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1

Radiometric Dating  

NSDL National Science Digital Library

The first website (1), created by Pamela J. W. Gore at Georgia Perimeter College, provides a concise explanation of the geologic principles of radiometric dating. Students can learn about the fundamentals of half lives, isotopes, and dating minerals. Secondly, the Museum Victoria offers a useful overview of radioactive decay of Potassium-40 and Carbon-14 (2). The website discusses the benefits of isotopes for the research interests of geologists and physicists. Next, Dr. Ben Waggoner at the University of Central Arkansas provides an online educational slide show discussing the assumptions, objections, and accuracy of radiometric dating (3). With an abundance of figures and images, visitors can learn about dateable materials, decay principles, and more. The fourth website, developed by Professor Stephen A. Nelson at Tulane University, provides a detailed mathematical explanation of the principles of radiometric dating (4). Users can view the data utilized for the corrections and can access the on-line form of CALIB, which converts radiocarbon ages to calendar years. The sixth website describes the Scottish Universities Research and Reactor Centre's work utilizing luminescence and radiocarbon dating (6). Through this expansive website, visitors can learn about the centre's many research projects including radioactive contamination, isotope geology, and environmental gamma spectrometry. Next, the North Carolina State University provides a fun, educational activity about radioactive isotope decay (7). Students can learn about the half lives of elements with the use of only candy, bags, and graph paper. Lastly, the University of North Carolina - Chapel Hill chemistry department discusses five different types of radioactive decay (8). After examining the numerous equations, students can test their dating skills by solving the practice problems.

2

Tulane University: Radiometric Dating  

NSDL National Science Digital Library

The fourth website, developed by Professor Stephen A. Nelson at Tulane University, provides a detailed mathematical explanation of the principles of radiometric dating. The site is divided into sections which include: Principles of Radiometric Dating; The Rb/Sr System; The U, Th, Pb System; and The Age of the Earth. Other dating methods are covered briefly as well, such as potassium argon (K-Ar) dating and carbon-14. Professor Nelson concludes with a description of other users of isotopes.

Nelson, Stephen A.

3

Radiometric Dating Does Work!  

ERIC Educational Resources Information Center

Discusses the accuracy of dating methods and creationist arguments that radiometric dating does not work. Explains the Manson meteorite impact and the Pierre shale, the ages of meteorites, the K-T tektites, and dating the Mount Vesuvius eruption. (Author/YDS)

Dalrymple, G. Brent

2000-01-01

4

Radiometric Dating in Geology.  

ERIC Educational Resources Information Center

Described are several aspects and methods of quantitatively measuring geologic time using a constant-rate natural process of radioactive decay. Topics include half lives and decay constants, radiogenic growth, potassium-argon dating, rubidium-strontium dating, and the role of geochronology in support of geological exploration. (DS)

Pankhurst, R. J.

1980-01-01

5

Museum Victoria: Radiometric Dating  

NSDL National Science Digital Library

The Museum Victoria offers a useful overview of radioactive decay of Potassium-40 and Carbon-14. The website discusses the benefits of isotopes for the research interests of geologists and physicists. There is also information about the dating capabilities of uranium, thorium, and ribidium.

6

Radiometric dating/techniques The International Encyclopedia of Geography: People, the Earth,  

E-print Network

;ForReview Only Figure 2. Shaded relief map of southern Minnesota highlighting the Minnesota River core sites dated by Fisher (2003). LeS represents the approximate location of the LeSueur River which

Dorn, Ron

7

Absolute Time Radiometric Dating: the source of the dates on  

E-print Network

Time Scale · Radiometric dates from igneous rocks can be used to indirectly date sedimentary rocks.029x109 · t = 360,178,000 +/- 859,000 years Setting the Radiometric Clock · When an igneous melt, muscovite, and biotite. · Note that whole rock analysis would not give the age of cooling. #12;Setting

Kammer, Thomas

8

Topic in Depth - Radiometric Dating  

NSDL National Science Digital Library

There have been many modern scientific pushes to discover the age of natural and human-made artifacts and this folder describes some of them. Carbon-14 and Potassium Argon dating are just a few covered here in lesson plans, lectures, and overviews.

9

Selected applications of microwave radiometric techniques  

E-print Network

SELECTED APPLICATIONS OF MICROWAVE RADI OMETRI C TECHNIQUES A Thesis by BUFORD RANDALL JEAN Submitted to the Graduate College of Texas A/M University in partial fulfillment of the requirement for the degree of MASTER OF SCIENCE Au gus t 19... 71 Major Subject: Electrical Engineering SELECTED APPLICATIONS OF MICROWAVE RADIOMETRIC TECHNIQUES A Thesis BVFORD RANDALL JEAN Approved as to style and content by: (Ch man of Commit t (Head f Dep rtment) (Memb e r) (Member) (Memb e r...

Jean, Buford Randall

1971-01-01

10

Radiometric 81Kr dating identifies 120,000-year-old ice at Taylor Glacier, Antarctica.  

