li<span class="hlt">DAR</span> point clouds and the point clouds are organized into scan lines. In the road points extraction step, seed road points are first extracted by Height Difference (HD) between trajectory data and road surface, then full road points are extracted from the point clouds by moving least squares line fitting. In the road markings extraction and refinement step, the intensity values of road points in a scan line are first smoothed by a dynamic window median filter to suppress intensity noises, then road markings are extracted by Edge Detection and Edge Constraint (EDEC) method, and the Fake Road Marking Points (FRMPs) are eliminated from the detected road markings by segment and dimensionality feature-based refinement. The performance of the proposed method is evaluated by three data samples and the experiment results indicate that road points are well extracted from MLS data and road markings are well extracted from road points by the applied method. A quantitative study shows that the proposed method achieves an average</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ISPAn.II5b..61C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ISPAn.II5b..61C"><span>Temporal Analysis and Automatic Calibration of the Velodyne HDL-32E Li<span class="hlt">DAR</span> System</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chan, T. O.; Lichti, D. D.; Belton, D.</p> <p>2013-10-01</p> <p>At the end of the first quarter of 2012, more than 600 Velodyne Li<span class="hlt">DAR</span> systems had been sold worldwide for various robotic and high-accuracy survey applications. The ultra-compact Velodyne HDL-32E Li<span class="hlt">DAR</span> has become a predominant sensor for many applications that require lower sensor size/weight and cost. For high accuracy applications, cost-effective calibration methods with minimal manual intervention are always desired by users. However, the calibrations are complicated by the Velodyne Li<span class="hlt">DAR</span>'s narrow vertical field of view and the very highly time-variant nature of its measurements. In the paper, the temporal stability of the HDL-32E is first analysed as the motivation for developing a new, automated calibration method. This is followed by a detailed description of the calibration method that is driven by a novel segmentation method for extracting vertical cylindrical features from the Velodyne point clouds. The proposed segmentation method utilizes the Velodyne point cloud's slice-like nature and first decomposes the point clouds into 2D layers. Then the layers are treated as 2D images and are processed with the Generalized Hough Transform which extracts the points distributed in circular patterns from the point cloud layers. Subsequently, the vertical cylindrical features can be readily extracted from the whole point clouds based on the previously extracted points. The points are passed to the calibration that estimates the cylinder parameters and the Li<span class="hlt">DAR</span>'s additional parameters simultaneously by constraining the segmented points to fit to the cylindrical geometric model in such a way the weighted sum of the adjustment residuals are minimized. The proposed calibration is highly automatic and this allows end users to obtain the time-variant additional parameters instantly and frequently whenever there are vertical cylindrical features presenting in scenes. The methods were verified with two different real datasets, and the results suggest that up to 78</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27322279','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27322279"><span>Scan Line Based Road Marking Extraction from Mobile Li<span class="hlt">DAR</span> Point Clouds.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Yan, Li; Liu, Hua; Tan, Junxiang; Li, Zan; Xie, Hong; Chen, Changjun</p> <p>2016-06-17</p> <p>Mobile Mapping Technology (MMT) is one of the most important 3D spatial data acquisition technologies. The state-of-the-art mobile mapping systems, equipped with laser scanners and named Mobile Li<span class="hlt">DAR</span> Scanning (MLS) systems, have been widely used in a variety of areas, especially in road mapping and road inventory. With the commercialization of Advanced Driving Assistance Systems (ADASs) and self-driving technology, there will be a great demand for lane-level detailed 3D maps, and MLS is the most promising technology to generate such lane-level detailed 3D maps. Road markings and road edges are necessary information in creating such lane-level detailed 3D maps. This paper proposes a scan line based method to extract road markings from mobile Li<span class="hlt">DAR</span> point clouds in three steps: (1) preprocessing; (2) road points extraction; (3) road markings extraction and refinement. In preprocessing step, the isolated Li<span class="hlt">DAR</span> points in the air are removed from the Li<span class="hlt">DAR</span> point clouds and the point clouds are organized into scan lines. In the road points extraction step, seed road points are first extracted by Height Difference (HD) between trajectory data and road surface, then full road points are extracted from the point clouds by moving least squares line fitting. In the road markings extraction and refinement step, the intensity values of road points in a scan line are first smoothed by a dynamic window median filter to suppress intensity noises, then road markings are extracted by Edge Detection and Edge Constraint (EDEC) method, and the Fake Road Marking Points (FRMPs) are eliminated from the detected road markings by segment and dimensionality feature-based refinement. The performance of the proposed method is evaluated by three data samples and the experiment results indicate that road points are well extracted from MLS data and road markings are well extracted from road points by the applied method. A quantitative study shows that the proposed method achieves an average</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24246579','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24246579"><span>Financial sustainability in municipal solid waste management--costs and revenues in Bahir <span class="hlt">Dar</span>, Ethiopia.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Lohri, Christian Riuji; Camenzind, Ephraim Joseph; Zurbrügg, Christian</p> <p>2014-02-01</p> <p>Providing good solid waste management (SWM) services while also ensuring financial sustainability of the system continues to be a major challenge in cities of developing countries. Bahir <span class="hlt">Dar</span> in northwestern Ethiopia outsourced municipal waste services to a private waste company in 2008. While this institutional change has led to substantial improvement in the cleanliness of the city, its financial sustainability remains unclear. Is the private company able to generate sufficient revenues from their activities to offset the costs and generate some profit? This paper presents a cost-revenue analysis, based on data from July 2009 to June 2011. The analysis reveals that overall costs in Bahir <span class="hlt">Dar</span>'s SWM system increased significantly during this period, mainly due to rising costs related to waste transportation. On the other hand, there is only one major revenue stream in place: the waste collection fee from households, commercial enterprises and institutions. As the efficiency of fee collection from households is only around 50%, the total amount of revenues are not sufficient to cover the running costs. This results in a substantial yearly deficit. The results of the research therefore show that a more detailed cost structure and cost-revenue analysis of this waste management service is important with appropriate measures, either by the privates sector itself or with the support of the local authorities, in order to enhance cost efficiency and balance the cost-revenues towards cost recovery. Delays in mitigating the evident financial deficit could else endanger the public-private partnership (PPP) and lead to failure of this setup in the medium to long term, thus also endangering the now existing improved and currently reliable service. We present four options on how financial sustainability of the SWM system in Bahir <span class="hlt">Dar</span> might be enhanced: (i) improved fee collection efficiency by linking the fees of solid waste collection to water supply; (ii) increasing the value</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFMED51A0519R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFMED51A0519R"><span>Wallace Creek Virtual Field Trip: Teaching Geoscience Concepts with Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Robinson, S. E.; Arrowsmith, R.; Crosby, C. J.</p> <p>2009-12-01</p> <p>Recently available data such as Li<span class="hlt">DAR</span> (Light Detection and Ranging) high-resolution topography can assist students to better visualize and understand geosciences concepts. It is important to bring these data into geosciences curricula as teaching aids while ensuring that the visualization tools, virtual environments, etc. do not serve as barriers to student learning. As a Southern California Earthquake Center ACCESS-G intern, I am creating a “virtual field trip” to Wallace Creek along the San Andreas Fault (SAF) using Google Earth as a platform and the B4 project Li<span class="hlt">DAR</span> data. Wallace Creek is an excellent site for understanding the centennial-to-millennial record of SAF slip because of its dramatic stream offsets. Using the Li<span class="hlt">DAR</span> data instead of, or alongside, traditional visualizations and teaching methods enhances a student’s ability to understand plate tectonics, the earthquake cycle, strike-slip faults, and geomorphology. Viewing a high-resolution representation of the topography in Google Earth allows students to analyze the landscape and answer questions about the behavior of the San Andreas Fault. The activity guides students along the fault allowing them to measure channel offsets using the Google Earth measuring tool. Knowing the ages of channels, they calculate slip rate. They look for the smallest channel offsets around Wallace Creek in order to determine the slip per event. At both a “Li<span class="hlt">DAR</span> and Education” workshop and the Cyberinfrastructure Summer Institute for Geoscientists (CSIG), I presented the Wallace Creek activity to high school and college earth science teachers. The teachers were positive in their responses and had numerous important suggestions including the need for a teacher’s manual for instruction and scientific background, and that the student goals and science topics should be specific and well-articulated for the sake of both the teacher and the student. The teachers also noted that the technology in classrooms varies</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3495844','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3495844"><span><span class="hlt">AL</span> Amyloidosis</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2012-01-01</p> <p>Definition of the disease <span class="hlt">AL</span> amyloidosis results from extra-cellular deposition of fibril-forming monoclonal immunoglobulin (Ig) light chains (LC) (most commonly of lambda isotype) usually secreted by a small plasma cell clone. Most patients have evidence of isolated monoclonal gammopathy or smoldering myeloma, and the occurrence of <span class="hlt">AL</span> amyloidosis in patients with symptomatic multiple myeloma or other B-cell lymphoproliferative disorders is unusual. The key event in the development of <span class="hlt">AL</span> amyloidosis is the change in the secondary or tertiary structure of an abnormal monoclonal LC, which results in instable conformation. This conformational change is responsible for abnormal folding of the LC, rich in β leaves, which assemble into monomers that stack together to form amyloid fibrils. Epidemiology <span class="hlt">AL</span> amyloidosis is the most common type of systemic amyloidois in developed countries with an estimated incidence of 9 cases/million inhabitant/year. The average age of diagnosed patients is 65 years and less than 10% of patients are under 50. Clinical description The clinical presentation is protean, because of the wide number of tissues or organs that may be affected. The most common presenting symptoms are asthenia and dyspnoea, which are poorly specific and may account for delayed diagnosis. Renal manifestations are the most frequent, affecting two thirds of patients at presentation. They are characterized by heavy proteinuria, with nephrotic syndrome and impaired renal function in half of the patients. Heart involvement, which is present at diagnosis in more than 50% of patients, leading to restrictive cardiopathy, is the most serious complication and engages prognosis. Diagnostic methods The diagnosis relies on pathological examination of an involved site showing Congo red-positive amyloid deposits, with typical apple-green birefringence under polarized light, that stain positive with an anti-LC antibody by immunohistochemistry and/or immunofluorescence. Due to the</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_17");'>17</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li class="active"><span>19</span></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_19 --> <div id="page_20" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="381"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MeScT..28d5203M','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MeScT..28d5203M"><span>Decomposition of small-footprint full waveform Li<span class="hlt">DAR</span> data based on generalized Gaussian model and grouping LM optimization</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ma, Hongchao; Zhou, Weiwei; Zhang, Liang; Wang, Suyuan</p> <p>2017-04-01</p> <p>Full waveform airborne Light Detection And Ranging(Li<span class="hlt">DAR</span>) data contains abundant information which may overcome some deficiencies of discrete Li<span class="hlt">DAR</span> point cloud data provided by conventional Li<span class="hlt">DAR</span> systems. Processing full waveform data to extract more information than coordinate values alone is of great significance for potential applications. The Levenberg–Marquardt (LM) algorithm is a traditional method used to estimate parameters of a Gaussian model when Gaussian decomposition of full waveform Li<span class="hlt">DAR</span> data is performed. This paper employs the generalized Gaussian mixture function to fit a waveform, and proposes using the grouping LM algorithm to optimize the parameters of the function. It is shown that the grouping LM algorithm overcomes the common drawbacks which arise from the conventional LM for parameter optimization, such as the final results being influenced by the initial parameters, possible algorithm interruption caused by non-numerical elements that occurred in the Jacobian matrix, etc. The precision of the point cloud generated by the grouping LM is evaluated by comparing it with those provided by the Li<span class="hlt">DAR</span> system and those generated by the conventional LM. Results from both simulation and real data show that the proposed algorithm can generate a higher-quality point cloud, in terms of point density and precision, and can extract other information, such as echo location, pulse width, etc., more precisely as well.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26072748','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26072748"><span>Synergistic application of geometric and radiometric features of Li<span class="hlt">DAR</span> data for urban land cover mapping.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Qin, Yuchu; Li, Shihua; Vu, Tuong-Thuy; Niu, Zheng; Ban, Yifang</p> <p>2015-06-01</p> <p>Urban land cover map is essential for urban planning, environmental studies and management. This paper aims to demonstrate the potential of geometric and radiometric features derived from Li<span class="hlt">DAR</span> waveform and point cloud data in urban land cover mapping with both parametric and non-parametric classification algorithms. Small footprint Li<span class="hlt">DAR</span> waveform data acquired by RIEGL LMS-Q560 in Zhangye city, China is used in this study. A Li<span class="hlt">DAR</span> processing chain is applied to perform waveform decomposition, range determination and radiometric characterization. With the synergic utilization of geometric and radiometric features derived from Li<span class="hlt">DAR</span> data, urban land cover classification is then conducted using the Maximum Likelihood Classification (MLC), Support Vector Machines (SVM) and random forest algorithms. The results suggest that the random forest classifier achieved the most accurate result with overall classification accuracy of 91.82% and the kappa coefficient of 0.88. The overall accuracies of MLC and SVM are 84.02, and 88.48, respectively. The study suggest that the synergic utilization of geometric and radiometric features derived from Li<span class="hlt">DAR</span> data can be efficiently used for urban land cover mapping, the non-parametric random forest classifier is a promising approach for the various features with different physical meanings.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26389906','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26389906"><span>INS/GPS/Li<span class="hlt">DAR</span> Integrated Navigation System for Urban and Indoor Environments Using Hybrid Scan Matching Algorithm.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Gao, Yanbin; Liu, Shifei; Atia, Mohamed M; Noureldin, Aboelmagd</p> <p>2015-09-15</p> <p>This paper takes advantage of the complementary characteristics of Global Positioning System (GPS) and Light Detection and Ranging (Li<span class="hlt">DAR</span>) to provide periodic corrections to Inertial Navigation System (INS) alternatively in different environmental conditions. In open sky, where GPS signals are available and Li<span class="hlt">DAR</span> measurements are sparse, GPS is integrated with INS. Meanwhile, in confined outdoor environments and indoors, where GPS is unreliable or unavailable and Li<span class="hlt">DAR</span> measurements are rich, Li<span class="hlt">DAR</span> replaces GPS to integrate with INS. This paper also proposes an innovative hybrid scan matching algorithm that combines the feature-based scan matching method and Iterative Closest Point (ICP) based scan matching method. The algorithm can work and transit between two modes depending on the number of matched line features over two scans, thus achieving efficiency and robustness concurrently. Two integration schemes of INS and Li<span class="hlt">DAR</span> with hybrid scan matching algorithm are implemented and compared. Real experiments are performed on an Unmanned Ground Vehicle (UGV) for both outdoor and indoor environments. Experimental results show that the multi-sensor integrated system can remain sub-meter navigation accuracy during the whole trajectory.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4610570','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4610570"><span>INS/GPS/Li<span class="hlt">DAR</span> Integrated Navigation System for Urban and Indoor Environments Using Hybrid Scan Matching Algorithm</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Gao, Yanbin; Liu, Shifei; Atia, Mohamed M.; Noureldin, Aboelmagd</p> <p>2015-01-01</p> <p>This paper takes advantage of the complementary characteristics of Global Positioning System (GPS) and Light Detection and Ranging (Li<span class="hlt">DAR</span>) to provide periodic corrections to Inertial Navigation System (INS) alternatively in different environmental conditions. In open sky, where GPS signals are available and Li<span class="hlt">DAR</span> measurements are sparse, GPS is integrated with INS. Meanwhile, in confined outdoor environments and indoors, where GPS is unreliable or unavailable and Li<span class="hlt">DAR</span> measurements are rich, Li<span class="hlt">DAR</span> replaces GPS to integrate with INS. This paper also proposes an innovative hybrid scan matching algorithm that combines the feature-based scan matching method and Iterative Closest Point (ICP) based scan matching method. The algorithm can work and transit between two modes depending on the number of matched line features over two scans, thus achieving efficiency and robustness concurrently. Two integration schemes of INS and Li<span class="hlt">DAR</span> with hybrid scan matching algorithm are implemented and compared. Real experiments are performed on an Unmanned Ground Vehicle (UGV) for both outdoor and indoor environments. Experimental results show that the multi-sensor integrated system can remain sub-meter navigation accuracy during the whole trajectory. PMID:26389906</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20170001342','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20170001342"><span>Partitioning of F and Cl Between Apatite and a Synthetic <span class="hlt">Shergottite</span> Liquid (QUE 94201) at 4 Gpa from 1300 TO 1500 C</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>McCubbin, F. M.; Barnes, J. J.; Vander Kaaden, K. E.; Boyce, J. W.</p> <p>2017-01-01</p> <p>Apatite [Ca5(PO4)3(F,Cl,OH)] is present in a wide range of planetary materials. Due to the presence of volatiles within its crystal structure (Xsite), many recent studies have attempted to use apatite to constrain the volatile contents of planetary magmas and mantle sources. In order to use the volatile contents of apatite to accurately determine the abundances of volatiles in coexisting silicate melt or fluids, thermodynamic models for the apatite solid solution and for the apatite components in multicomponent silicate melts and fluids are required. Although some thermodynamic models for apatite have been developed, they are incomplete. Furthermore, no mixing model is available for all of the apatite components in silicate melts or fluids, especially for F and Cl components. Several experimental studies have investigated the apatite-melt and apatite-fluid partitioning behavior of F, Cl, and OH in terrestrial and planetary systems, which have determined that apatite-melt partitioning of volatiles are best described as exchange equilibria similar to Fe-Mg partitioning between olivine and silicate melt. However, McCubbin et <span class="hlt">al</span>., recently reported that the exchange coefficients vary in portions of apatite compositional space where F, Cl, and OH do not mix ideally in apatite. In particular, solution calorimetry data of apatite compositions along the F-Cl join exhibit substantial excess enthalpies of mixing, and McCubbin et <span class="hlt">al</span>. reported substantial deviations in the Cl-F exchange Kd along the F-Cl apatite join that could be explained by the preferential incorporation of F into apatite. In the present study, we assess the effect of apatite crystal chemistry on F-Cl exchange equilibria between apatite and melt at 4 GPa over the temperature range of 1300-1500 C. The goal of these experiments is to assess the variation in the Ap-melt Cl-F exchange Kd over a broad range of F:Cl ratios in apatite. The results of these experiments could be used to understand at what</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26184206','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26184206"><span>Li<span class="hlt">DAR</span> Scan Matching Aided Inertial Navigation System in GNSS-Denied Environments.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Tang, Jian; Chen, Yuwei; Niu, Xiaoji; Wang, Li; Chen, Liang; Liu, Jingbin; Shi, Chuang; Hyyppä, Juha</p> <p>2015-07-10</p> <p>A new scan that matches an aided Inertial Navigation System (INS) with a low-cost Li<span class="hlt">DAR</span> is proposed as an alternative to GNSS-based navigation systems in GNSS-degraded or -denied environments such as indoor areas, dense forests, or urban canyons. In these areas, INS-based Dead Reckoning (DR) and Simultaneous Localization and Mapping (SLAM) technologies are normally used to estimate positions as separate tools. However, there are critical implementation problems with each standalone system. The drift errors of velocity, position, and heading angles in an INS will accumulate over time, and on-line calibration is a must for sustaining positioning accuracy. SLAM performance is poor in featureless environments where the matching errors can significantly increase. Each standalone positioning method cannot offer a sustainable navigation solution with acceptable accuracy. This paper integrates two complementary technologies-INS and Li<span class="hlt">DAR</span> SLAM-into one navigation frame with a loosely coupled Extended Kalman Filter (EKF) to use the advantages and overcome the drawbacks of each system to establish a stable long-term navigation process. Static and dynamic field tests were carried out with a self-developed Unmanned Ground Vehicle (UGV) platform-NAVIS. The results prove that the proposed approach can provide positioning accuracy at the centimetre level for long-term operations, even in a featureless indoor environment.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4372933','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4372933"><span>Body-Art Practices Among Undergraduate Medical University Students in <span class="hlt">Dar</span> Es Salaam, Tanzania, 2014</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chacha, Chacha Emmanuel; Kazaura, Method R.</p> <p>2015-01-01</p> <p>Background: Body-art practices are increasing among adolescents and young adults. Although substantial data are available in developed countries, little has been documented about body-art practices in developing countries. Objective: To determine the magnitude, types and reasons for practicing body-art practices among undergraduate medical University students in <span class="hlt">Dar</span> es Salaam, Tanzania. Materials and Methods: A cross-sectional descriptive study was conducteed among undergraduate University students in <span class="hlt">Dar</span> es Salaam involving 536 respondents from two Universities. We used a self-administered questionnaire to collect data. Analyses were based on summary measures and bivariate analyses. Results: While 7.5% of undergraduate students reported having tattoos, 20% reported having body puncturing or piercing. Body piercing is reported more among female university undergraduate students than their male counterparts. Reported main reasons for undergoing body-art include “a mark of beauty,” 24%, “just wanted one,” 18% and “a mark of femininity or masculinity,” 17%. The majority (98%) of students were aware that unsafe body-art practices may lead to contracting HIV and more than half (52%) reported awareness of the risk of Hepatitis B infection. Conclusions: Despite high awareness of the potential risks involved in unsafe body arts that include tattoo and piercing, these practices are increasing among adolescents and young adults. There is need to have educational and counseling efforts so as to minimize associated health risks. PMID:25814729</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE10156E..1XL','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE10156E..1XL"><span>Research on high resolution spectral method of hyperspectral Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Feng; Jiang, Chenghao; Zhu, Jingguo; Li, Menglin; Meng, Zhe</p> <p>2016-10-01</p> <p>Hyperspectral Li<span class="hlt">DAR</span> using supercontinuum laser as light source, applying spectroscopic technology gets backscattered reflectance of different wavelengths, and can acquire both the geometry and spectral information on the target. Due to the development of the photoelectric sensor, hyperspectral Li<span class="hlt">DAR</span> has fewer spectral channels, which limits its application in physical properties detection. To solve this problem, this paper proposes a new method based on the micro mirror array. By blaze grating, the supercontinuum laser is grating into monochromatic light in space, first projected to the micro mirror array, by controlling the micro mirror array flip, specific spectrum and reflection to corresponding photoelectric sensor channels, improve the spectral resolution. The micro mirror array photoelectric sensor resolution is much higher than the number of channels, through this method, can greatly improve the spectral resolution. In this paper, based on the micro mirror array, the simulation design is carried out and the feasibility of the method is verified by experiments. The simulation and experimental results show that the spectral resolution can be improved greatly by controlling the turning of the micro mirror.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015OptLT..70...63R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015OptLT..70...63R"><span>Automatic detection of zebra crossings from mobile Li<span class="hlt">DAR</span> data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Riveiro, B.; González-Jorge, H.; Martínez-Sánchez, J.; Díaz-Vilariño, L.; Arias, P.</p> <p>2015-07-01</p> <p>An algorithm for the automatic detection of zebra crossings from mobile Li<span class="hlt">DAR</span> data is developed and tested to be applied for road management purposes. The algorithm consists of several subsequent processes starting with road segmentation by performing a curvature analysis for each laser cycle. Then, intensity images are created from the point cloud using rasterization techniques, in order to detect zebra crossing using the Standard Hough Transform and logical constrains. To optimize the results, image processing algorithms are applied to the intensity images from the point cloud. These algorithms include binarization to separate the painting area from the rest of the pavement, median filtering to avoid noisy points, and mathematical morphology to fill the gaps between the pixels in the border of white marks. Once the road marking is detected, its position is calculated. This information is valuable for inventorying purposes of road managers that use Geographic Information Systems. The performance of the algorithm has been evaluated over several mobile Li<span class="hlt">DAR</span> strips accounting for a total of 30 zebra crossings. That test showed a completeness of 83%. Non-detected marks mainly come from painting deterioration of the zebra crossing or by occlusions in the point cloud produced by other vehicles on the road.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4999160','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4999160"><span>Identifying Ancient Settlement Patterns through Li<span class="hlt">DAR</span> in the Mosquitia Region of Honduras</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Fernández-Diaz, Juan Carlos; Cohen, Anna S.; Neil Cruz, Oscar; Gonzáles, Alicia M.; Leisz, Stephen J.; Pezzutti, Florencia; Shrestha, Ramesh; Carter, William</p> <p>2016-01-01</p> <p>The Mosquitia ecosystem of Honduras occupies the fulcrum between the American continents and as such constitutes a critical region for understanding past patterns of socio-political development and interaction. Heavy vegetation, rugged topography, and remoteness have limited scientific investigation. This paper presents prehistoric patterns of settlement and landuse for a critical valley within the Mosquitia derived from airborne Li<span class="hlt">DAR</span> scanning and field investigation. We show that (i) though today the valley is a wilderness it was densely inhabited in the past; (ii) that this population was organized into a three-tiered system composed of 19 settlements dominated by a city; and, (iii) that this occupation was embedded within a human engineered landscape. We also add to a growing body of literature that demonstrates the utility of Li<span class="hlt">DAR</span> as means for rapid cultural assessments in undocumented regions for analysis and conservation. Our ultimate hope is for our work to promote protections to safeguard the unique and critically endangered Mosquitia ecosystem and other similar areas in need of preservation. PMID:27560962</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JPRS..101...22W','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JPRS..101...22W"><span>A comparison of waveform processing algorithms for single-wavelength Li<span class="hlt">DAR</span> bathymetry</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Wang, Chisheng; Li, Qingquan; Liu, Yanxiong; Wu, Guofeng; Liu, Peng; Ding, Xiaoli</p> <p>2015-03-01</p> <p>Due to the low-cost and lightweight units, single-wavelength Li<span class="hlt">DAR</span> bathymetric systems are an ideal option for shallow-water (<12 m) bathymetry. However, one disadvantage of such systems is the lack of near-infrared and Raman channels, which results in difficulties in extracting the water surface. Therefore, the choice of a suitable waveform processing method is extremely important to guarantee the accuracy of the bathymetric retrieval. In this paper, we test six algorithms for single-wavelength bathymetric waveform processing, i.e. peak detection (PD), the average square difference function (ASDF), Gaussian decomposition (GD), quadrilateral fitting (QF), Richardson-Lucy deconvolution (RLD), and Wiener filter deconvolution (WD). To date, most of these algorithms have previously only been applied in topographic Li<span class="hlt">DAR</span> waveforms captured over land. A simulated dataset and an Optech Aquarius dataset were used to assess the algorithms, with the focus being on their capability of extracting the depth and the bottom response. The influences of a number of water and equipment parameters were also investigated by the use of a Monte Carlo method. The results showed that the RLD method had a superior performance in terms of a high detection rate and low errors in the retrieved depth and magnitude. The attenuation coefficient, noise level, water depth, and bottom reflectance had significant influences on the measurement error of the retrieved depth, while the effects of scan angle and water surface roughness were not so obvious.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015WRR....5110029H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015WRR....5110029H"><span>Wet channel network extraction by integrating Li<span class="hlt">DAR</span> intensity and elevation data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hooshyar, Milad; Kim, Seoyoung; Wang, Dingbao; Medeiros, Stephen C.</p> <p>2015-12-01</p> <p>The temporal dynamics of stream networks are vitally important for understanding hydrologic processes including surface water and groundwater interaction and hydrograph recession. However, observations of wet channel networks are limited, especially in headwater catchments. Near-infrared Li<span class="hlt">DAR</span> data provide an opportunity to map wet channel networks owing to the fine spatial resolution and strong absorption of light energy by water surfaces. A systematic method is developed to map wet channel networks by integrating elevation and signal intensity of ground returns. The signal intensity thresholds for identifying wet pixels are extracted from frequency distributions of intensity return within the convergent topography extent using a Gaussian mixture model. Moreover, the concept of edge in digital image processing, defined based on the intensity gradient, is utilized to enhance detection of small wet channels. The developed method is applied to the Lake Tahoe area based on eight Li<span class="hlt">DAR</span> snapshots during recession periods in five watersheds. A power law relationship between streamflow and wetted channel length during recession periods is derived, and the scaling exponent (L∝Q0.44) is within the range of reported values from fieldwork in other regions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/21637652','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/21637652"><span>Genetic diversity of carotenoid-rich bananas evaluated by Diversity Arrays Technology (<span class="hlt">DAr</span>T).</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Amorim, Edson P; Vilarinhos, Alberto D; Cohen, Kelly O; Amorim, Vanusia B O; Dos Santos-Serejo, Janay A; Silva, Sebastião Oliveira E; Pestana, Kátia N; Dos Santos, Vânia J; Paes, Norma S; Monte, Damares C; Dos Reis, Ronaldo V</p> <p>2009-01-01</p> <p>The aim of this work was to evaluate the carotenoid content and genetic variability of banana accessions from the Musa germplasm collection held at Embrapa Cassava and Tropical Fruits, Brazil. Forty-two samples were analyzed, including 21 diploids, 19 triploids and two tetraploids. The carotenoid content was analyzed spectrophotometrically and genetic variability was estimated using 653 <span class="hlt">DAr</span>T markers. The average carotenoid content was 4.73 μg.g (-1) , and ranged from 1.06 μg.g (-1) for the triploid Nanica (Cavendish group) to 19.24 μg.g (-1) for the triploid Saney. The diploids Modok Gier and NBA-14 and the triploid Saney had a carotenoid content that was, respectively, 7-fold, 6-fold and 9-fold greater than that of cultivars from the Cavendish group (2.19 μg.g (-1)). The mean similarity among the 42 accessions was 0.63 (range: 0.24 to 1.00). <span class="hlt">DAr</span>T analysis revealed extensive genetic variability in accessions from the Embrapa Musa germplasm bank.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27338416','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27338416"><span>Indirect Correspondence-Based Robust Extrinsic Calibration of Li<span class="hlt">DAR</span> and Camera.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Sim, Sungdae; Sock, Juil; Kwak, Kiho</p> <p>2016-06-22</p> <p>Li<span class="hlt">DAR</span> and cameras have been broadly utilized in computer vision and autonomous vehicle applications. However, in order to convert data between the local coordinate systems, we must estimate the rigid body transformation between the sensors. In this paper, we propose a robust extrinsic calibration algorithm that can be implemented easily and has small calibration error. The extrinsic calibration parameters are estimated by minimizing the distance between corresponding features projected onto the image plane. The features are edge and centerline features on a v-shaped calibration target. The proposed algorithm contributes two ways to improve the calibration accuracy. First, we use different weights to distance between a point and a line feature according to the correspondence accuracy of the features. Second, we apply a penalizing function to exclude the influence of outliers in the calibration datasets. Additionally, based on our robust calibration approach for a single Li<span class="hlt">DAR</span>-camera pair, we introduce a joint calibration that estimates the extrinsic parameters of multiple sensors at once by minimizing one objective function with loop closing constraints. We conduct several experiments to evaluate the performance of our extrinsic calibration algorithm. The experimental results show that our calibration method has better performance than the other approaches.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27560962','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27560962"><span>Identifying Ancient Settlement Patterns through Li<span class="hlt">DAR</span> in the Mosquitia Region of Honduras.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Fisher, Christopher T; Fernández-Diaz, Juan Carlos; Cohen, Anna S; Neil Cruz, Oscar; Gonzáles, Alicia M; Leisz, Stephen J; Pezzutti, Florencia; Shrestha, Ramesh; Carter, William</p> <p>2016-01-01</p> <p>The Mosquitia ecosystem of Honduras occupies the fulcrum between the American continents and as such constitutes a critical region for understanding past patterns of socio-political development and interaction. Heavy vegetation, rugged topography, and remoteness have limited scientific investigation. This paper presents prehistoric patterns of settlement and landuse for a critical valley within the Mosquitia derived from airborne Li<span class="hlt">DAR</span> scanning and field investigation. We show that (i) though today the valley is a wilderness it was densely inhabited in the past; (ii) that this population was organized into a three-tiered system composed of 19 settlements dominated by a city; and, (iii) that this occupation was embedded within a human engineered landscape. We also add to a growing body of literature that demonstrates the utility of Li<span class="hlt">DAR</span> as means for rapid cultural assessments in undocumented regions for analysis and conservation. Our ultimate hope is for our work to promote protections to safeguard the unique and critically endangered Mosquitia ecosystem and other similar areas in need of preservation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/24908469','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/24908469"><span>The use of social media among adolescents in <span class="hlt">Dar</span> es Salaam and Mtwara, Tanzania.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Pfeiffer, Constanze; Kleeb, Matthis; Mbelwa, Alice; Ahorlu, Collins</p> <p>2014-05-01</p> <p>Social media form part of the rapid worldwide digital development that is re-shaping the life of many young people. While the use of social media by youths is increasingly researched in the North, studies about youth in the South are missing. It therefore remains unclear how social media can be included in interventions that aim at informing young people in many countries of the global South about sexual and reproductive health. This paper presents findings of a mixed-methods study of young people's user behaviour on the internet and specifically of social media as a platform for sexual health promotion in Tanzania. The study used questionnaires with 60 adolescents and in-depth interviews with eight students aged 15 to 19 years in <span class="hlt">Dar</span> es Salaam, and in Mtwara, Southern Tanzania. Findings show that youth in <span class="hlt">Dar</span> es Salaam and Mtwara access the internet mainly through mobile phones. Facebook is by far the most popular internet site. Adolescents highlighted their interest in reproductive and sexual health messages and updates being delivered through humorous posts, links and clips, as well as by youth role models like music stars and actors that are entertaining and reflect up-to-date trends of modern youth culture.