PubMed

We present successful (81)Kr-Kr radiometric dating of ancient polar ice. Krypton was extracted from the air bubbles in four ?350-kg polar ice samples from Taylor Glacier in the McMurdo Dry Valleys, Antarctica, and dated using Atom Trap Trace Analysis (ATTA). The (81)Kr radiometric ages agree with independent age estimates obtained from stratigraphic dating techniques with a mean absolute age offset of 6 2.5 ka. Our experimental methods and sampling strategy are validated by (i) (85)Kr and (39)Ar analyses that show the samples to be free of modern air contamination and (ii) air content measurements that show the ice did not experience gas loss. We estimate the error in the (81)Kr ages due to past geomagnetic variability to be below 3 ka. We show that ice from the previous interglacial period (Marine Isotope Stage 5e, 130-115 ka before present) can be found in abundance near the surface of Taylor Glacier. Our study paves the way for reliable radiometric dating of ancient ice in blue ice areas and margin sites where large samples are available, greatly enhancing their scientific value as archives of old ice and meteorites. At present, ATTA (81)Kr analysis requires a 40-80-kg ice sample; as sample requirements continue to decrease, (81)Kr dating of ice cores is a future possibility. PMID:24753606

Buizert, Christo; Baggenstos, Daniel; Jiang, Wei; Purtschert, Roland; Petrenko, Vasilii V; Lu, Zheng-Tian; Mller, Peter; Kuhl, Tanner; Lee, James; Severinghaus, Jeffrey P; Brook, Edward J

2014-05-13

11

Radiometric dating of sediments using fission tracks in conodonts  

USGS Publications Warehouse

Conodonts are microfossils which are commonly found in marine rocks of Cambrian to Triassic age. Although their biological affinities are difficult to assess, conodonts are valuable stratigraphical indices for much of their geological range1. Recent work has also established that conodont colour alteration indices (CAI) are useful guides to diagenetic temperatures and hence burial depth2. Fission tracks3 in conodonts allow measurement of uranium concentrations and estimates of 'age' to be made using isotopic methods4. We report here that fission tracks counted in irradiated, thermally unaltered (as indicated by CAI) middle Palaeozoic conodonts indicate typical uranium concentrations of ???1 part in 10 9, with some samples higher. A single specimen of Siphonodella from the Lower Mississippian yielded an age estimate of 380??140 Myr consistent with conventional interpolations. This method may also allow the unroofing of deeply buried sediments to be dated. ?? 1980 Nature Publishing Group.

Sachs, H.M.; Denkinger, M.; Bennett, C.L.; Harris, A.G.

1980-01-01

12

Calibrating Late Quaternary terrestrial climate signals: radiometrically dated pollen evidence from the southern Sierra Nevada, USA  

USGS Publications Warehouse

We constructed a radiometrically calibrated proxy record of Late Pleistocene and Holocene climate change exceeding 230,000 yr duration, using pollen profiles from two cores taken through age-equivalent dry lakes - one core having greater age control (via 230Th alpha mass-spectrometry) and the other having greater stratigraphic completeness. The better dated of these two serial pollen records (Searles Lake) served as a reference section for improving the effective radiometric age control in a nearby and more complete pollen record (Owens Lake) because they: (1) are situated ~90 km apart in the same drainage system (on, and immediately leeward of, the eastern flank of the Sierra Nevada), and (2) preserved strikingly similar pollen profiles and concordant sequences of sedimentological changes. Pollen assemblages from both lakes are well preserved and diverse, and document serial changes in Late Pleistocene and Holocene plant zone distribution and composition in the westernmost Great Basin; they consist of taxa now inhabiting montane forest, woodland, steppe, and desert-scrub environments. The studied core intervals are interpreted here to be the terrestrial equivalent of marine ?18O stages 1 through 9; these pollen profiles now appear to be among the best radiometrically dated Late Pleistocene records of terrestrial climate change known.

Litwin, Ronald J.; Smoot, Joseph P.; Durika, Nancy J.; Smith, George I.

1999-01-01

13

Radiometric Dating  

NSDL National Science Digital Library

This site covers the use of radioactive decay as a clock to determine the age in years of events in earth history. The activity uses coin tosses to describe isotopes, both stable and unstable, and radioactive decay.

G. Kent Colbath

14

Radiometric Calibration Techniques for Signal-of-Opportunity Reflectometers  

NASA Technical Reports Server (NTRS)

Bi-static reflection measurements utilizing global navigation satellite service (GNSS) or other signals of opportunity (SoOp) can be used to sense ocean and terrestrial surface properties. End-to-end calibration of GNSS-R has been performed using well-characterized reflection surface (e.g., water), direct path antenna, and receiver gain characterization. We propose an augmented approach using on-board receiver electronics for radiometric calibration of SoOp reflectometers utilizing direct and reflected signal receiving antennas. The method calibrates receiver and correlator gains and offsets utilizing a reference switch and common noise source. On-board electronic calibration sources, such as reference switches, noise diodes and loop-back circuits, have shown great utility in stabilizing total power and correlation microwave radiometer and scatterometer receiver electronics in L-band spaceborne instruments. Application to SoOp instruments is likely to bring several benefits. For example, application to provide short and long time scale calibration stability of the direct path channel, especially in low signal-to-noise ratio configurations, is directly analogous to the microwave radiometer problem. The direct path channel is analogous to the loopback path in a scatterometer to provide a reference of the transmitted power, although the receiver is independent from the reflected path channel. Thus, a common noise source can be used to measure the gain ratio of the two paths. Using these techniques long-term (days to weeks) calibration stability of spaceborne L-band scatterometer and radiometer has been achieved better than 0.1. Similar long-term stability would likely be needed for a spaceborne reflectometer mission to measure terrestrial properties such as soil moisture.

Piepmeier, Jeffrey R.; Shah, Rashmi; Deshpande, Manohar; Johnson, Carey

2014-01-01

15

Antiquity of man in America indicated by radiometric dates on the Yuha burial site  

USGS Publications Warehouse

MUCH evidence suggests that man was present in the Western Hemisphere before 12,000 yr ago, but the case has remained less than conclusive 1. In some situations, the geological age of the site is reasonably well established but the association or nature of the artefacts is questionable2,3. In other cases, museum specimens of human bones dated by radiocarbon analysis of collagen lack desirable information concerning site location, geology, and stratigraphy even though the accuracy of their absolute ages seems valid4-6. We report here the results of radiometric dates of the Yuha burial site from Imperial County, California, for which the geology and stratigraphy have been documented and reported in detail7. ?? 1976 Nature Publishing Group.

Bischoff, J.L.; Merriam, R.; Childers, W.M.; Protsch, R.

1976-01-01

16

The Relationship between Balancing Reactions and Reaction Lifetimes: A Consideration of the Potassium-Argon Radiometric Method for Dating Minerals  

ERIC Educational Resources Information Center

A detailed examination of a commonly accepted practice in geology offers an example of how to stimulate critical thinking, teaches students how to read reactions, and challenges students to formulate better experiments for determining mineral ages more accurately. A demonstration of a Potassium-Argon radiometric method for dating minerals is

Howard, William A.

2005-01-01

17

14C-AMS at the Leibniz-Labor: radiometric dating and isotope research  

NASA Astrophysics Data System (ADS)

The Leibniz-Labor was founded to provide radiometric dating services using AMS and measured over 15 000 samples and 26 800 targets up to September 2002. Research and development have primarily been directed at improving the efficiency and reliability of AMS measurements, optimising existing sample preparation procedures for AMS and developing new ones. The standard chemical pre-treatment of organic radiocarbon samples produces often two fractions: one from which contaminants have been removed, and one in which they have been enriched. Dating both fractions reveals the degree of sample contamination. This provides a useful indication of the reliability of the sample age obtained and of the environmental conditions where the sample was taken. Upgrades to reduce maintenance include replacing four cryo- by turbo pumps, installing a deionizer loop, which keeps conductivity between 100 and 150 ?S/cm to control corrosion, in the closed cooling water circuit, and developing a new sample wheel, which holds target holders with a groove and spring clip. Long term stability is demonstrated by the results obtained for IAEA reference materials, measured routinely and regularly over the years. Tests made as part of the FIRI project demonstrate that reliable measurements down to <0.1 mg C can be made.

Grootes, Pieter M.; Nadeau, Marie-Jose; Rieck, Anke

2004-08-01

18

Artifact correction and absolute radiometric calibration techniques employed in the Landsat 7 image assessment system  

USGS Publications Warehouse

The Landsat-7 Image Assessment System (IAS), part of the Landsat-7 Ground System, will calibrate and evaluate the radiometric and geometric performance of the Enhanced Thematic Mapper Plus (ETM +) instrument. The IAS incorporates new instrument radiometric artifact correction and absolute radiometric calibration techniques which overcome some limitations to calibration accuracy inherent in historical calibration methods. Knowledge of ETM + instrument characteristics gleaned from analysis of archival Thematic Mapper in-flight data and from ETM + prelaunch tests allow the determination and quantification of the sources of instrument artifacts. This a priori knowledge will be utilized in IAS algorithms designed to minimize the effects of the noise sources before calibration, in both ETM + image and calibration data.

Boncyk, Wayne C.; Markham, Brian L.; Barker, John L.; Helder, Dennis

1996-01-01

19

Dating Techniques in Archaeology and Paleoanthropology.  

ERIC Educational Resources Information Center

Discusses some of the new physical dating methods being used by archaeologists and paleoanthropologists to study the material remains of ancient primates. Describes the quaternary physical dating techniques, advances in radiocarbon dating, and the radiocalcium data method. (TW)

Taylor, R. E.

1987-01-01

20

Dating techniques in archaeology and paleoanthropology  

SciTech Connect

Archaeologists have an increasing array of physical dating methods at their disposal. R.E. Taylor of the University of California discusses available techniques, recent advances in radiocarbon dating, and current developments in radiocalcium dating.

Taylor, R.E.

1987-02-15

21

Determination of serum estradiol levels by radiometric and chemiluminescent techniques.  