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JPRS..117...79Z','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JPRS..117...79Z"><span>Improved progressive TIN densification filtering algorithm for airborne Li<span class="hlt">DAR</span> data in forested areas</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Zhao, Xiaoqian; Guo, Qinghua; Su, Yanjun; Xue, Baolin</p> <p>2016-07-01</p> <p>Filtering of light detection and ranging (Li<span class="hlt">DAR</span>) data into the ground and non-ground points is a fundamental step in processing raw airborne Li<span class="hlt">DAR</span> data. This paper proposes an improved progressive triangulated irregular network (TIN) densification (IPTD) filtering algorithm that can cope with a variety of forested landscapes, particularly both topographically and environmentally complex regions. The IPTD filtering algorithm consists of three steps: (1) acquiring potential ground seed points using the morphological method; (2) obtaining accurate ground seed points; and (3) building a TIN-based model and iteratively densifying TIN. The IPTD filtering algorithm was tested in 15 forested sites with various terrains (i.e., elevation and slope) and vegetation conditions (i.e., canopy cover and tree height), and was compared with seven other commonly used filtering algorithms (including morphology-based, slope-based, and interpolation-based filtering algorithms). Results show that the IPTD achieves the highest filtering accuracy for nine of the 15 sites. In general, it outperforms the other filtering algorithms, yielding the lowest average total error of 3.15% and the highest average kappa coefficient of 89.53%.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3032974','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=3032974"><span>Genetic diversity of carotenoid-rich bananas evaluated by Diversity Arrays Technology (<span class="hlt">DAr</span>T)</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p></p> <p>2009-01-01</p> <p>The aim of this work was to evaluate the carotenoid content and genetic variability of banana accessions from the Musa germplasm collection held at Embrapa Cassava and Tropical Fruits, Brazil. Forty-two samples were analyzed, including 21 diploids, 19 triploids and two tetraploids. The carotenoid content was analyzed spectrophotometrically and genetic variability was estimated using 653 <span class="hlt">DAr</span>T markers. The average carotenoid content was 4.73 μg.g -1 , and ranged from 1.06 μg.g -1 for the triploid Nanica (Cavendish group) to 19.24 μg.g -1 for the triploid Saney. The diploids Modok Gier and NBA-14 and the triploid Saney had a carotenoid content that was, respectively, 7-fold, 6-fold and 9-fold greater than that of cultivars from the Cavendish group (2.19 μg.g -1). The mean similarity among the 42 accessions was 0.63 (range: 0.24 to 1.00). <span class="hlt">DAr</span>T analysis revealed extensive genetic variability in accessions from the Embrapa Musa germplasm bank. PMID:21637652</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4541902','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4541902"><span>Li<span class="hlt">DAR</span> Scan Matching Aided Inertial Navigation System in GNSS-Denied Environments</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Tang, Jian; Chen, Yuwei; Niu, Xiaoji; Wang, Li; Chen, Liang; Liu, Jingbin; Shi, Chuang; Hyyppä, Juha</p> <p>2015-01-01</p> <p>A new scan that matches an aided Inertial Navigation System (INS) with a low-cost Li<span class="hlt">DAR</span> is proposed as an alternative to GNSS-based navigation systems in GNSS-degraded or -denied environments such as indoor areas, dense forests, or urban canyons. In these areas, INS-based Dead Reckoning (DR) and Simultaneous Localization and Mapping (SLAM) technologies are normally used to estimate positions as separate tools. However, there are critical implementation problems with each standalone system. The drift errors of velocity, position, and heading angles in an INS will accumulate over time, and on-line calibration is a must for sustaining positioning accuracy. SLAM performance is poor in featureless environments where the matching errors can significantly increase. Each standalone positioning method cannot offer a sustainable navigation solution with acceptable accuracy. This paper integrates two complementary technologies—INS and Li<span class="hlt">DAR</span> SLAM—into one navigation frame with a loosely coupled Extended Kalman Filter (EKF) to use the advantages and overcome the drawbacks of each system to establish a stable long-term navigation process. Static and dynamic field tests were carried out with a self-developed Unmanned Ground Vehicle (UGV) platform—NAVIS. The results prove that the proposed approach can provide positioning accuracy at the centimetre level for long-term operations, even in a featureless indoor environment. PMID:26184206</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008AGUFMOS11F..06R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008AGUFMOS11F..06R"><span>An Airborne Scanning Li<span class="hlt">DAR</span> System for Ocean and Coastal Applications</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Reineman, B. D.; Lenain, L.; Castel, D.; Melville, W. K.</p> <p>2008-12-01</p> <p>We have developed an airborne scanning Li<span class="hlt">DAR</span> (Light Detection And Ranging) system and demonstrated its functionality for terrestrial and oceanographic measurements. Differential GPS (DGPS) and an Inertial Navigation System (INS) are synchronized with the Li<span class="hlt">DAR</span>, providing end result vertical rms errors of approximately 6~cm. Flying 170~m above the surface, we achieve a point density of ~ 0.7 m-2 and a swath width of 90 to 120~m over ocean and 200~m over land. Georeferencing algorithms were developed in-house and earth-referenced data are available several hours after acquisition. Surveys from the system are compared with ground DGPS surveys and existing airborne surveys of fixed targets. Twelve research flights in a Piper Twin Comanche from August 2007 to July 2008 have provided topography of the Southern California coastline and sea surface wave fields in the nearshore ocean environment. Two of the flights also documented the results of the October 2007 landslide on Mt.~Soledad in La Jolla, California. Eight research flights aboard a Cessna Caravan surveyed the topography, lagoon, reef, and surrounding seas of Lady Elliot Island (LEI) in Australia's Great Barrier Reef in April 2008. We describe applications for the system, including coastal topographic surveys, wave measurements, reef research, and ship wake studies.</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_18");'>18</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li class="active"><span>20</span></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_20 --> <div id="page_21" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="401"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016JARS...10d6025C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016JARS...10d6025C"><span>Strata-based forest fuel classification for wild fire hazard assessment using terrestrial Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Yang; Zhu, Xuan; Yebra, Marta; Harris, Sarah; Tapper, Nigel</p> <p>2016-10-01</p> <p>Fuel structural characteristics affect fire behavior including fire intensity, spread rate, flame structure, and duration, therefore, quantifying forest fuel structure has significance in understanding fire behavior as well as providing information for fire management activities (e.g., planned burns, suppression, fuel hazard assessment, and fuel treatment). This paper presents a method of forest fuel strata classification with an integration between terrestrial light detection and ranging (Li<span class="hlt">DAR</span>) data and geographic information system for automatically assessing forest fuel structural characteristics (e.g., fuel horizontal continuity and vertical arrangement). The accuracy of fuel description derived from terrestrial Li<span class="hlt">DAR</span> scanning (TLS) data was assessed by field measured surface fuel depth and fuel percentage covers at distinct vertical layers. The comparison of TLS-derived depth and percentage cover at surface fuel layer with the field measurements produced root mean square error values of 1.1 cm and 5.4%, respectively. TLS-derived percentage cover explained 92% of the variation in percentage cover at all fuel layers of the entire dataset. The outcome indicated TLS-derived fuel characteristics are strongly consistent with field measured values. TLS can be used to efficiently and consistently classify forest vertical layers to provide more precise information for forest fuel hazard assessment and surface fuel load estimation in order to assist forest fuels management and fire-related operational activities. It can also be beneficial for mapping forest habitat, wildlife conservation, and ecosystem management.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/26941756','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/26941756"><span>Characterizing Croatian Wheat Germplasm Diversity and Structure in a European Context by <span class="hlt">DAr</span>T Markers.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Novoselović, Dario; Bentley, Alison R; Šimek, Ruđer; Dvojković, Krešimir; Sorrells, Mark E; Gosman, Nicolas; Horsnell, Richard; Drezner, Georg; Šatović, Zlatko</p> <p>2016-01-01</p> <p>Narrowing the genetic base available for future genetic progress is a major concern to plant breeders. In order to avoid this, strategies to characterize and protect genetic diversity in regional breeding pools are required. In this study, 89 winter wheat cultivars released in Croatia between 1936 and 2006 were genotyped using 1,229 <span class="hlt">DAr</span>T (diversity array technology) markers to assess the diversity and population structure. In order to place Croatian breeding pool (CBP) in a European context, Croatian wheat cultivars were compared to 523 European cultivars from seven countries using a total of 166 common <span class="hlt">DAr</span>T markers. The results show higher genetic diversity in the wheat breeding pool from Central Europe (CE) as compared to that from Northern and Western European (NWE) countries. The most of the genetic diversity was attributable to the differences among cultivars within countries. When the geographical criterion (CE vs. NWE) was applied, highly significant difference between regions was obtained that accounted for 16.19% of the total variance, revealing that the CBP represents genetic variation not currently captured in elite European wheat. The current study emphasizes the important contribution made by plant breeders to maintaining wheat genetic diversity and suggests that regional breeding is essential to the maintenance of this diversity. The usefulness of open-access wheat datasets is also highlighted.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70034055','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70034055"><span>Li<span class="hlt">DAR</span>-Assisted identification of an active fault near Truckee, California</span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Hunter, L.E.; Howle, J.F.; Rose, R.S.; Bawden, G.W.</p> <p>2011-01-01</p> <p>We use high-resolution (1.5-2.4 points/m2) bare-earth airborne Light Detection and Ranging (Li<span class="hlt">DAR</span>) imagery to identify, map, constrain, and visualize fault-related geomorphology in densely vegetated terrain surrounding Martis Creek Dam near Truckee, California. Bare-earth Li<span class="hlt">DAR</span> imagery reveals a previously unrecognized and apparently youthful right-lateral strike-slip fault that exhibits laterally continuous tectonic geomorphic features over a 35-km-long zone. If these interpretations are correct, the fault, herein named the Polaris fault, may represent a significant seismic hazard to the greater Truckee-Lake Tahoe and Reno-Carson City regions. Three-dimensional modeling of an offset late Quaternary terrace riser indicates a minimum tectonic slip rate of 0.4 ?? 0.1 mm/yr.Mapped fault patterns are fairly typical of regional patterns elsewhere in the northern Walker Lane and are in strong coherence with moderate magnitude historical seismicity of the immediate area, as well as the current regional stress regime. Based on a range of surface-rupture lengths and depths to the base of the seismogenic zone, we estimate a maximum earthquake magnitude (M) for the Polaris fault to be between 6.4 and 6.9.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5073150','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5073150"><span>Invasive Shrub Mapping in an Urban Environment from Hyperspectral and Li<span class="hlt">DAR</span>-Derived Attributes</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Chance, Curtis M.; Coops, Nicholas C.; Plowright, Andrew A.; Tooke, Thoreau R.; Christen, Andreas; Aven, Neal</p> <p>2016-01-01</p> <p>Proactive management of invasive species in urban areas is critical to restricting their overall distribution. The objective of this work is to determine whether advanced remote sensing technologies can help to detect invasions effectively and efficiently in complex urban ecosystems such as parks. In Surrey, BC, Canada, Himalayan blackberry (Rubus armeniacus) and English ivy (Hedera helix) are two invasive shrub species that can negatively affect native ecosystems in cities and managed urban parks. Random forest (RF) models were created to detect these two species using a combination of hyperspectral imagery, and light detection and ranging (Li<span class="hlt">DAR</span>) data. Li<span class="hlt">DAR</span>-derived predictor variables included irradiance models, canopy structural characteristics, and orographic variables. RF detection accuracy ranged from 77.8 to 87.8% for Himalayan blackberry and 81.9 to 82.1% for English ivy, with open areas classified more accurately than areas under canopy cover. English ivy was predicted to occur across a greater area than Himalayan blackberry both within parks and across the entire city. Both Himalayan blackberry and English ivy were mostly located in clusters according to a Local Moran’s I analysis. The occurrence of both species decreased as the distance from roads increased. This study shows the feasibility of producing highly accurate detection maps of plant invasions in urban environments using a fusion of remotely sensed data, as well as the ability to use these products to guide management decisions. PMID:27818664</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017AnGeo..35...97K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017AnGeo..35...97K"><span>Scintillation measurements at Bahir <span class="hlt">Dar</span> during the high solar activity phase of solar cycle 24</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Kriegel, Martin; Jakowski, Norbert; Berdermann, Jens; Sato, Hiroatsu; Wassaie Mersha, Mogese</p> <p>2017-01-01</p> <p>Small-scale ionospheric disturbances may cause severe radio scintillations of signals transmitted from global navigation satellite systems (GNSSs). Consequently, small-scale plasma irregularities may heavily degrade the performance of current GNSSs such as GPS, GLONASS or Galileo. This paper presents analysis results obtained primarily from two high-rate GNSS receiver stations designed and operated by the German Aerospace Center (DLR) in cooperation with Bahir <span class="hlt">Dar</span> University (BDU) at 11.6° N, 37.4° E. Both receivers collect raw data sampled at up to 50 Hz, from which characteristic scintillation parameters such as the S4 index are deduced. This paper gives a first overview of the measurement set-up and the observed scintillation events over Bahir <span class="hlt">Dar</span> in 2015. Both stations are located close to one another and aligned in an east-west, direction which allows us to estimate the zonal drift velocity and spatial dimension of equatorial ionospheric plasma irregularities. Therefore, the lag times of moving electron density irregularities and scintillation patterns are derived by applying cross-correlation analysis to high-rate measurements of the slant total electron content (sTEC) along radio links between a GPS satellite and both receivers and to the associated signal power, respectively. Finally, the drift velocity is derived from the estimated lag time, taking into account the geometric constellation of both receiving antennas and the observed GPS satellites.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4934358','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4934358"><span>Indirect Correspondence-Based Robust Extrinsic Calibration of Li<span class="hlt">DAR</span> and Camera</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Sim, Sungdae; Sock, Juil; Kwak, Kiho</p> <p>2016-01-01</p> <p>Li<span class="hlt">DAR</span> and cameras have been broadly utilized in computer vision and autonomous vehicle applications. However, in order to convert data between the local coordinate systems, we must estimate the rigid body transformation between the sensors. In this paper, we propose a robust extrinsic calibration algorithm that can be implemented easily and has small calibration error. The extrinsic calibration parameters are estimated by minimizing the distance between corresponding features projected onto the image plane. The features are edge and centerline features on a v-shaped calibration target. The proposed algorithm contributes two ways to improve the calibration accuracy. First, we use different weights to distance between a point and a line feature according to the correspondence accuracy of the features. Second, we apply a penalizing function to exclude the influence of outliers in the calibration datasets. Additionally, based on our robust calibration approach for a single Li<span class="hlt">DAR</span>-camera pair, we introduce a joint calibration that estimates the extrinsic parameters of multiple sensors at once by minimizing one objective function with loop closing constraints. We conduct several experiments to evaluate the performance of our extrinsic calibration algorithm. The experimental results show that our calibration method has better performance than the other approaches. PMID:27338416</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27818664','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27818664"><span>Invasive Shrub Mapping in an Urban Environment from Hyperspectral and Li<span class="hlt">DAR</span>-Derived Attributes.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Chance, Curtis M; Coops, Nicholas C; Plowright, Andrew A; Tooke, Thoreau R; Christen, Andreas; Aven, Neal</p> <p>2016-01-01</p> <p>Proactive management of invasive species in urban areas is critical to restricting their overall distribution. The objective of this work is to determine whether advanced remote sensing technologies can help to detect invasions effectively and efficiently in complex urban ecosystems such as parks. In Surrey, BC, Canada, Himalayan blackberry (Rubus armeniacus) and English ivy (Hedera helix) are two invasive shrub species that can negatively affect native ecosystems in cities and managed urban parks. Random forest (RF) models were created to detect these two species using a combination of hyperspectral imagery, and light detection and ranging (Li<span class="hlt">DAR</span>) data. Li<span class="hlt">DAR</span>-derived predictor variables included irradiance models, canopy structural characteristics, and orographic variables. RF detection accuracy ranged from 77.8 to 87.8% for Himalayan blackberry and 81.9 to 82.1% for English ivy, with open areas classified more accurately than areas under canopy cover. English ivy was predicted to occur across a greater area than Himalayan blackberry both within parks and across the entire city. Both Himalayan blackberry and English ivy were mostly located in clusters according to a Local Moran's I analysis. The occurrence of both species decreased as the distance from roads increased. This study shows the feasibility of producing highly accurate detection maps of plant invasions in urban environments using a fusion of remotely sensed data, as well as the ability to use these products to guide management decisions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9839E..0IC','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9839E..0IC"><span>Characterization of the OPAL Li<span class="hlt">DAR</span> under controlled obscurant conditions</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cao, Xiaoying; Church, Philip; Matheson, Justin</p> <p>2016-05-01</p> <p>Neptec Technologies' OPAL-120 3D Li<span class="hlt">DAR</span> is optimized for obscurant penetration. The OPAL-120 uses a scanning mechanism based on the Risley prism pair. The scan patterns are created by rotating two prisms under independent motor control. The geometry and material properties of the prisms define the conical field-of-view of the sensor, which can be built to between 60 to 120 degrees. The OPAL-120 was recently evaluated using a controlled obscurant chamber capable of generating clouds of obscurants over a depth of 22m. Obscurants used in this investigation include: Arizona road dust, water fog, and fog-oil. The obscurant cloud optical densities were monitored with a transmissometer. Optical depths values ranged from an upper value of 6 and progressively decreased to 0. Targets were positioned at the back of the obscurant chamber at a distance of 60m from the Li<span class="hlt">DAR</span>. The targets are made of a foreground array of equally spaced painted wood stripes in front of a solid background. Reflectivity contrasts were achieved with foreground/background combinations of white/white, white/black and black/white. Data analysis will be presented on the effect of optical densities on range and cross-range resolution, and accuracy. The analysis includes the combinations of all obscurant types and target reflectivity contrasts.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9976E..0II','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9976E..0II"><span>New SHARE 2010 HSI-Li<span class="hlt">DAR</span> dataset: re-calibration, detection assessment and delivery</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Ientilucci, Emmett J.</p> <p>2016-09-01</p> <p>This paper revisits hyperspectral data collected from the SpecTIR hyperspectral airborne Rochester Experiment (SHARE) in 2010. It has been determined that there were calibration issues in the SWIR portion of the data. This calibration issue is discussed and has been rectified. Approaches for calibration to radiance and compensation to reflectance are discussed based on in-scene information and radiative transfer codes. In addition to the entire flight line, a much large target detection test and evaluation chip has been created which includes an abundance of potential false alarms. New truth masks are created along with results from target detection algorithms. Co-registered Li<span class="hlt">DAR</span> data is also presented. Finally, all ground truth information (ground photos, metadata, MODTRAN tape5, ASD ground spectral measurements, target truth masks, etc.), in addition to the HSI flight lines and co-registered Li<span class="hlt">DAR</span> data, has been organized, packaged and uploaded to the Center for Imaging Science / Digital Imaging and Remote Sensing Lab web server for public use.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9998E..0XM','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9998E..0XM"><span>Irrigation network extraction methodology from Li<span class="hlt">DAR</span> DTM using Whitebox and ArcGIS</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Mahor, M. A. P.; De La Cruz, R. M.; Olfindo, N. T.; Perez, A. M. C.</p> <p>2016-10-01</p> <p>Irrigation networks are important in distributing water resources to areas where rainfall is not enough to sustain agriculture. They are also crucial when it comes to being able to redirect vast amounts of water to decrease the risks of flooding in flat areas, especially near sources of water. With the lack of studies about irrigation feature extraction, which range from wide canals to small ditches, this study aims to present a method of extracting these features from Li<span class="hlt">DAR</span>-derived digital terrain models (DTMs) using Geographic Information Systems (GIS) tools such as ArcGIS and Whitebox Geospatial Analysis Tools (Whitebox GAT). High-resolution Li<span class="hlt">DAR</span> DTMs with 1-meter horizontal and 0.25-meter vertical accuracies were processed to generate the gully depth map. This map was then reclassified, converted to vector, and filtered according to segment length, and sinuosity to be able to isolate these irrigation features. Initial results in the test area show that the extraction completeness is greater than 80% when compared with data obtained from the National Irrigation Administration (NIA).</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008E%26ES....1a2060T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008E%26ES....1a2060T"><span>Arrangements for enhanced measurements of a large turbine near-wake using Li<span class="hlt">DAR</span> from the nacelle</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Trujillo, J. J.; Rettenmeier, A.; Schlipf, D.</p> <p>2008-05-01</p> <p>New Li<span class="hlt">DAR</span> techniques are being tested and developed to support the development of large offshore wind turbines. Our interest in this paper is concentrated in wake measurements; therefore, a pulsed standard Li<span class="hlt">DAR</span> is adapted for fullscale wind field measurements from the nacelle of a large wind turbine. We show the conceptual framework for planned adaptations to a Windcube® Li<span class="hlt">DAR</span> for operation at the nacelle of a 5 MW wind turbine. The standard scanning mode is to be modified to properly obtain downstream and also upstream wind speeds. The wind field measurements are intended for verification of models for near-wake wind speed, wake meandering and new predictive control estrategies.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.G51B0662G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.G51B0662G"><span>Impact of survey workflow on precision and accuracy of terrestrial Li<span class="hlt">DAR</span> datasets</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Gold, P. O.; Cowgill, E.; Kreylos, O.</p> <p>2009-12-01</p> <p>Ground-based Li<span class="hlt">DAR</span> (Light Detection and Ranging) survey techniques are enabling remote visualization and quantitative analysis of geologic features at unprecedented levels of detail. For example, digital terrain models computed from Li<span class="hlt">DAR</span> data have been used to measure displaced landforms along active faults and to quantify fault-surface roughness. But how accurately do terrestrial Li<span class="hlt">DAR</span> data represent the true ground surface, and in particular, how internally consistent and precise are the mosaiced Li<span class="hlt">DAR</span> datasets from which surface models are constructed? Addressing this question is essential for designing survey workflows that capture the necessary level of accuracy for a given project while minimizing survey time and equipment, which is essential for effective surveying of remote sites. To address this problem, we seek to define a metric that quantifies how scan registration error changes as a function of survey workflow. Specifically, we are using a Trimble GX3D laser scanner to conduct a series of experimental surveys to quantify how common variables in field workflows impact the precision of scan registration. Primary variables we are testing include 1) use of an independently measured network of control points to locate scanner and target positions, 2) the number of known-point locations used to place the scanner and point clouds in 3-D space, 3) the type of target used to measure distances between the scanner and the known points, and 4) setting up the scanner over a known point as opposed to resectioning of known points. Precision of the registered point cloud is quantified using Trimble Realworks software by automatic calculation of registration errors (errors between locations of the same known points in different scans). Accuracy of the registered cloud (i.e., its ground-truth) will be measured in subsequent experiments. To obtain an independent measure of scan-registration errors and to better visualize the effects of these errors on a registered point</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.3930B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.3930B"><span>Modeling Urban Growth Spatial Dynamics: Case studies of Addis Ababa and <span class="hlt">Dar</span> es Salaam</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Buchta, Katja; Abo El Wafa, Hany; Printz, Andreas; Pauleit, Stephan</p> <p>2013-04-01</p> <p>Rapid urbanization, and consequently, the dramatic spatial expansion of mostly informal urban areas increases the vulnerability of African cities to the effects of climate change such as sea level rise, more frequent flooding, droughts and heat waves. The EU FP 7 funded project CLUVA (Climate Change and Urban Vulnerability in Africa, www.cluva.eu) aims to develop strategies for minimizing the risks of natural hazards caused by climate change and to improve the coping capacity of African cities. Green infrastructure may play a particular role in climate change adaptation by providing ecosystem services for flood protection, stormwater retention, heat island moderation and provision of food and fuel wood. In this context, a major challenge is to gain a better understanding of the spatial and temporal dynamics of the cities and how these impact on green infrastructure and hence their vulnerability. Urban growth scenarios for two African cities, namely Addis Ababa, Ethiopia and <span class="hlt">Dar</span> es Salaam, Tanzania, were developed based on a characterization of their urban morphology. A population growth driven - GIS based - disaggregation modeling approach was applied. Major impact factors influencing the urban dynamics were identified both from literature and interviews with local experts. Location based factors including proximity to road infrastructure and accessibility, and environmental factors including slope, surface and flood risk areas showed a particular impact on urban growth patterns. In Addis Ababa and <span class="hlt">Dar</span> es Salaam, population density scenarios were modeled comparing two housing development strategies. Results showed that a densification scenario significantly decreases the loss of agricultural and green areas such as forests, bushland and sports grounds. In <span class="hlt">Dar</span> es Salaam, the scenario of planned new settlements with a population density of max. 350 persons per hectare would lead until 2025 to a loss of agricultural land (-10.1%) and green areas (-6.6%). On the other</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012AGUFM.G23A0903K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012AGUFM.G23A0903K"><span>3-D earthquake surface displacements from differencing pre- and post-event Li<span class="hlt">DAR</span> point clouds</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Krishnan, A. K.; Nissen, E.; Arrowsmith, R.; Saripalli, S.</p> <p>2012-12-01</p> <p>The explosion in aerial Li<span class="hlt">DAR</span> surveying along active faults across the western United States and elsewhere provides a high-resolution topographic baseline against which to compare repeat Li<span class="hlt">DAR</span> datasets collected after future earthquakes. We present a new method for determining 3-D coseismic surface displacements and rotations by differencing pre- and post-earthquake Li<span class="hlt">DAR</span> point clouds using an adaptation of the Iterative Closest Point (ICP) algorithm, a point set registration technique widely used in medical imaging, computer vision and graphics. There is no need for any gridding or smoothing of the Li<span class="hlt">DAR</span> data and the method works well even with large mismatches in the density of the two point clouds. To explore the method's performance, we simulate pre- and post-event point clouds using real ("B4") Li<span class="hlt">DAR</span> data on the southern San Andreas Fault perturbed with displacements of known magnitude. For input point clouds with ~2 points per square meter, we are able to reproduce displacements with a 50 m grid spacing and with horizontal and vertical accuracies of ~20 cm and ~4 cm. In the future, finer grids and improved precisions should be possible with higher shot densities and better survey geo-referencing. By capturing near-fault deformation in 3-D, Li<span class="hlt">DAR</span> differencing with ICP will complement satellite-based techniques such as InSAR which map only certain components of the surface deformation and which often break down close to surface faulting or in areas of dense vegetation. It will be especially useful for mapping shallow fault slip and rupture zone deformation, helping inform paleoseismic studies and better constrain fault zone rheology. Because ICP can image rotations directly, the technique will also help resolve the detailed kinematics of distributed zones of faulting where block rotations may be common.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013AGUFM.B41E0459G','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013AGUFM.B41E0459G"><span>Quantification of Li<span class="hlt">DAR</span> measurement uncertainty through propagation of errors due to sensor sub-systems and terrain morphology</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Goulden, T.; Hopkinson, C.</p> <p>2013-12-01</p> <p>The quantification of Li<span class="hlt">DAR</span> sensor measurement uncertainty is important for evaluating the quality of derived DEM products, compiling risk assessment of management decisions based from Li<span class="hlt">DAR</span> information, and enhancing Li<span class="hlt">DAR</span> mission planning capabilities. Current quality assurance estimates of Li<span class="hlt">DAR</span> measurement uncertainty are limited to post-survey empirical assessments or vendor estimates from commercial literature. Empirical evidence can provide valuable information for the performance of the sensor in validated areas; however, it cannot characterize the spatial distribution of measurement uncertainty throughout the extensive coverage of typical Li<span class="hlt">DAR</span> surveys. Vendor advertised error estimates are often restricted to strict and optimal survey conditions, resulting in idealized values. Numerical modeling of individual pulse uncertainty provides an alternative method for estimating Li<span class="hlt">DAR</span> measurement uncertainty. Li<span class="hlt">DAR</span> measurement uncertainty is theoretically assumed to fall into three distinct categories, 1) sensor sub-system errors, 2) terrain influences, and 3) vegetative influences. This research details the procedures for numerical modeling of measurement uncertainty from the sensor sub-system (GPS, IMU, laser scanner, laser ranger) and terrain influences. Results show that errors tend to increase as the laser scan angle, altitude or laser beam incidence angle increase. An experimental survey over a flat and paved runway site, performed with an Optech ALTM 3100 sensor, showed an increase in modeled vertical errors of 5 cm, at a nadir scan orientation, to 8 cm at scan edges; for an aircraft altitude of 1200 m and half scan angle of 15°. In a survey with the same sensor, at a highly sloped glacial basin site absent of vegetation, modeled vertical errors reached over 2 m. Validation of error models within the glacial environment, over three separate flight lines, respectively showed 100%, 85%, and 75% of elevation residuals fell below error predictions. Future</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015JSR...104....9Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015JSR...104....9Y"><span>Measuring the effects of morphological changes to sea turtle nesting beaches over time with Li<span class="hlt">DAR</span> data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yamamoto, Kristina H.; Anderson, Sharolyn J.; Sutton, Paul C.</p> <p>2015-10-01</p> <p>Sea turtle nesting beaches in southeastern Florida were evaluated for changes from 1999 to 2005 using Li<span class="hlt">DAR</span> datasets. Changes to beach volume were correlated with changes in several elevation-derived characteristics, such as elevation and slope. In addition, these changes to beach geomorphology were correlated to changes in nest success, illustrating that beach alterations may affect sea turtle nesting behavior. The ability to use Li<span class="hlt">DAR</span> datasets to quickly and efficiently conduct beach comparisons for habitat use represents another benefit to this high spatial resolution data.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFMEP41A0583S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFMEP41A0583S"><span>Quantification of L-band InSAR decorrelation in volcanic terrains using airborne Li<span class="hlt">DAR</span> data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Sedze, M.; Heggy, E.; Jacquemoud, S.; Bretar, F.</p> <p>2011-12-01</p> <p>Repeat-pass InSAR LOS measurements of the Piton de La Fournaise (La Reunion Island, France) suffer from substantial phase decorrelation due to the occurrence of vegetation and ash deposits on the caldera and slopes of the edifice. To correct this deficiency, we combine normalized airborne Li<span class="hlt">DAR</span> (Light Detection and Ranging) intensity data with spaceborne InSAR coherence images from ALOS PALSAR L-band acquired over the volcano in 2008 and 2009, following the 2007 major eruption. The fusion of the two data sets improves the calculation of coherence and the textural classification of different volcanic surfaces. For future missions considering both InSAR and/or Li<span class="hlt">DAR</span> such as DESDynI (Deformation, Ecosystem Structure and Dynamics of Ice), such data fusion studies can provide a better analysis of the spatiotemporal variations in InSAR coherence in order to enhance the monitoring of pre-eruptive ground displacements. The airborne surveys conducted in 2008 and 2009, cover different types of vegetation and terrain roughness on the central and western parts of the volcano. The topographic data are first processed to generate a high-resolution digital terrain model (DTM) of the volcanic edifice with elevation accuracy better than 1 m. For our purposes, the phase variations caused by the surface relief can be eliminated using the Li<span class="hlt">DAR</span>-derived DTM. Then normalized Li<span class="hlt">DAR</span> intensities are correlated to the L-band polarimetric coherence for different zones of the volcano to assess the Li<span class="hlt">DAR</span>-InSAR statistical behavior of different lava flows, pyroclastics, and vegetated surfaces. Results suggest that each volcanic terrain type is characterized by a unique Li<span class="hlt">DAR</span>-InSAR histogram pattern. We identified four Li<span class="hlt">DAR</span>-InSAR distinguished relations: (1) pahoehoe lava flow surfaces show an agglomerate histogram pattern which may be explained by low surface scattering and low wave penetration into the geological medium; (2) eroded a'a lava surfaces is characterized by high standard deviation</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009AGUFM.G51B0661H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009AGUFM.G51B0661H"><span>Modeling right-lateral offset of a Late Pleistocene terrace riser along the Polaris fault using ground based Li<span class="hlt">DAR</span> imagery</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Howle, J. F.; Bawden, G. W.; Hunter, L. E.; Rose, R. S.</p> <p>2009-12-01</p> <p>High resolution (centimeter level) three-dimensional point-cloud imagery of offset glacial outwash deposits were collected by using ground based tripod Li<span class="hlt">DAR</span> (T-Li<span class="hlt">DAR</span>) to characterize the cumulative fault slip across the recently identified Polaris fault (Hunter et <span class="hlt">al</span>., 2009) near Truckee, California. The type-section site for the Polaris fault is located 6.5 km east of Truckee where progressive right-lateral displacement of middle to late Pleistocene deposits is evident. Glacial outwash deposits, aggraded during the Tioga glaciation, form a flat lying ‘fill’ terrace on both the north and south sides of the modern Truckee River. During the Tioga deglaciation melt water incised into the terrace producing fluvial scarps or terrace risers (Birkeland, 1964). Subsequently, the terrace risers on both banks have been right-laterally offset by the Polaris fault. By using T-Li<span class="hlt">DAR</span> on an elevated tripod (4.25 m high), we collected 3D high-resolution (thousands of points per square meter; ± 4 mm) point-cloud imagery of the offset terrace risers. Vegetation was removed from the data using commercial software, and large protruding boulders were manually deleted to generate a bare-earth point-cloud dataset with an average data density of over 240 points per square meter. From the bare-earth point cloud we mathematically reconstructed a pristine terrace/scarp morphology on both sides of the fault, defined coupled sets of piercing points, and extracted a corresponding displacement vector. First, the Polaris fault was approximated as a vertical plane that bisects the offset terrace risers, as well as bisecting linear swales and tectonic depressions in the outwash terrace. Then, piercing points to the vertical fault plane were constructed from the geometry of the geomorphic elements on either side of the fault. On each side of the fault, the best-fit modeled outwash plane is projected laterally and the best-fit modeled terrace riser projected upward to a virtual intersection in</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9879E..1CT','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9879E..1CT"><span>Diameter at breast height estimation in Mt. Makiling, Laguna, Philippines using metrics derived from airborne Li<span class="hlt">DAR</span> data and Worldview-2 bands</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tandoc, Fe Andrea M.; Paringit, Enrico C.; Bantayan, Nathaniel C.; Argamosa, Reginald Jay L.; Faelga, Regine Anne G.; Ibañez, Carlyn Ann G.; Posilero, Mark Anthony V.; Zaragosa, Gio P.; Malabanan, Matthew V.