PubMed

The ability to precisely measure circulating levels of hormones is a foundation of modern endocrinology. For assisted reproductive technologies such as in vitro fertilization (IVF), accurate determination of circulating levels of estradiol are crucial for patient management, retrieval of fertilizable oocytes, and successful pregnancy outcome. For many years, circulating levels of estradiol were determined by radioimmunoassay. More recently, nonradioactive techniques such as ELISAs or chemiluminescent approaches have replaced traditional radioimmunoassays. In the current chapter, we outline the procedures for analysis of circulating levels of estradiol by both radioimmunoassay and chemiluminescent techniques. PMID:19763495

Bryant, Carole; Moore, John; Curry, Thomas E

2009-01-01

22

GEOL 103 Writing Assignment 4: Radiometric Dating Name _KEY______________ Lab section: Monday or Tuesday (circle one)  

E-print Network

that the basaltic intrusion is younger. 4A). Pebbles of an igneous rock are incorporated within a conglomerate. The pebbles yield a radiometric age of 300 million years. What can you say about age of the conglomerate based on this data? The conglomerate is younger than the pebbles, so it's younger than 300 million years. 4B

Kirby, Carl S.

23

Radiometric dating of the type-site for Homo heidelbergensis at Mauer, Germany  

PubMed Central

The Mauer mandible, holotype of Homo heidelbergensis, was found in 1907 in fluvial sands deposited by the Neckar River 10 km southeast of Heidelberg, Germany. The fossil is an important key to understanding early human occupation of Europe north of the Alps. Given the associated mammal fauna and the geological context, the find layer has been placed in the early Middle Pleistocene, but confirmatory chronometric evidence has hitherto been missing. Here we show that two independent techniques, the combined electron spin resonance/U-series method used with mammal teeth and infrared radiofluorescence applied to sand grains, date the type-site of Homo heidelbergensis at Mauer to 609 40 ka. This result demonstrates that the mandible is the oldest hominin fossil reported to date from central and northern Europe and raises questions concerning the phyletic relationship of Homo heidelbergensis to more ancient populations documented from southern Europe and in Africa. We address the paleoanthropological significance of the Mauer jaw in light of this dating evidence. PMID:21041630

Wagner, Gnther A.; Krbetschek, Matthias; Degering, Detlev; Bahain, Jean-Jacques; Shao, Qingfeng; Falgures, Christophe; Voinchet, Pierre; Dolo, Jean-Michel; Garcia, Tristan; Rightmire, G. Philip

2010-01-01

24

Radiometric dating of the type-site for Homo heidelbergensis at Mauer, Germany.  

PubMed

The Mauer mandible, holotype of Homo heidelbergensis, was found in 1907 in fluvial sands deposited by the Neckar River 10 km southeast of Heidelberg, Germany. The fossil is an important key to understanding early human occupation of Europe north of the Alps. Given the associated mammal fauna and the geological context, the find layer has been placed in the early Middle Pleistocene, but confirmatory chronometric evidence has hitherto been missing. Here we show that two independent techniques, the combined electron spin resonance/U-series method used with mammal teeth and infrared radiofluorescence applied to sand grains, date the type-site of Homo heidelbergensis at Mauer to 609 40 ka. This result demonstrates that the mandible is the oldest hominin fossil reported to date from central and northern Europe and raises questions concerning the phyletic relationship of Homo heidelbergensis to more ancient populations documented from southern Europe and in Africa. We address the paleoanthropological significance of the Mauer jaw in light of this dating evidence. PMID:21041630

Wagner, Gnther A; Krbetschek, Matthias; Degering, Detlev; Bahain, Jean-Jacques; Shao, Qingfeng; Falgures, Christophe; Voinchet, Pierre; Dolo, Jean-Michel; Garcia, Tristan; Rightmire, G Philip

2010-11-16

25

Potential drug targets for Mycobacterium avium defined by radiometric drug-inhibitor combination techniques.  

PubMed Central

Previously established radiometric techniques were used to assess the effectiveness of combined antimicrobial drug-inhibitory drug (drug-inhibitor) treatment on two clinical isolates of the Mycobacterium avium complex representing three colony variants: smooth opaque (dome) (SmO), smooth transparent (SmT), and rough (Rg). All variants were identified as members of the M. avium complex; however, only the SmT colony type of strain 373 possessed characteristic serovar-specific glycopeptidolipid (GPL) antigens. MICs, determined radiometrically, of drugs with the potential to inhibit the biosynthesis of GPL antigens or other cell envelope constituents were similar for all strains. These drugs included cerulenin, N-carbamyl-DL-phenylalanine, N-carbamyl-L-isoleucine, trans-cinnamic acid, ethambutol, 1-fluoro-1-deoxy-beta-D-glucose, 2-deoxy-D-glucose, and m-fluoro-phenylalanine. The MICs of the antimicrobial drugs amikacin, sparfloxacin, and clarithromycin varied, but overall the MICs for the SmO variant were the lowest. Radiometric assessment of drug-inhibitor combinations by using established x/y determinations revealed enhanced activity when either ethambutol or cerulenin were used in combination with all antimicrobial agents for all variants except the Rg variant of strain 424, for which ethambutol was not effective. Enhanced activity with amino acid analogs was observed with the Rg colony variants of strains 373 and 424. Two potential sites for drug targeting were identified: fatty acid synthesis, for all strains assayed, and peptide biosynthesis, particularly for Rg colony variants that possess previously identified phenylalanine-containing lipopeptides as potential targets for future drug development. Images PMID:7840559

Rastogi, N; Goh, K S; Wright, E L; Barrow, W W

1994-01-01

26

Ar-Ar dating techniques for terrestrial meteorite impacts  

NASA Astrophysics Data System (ADS)