</p> <p>2016-05-01</p> <p>Airborne Li<span class="hlt">DAR</span> is fast becoming an innovation for forest inventory. It aids in obtaining forest characteristics in areas or cases where actual field inventory would be very tedious. This study aims to estimate diameter at breast height (DBH) using airborne Li<span class="hlt">DAR</span> point-cloud parameters with Worldview-2 satellite images, and to validate these with actual measurements done in the field. The study site is a field plot with forest inventory at Mt. Makiling, Laguna, Philippines that was surveyed into 20m, 10m and 5m subplots or grids. The estimation of DBH was carried out by extracting the said parameters from the Li<span class="hlt">DAR</span> point-cloud, and extracting different bands from the Worldview image and performing linear and log-linear regression of these values. The regressions were done in four different cases, namely: Li<span class="hlt">DAR</span> parameters without intensity (case1), Li<span class="hlt">DAR</span> parameters without intensity with Worldview bands (case 2), intensity of Li<span class="hlt">DAR</span> points (case 3), and Li<span class="hlt">DAR</span> parameters with intensity and Worldview bands (case 4). From these it was found that the best case for estimating DBH is with the use of Li<span class="hlt">DAR</span> parameters with intensity and Worldview bands in a 10x10 grid, in Log-Linear regression with a root mean squared error of 1.96 cm and an adjusted R2 value of 0.65. This was further improved through stepwise regression, and adjusted R2 value was 0.71.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014EGUGA..1615030C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014EGUGA..1615030C"><span>Building a Li<span class="hlt">DAR</span> point cloud simulator: Testing algorithms for high resolution topographic change</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carrea, Dario; Abellán, Antonio; Derron, Marc-Henri; Jaboyedoff, Michel</p> <p>2014-05-01</p> <p>Terrestrial laser technique (TLS) is becoming a common tool in Geosciences, with clear applications ranging from the generation of a high resolution 3D models to the monitoring of unstable slopes and the quantification of morphological changes. Nevertheless, like every measurement techniques, TLS still has some limitations that are not clearly understood and affect the accuracy of the dataset (point cloud). A challenge in Li<span class="hlt">DAR</span> research is to understand the influence of instrumental parameters on measurement errors during Li<span class="hlt">DAR</span> acquisition. Indeed, different critical parameters interact with the scans quality at different ranges: the existence of shadow areas, the spatial resolution (point density), and the diameter of the laser beam, the incidence angle and the single point accuracy. The objective of this study is to test the main limitations of different algorithms usually applied on point cloud data treatment, from alignment to monitoring. To this end, we built in MATLAB(c) environment a Li<span class="hlt">DAR</span> point cloud simulator able to recreate the multiple sources of errors related to instrumental settings that we normally observe in real datasets. In a first step we characterized the error from single laser pulse by modelling the influence of range and incidence angle on single point data accuracy. In a second step, we simulated the scanning part of the system in order to analyze the shifting and angular error effects. Other parameters have been added to the point cloud simulator, such as point spacing, acquisition window, etc., in order to create point clouds of simple and/or complex geometries. We tested the influence of point density and vitiating point of view on the Iterative Closest Point (ICP) alignment and also in some deformation tracking algorithm with same point cloud geometry, in order to determine alignment and deformation detection threshold. We also generated a series of high resolution point clouds in order to model small changes on different environments</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_19");'>19</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li class="active"><span>21</span></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_21 --> <div id="page_22" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="421"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..1814595B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..1814595B"><span>Long-term persistence of throughfall yield assessed by small footprint Li<span class="hlt">DAR</span> data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bischoff, Sebastian; Levia, Delphis F.; Nieschulze, Jens; Schulz, Florian; Michalzik, Beate</p> <p>2016-04-01</p> <p>Throughfall (TF) represents an important relocation mechanism for the spatial distribution of intercepted precipitation and hence associated nutrients in wooded ecosystems. To date, a broad range of studies showed that the spatial patterns of TF distribution exhibit a pronounced temporal stability. These studies, however, have examined TF temporal stability at the tree scale or they were computed from event-based data. Here, we seek to evaluate the utility of temporally aggregated TF data at one, three, and six year intervals to determine whether such long-term TF monitoring data could serve as the basis for TF temporal persistence measurements for both beech and spruce forests. In addition, we examine the temporal persistence of TF in relation to small footprint Li<span class="hlt">DAR</span> data. In context of the German Science Foundation (DFG) founded "Biodiversity Exploratories" (www.biodiversity-exploratories.de) we studied water-bound nutrient fluxes on a set of three differently managed forest plots (spruce plantation, age class forest beech, unmanaged beech) in central Germany throughout the vegetation periods of 2010 - 2015. For long-term monitoring purposes, TF samples were collected in biweekly routine sampling intervals using X-shaped transects of 20 bulk samplers (axis length 32 m) per experimental plot. In this study, we aim to identify canopy structural parameters explaining the temporal patterns observed. We therefore used small footprint Li<span class="hlt">DAR</span> (Light Detection And Ranging) data to calculate several canopy structural parameters on base of a gridded canopy model (grid cell resolution = 0.75 m). As Li<span class="hlt">DAR</span> allows a three-dimensional description of the complex forest canopy structure it might help to extend our understanding of complex canopy processes influencing the spatial dispersal of precipitation water, and hence associated nutrient fluxes, in wooded ecosystems. Preliminary data analysis reveals that normalized TF values identify a number of TF collectors on each of the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.H43D0984Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.H43D0984Y"><span>Human Impact Intertwined with Glacial Legacy: Hydro-Geomorphologic Exploration using Li<span class="hlt">DAR</span> data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yan, Q.; Kumar, P.</p> <p>2014-12-01</p> <p>Intensively managed landscapes (IMLs) in the Midwestern United States are heavily modified by agriculture, artificial drainage, deforestation, urbanization, and wetland destruction. These landscapes have been shaped by repeated glacial events over geologic time scales followed with rapid human modifications for agriculture and drainage that are overlaid on extremely low gradient stream networks. In this study, using Li<span class="hlt">DAR</span> data from the Upper Sangamon River Basin in Illinois, we attempt to understand how the long-term glacial legacy has shaped the landscape and what is the impact from short-term human activities, such as channel straightening and periodic dredging. Glacial and human legacy impact landscape dynamics simultaneously. Therefore, we evaluate the present-day dynamics of landscapes by attempting to address several questions. First, we explore whether the watershed is in equilibrium conditions or away from it due to human activities. Second, we study how this relates to the degree of maturity in the river valley. Moreover, we map the spatial distributions of terraces and floodplains to understand depositional and erosional history. High-resolution Li<span class="hlt">DAR</span> data is ideal for such a study as it reveals the impact of both glacial episodes and human activities. Methods used for extraction of useful information from Li<span class="hlt">DAR</span> data include the TerEx tool, Stream Profiler, and Hec-GeoRas, among others. We analyze the terrace and floodplain geomorphic features, quantify stream sinuosity, and cross section geometries. An integral method is built based on stream power incision model to obtain sub-basin steady state condition. These features help to reveal local and global watershed properties. A bounded relationship between terraces/floodplains, sinuosity, cross section maturity, as well as sub-basin equilibrium condition is explored. In general, we find that the glacial legacy and present-day human activity have opposed each other in regards to the sub-basin equilibrium</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1744337','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=1744337"><span>Sexual behaviour among youths at high risk for HIV-1 infection in <span class="hlt">Dar</span> es Salaam, Tanzania</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Mwakagile, D; Mmari, E; Makwaya, C; Mbwana, J; Biberfeld, G; Mhalu, F; Sandstrom, E</p> <p>2001-01-01</p> <p>Objectives: To investigate sex specific sexual behaviour in youths visiting a youth clinic for sexual and reproductive health in <span class="hlt">Dar</span> es Saalam. Methods: A questionnaire was administered to a random sample of youths between 10 and 24 years of age attending the youth health clinic in <span class="hlt">Dar</span> es Saalam. The clinical investigation included testing for syphilis and HIV-1 antibodies Results: 1423 youths attended the clinic between September 1997 and August 1998. The study population comprised 213 (53.5%) males and 185 (46.5%) females. 97 (24.4%) were below 20 years. The mean age at coitarche was 16.5 and 17.0 years of age for males and females, respectively. The coitarche was involuntary in 15 females (8.6%). 49.5% males reported more than five lifetime partners compared with 14.1% for females (p<0.0001). Males reported recent partners to be 2.5 years younger, while females reported them to be 5.0 years older. No contraceptive use was reported by 29.7% of the males and 40.3% of females. 52.7% females had been pregnant and 26 (14.1%) reported induced abortions. Genital discharge was found in 69.5% and 73.9% and GUD in 36.6% and 27.1% of males and females respectively. 12 males (5.9%) and 43 females (24.6%) were found to be HIV-1 infected. 13.8% of the females with only one lifetime partner were HIV-1 infected compared with 40.9% with more than five partners (p = 0.028). Conclusions: Many youths in <span class="hlt">Dar</span> es Salaam engage in sexual behaviours that put them at risk of unwanted pregnancies and STIs including HIV infection. Female youths were more likely to contract HIV infection than males. In African urban areas youth oriented clinics can have a pivotal role in HIV/STI prevention and control Key Words: youth; sexual behaviour; HIV PMID:11463924</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1710643C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1710643C"><span>A Li<span class="hlt">DAR</span> intensity correction model for vertical geological mapping</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Carrea, Dario; Humair, Florian; Matasci, Battista; Abellan, Antonio; Derron, Marc-Henri; Jaboyedoff, Michel</p> <p>2015-04-01</p> <p>Ground-based Li<span class="hlt">DAR</span> has been traditionally used for surveying purposes via 3D point clouds. In addition to XYZ coordinates, an intensity attribute is also recorded by the Li<span class="hlt">DAR</span> devices but this parameter is rarely used for geological applications. The intensity of the backscattered signal can be a significant source of information in different geological applications, such as geological remote mapping of vertical surfaces, mineral exploration, stratigraphy, engineering, etc. However, the Intensity value recorded by the Li<span class="hlt">DAR</span> is a function of several external parameters, thus a correction of the raw intensity information is required prior to make use of this parameter. This study proposes an intensity correction model which takes into account of the range, the incidence angle and the surface roughness based on Oren-Nayar reflectance model (Oren and Nayar, 1994). The Oren-Nayar reflectance model is based on the idea that a surface is composed of micro-facets of various slope angles. The simplified version of this model requires only one parameter to characterize a surface, the standard deviation of the slope angle of the facets. Different discrete pulse laser scanners of Optech's ILRIS category were used to understand how the back-scattered intensity evolves in function of range and incidence angle. This was performed by carrying out different indoor and outdoor experiments, using the following targets: 1) mobile 2m2 board covered by black/white paper, 2) white plaster corridor walls and 3) finally on natural outcrops. First of all, we carried out a simple experiment by placing the mobile board at different distances ranging from 10 to 1000 meters. The analysis of the datasets revealed that the intensity of the backscattered signal decreases with the square of the range to the target, as was expected. However, both for the wall and the natural outcrops, the influence of the incidence angle appears to be more complex than the classical cosine law due to the roughness</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011PhDT.......347S','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011PhDT.......347S"><span>Fusion of Li<span class="hlt">DAR</span> and aerial imagery for the estimation of downed tree volume using Support Vector Machines classification and region based object fitting</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Selvarajan, Sowmya</p> <p></p> <p>The study classifies 3D small footprint full waveform digitized Li<span class="hlt">DAR</span> fused with aerial imagery to downed trees using Support Vector Machines (SVM) algorithm. Using small footprint waveform Li<span class="hlt">DAR</span>, airborne Li<span class="hlt">DAR</span> systems can provide better canopy penetration and very high spatial resolution. The small footprint waveform scanner system Riegl LMS-Q680 is addition with an UltraCamX aerial camera are used to measure and map downed trees in a forest. The various data preprocessing steps helped in the identification of ground points from the dense Li<span class="hlt">DAR</span> dataset and segment the Li<span class="hlt">DAR</span> data to help reduce the complexity of the algorithm. The haze filtering process helped to differentiate the spectral signatures of the various classes within the aerial image. Such processes, helped to better select the features from both sensor data. The six features: Li<span class="hlt">DAR</span> height, Li<span class="hlt">DAR</span> intensity, Li<span class="hlt">DAR</span> echo, and three image intensities are utilized. To do so, Li<span class="hlt">DAR</span> derived, aerial image derived and fused Li<span class="hlt">DAR</span>-aerial image derived features are used to organize the data for the SVM hypothesis formulation. Several variations of the SVM algorithm with different kernels and soft margin parameter C are experimented. The algorithm is implemented to classify downed trees over a pine trees zone. The Li<span class="hlt">DAR</span> derived features provided an overall accuracy of 98% of downed trees but with no classification error of 86%. The image derived features provided an overall accuracy of 65% and fusion derived features resulted in an overall accuracy of 88%. The results are observed to be stable and robust. The SVM accuracies were accompanied by high false alarm rates, with the Li<span class="hlt">DAR</span> classification producing 58.45%, image classification producing 95.74% and finally the fused classification producing 93% false alarm rates The Canny edge correction filter helped control the Li<span class="hlt">DAR</span> false alarm to 35.99%, image false alarm to 48.56% and fused false alarm to 37.69% The implemented classifiers provided a powerful tool for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9999E..0YC','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9999E..0YC"><span>A temperature calibration method for CDOM fluorescence LIF Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Chen, Peng; Mao, Zhihua; Huang, Haiqing; Bai, Yan; Wang, Tianyu</p> <p>2016-10-01</p> <p>The influence of temperature variations on the determined concentrations of dissolved organic matter (DOM) in water was investigated by laser induced fluorescence (LIF) technique in laboratory. The effect of temperature on CDOM fluorescence was investigated in freshwaters of Xixi River and in aqueous standards. The total luminescence spectra (TLS) of CDOM in several types of water samples with laser-induced fluorescence (LIF) measurements using a 405 nm wavelength excitation source were measured in the laboratory. A temperature calibration equation was derived to standardize CDOM fluorescence measurements to a specific reference temperature. Laboratory experiments with a portable LIF Li<span class="hlt">DAR</span> showed that CDOM fluorescence intensity decreased as ambient water temperature increased. High correlation (R2=0.91) was observed between concentration of CDOM and fluorescence normalized to water Raman scattering with the temperature calibration method. The results demonstrated that temperature calibration is a necessary and important aspect of CDOM monitoring using in situ fluorescence sensors.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..1710345C','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..1710345C"><span>Potential Landslide Detection with Fractal and Roughness by Li<span class="hlt">DAR</span> Data in Taiwan</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Cheng, Youg-Sin; Yu, Teng-To</p> <p>2015-04-01</p> <p>The purpose of this study is to detect the potential landslides since they would be triggered by heavy rain, earthquake and/or larger degree of geomorphology alteration under different terrain characteristics. Not only the newly area but also the past landslide area would generate landslide after serious events. To gather the newly landslides and past landslides overwhelmed by thick vegetation, Li<span class="hlt">DAR</span> could produce the high resolution DEM, denote actual surface terrain information and identify landform with a spatial resolution of 1m in different time interval. The 1-m interval DEM of Laonong watershed of southern Taiwan is utilized by fractal and roughness calculating with MATLAB code. DEM, aspect, and slope images are adopted to improve the accuracy of potential landslide detection with the random forest (RF) classifier. In present study, we provide the analysis results of the potential landslide area including these features calculation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2012EGUGA..14.8299B','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2012EGUGA..14.8299B"><span>How integrating 3D Li<span class="hlt">DAR</span> data in the dike surveillance protocol: The French case</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Bretar, F.; Mériaux, P.; Fauchard, C.