The ages of the largest (>100 km) known impacts on Earth are now well characterised. However the ages of many intermediate sized craters (20-100 km) are still poorly known, often the only constraints are stratigraphic - the difference between the target rock age and the age of crater filling sediments. The largest impacts result in significant melt bodies which cool to form igneous rocks and can be dated using conventional radiometric techniques. Smaller impacts give rise to thin bands of melted rock or melt clasts intimately mixed with country rock clasts in breccia deposits, and present much more of a challenge to dating. The Ar-Ar dating technique can address a wide variety of complex and heterogeneous samples associated with meteorite impacts and obtain reasonable ages. Ar-Ar results will be presented from a series of terrestrial meteorite impact craters including Boltysh (65.170.64 Ma, Strangways (64642 Ma), and St Martin (22032 Ma) and a Late Triassic spherule bed, possibly representing distal deposits from Manicouagan (2141 Ma) crater. Samples from the Boltysh and Strangways craters demonstrate the importance of rapid cooling upon the retention of old ages in glassy impact rocks. A Late Triassic spherule bed in SW England is cemented by both carbonate and K-feldspar cements allowing Ar-Ar dating of fine grained cement to place a mimimum age upon the age of the associated impact. An age of 214.72.5 Ma places the deposit with errors of the age of the Manicouagan impact, raising the possibility that it may represent a distal deposit (the deposit lay around 2000 km away from the site of the Manicouagan crater during the Late Triassic). Finally the limits of the technique will be demonstrated using an attempt to date melt rocks from the St Martin Crater in Canada.

Kelley, S. P.

2003-04-01

27

Radiometric Dating of Ignimbrite from Inner Mongolia Provides no Indication of a Post-Middle Jurassic Age for the Daohugou Beds  

Microsoft Academic Search

Lacustrine deposits exposed at Daohugou, Inner Mongolia, China, have yielded superbly preserved vertebrate fossils. The fossil beds were first misinterpreted as of Early Cretaceous age, based on alleged occurrences of key fossils of the Jehol Biota. Compelling evidence revealed by more rigorous research involving regional biostratigraphy, radiometric dating, and paleontology supports the Middle Jurassic age of the fossil beds. Despite

GAO Ke-Qin; REN Dong

28

Teaching radioactive decay & radiometric dating: an analog activity based on fluid dynamics  

NSDL National Science Digital Library

A fluid flowing from an upper beaker into a lower beaker (shampoo in this case) behaves mathematically identically to radioactive decay, mimicking the exponential decay process, dependent on the amount of fluid in the upper beaker (representing the amount of parent isotopes) and the size of the hole in the beaker (representing the decay constant). Students measure the fluid depth with time for several "runs" with varied conditions, then graph their results, create decay equations, manipulate these equations and use them to "date" another experiment. They then apply their new understanding to make predictions regarding complications involved in the decay process and its use in dating (such as daughter loss). Developed by Lily Claiborne and Calvin Miller.

Erika Grundstrom

29

Radiometric dating of quaternary deposits and the hominid mandible of lake banyolas, Spain  

USGS Publications Warehouse

We report results of U-series analyses of the travertine matrix surrounding the Banyolas mandible that indicate an age of 45??4 ka bp. The mandible, an archaic hominid fossil generally deemed of mid-Pleistocene age, was recovered from a travertine matrix in 1887. Similar analyses on 21 travertine samples from quarries near the discovery site yield coherent U-series dates in correct stratigraphic order, ranging from 44 ka bp to 117 ka bp. Isotopic composition of these samples and the mandible matrix show no evidence of open system behaviour. Coherent isotopic results from adjacent quarries support the validity of the date on the mandible travertine, and we conclude the mandible is much younger than previously believed. ?? 1991.

Julia, R.; Bischoff, J.L.

1991-01-01

30

NASA IKONOS Radiometric Characterization  

NASA Technical Reports Server (NTRS)

The objective of this program: Perform radiometric vicarious calibrations of IKQNOS imagery and compare with Space Imaging calibration coefficients The approach taken: utilize multiple well-characterized sites which are widely used by the NASA science community for radiometric characterization of airborne and spaceborne sensors; and to Perform independent characterizations with independent teams. Each team has slightly different measurement techniques and data processing methods.

Pagnutti, Mary; Frisbee, Troy; Zanoni, Vicki; Blonski, Slawek; Daehler, Erik; Grant, Brennan; Holekamp, Kara; Ryan, Robert; Sellers, Richard; Smith, Charles

2002-01-01

31

Radiometric correction procedure study  

NASA Technical Reports Server (NTRS)

A comparison of MSS radiometric processing techniques identified as a preferred radiometric processing technique a procedure which equalizes the mean and standard deviation of detector-specific histograms of uncalibrated scene data. Evaluation of MSS calibration data demonstrated that the relationship between detector responses is essentially linear over the range of intensities typically observed in MSS data, and that the calibration wedge data possess a high degree of temporal stability. An analysis of the preferred radiometric processing technique showed that it could be incorporated into the MDP-MSS system without a major redesign of the system, and with minimal impact on system throughput.

Colby, C.; Sands, R.; Murphrey, S.

1978-01-01

32

Initial Radiometric Calibration of the AWiFS using Vicarious Calibration Techniques  

NASA Technical Reports Server (NTRS)

NASA SSC maintains four ASD FieldSpec FR spectroradiometers: 1) Laboratory transfer radiometers; 2) Ground surface reflectance for V&V field collection activities. Radiometric Calibration consists of a NIST-calibrated integrating sphere which serves as a source with known spectral radiance. Spectral Calibration consists of a laser and pen lamp illumination of integrating sphere. Environmental Testing includes temperature stability tests performed in environmental chamber.

Pagnutti, Mary; Thome, Kurtis; Aaron, David; Leigh, Larry

2006-01-01

33

Ground-based radiometric calibration of the Landsat 8 Operational Land Imager (OLI) using in situ techniques  

NASA Astrophysics Data System (ADS)

Landsat 8 was successfully launched from Vandenberg Air Force Base in California on 11 February 2013, and was placed into the orbit previously occupied by Landsat 5. Landsat 8 is the latest platform in the 40-year history of the Landsat series of satellites, and it contains two instruments that operate in the solar-reflective and the thermal infrared regimes. The Operational Land Imager (OLI) is a pushbroom sensor that contains eight multispectral bands ranging from 400-2300 nm, and one panchromatic band. The spatial resolution of the multispectral bands is 30 m, which is similar to previous Landsat sensors, and the panchromatic band has a 15-m spatial resolution, which is also similar to previous Landsat sensors. The 12-bit radiometric resolution of OLI improves upon the 8-bit resolution of the Enhanced Thematic Mapper Plus (ETM+) onboard Landsat 7. An important requirement for the Landsat program is the long-term radiometric continuity of its sensors. Ground-based vicarious techniques have been used for over 20 years to determine the absolute radiometric calibration of sensors that encompass a wide variety of spectral and spatial characteristics. This work presents the early radiometric calibration results of Landsat 8 OLI that were obtained using the traditional reflectance-based approach. University of Arizona personnel used five sites in Arizona, California, and Nevada to collect ground-based data. In addition, a unique set of in situ data were collected in March 2013, when Landsat 7 and Landsat 8 were observing the same site within minutes of each other. The tandem overfly schedule occurred while Landsat 8 was shifting to the WRS-2 orbital grid, and lasted only a few days. The ground-based data also include results obtained using the University of Arizona's Radiometric Calibration Test Site (RadCaTS), which is an automated suite of instruments located at Railroad Valley, Nevada. The results presented in this work include a comparison to the L1T at-sensor spectral radiance and the top-of-atmosphere reflectance, both of which are standard products available from the US Geological Survey.

Czapla-Myers, J.

2013-12-01

34

Radiometric Calibration of the AWiFS Using Vicarious Calibration Techniques  

NASA Technical Reports Server (NTRS)

A radiometric calibration assessment of the AWiFS (Advanced Wide Field Sensor) on the Indian Remote Sensing Resourcesat-1 satellite was performed by the NASA Applied Research & Technology Project Office (formerly the Applied Sciences Directorate) at the John C. Stennis Space Center. A reflectance-based vicarious calibration approach, requiring ground-based measurements coincident with satellite acquisitions and radiative transfer calculations, was used to estimate at-sensor radiance. The AWiFS is a 4-band, multispectral, moderate-resolution (60 m) imaging sensor that operates in the visible through short-wave infrared spectrum and is currently being considered as a Landsat-like alternative. Several study sites near the Stennis Space Center that attempted to span the dynamic range of the sensor were employed. Satellite at-sensor radiance values were compared to those estimated to determine the sensor's radiometric accuracy. The results of this evaluation provide the user community with an independent assessment of the radiometric accuracy of AWiFS image products, which are commercially available through GeoEye. These results are an extension of an independent assessment made by the University of Arizona Remote Sensing Group, the South Dakota State University Satellite Calibration Group & Image Processing Lab, and the NASA Applied Sciences Directorate at the John C. Stennis Space Center the previous year.

Pagnutti, Mary; Holekamp, Kara

2007-01-01

35

A comparison of radiometric correction techniques in the evaluation of the relationship between LST and NDVI in Landsat imagery.  

PubMed

Atmospheric corrections for multi-temporal optical satellite images are necessary, especially in change detection analyses, such as normalized difference vegetation index (NDVI) rationing. Abrupt change detection analysis using remote-sensing techniques requires radiometric congruity and atmospheric correction to monitor terrestrial surfaces over time. Two atmospheric correction methods were used for this study: relative radiometric normalization and the simplified method for atmospheric correction (SMAC) in the solar spectrum. A multi-temporal data set consisting of two sets of Landsat images from the period between 1991 and 2002 of Penang Island, Malaysia, was used to compare NDVI maps, which were generated using the proposed atmospheric correction methods. Land surface temperature (LST) was retrieved using ATCOR3_T in PCI Geomatica 10.1 image processing software. Linear regression analysis was utilized to analyze the relationship between NDVI and LST. This study reveals that both of the proposed atmospheric correction methods yielded high accuracy through examination of the linear correlation coefficients. To check for the accuracy of the equation obtained through linear regression analysis for every single satellite image, 20 points were randomly chosen. The results showed that the SMAC method yielded a constant value (in terms of error) to predict the NDVI value from linear regression analysis-derived equation. The errors (average) from both proposed atmospheric correction methods were less than 10%. PMID:21755424

Tan, Kok Chooi; Lim, Hwee San; Matjafri, Mohd Zubir; Abdullah, Khiruddin

2012-06-01

36

The Dating Game: Radioactive Half-Life and Dating Techniques  

NSDL National Science Digital Library

In this lab activity using M&M candy, students will explore the concepts of radioactive decay and dating. Students generate a radioactive decay table to simplify the math, use their data to plot a decay graph, develop the concept of half-life, and then use the graph to find the age of a mummified seal in Wright Valley, Antarctica. In a follow-up exercise, students will solve a mysterious Arctic murder.