</p> <p>2012-04-01</p> <p> carried out. A Li<span class="hlt">DAR</span> system is able to acquire data on a dike structure of up to 80 km per day, which makes the use of this technique also valuable in case of emergency situations. It provides additional valuable products like precious information on dike slopes and crest or their near environment (river banks, etc.). Moreover, in case of vegetation, Li<span class="hlt">DAR</span> data makes possible to study hidden structures or defaults from images like the erosion of riverbanks under forestry vegetation. The possibility of studying the vegetation is also of high importance: the development of woody vegetation near or onto the dike is a major risk factor. Surface singularities are often signs of disorder or suspected disorder in the dike itself: for example a subsidence or a sinkhole on a ridge may result from internal erosion collapse. Finally, high resolution topographic data contribute to build specific geomechanical model of the dike that, after incorporating data provided by geophysical and geotechnical surveys, are integrated in the calculations of the structure stability. Integrating the regular use of Li<span class="hlt">DAR</span> data in the dike surveillance protocol is not yet operational in France. However, the high number of French stakeholders at the national level (on average, there is one stakeholder for only 8-9km of dike !) and the real added value of Li<span class="hlt">DAR</span> data makes a spatial data infrastructure valuable (webservices for processing the data, consulting and filling the database on the field when performing the local diagnosis)</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ISPAr41B8..747P','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ISPAr41B8..747P"><span>Subtropical Forest Biomass Estimation Using Airborne Li<span class="hlt">DAR</span> and Hyperspectral Data</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Pang, Yong; Li, Zengyuan</p> <p>2016-06-01</p> <p>Forests have complex vertical structure and spatial mosaic pattern. Subtropical forest ecosystem consists of vast vegetation species and these species are always in a dynamic succession stages. It is very challenging to characterize the complexity of subtropical forest ecosystem. In this paper, CAF's (The Chinese Academy of Forestry) LiCHy (Li<span class="hlt">DAR</span>, CCD and Hyperspectral) Airborne Observation System was used to collect waveform Lidar and hyperspectral data in Puer forest region, Yunnan province in the Southwest of China. The study site contains typical subtropical species of coniferous forest, evergreen broadleaf forest, and some other mixed forests. The hypersectral images were orthorectified and corrected into surface reflectance with support of Lidar DTM product. The fusion of Lidar and hyperspectral can classify dominate forest types. The lidar metrics improved the classification accuracy. Then forest biomass estimation was carried out for each dominate forest types using waveform Lidar data, which get improved than single Lidar data source.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013OptLT..54..288L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013OptLT..54..288L"><span>A gradient-constrained morphological filtering algorithm for airborne Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Yong; Wu, Huayi; Xu, Hanwei; An, Ru; Xu, Jia; He, Qisheng</p> <p>2013-12-01</p> <p>This paper presents a novel gradient-constrained morphological filtering algorithm for bare-earth extraction from light detection and ranging (Li<span class="hlt">DAR</span>) data. Based on the gradient feature points determined by morphological half-gradients, the potential object points are located prior to filtering. Innovative gradient-constrained morphological operations are created, which are executed only for the potential object points. Compared with the traditional morphological operations, the new operations reduce many meaningless operations for object removal and consequently decrease the possibility of losing terrain to a great extent. The applicability and reliability of this algorithm are demonstrated by evaluating the filtering performance for fifteen sample datasets in various complex scenes. The proposed algorithm is found to achieve a high level of accuracy compared with eight other filtering algorithms tested by the International Society for Photogrammetry and Remote Sensing. Moreover, the proposed algorithm has minimal error oscillation for different landscapes, which is important for quality control of digital terrain model generation.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4241716','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4241716"><span>Urban mosquitoes, situational publics, and the pursuit of interspecies separation in <span class="hlt">Dar</span> es Salaam</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>KELLY, ANN H.; LEZAUN, JAVIER</p> <p>2014-01-01</p> <p>Recent work in anthropology points to the recognition of multispecies entanglements as the grounds for a more ethical politics. In this article, we examine efforts to control mosquitoes in <span class="hlt">Dar</span> es Salaam, Tanzania, as an example of the laborious tasks of disentanglement that characterize public health interventions. The mosquito surveillance and larval elimination practices of an urban malaria control program offer an opportunity to observe how efforts to create distance between species relate to the physical and civic textures of the city. Seen in the particular context of the contemporary African metropolis, the work of public health appears less a matter of control than a commitment to constant urban maintenance and political mobilization. PMID:25429167</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013EGUGA..15.9116T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013EGUGA..15.9116T"><span>Climate change induced risk analysis of <span class="hlt">Dar</span> es Salaam city (Tanzania)</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Topa, Maria Elena; Herslund, Lise; Cavan, Gina; Printz, Andreas; Simonis, Ingo; Bucchignani, Edoardo; Jean-Baptiste, Nathalie; Hellevik, Siri; Johns, Regina; Kibassa, Deusdedit; Kweka, Clara; Magina, Fredrick; Mangula, Alpha; Mbuya, Elinorata; Uhinga, Guido; Kassenga, Gabriel; Kyessi, Alphonce; Shemdoe, Riziki; Kombe, Wilbard</p> <p>2013-04-01</p> <p>CLUVA (CLimate change and Urban Vulnerability in Africa; http://www.cluva.eu/) is a 3 years project, funded by the European Commission in 2010. The main objective of CLUVA is to develop context-centered methods and knowledge to be applied to African cities to assess vulnerabilities and increase knowledge on managing climate related risks. The project estimates the impacts of climate changes in the next 40 years at urban scale and downscales IPCC climate projections to evaluate specific threats to selected African test cities. These are mainly from floods, sea-level rise, droughts, heat waves, and desertification. The project evaluates and links: social vulnerability; urban green structures and ecosystem services; urban-rural interfaces; vulnerability of urban built environment and lifelines; and related institutional and governance dimensions of adaptation. The multi-scale and multi-disciplinary qualitative, quantitative and probabilistic approach of CLUVA is currently being applied to selected African test cities (Addis Ababa - Ethiopia; <span class="hlt">Dar</span> es Salaam - Tanzania; Douala - Cameroun; Ouagadougou - Burkina Faso; St. Louis - Senegal). In particular, the poster will present preliminary findings for the <span class="hlt">Dar</span> es Salaam case study. <span class="hlt">Dar</span> es Salaam, which is Tanzania's largest coastal city, is exposed to floods, coastal erosion, droughts and heat waves, and highly vulnerable to impacts as a result of ineffective urban planning (about 70% unplanned settlements), poverty and lack of basic infrastructure (e.g. lack of or poor quality storm water drainage systems). Climate change could exacerbate the current situation increasing hazard-exposure alongside the impacts of development pressures which act to increase urban vulnerability for example because of informal (unregulated) urbanization. The CLUVA research team - composed of climate and environmental scientists, risk management experts, urban planners and social scientists from both European and African institutions - has</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4721774','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4721774"><span>Joint Temperature-Lasing Mode Compensation for Time-of-Flight Li<span class="hlt">DAR</span> Sensors</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Alhashimi, Anas; Varagnolo, Damiano; Gustafsson, Thomas</p> <p>2015-01-01</p> <p>We propose an expectation maximization (EM) strategy for improving the precision of time of flight (ToF) light detection and ranging (Li<span class="hlt">DAR</span>) scanners. The novel algorithm statistically accounts not only for the bias induced by temperature changes in the laser diode, but also for the multi-modality of the measurement noises that is induced by mode-hopping effects. Instrumental to the proposed EM algorithm, we also describe a general thermal dynamics model that can be learned either from just input-output data or from a combination of simple temperature experiments and information from the laser’s datasheet. We test the strategy on a SICK LMS 200 device and improve its average absolute error by a factor of three. PMID:26690445</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2015EGUGA..17.7515A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2015EGUGA..17.7515A"><span>Tropical Airborne Li<span class="hlt">DAR</span> for Landslide Assessment in Malaysia: a technical perspective</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Abd Manap, Mohamad; Azhari Razak, Khamarrul; Mohamad, Zakaria; Ahmad, Azhari; Ahmad, Ferdaus; Mohamad Zin, Mazlan; A'zad Rosle, Qalam</p> <p>2015-04-01</p> <p>Malaysia has faced a substantial number of landslide events every year. Cameron Highlands, Pahang is one of the badly areas affected by slope failures characterized by extreme climate, rugged topographic and weathered geological structures in a tropical environment. A high frequency of landslide occurrence in the hilly areas is predominantly due to the geological materials, tropical monsoon seasons and uncontrolled agricultural activities. Therefore the Government of Malaysia through the Prime Minister Department has allocated a special budget to conduct national level hazard and risk mapping project through Minerals and Geoscience Department Malaysia, the Ministry of Natural Resources and Environment. The primary aim of this project is to provide slope hazard risk information for a better slope management in Malaysia. In addition this project will establish national infrastructure for geospatial information on the geological terrain and slope by emphasizing the disaster risk throughout the country. The areas of interest are located in the three different selected areas i.e. Cameron Highlands (275 square kilometers), Ipoh (200 square kilometers) and Cheras Kajang -- Batang kali (650 square kilometers). These areas are selected based on National Slope Master Plan (2009 -- 2023) that endorsed by Malaysia Government Cabinet. The national hazard and risk mapping project includes six parts of major tasks: (1) desk study and mobilization, (2) airborne Li<span class="hlt">DAR</span> data acquisition and analysis, (3) field data acquisition and verification, (4) hazard and risk for natural terrain, (5) hazard and risk analysis for man-made slope and (6) Man-made slope mitigation/preventive measures. The project was authorized in September, 2014 and will be ended in March, 2016. In this paper, the main focus is to evaluate the suitability of integrated capability of airborne- and terrestrial Li<span class="hlt">DAR</span> data acquisition and analysis, and also digital photography for regional landslide assessment. The</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://hdl.handle.net/2060/20120015386','NASA-TRS'); return false;" href="http://hdl.handle.net/2060/20120015386"><span>G-LiHT: Goddard's Li<span class="hlt">DAR</span>, Hyperspectral and Thermal Airborne Imager</span></a></p> <p><a target="_blank" href="http://ntrs.nasa.gov/search.jsp">NASA Technical Reports Server (NTRS)</a></p> <p>Cook, Bruce; Corp, Lawrence; Nelson, Ross; Morton, Douglas; Ranson, Kenneth J.; Masek, Jeffrey; Middleton, Elizabeth</p> <p>2012-01-01</p> <p>Scientists at NASA's Goddard Space Flight Center have developed an ultra-portable, low-cost, multi-sensor remote sensing system for studying the form and function of terrestrial ecosystems. G-LiHT integrates two LIDARs, a 905 nanometer single beam profiler and 1550 nm scanner, with a narrowband (1.5 nanometers) VNIR imaging spectrometer and a broadband (8-14 micrometers) thermal imager. The small footprint (approximately 12 centimeters) LIDAR data and approximately 1 meter ground resolution imagery are advantageous for high resolution applications such as the delineation of canopy crowns, characterization of canopy gaps, and the identification of sparse, low-stature vegetation, which is difficult to detect from space-based instruments and large-footprint Li<span class="hlt">DAR</span>. The hyperspectral and thermal imagery can be used to characterize species composition, variations in biophysical variables (e.g., photosynthetic pigments), surface temperature, and responses to environmental stressors (e.g., heat, moisture loss). Additionally, the combination of LIDAR optical, and thermal data from G-LiHT is being used to assess forest health by sensing differences in foliage density, photosynthetic pigments, and transpiration. Low operating costs (approximately $1 ha) have allowed us to evaluate seasonal differences in Li<span class="hlt">DAR</span>, passive optical and thermal data, which provides insight into year-round observations from space. Canopy characteristics and tree allometry (e.g., crown height:width, canopy:ground reflectance) derived from G-LiHT data are being used to generate realistic scenes for radiative transfer models, which in turn are being used to improve instrument design and ensure continuity between Li<span class="hlt">DAR</span> instruments. G-LiHT has been installed and tested in aircraft with fuselage viewports and in a custom wing-mounted pod that allows G-LiHT to be flown on any Cessna 206, a common aircraft in use throughout the world. G-LiHT is currently being used for forest biomass and growth estimation</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2011AGUFM.V13C2609R','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2011AGUFM.V13C2609R"><span>Fine-scale ignimbrite morphology revealed in Li<span class="hlt">DAR</span> at Crater Lake, OR</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Robinson, J. E.; Bacon, C. R.; Wright, H. M.</p> <p>2011-12-01</p> <p>Mount Mazama erupted ~7,700 years ago resulting in the collapse of Crater Lake caldera, ash fall across the Pacific Northwest, and emplacement of compositionally zoned ignimbrite. Early climactic ignimbrite contains uniform rhyodacitic pumice and traveled far from the vent, whereas late, less mobile ignimbrite is dominated by crystal-rich andesitic scoria and mafic crystal mush. Funded by the USGS, NPS, and FHWA, the DOGAMI-led Oregon Li<span class="hlt">DAR</span> Consortium contracted with Watershed Services to collect ~800 km2 of Li<span class="hlt">DAR</span> over Crater Lake National Park from Aug 2010 to Sept 2010. Ground laser returns have an average density of 1.63 returns/m2 over the heavily forested area of interest. The data have a lateral RMSE and vertical accuracy of 0.05 m. A bare earth terrain model allows a virtual removal of the forest, revealing fine-scale surface morphology, notably in the climactic ignimbrite. Secondary pyroclastic flows, explosion craters, erosion by water, and compaction-related deformation modified the originally smooth ignimbrite surface. Distinct pyroclastic flow fronts are evident in the Li<span class="hlt">DAR</span> in Annie Creek valley. Leveed flows stand approximately 5 m above the lower ignimbrite surface, and individual toes are about 1-2 m high. Preliminary field checking indicates that rhyodacitic pumice dominates the lower ignimbrite surface, but the leveed flows are a subequal mix of locally oxidized rhyodacitic pumice and andesitic scoria. We hypothesize that these deposits were secondary pyroclastic flows formed by gravitational failure of late ignimbrite. In the Castle Creek valley, is a 2-meter collapse scarp that may have spawned a small secondary pyroclastic flow; several such headwall scarps are present in Sand Creek valley. Differential compaction features are common in many thick ignimbrites. We suggest this caused the deformation of the ignimbrite apparent in the Li<span class="hlt">DAR</span>. In Annie Creek valley are a series of flow parallel asymmetric ridges, with shallower slopes toward the</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2009EGUGA..11.7524V','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2009EGUGA..11.7524V"><span>On the use of airborne Li<span class="hlt">DAR</span> for braided river monitoring and water surface delineation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Vetter, M.; Höfle, B.; Pfeifer, N.; Rutzinger, M.; Stötter, J.</p> <p>2009-04-01</p> <p>Airborne Li<span class="hlt">DAR</span> is an established technology for Earth surface surveying. With Li<span class="hlt">DAR</span> data sets it is possible to derive maps with different land use classes, which are important for hydraulic simulations. We present a 3D point cloud based method for automatic water surface delineation using single as well as multitemporal Li<span class="hlt">DAR</span> data sets. With the developed method it is possible to detect the location of the water surface with high planimetric accuracy. The multitemporal analysis of different Li<span class="hlt">DAR</span> data sets makes it possible to visualize, monitor and quantify the changes of the flow path of braided rivers as well as derived water surface land use classes. The reflection properties from laser beams (1064 nm wavelength) on water surfaces are characterized by strong absorption or specular reflection resulting in a dominance of low signal amplitude values and a high number of laser shot dropouts (i.e. non-recorded laser echoes). The occurrence of dropouts is driven by (i) the incidence angle, (ii) the surface reflectance and (iii) the roughness of the water body. The input data of the presented delineation method are the modeled dropouts and the point cloud attributes of geometry and signal amplitude. A terrestrial orthophoto is used to explore the point cloud in order to find proper information about the geometry and amplitude attributes that are characteristic for water surfaces. The delineation method is divided into five major steps. (a) We compute calibrated amplitude values by reducing the atmospheric, topographic influences and the scan geometry for each laser echo. (b) Then, the dropouts are modeled by using the information from the time stamps, the pulse repetition frequency, the inertial measurement unit and the GPS information of the laser shots and the airplane. The next step is to calculate the standard deviation of the heights for all reflections and all modeled dropouts (c) in a specific radius around the points. (d) We compute the amplitude ratio</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016EGUGA..18.7528D','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016EGUGA..18.7528D"><span>Approaching a more Complete Picture of Rockfall Activity: Seismic and Li<span class="hlt">DAR</span> Detection, Loaction and Volume Estimates</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Dietze, Michael; Mohadjer, Solmaz; Turowski, Jens; Ehlers, Todd; Hovius, Niels</p> <p>2016-04-01</p> <p>Rockfall activity in steep alpine landscapes is often difficult to survey due to its infrequent nature. Classic approaches are limited by temporal and spatial resolution. In contrast, seismic monitoring provides access to catchment-wide analysis of activity patterns in rockfall-dominated environments. The deglaciated U-shaped Lauterbrunnen Valley in the Bernese Oberland, Switzerland, is a perfect example of such landscapes. It was instrumented with up to six broadband seismometers and repeatedly surveyed by terrestrial Li<span class="hlt">DAR</span> to provide independent validation data. During August-October 2014 and April-June 2015 more than 23 (Li<span class="hlt">DAR</span>) to hundred (seismic) events were detected. Their volumes range from < 0.01 to 5.80 cubic metres as detected by Li<span class="hlt">DAR</span>. The evolution of individual events (i.e., precursor activity, detachment, falling phase, impact, talus cone activity) can be quantified in terms of location and duration. For events that consist of single detachments rather than a series of releases, volume scaling relationships are possible. Seismic monitoring approaches are well-suited for studying not only the rockfall process but also for understanding the geomorphic framework and boundary conditions that control such processes in a comprehensive way. Taken together, the combined Li<span class="hlt">DAR</span> and seismic monitoring approach provides high fidelity spatial and temporal resolution of individual events.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016SPIE.9828E..0IF','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016SPIE.9828E..0IF"><span>Automatic construction of aerial corridor for navigation of unmanned aircraft systems in class G airspace using Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Feng, Dengchao; Yuan, Xiaohui</p> <p>2016-05-01</p> <p>According to the airspace classification by the Federal Aviation Agency, Class G airspace is the airspace at 1,200 feet or less to the ground, which is beneath class E airspace and between classes B-D cylinders around towered airstrips. However, the lack of flight supervision mechanism in this airspace, unmanned aerial system (UAS) missions pose many safety issues. Collision avoidance and route planning for UASs in class G airspace is critical for broad deployment of UASs in commercial and security applications. Yet, unlike road network, there is no stationary marker in airspace to identify corridors that are available and safe for UASs to navigate. In this paper, we present an automatic Li<span class="hlt">DAR</span>-based airspace corridor construction method for navigation in class G airspace and a method for route planning to minimize collision and intrusion. Our idea is to combine Li<span class="hlt">DAR</span> to automatically identify ground objects that pose navigation restrictions such as airports and high-rises. Digital terrain model (DTM) is derived from Li<span class="hlt">DAR</span> point cloud to provide an altitude-based class G airspace description. Following the FAA Aeronautical Information Manual, the ground objects that define the restricted airspaces are used together with digital surface model derived from Li<span class="hlt">DAR</span> data to construct the aerial corridor for navigation of UASs. Preliminary results demonstrate competitive performance and the construction of aerial corridor can be automated with much great efficiency.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=227724&keyword=geology&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=78675326&CFTOKEN=61321265','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=227724&keyword=geology&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=78675326&CFTOKEN=61321265"><span>Calculating the ecosystem service of water storage in isolated wetlands using Li<span class="hlt">DAR</span> in north central Florida, USA (presentation)</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>This study used remotely-sensed Light Detection and Ranging (Li<span class="hlt">DAR</span>) data to estimate potential water storage capacity of isolated wetlands in north central Florida. The data were used to calculate the water storage potential of >8500 polygons identified as isolated wetlands. We f...</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_20");'>20</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li class="active"><span>22</span></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_22 --> <div id="page_23" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="441"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014PhDT........81K','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014PhDT........81K"><span>Assessing Surface Fuel Hazard in Coastal Conifer Forests through the Use of Li<span class="hlt">DAR</span> Remote Sensing</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Koulas, Christos</p> <p></p> <p>The research problem that this thesis seeks to examine is a method of predicting conventional fire hazards using data drawn from specific regions, namely the Sooke and Goldstream watershed regions in coastal British Columbia. This thesis investigates whether Li<span class="hlt">DAR</span> data can be used to describe conventional forest stand fire hazard classes. Three objectives guided this thesis: to discuss the variables associated with fire hazard, specifically the distribution and makeup of fuel; to examine the relationship between derived Li<span class="hlt">DAR</span> biometrics and forest attributes related to hazard assessment factors defined by the Capitol Regional District (CRD); and to assess the viability of the Li<span class="hlt">DAR</span> biometric decision tree in the CRD based on current frameworks for use. The research method uses quantitative datasets to assess the optimal generalization of these types of fire hazard data through discriminant analysis. Findings illustrate significant Li<span class="hlt">DAR</span>-derived data limitations, and reflect the literature in that flawed field application of data modelling techniques has led to a disconnect between the ways in which fire hazard models have been intended to be used by scholars and the ways in which they are used by those tasked with prevention of forest fires. It can be concluded that a significant trade-off exists between computational requirements for wildfire simulation models and the algorithms commonly used by field teams to apply these models with remote sensing data, and that CRD forest management practices would need to change to incorporate a decision tree model in order to decrease risk.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=331151&keyword=Biodiversity&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=78762827&CFTOKEN=50744854','EPA-EIMS'); return false;" href="http://cfpub.epa.gov/si/si_public_record_report.cfm?dirEntryId=331151&keyword=Biodiversity&actType=&TIMSType=+&TIMSSubTypeID=&DEID=&epaNumber=&ntisID=&archiveStatus=Both&ombCat=Any&dateBeginCreated=&dateEndCreated=&dateBeginPublishedPresented=&dateEndPublishedPresented=&dateBeginUpdated=&dateEndUpdated=&dateBeginCompleted=&dateEndCompleted=&personID=&role=Any&journalID=&publisherID=&sortBy=revisionDate&count=50&CFID=78762827&CFTOKEN=50744854"><span>Computing Risk to West Coast Intertidal Rocky Habitat due to Sea Level Rise using Li<span class="hlt">DAR</span> Topobathy</span></a></p> <p><a target="_blank" href="http://oaspub.epa.gov/eims/query.page">EPA Science Inventory</a></p> <p></p> <p></p> <p>Compared to marshes, little information is available on the potential for rocky intertidal habitats to migrate upward in response to sea level rise (SLR). To address this gap, we utilized topobathy Li<span class="hlt">DAR</span> digital elevation models (DEMs) downloaded from NOAA’s Digital Coast G...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=HIV+AND+women&pg=4&id=EJ896554','ERIC'); return false;" href="http://eric.ed.gov/?q=HIV+AND+women&pg=4&id=EJ896554"><span>Intimate Partner Violence and the Association with HIV Risk Behaviors among Young Men in <span class="hlt">Dar</span> Es Salaam, Tanzania</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Maman, Suzanne; Yamanis, Thespina; Kouyoumdjian, Fiona; Watt, Melissa; Mbwambo, Jessie</p> <p>2010-01-01</p> <p>There is growing evidence of the association between gender-based violence and HIV from the perspective and experiences of women. The purpose of this study is to examine these associations from the perspective of young men living in <span class="hlt">Dar</span> es Salaam, Tanzania. A community-based sample of 951 men were interviewed, of whom 360 had sex in the past 6…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.ncbi.nlm.nih.gov/pubmed/27608025','PUBMED'); return false;" href="https://www.ncbi.nlm.nih.gov/pubmed/27608025"><span>Testing the Suitability of a Terrestrial 2D Li<span class="hlt">DAR</span> Scanner for Canopy Characterization of Greenhouse Tomato Crops.</span></a></p> <p><a target="_blank" href="https://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pubmed">PubMed</a></p> <p>Llop, Jordi; Gil, Emilio; Llorens, Jordi; Miranda-Fuentes, Antonio; Gallart, Montserrat</p> <p>2016-09-06</p> <p>Canopy characterization is essential for pesticide dosage adjustment according to vegetation volume and density. It is especially important for fresh exportable vegetables like greenhouse tomatoes. These plants are thin and tall and are planted in pairs, which makes their characterization with electronic methods difficult. Therefore, the accuracy of the terrestrial 2D Li<span class="hlt">DAR</span> sensor is evaluated for determining canopy parameters related to volume and density and established useful correlations between manual and electronic parameters for leaf area estimation. Experiments were performed in three commercial tomato greenhouses with a paired plantation system. In the electronic characterization, a Li<span class="hlt">DAR</span> sensor scanned the plant pairs from both sides. The canopy height, canopy width, canopy volume, and leaf area were obtained. From these, other important parameters were calculated, like the tree row volume, leaf wall area, leaf area index, and leaf area density. Manual measurements were found to overestimate the parameters compared with the Li<span class="hlt">DAR</span> sensor. The canopy volume estimated with the scanner was found to be reliable for estimating the canopy height, volume, and density. Moreover, the Li<span class="hlt">DAR</span> scanner could assess the high variability in canopy density along rows and hence is an important tool for generating canopy maps.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.osti.gov/scitech/servlets/purl/1286923','SCIGOV-STC'); return false;" href="http://www.osti.gov/scitech/servlets/purl/1286923"><span>Characterization and classification of vegetation canopy structure and distribution within the Great Smoky Mountains National Park using Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://www.osti.gov/scitech">SciTech Connect</a></p> <p>Kumar, Jitendra; HargroveJr., William Walter; Norman, Steven P; Hoffman, Forrest M; Newcomb, Doug</p> <p>2015-01-01</p> <p>Vegetation canopy structure is a critically important habit characteristic for many threatened and endangered birds and other animal species, and it is key information needed by forest and wildlife managers for monitoring and managing forest resources, conservation planning and fostering biodiversity. Advances in Light Detection and Ranging (Li<span class="hlt">DAR</span>) technologies have enabled remote sensing-based studies of vegetation canopies by capturing three-dimensional structures, yielding information not available in two-dimensional images of the landscape pro- vided by traditional multi-spectral remote sensing platforms. However, the large volume data sets produced by airborne Li<span class="hlt">DAR</span> instruments pose a significant computational challenge, requiring algorithms to identify and analyze patterns of interest buried within Li<span class="hlt">DAR</span> point clouds in a computationally efficient manner, utilizing state-of-art computing infrastructure. We developed and applied a computationally efficient approach to analyze a large volume of Li<span class="hlt">DAR</span> data and to characterize and map the vegetation canopy structures for 139,859 hectares (540 sq. miles) in the Great Smoky Mountains National Park. This study helps improve our understanding of the distribution of vegetation and animal habitats in this extremely diverse ecosystem.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014JARS....8.3572N','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014JARS....8.3572N"><span>Fine-spatial scale predictions of understory species using climate- and Li<span class="hlt">DAR</span>-derived terrain and canopy metrics</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Nijland, Wiebe; Nielsen, Scott E.; Coops, Nicholas C.; Wulder, Michael A.; Stenhouse, Gordon B.</p> <p>2014-01-01</p> <p>Food and habitat resources are critical components of wildlife management and conservation efforts. The grizzly bear (Ursus arctos) has diverse diets and habitat requirements particularly for understory plant species, which are impacted by human developments and forest management activities. We use light detection and ranging (Li<span class="hlt">DAR</span>) data to predict the occurrence of 14 understory plant species relevant to bear forage and compare our predictions with more conventional climate- and land cover-based models. We use boosted regression trees to model each of the 14 understory species across 4435 km2 using occurrence (presence-absence) data from 1941 field plots. Three sets of models were fitted: climate only, climate and basic land and forest covers from Landsat 30-m imagery, and a climate- and Li<span class="hlt">DAR</span>-derived model describing both the terrain and forest canopy. Resulting model accuracies varied widely among species. Overall, 8 of 14 species models were improved by including the Li<span class="hlt">DAR</span>-derived variables. For climate-only models, mean annual precipitation and frost-free periods were the most important variables. With inclusion of Li<span class="hlt">DAR</span>-derived attributes, depth-to-water table, terrain-intercepted annual radiation, and elevation were most often selected. This suggests that fine-scale terrain conditions affect the distribution of the studied species more than canopy conditions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://eric.ed.gov/?q=socialism&pg=7&id=ED523151','ERIC'); return false;" href="http://eric.ed.gov/?q=socialism&pg=7&id=ED523151"><span>National and Global: A History of Scholars' Experiences with Research at the University of <span class="hlt">Dar</span> Es Salaam, Tanzania (1961-Present)</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Jamison, Amy J.</p> <p>2010-01-01</p> <p>In this dissertation, I draw on research carried out at the University of <span class="hlt">Dar</span> es Salaam (UDSM), Tanzania in 2008 to examine Tanzanian academics' experience with research throughout the history of this institution. This dissertation is designed as an historical case study and investigates how economic and political changes in Tanzania's…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://files.eric.ed.gov/fulltext/EJ1079991.pdf','ERIC'); return false;" href="http://files.eric.ed.gov/fulltext/EJ1079991.pdf"><span>Provision of Vocational Skills Education to Orphans: Lessons from Orphanage Centres in <span class="hlt">Dar</span> es Salaam City, Tanzania</span></a></p> <p><a target="_blank" href="http://www.eric.ed.gov/ERICWebPortal/search/extended.jsp?_pageLabel=advanced">ERIC Educational Resources Information Center</a></p> <p>Meli, Benjamin Mbeba</p> <p>2015-01-01</p> <p>This paper utilises data from a study that investigated the efficacy of vocational skills training provided to orphans from three orphanages in Temeke District, <span class="hlt">Dar</span> es Salaam. The three orphanage centres that were studied are Kurasini National Children Home, Saudia and Don Bosco Vocational Centre. The sample comprised of 45 orphans, an official…</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=261338','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=261338"><span>A categorical, improper probability method for combining NDVI and Li<span class="hlt">DAR</span> elevation information for potential cotton precision agricultural applications</span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>An algorithm is presented to fuse the Normalized Difference Vegetation Index (NDVI) with Light Detection and Ranging (Li<span class="hlt">DAR</span>) elevation data to produce a map potentially useful for the site-specific scouting and pest management of several insect pests. In cotton, these pests include the Tarnished Pl...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://www.ars.usda.gov/research/publications/publication/?seqNo115=255850','TEKTRAN'); return false;" href="http://www.ars.usda.gov/research/publications/publication/?seqNo115=255850"><span>Vegetation and slope effects on accuracy of a Li<span class="hlt">DAR</span>-derived DEM in the sagebrush steppe</span></a></p> <p><a target="_blank" href="http://www.ars.usda.gov/services/TekTran.htm">Technology Transfer Automated Retrieval System (TEKTRAN)</a></p> <p></p> <p></p> <p>This study analyzed the errors associated with vegetation cover type and slope on a Li<span class="hlt">DAR</span> derived DEM in a semiarid environment in southwestern Idaho, USA. Reference data were collected over a range of vegetation cover types and slopes. Reference data were compared to ground raster values and Root...</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5038713','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=5038713"><span>Testing the Suitability of a Terrestrial 2D Li<span class="hlt">DAR</span> Scanner for Canopy Characterization of Greenhouse Tomato Crops</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Llop, Jordi; Gil, Emilio; Llorens, Jordi; Miranda-Fuentes, Antonio; Gallart, Montserrat</p> <p>2016-01-01</p> <p>Canopy characterization is essential for pesticide dosage adjustment according to vegetation volume and density. It is especially important for fresh exportable vegetables like greenhouse tomatoes. These plants are thin and tall and are planted in pairs, which makes their characterization with electronic methods difficult. Therefore, the accuracy of the terrestrial 2D Li<span class="hlt">DAR</span> sensor is evaluated for determining canopy parameters related to volume and density and established useful correlations between manual and electronic parameters for leaf area estimation. Experiments were performed in three commercial tomato greenhouses with a paired plantation system. In the electronic characterization, a Li<span class="hlt">DAR</span> sensor scanned the plant pairs from both sides. The canopy height, canopy width, canopy volume, and leaf area were obtained. From these, other important parameters were calculated, like the tree row volume, leaf wall area, leaf area index, and leaf area density. Manual measurements were found to overestimate the parameters compared with the Li<span class="hlt">DAR</span> sensor. The canopy volume estimated with the scanner was found to be reliable for estimating the canopy height, volume, and density. Moreover, the Li<span class="hlt">DAR</span> scanner could assess the high variability in canopy density along rows and hence is an important tool for generating canopy maps. PMID:27608025</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2008JAGeo...2..213L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2008JAGeo...2..213L"><span>A model for predicting GPS-GDOP and its probability using Li<span class="hlt">DAR</span> data and ultra rapid product</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Lohani, Bharat; Kumar, Raman</p> <p>2008-12-01</p> <p>This paper presents a model to predict the GDOP value (Geometric Dilution of Precision) and the probability of its occurrence at a point in space and time using airborne Li<span class="hlt">DAR</span> (Light Detection and Ranging) data and the ultra-rapid product (URP) available from the International GPS Service. Li<span class="hlt">DAR</span> data help to classify the terrain around a GPS (Global Positioning System) receiver into categories such as ground, opaque objects, translucent objects and transparent regions as per their response to the transmission of GPS signal. Through field experiments it is established that URP can be used satisfactorily to determine GDOP. Further experiments have shown that the translucent objects (mainly trees here) lower the GDOP quality as they obstruct the GPS signal. Li<span class="hlt">DAR</span> data density on trees is used as a measure of the translucency of trees to the GPS signal. Through GPS observations taken in field a relationship has been established between Li<span class="hlt">DAR</span> data density on trees and the probability that a satellite which is behind the tree is visible at the GPS receiver. A model is presented which, for all possible combinations of visible satellites, computes the GDOP value along with the probability of occurrence of this GDOP. A few results are presented to show the performance of the model developed and its possible application in location based queries.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2016ISPAr41B4..195T','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2016ISPAr41B4..195T"><span>Data Archiving and Distribution of Li<span class="hlt">DAR</span> and Derived Datasets in the Philippines</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Tupas, M. E. A.; Lat, S. C.; Magturo, R. A.</p> <p>2016-06-01</p> <p>Li<span class="hlt">DAR</span> programs in the Philippines have been generating valuable resource and hazard information for most of the country at a substantial rate since 2012. Significant progress have been made due to the programs design of engaging 16 Universities and research institutions spatially distributed across the country. Because of this, data has been accumulating at a brisk rate which poses significant technical and logistic issues. While a central node, the University of the Philippines, Diliman, handles data acquisition, pre-processing, and quality checking, processing and ground validation are devolved to the various nodes. For this setup to be successful, an efficient data access and distribution system should be in place. In this paper, we discuss the spatial data infrastructure and data access protocols implemented by the program. At the center of the data access and distribution operations is LiPAD or our Li<span class="hlt">DAR</span> portal for archiving and distribution. LiPAD is built on open source technologies, established web standards, and protocols. At its back-end a central data archive has been established using state of the art Object Storage technology to store both raw, processed Lidar and derived data sets. Catalog of available data sets ranging from data acquisition foot prints, to DEM coverages, to derived products such as flood hazard, and crop suitability are viewable and accessible on the main site based on the popular GeoNode application. Data exchange is performed using varying protocols to address various logistical problems. Given the various challenges the program is successful in distributing data sets not just to partner processing nodes but to other stakeholders where main requesters include national agencies and general research and academic institutions.