Hillary Tulley

37

Investigation of radiometric combustion monitoring techniques for coal-fired stoker boilers. Final report  

SciTech Connect

Fuel-ash bed disturbances are costly problems often encountered in operating coal-fired, mechanical-stoker boilers in military heat plants. In traveling grate, mechanical-stoker boilers, all or most of the coal burns on the traveling grate, so proper control of combustion grate fuel-ash bed thickness is critical for cost-effective, high-availability operation. In these plants, operators must adjust combustion equipment as the coal enters the combustion chamber. Because fuel bed problems take several minutes to develop, operators may not discover problems before they go past the point of easy correction. This study investigated the use of a remote sensing system to monitor conditions in the fuel bed. It is concluded that the technology to measure mechanical stoker boiler fuel-ash bed temperatures by radiation techniques is sufficiently developed to produce a fuel-ash bed temperatures-monitoring system. Such a system may significantly reduce fuel-ash bed disturbances by detecting bed temperature changes that indicate the onset of bed entrainment and clinker formation. Continuous, reliable measurement of fuel-ash bed temperatures could also detect smoking and conditions leading to smoking, and could be used to improve boiler efficiency through improved control of excess air. Central heating plants, Radiometry, Coal-fired mechanical stoker boiler, Combustion monitoring techniques.

Karlson, F.V.; Parsons, T.H.; Savoie, M.J.; Scholten, W.B.

1993-09-01

38

Infrared radiometric technique for rapid quantitative evaluation of heat flux distribution over large areas  

NASA Technical Reports Server (NTRS)

This paper describes a novel approach for rapid, quantitative measurement of spatially distributed heat flux incident on a plane. The technique utilizes the spatial temperature distribution on an opaque thin film at the location of interest, as measured by an imaging infrared radiometer. Knowledge of film radiative properties, plus quantitative estimates of convection cooling permit the steady state energy balance at any location on the film sheet to be solved for the incident heat flux. Absolute accuracies on the order of 10-15 percent have been obtained in tests performed in air. The method is particularly useful for evaluation of spatial heat flux uniformity from distributed heat sources over large areas. It has recently been used in several applications at the Jet Propulsion Laboratory, including flux uniformity measurements from large distributed quartz lamp arrays used during thermal vacuum testing of several spacecraft components, and flux mapping of a low power NdYg laser beam.

Glazer, Stuart; Siebes, Georg

1989-01-01

39

Dating human skeletal remains using a radiometric method: biogenic versus diagenetic 90Sr and 210Pb in vertebrae.  

PubMed

In forensic science, there is a strong interest in determining the post-mortem interval (PMI) of human skeletal remains up to 50 years after death. Currently, there are no reliable methods to resolve PMI, the determination of which relies almost exclusively on the experience of the investigating expert. Here we measured (90)Sr and (210)Pb ((210)Po) incorporated into bones through a biogenic process as indicators of the time elapsed since death. We hypothesised that the activity of radionuclides incorporated into trabecular bone will more accurately match the activity in the environment and the food chain at the time of death than the activity in cortical bone because of a higher remodelling rate. We found that determining (90)Sr can yield reliable PMI estimates as long as a calibration curve exists for (90)Sr covering the studied area and the last 50 years. We also found that adding the activity of (210)Po, a proxy for naturally occurring (210)Pb incorporated through ingestion, to the (90)Sr dating increases the reliability of the PMI value. Our results also show that trabecular bone is subject to both (90)Sr and (210)Po diagenesis. Accordingly, we used a solubility profile method to determine the biogenic radionuclide only, and we are proposing a new method of bone decontamination to be used prior to (90)Sr and (210)Pb dating. PMID:22497702

Schrag, Bettina; Uldin, Tanya; Mangin, Patrice; Froidevaux, Pascal

2012-07-10

40

(25143) Itokawa: The power of radiometric techniques for the interpretation of remote thermal observations in the light of the Hayabusa rendezvous results*  

NASA Astrophysics Data System (ADS)