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2010AGUFMEP43E..06L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2010AGUFMEP43E..06L"><span>First Li<span class="hlt">DAR</span> images of the Alpine Fault, central South Island, New Zealand</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Langridge, R. M.; Toy, V. G.; Barth, N.; de Pascale, G. P.; Sutherland, R.; Farrier, T.</p> <p>2010-12-01</p> <p>In central South Island, New Zealand, the dextral-reverse Alpine fault forms the principal component of the Australia-Pacific plate boundary. The fault typically accommodates slip rates of the order of ~27-29 mm/yr (dextral) and up to 6-11 mm/yr (reverse), mostly uplifting Pacific plate rocks that form the Southern Alps. However, the associated high relief, rapid uplift and erosion and high rainfall and accompanying dense temperate rainforest along the western side of the island has typically hampered geological efforts to better understand the neotectonics of the Alpine fault. Li<span class="hlt">DAR</span> data have been acquired over a 34 km stretch of the fault between Whataroa in the northeast and Franz Josef in the southwest to test the viability of this technique under dense vegetation and in steep, dissected terrain. Li<span class="hlt">DAR</span> has been collected from a fixed wing base (1300m above ground level) at a frequency of 70k Hz, with 33.5 Hz scan frequency and a 39° field of view. We employed a strategy of flying a dense pattern of 6 flight lines across a swath width of 1.3 km. This creates areas of both single and double overlap coverage that have allowed for accurate landscape models to be created. Results show that this strategy has provided an optimum level of forest penetration and ground returns. Initial results show remarkable level of detail in DEM’s of the landscape along the Alpine fault. Examples of results presented here include: Franz Josef, where the fault traverses the township; and Gaunt Creek, where a Deep Fault Drilling Project will be sited in early 2011.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2017MeScT..28d5205L','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2017MeScT..28d5205L"><span>Full-waveform Li<span class="hlt">DAR</span> echo decomposition based on wavelet decomposition and particle swarm optimization</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Li, Duan; Xu, Lijun; Li, Xiaolu</p> <p>2017-04-01</p> <p>To measure the distances and properties of the objects within a laser footprint, a decomposition method for full-waveform light detection and ranging (Li<span class="hlt">DAR</span>) echoes is proposed. In this method, firstly, wavelet decomposition is used to filter the noise and estimate the noise level in a full-waveform echo. Secondly, peak and inflection points of the filtered full-waveform echo are used to detect the echo components in the filtered full-waveform echo. Lastly, particle swarm optimization (PSO) is used to remove the noise-caused echo components and optimize the parameters of the most probable echo components. Simulation results show that the wavelet-decomposition-based filter is of the best improvement of SNR and decomposition success rates than Wiener and Gaussian smoothing filters. In addition, the noise level estimated using wavelet-decomposition-based filter is more accurate than those estimated using other two commonly used methods. Experiments were carried out to evaluate the proposed method that was compared with our previous method (called GS-LM for short). In experiments, a lab-build full-waveform Li<span class="hlt">DAR</span> system was utilized to provide eight types of full-waveform echoes scattered from three objects at different distances. Experimental results show that the proposed method has higher success rates for decomposition of full-waveform echoes and more accurate parameters estimation for echo components than those of GS-LM. The proposed method based on wavelet decomposition and PSO is valid to decompose the more complicated full-waveform echoes for estimating the multi-level distances of the objects and measuring the properties of the objects in a laser footprint.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014SPIE.9250E..13Y','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014SPIE.9250E..13Y"><span>Underwater monitoring experiment using hyperspectral sensor, Li<span class="hlt">DAR</span> and high resolution satellite imagery</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Yang, Chan-Su; Kim, Sun-Hwa</p> <p>2014-10-01</p> <p>In general, hyper-spectral sensor, Li<span class="hlt">DAR</span> and high spatial resolution satellite imagery for underwater monitoring are dependent on water clarity or water transparency that can be measured using a Secchi disk or satellite ocean color data. Optical properties in the sea waters of South Korea are influenced mainly by a strong tide and oceanic currents, diurnal, daily and seasonal variations of water transparency. The satellite-based Secchi depth (ZSD) analysis showed the applicability of hyper-spectral sensor, Li<span class="hlt">DAR</span> and optical satellite, determined by the location connected with the local distribution of Case 1 and 2 waters. The southeast coastal areas of Jeju Island are selected as test sites for a combined underwater experiment, because those areas represent Case 1 water. Study area is a small port (<15m) in the southeast area of the island and linear underwater target used by sewage pipe is located in this area. Our experiments are as follows: 1. atmospheric and sun-glint correction methods to improve the underwater monitoring ability; 2. intercomparison of water depths obtained from three different sensors. Three sensors used here are the CASI-1500 (Wide-Array Airborne Hyperspectral VNIR Imager (0.38-1.05 microns), the Coastal Zone Mapping and Imaging Lidar (CZMIL) and Korean Multi-purpose Satellite-3 (KOMPSAT-3) with 2.8 meter multi-spectral resolution. The experimental results were affected by water clarity and surface condition, and the bathymetric results of three sensors show some differences caused by sensor-itself, bathymetric algorithm and tide level. It is shown that CASI-1500 was applicable for bathymetry and underwater target detection in this area, but KOMPSAT-3 should be improved for Case 1 water. Although this experiment was designed to compare underwater monitoring ability of LIDAR, CASI-1500, KOMPSAT-3 data, this paper was based on initial results and suggested only results about the bathymetry and underwater target detection.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70119267','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70119267"><span>Tracking geomorphic signatures of watershed suburbanization with multi-temporal Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Jones, Daniel K.; Baker, Matthew E.; Miller, Andrew J.; Jarnagin, S. Taylor; Hogan, Dianna M.</p> <p>2014-01-01</p> <p>Urban development practices redistribute surface materials through filling, grading, and terracing, causing drastic changes to the geomorphic organization of the landscape. Many studies document the hydrologic, biologic, or geomorphic consequences of urbanization using space-for-time comparisons of disparate urban and rural landscapes. However, no previous studies have documented geomorphic changes from development using multiple dates of high-resolution topographic data at the watershed scale. This study utilized a time series of five sequential light detection and ranging (Li<span class="hlt">DAR</span>) derived digital elevation models (DEMs) to track watershed geomorphic changes within two watersheds throughout development (2002–2008) and across multiple spatial scales (0.01–1 km2). Development-induced changes were compared against an undeveloped forested watershed during the same time period. Changes in elevations, slopes, hypsometry, and surface flow pathways were tracked throughout the development process to assess watershed geomorphic alterations. Results suggest that development produced an increase in sharp topographic breaks between relatively flat surfaces and steep slopes, replacing smoothly varying hillslopes and leading to greater variation in slopes. Examinations of flowpath distributions highlight systematic modifications that favor rapid convergence in unchanneled upland areas. Evidence of channel additions in the form of engineered surface conduits is apparent in comparisons of pre- and post-development stream maps. These results suggest that topographic modification, in addition to impervious surfaces, contributes to altered hydrologic dynamics observed in urban systems. This work highlights important considerations for the use of repeat Li<span class="hlt">DAR</span> flights in analyzing watershed change through time. Novel methods introduced here may allow improved understanding and targeted mitigation of the processes driving geomorphic changes during development and help guide future</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014AGUFM.B53C0209H','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014AGUFM.B53C0209H"><span>Using Li<span class="hlt">DAR</span>, RADAR, and Optical data to improve a NFMS in Kalimantan, Indonesia</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Hagen, S. C.; Saatchi, S. S.; Braswell, B. H., Jr.; Palace, M. W.; Salas, W.; Walker, S.; Hoekman, D.; Ipsan, C.; Brown, S.; Sullivan, F.</p> <p>2014-12-01</p> <p>Around the world, governments are establishing national forest monitoring systems (NFMS) that use a combination of remote sensing and ground-based forest carbon inventory approaches to estimate anthropogenic forest-related greenhouse gas emissions and removals. The NFMS forms the link between historical assessments and current/future assessments of forests, enabling consistency in the data and information to support the implementation of REDD+ activities. The creation of a reliable, transparent, and comprehensive NFMS is currently limited by a dearth of relevant data that are accurate, low-cost, and spatially resolved at subnational scales. With funding from a 3-year NASA Carbon Monitoring System project beginning in September 2013, we are developing, evaluating, and validating several critical components of an NFMS in Kalimantan, Indonesia, focusing on the use of Li<span class="hlt">DAR</span> and radar imagery for improved carbon stock and forest degradation information. Here, we present results from an initial analysis of a spatially extensive set of Li<span class="hlt">DAR</span> data collected across the Indonesian provinces on the island of Borneo together with RADAR and optical data. Our objectives are to evaluate sensor and platform tradeoffs systematically against in situ investments, as well as provide detailed tracking and characterization of uncertainty in a cost-benefit framework. Kalimantan is an ideal area to evaluate the use of remote sensing methods because measuring forest carbon stocks and their human caused changes with a high degree of certainty on the ground can be difficult. While our work focuses at the subnational scale for Kalimantan, we are targeting these methods for applicability across broader geographies and for implementation at various scales.</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2014Geomo.219...42J','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2014Geomo.219...42J"><span>Tracking geomorphic signatures of watershed suburbanization with multitemporal Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Jones, Daniel K.; Baker, Matthew E.; Miller, Andrew J.; Jarnagin, S. Taylor; Hogan, Dianna M.</p> <p>2014-08-01</p> <p>Urban development practices redistribute surface materials through filling, grading, and terracing, causing drastic changes to the geomorphic organization of the landscape. Many studies document the hydrologic, biologic, or geomorphic consequences of urbanization using space-for-time comparisons of disparate urban and rural landscapes. However, no previous studies have documented geomorphic changes from development using multiple dates of high-resolution topographic data at the watershed scale. This study utilized a time series of five sequential light detection and ranging (Li<span class="hlt">DAR</span>) derived digital elevation models (DEMs) to track watershed geomorphic changes within two watersheds throughout development (2002-2008) and across multiple spatial scales (0.01-1 km2). Development-induced changes were compared against an undeveloped forested watershed during the same time period. Changes in elevations, slopes, hypsometry, and surface flow pathways were tracked throughout the development process to assess watershed geomorphic alterations. Results suggest that development produced an increase in sharp topographic breaks between relatively flat surfaces and steep slopes, replacing smoothly varying hillslopes and leading to greater variation in slopes. Examinations of flowpath distributions highlight systematic modifications that favor rapid convergence in unchanneled upland areas. Evidence of channel additions in the form of engineered surface conduits is apparent in comparisons of pre- and post-development stream maps. These results suggest that topographic modification, in addition to impervious surfaces, contributes to altered hydrologic dynamics observed in urban systems. This work highlights important considerations for the use of repeat Li<span class="hlt">DAR</span> flights in analyzing watershed change through time. Novel methods introduced here may allow improved understanding and targeted mitigation of the processes driving geomorphic changes during development and help guide future</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4507651','PMC'); return false;" href="https://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=4507651"><span>Assessing and Correcting Topographic Effects on Forest Canopy Height Retrieval Using Airborne Li<span class="hlt">DAR</span> Data</span></a></p> <p><a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?DB=pmc">PubMed Central</a></p> <p>Duan, Zhugeng; Zhao, Dan; Zeng, Yuan; Zhao, Yujin; Wu, Bingfang; Zhu, Jianjun</p> <p>2015-01-01</p> <p>Topography affects forest canopy height retrieval based on airborne Light Detection and Ranging (Li<span class="hlt">DAR</span>) data a lot. This paper proposes a method for correcting deviations caused by topography based on individual tree crown segmentation. The point cloud of an individual tree was extracted according to crown boundaries of isolated individual trees from digital orthophoto maps (DOMs). Normalized canopy height was calculated by subtracting the elevation of centres of gravity from the elevation of point cloud. First, individual tree crown boundaries are obtained by carrying out segmentation on the DOM. Second, point clouds of the individual trees are extracted based on the boundaries. Third, precise DEM is derived from the point cloud which is classified by a multi-scale curvature classification algorithm. Finally, a height weighted correction method is applied to correct the topological effects. The method is applied to Li<span class="hlt">DAR</span> data acquired in South China, and its effectiveness is tested using 41 field survey plots. The results show that the terrain impacts the canopy height of individual trees in that the downslope side of the tree trunk is elevated and the upslope side is depressed. This further affects the extraction of the location and crown of individual trees. A strong correlation was detected between the slope gradient and the proportions of returns with height differences more than 0.3, 0.5 and 0.8 m in the total returns, with coefficient of determination R2 of 0.83, 0.76, and 0.60 (n = 41), respectively. PMID:26016907</p> </li> </ol> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li class="active"><span>23</span></li> <li><a href="#" onclick='return showDiv("page_24");'>24</a></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div><!-- col-sm-12 --> </div><!-- row --> </div><!-- page_23 --> <div id="page_24" class="hiddenDiv"> <div class="row"> <div class="col-sm-12"> <div class="pull-right"> <ul class="pagination"> <li><a href="#" onclick='return showDiv("page_1");'>«</a></li> <li><a href="#" onclick='return showDiv("page_21");'>21</a></li> <li><a href="#" onclick='return showDiv("page_22");'>22</a></li> <li><a href="#" onclick='return showDiv("page_23");'>23</a></li> <li class="active"><span>24</span></li> <li><a href="#" onclick='return showDiv("page_25");'>25</a></li> <li><a href="#" onclick='return showDiv("page_25");'>»</a></li> </ul> </div> </div> </div> <div class="row"> <div class="col-sm-12"> <ol class="result-class" start="461"> <li> <p><a target="_blank" onclick="trackOutboundLink('http://adsabs.harvard.edu/abs/2013ISPAn.II5b..19A','NASAADS'); return false;" href="http://adsabs.harvard.edu/abs/2013ISPAn.II5b..19A"><span>Automatic extraction of insulators from 3D Li<span class="hlt">DAR</span> data of an electrical substation</span></a></p> <p><a target="_blank" href="http://adsabs.harvard.edu/abstract_service.html">NASA Astrophysics Data System (ADS)</a></p> <p>Arastounia, M.; Lichti, D. D.</p> <p>2013-10-01</p> <p>A considerable percentage of power outages are caused by animals that come into contact with conductive elements of electrical substations. These can be prevented by insulating conductive electrical objects, for which a 3D as-built plan of the substation is crucial. This research aims to create such a 3D as-built plan using terrestrial Li<span class="hlt">DAR</span> data while in this paper the aim is to extract insulators, which are key objects in electrical substations. This paper proposes a segmentation method based on a new approach of finding the principle direction of points' distribution. This is done by forming and analysing the distribution matrix whose elements are the range of points in 9 different directions in 3D space. Comparison of the computational performance of our method with PCA (principal component analysis) shows that our approach is 25% faster since it utilizes zero-order moments while PCA computes the first- and second-order moments, which is more time-consuming. A knowledge-based approach has been developed to automatically recognize points on insulators. The method utilizes known insulator properties such as diameter and the number and the spacing of their rings. The results achieved indicate that 24 out of 27 insulators could be recognized while the 3 un-recognized ones were highly occluded. Check point analysis was performed by manually cropping all points on insulators. The results of check point analysis show that the accuracy, precision and recall of insulator recognition are 98%, 86% and 81%, respectively. It is concluded that automatic object extraction from electrical substations using only Li<span class="hlt">DAR</span> data is not only possible but also promising. Moreover, our developed approach to determine the directional distribution of points is computationally more efficient for segmentation of objects in electrical substations compared to PCA. Finally our knowledge-based method is promising to recognize points on electrical objects as it was successfully applied for</p> </li> <li> <p><a target="_blank" onclick="trackOutboundLink('http://pubs.er.usgs.gov/publication/70074095','USGSPUBS'); return false;" href="http://pubs.er.usgs.gov/publication/70074095"><span>Quantifying landscape change in an arctic coastal lowland using repeat airborne Li<span class="hlt">DAR</span></span></a></p> <p><a target="_blank" href="http://pubs.er.usgs.gov/pubs/index.jsp?view=adv">USGS Publications Warehouse</a></p> <p>Jones, Benjamin M.; Stoker, Jason M.; Gibbs, Ann E.; Grosse, Guido; Romanovsky, Vladimir E.; Douglas, Thomas A.; Kinsman, Nichole E.M.; Richmond, Bruce M.</p> <p>2013-01-01</p> <p>Increases in air, permafrost, and sea surface temperature, loss of sea ice, the potential for increased wave energy, and higher river discharge may all be interacting to escalate erosion of arctic coastal lowland landscapes. Here we use airborne light detection and ranging (Li<span class="hlt">DAR</span>) data acquired in 2006 and 2010 to detect landscape change in a 100 km2 study area on the Beaufort Sea coastal plain of northern