The near-Earth asteroid (25143) Itokawa was characterized in great detail by the Japanese Hayabusa mission. We revisited the available thermal observations in the light of the true asteroid properties with the goal of evaluating the possibilities and limitations of thermal model techniques. In total, we used 25 published ground-based mid-infrared photometric observations and five so far unpublished measurements from the Japanese infrared astronomical satellite AKARI in combination with improved H-G values (absolute magnitude and slope parameter). Our thermophysical model (TPM) approach allowed us to determine correctly the sense of rotation, to estimate the thermal inertia and to derive robust effective size and albedo values by only using a simple spherical shape model. A more complex shape model, derived from light-curve inversion techniques, improved the quality of the predictions considerably and made the interpretation of the thermal light curve possible. The radiometrically derived effective diameter value agrees within 2% with the true Itokawa size value. The combination of our TPM and the final (25143) Itokawa in-situ shape model was then used as a benchmark for deriving and testing radiometric solutions. The consolidated value for the surface-averaged thermal inertia is ? = 700 200 J m-2 s-0.5 K-1. We found that even the high-resolution shape models still require additional small-scale roughness in order to explain the disk-integrated infrared measurements. Our description of the thermal effects as a function of wavelengths, phase angle, and rotational phase facilitates the planning of crucial thermal observations for sophisticated characterization of small bodies, including other potentially hazardous asteroids. Our analysis shows the power of radiometric techniques to derive the size, albedo, thermal inertia, and also spin-axis orientation from small sets of measurements at thermal infrared wavelengths.

Mller, Thomas G.; Hasegawa, Sunao; Usui, Fumihiko

2014-06-01

41

Simplified Vicarious Radiometric Calibration  

NASA Technical Reports Server (NTRS)

A measurement-based radiance estimation approach for vicarious radiometric calibration of spaceborne multispectral remote sensing systems has been developed. This simplified process eliminates the use of radiative transfer codes and reduces the number of atmospheric assumptions required to perform sensor calibrations. Like prior approaches, the simplified method involves the collection of ground truth data coincident with the overpass of the remote sensing system being calibrated, but this approach differs from the prior techniques in both the nature of the data collected and the manner in which the data are processed. In traditional vicarious radiometric calibration, ground truth data are gathered using ground-viewing spectroradiometers and one or more sun photometer( s), among other instruments, located at a ground target area. The measured data from the ground-based instruments are used in radiative transfer models to estimate the top-of-atmosphere (TOA) target radiances at the time of satellite overpass. These TOA radiances are compared with the satellite sensor readings to radiometrically calibrate the sensor. Traditional vicarious radiometric calibration methods require that an atmospheric model be defined such that the ground-based observations of solar transmission and diffuse-to-global ratios are in close agreement with the radiative transfer code estimation of these parameters. This process is labor-intensive and complex, and can be prone to errors. The errors can be compounded because of approximations in the model and inaccurate assumptions about the radiative coupling between the atmosphere and the terrain. The errors can increase the uncertainty of the TOA radiance estimates used to perform the radiometric calibration. In comparison, the simplified approach does not use atmospheric radiative transfer models and involves fewer assumptions concerning the radiative transfer properties of the atmosphere. This new technique uses two neighboring uniform ground target areas having different reflectance values. The target areas can be natural or artificial and must be large enough to minimize adjacent-pixel contamination effects. The radiative coupling between the atmosphere and the terrain needs to be approximately the same for the two targets. This condition can be met for relatively uniform backgrounds when the distance between the targets is within a few hundred meters. For each target area, the radiance leaving the ground in the direction of the satellite is measured with a radiometrically calibrated spectroradiometer. Using the radiance measurements from the two targets, atmospheric adjacency and atmospheric scattering effects can be subtracted, thereby eliminating many assumptions about the atmosphere and the radiative interaction between the atmosphere and the terrain. In addition, the radiometrically calibrated spectroradiometer can be used with a known reflectance target to estimate atmospheric transmission and diffuse- to-global ratios without the need for ancillary sun photometers. Several comparisons between the simplified method and traditional techniques were found to agree within a few percent. Hence, the simplified method reduces the overall complexity of performing vicarious calibrations and can serve as a method for validating traditional radiative transfer models

Stanley, Thomas; Ryan, Robert; Holekamp, Kara; Pagnutti, Mary

2010-01-01

42

TES radiometric assessment  

NASA Technical Reports Server (NTRS)

TES is an infrared Fourier transform spectrometer on board the EOS-Aura spacecraft launched July 15, 2004. Improvements to the radiometric calibration and consequent assessment of radiometric accuracy have been on-going since launch.

Worden, H.; Sarkissian, E.; Bowman, K.; Fisher, B.; Rider, D.; Aumann, H. H.; Apolinski, M.; Debaca, R. C.; Gluck, S.; Madatyan, M.; McDuffie, J.; Tremblay, D.; Shephard, M.; Cady-Pereira, K.; Tobin, D.; Revercomb, H.

2005-01-01

43

New twist on dating: radiocarbon dating techniques applied to air pollution studies  

SciTech Connect

This paper deals with the problem of urban air pollution and to what extent it is caused by the burning of fossil fuels at factories or in cars, and to what extent it is due to the breathing processes of trees or the burning of natural fuels like wood. With the use of radiocarbon dating techniques the distinction between the pollutants can be made. The article describes the design of the gas proportional counter used to measure the extremely small samples of carbon in polluted air. (KRM)

Porter, G.

1981-05-01

44

Assessing soil erosion and control factors by radiometric technique in the source region of the Yellow River, Tibetan Plateau  

NASA Astrophysics Data System (ADS)

Measurements of 137Cs concentration in soils were made in a representative catchment to quantify erosion rates and identify the main factors involved in the erosion in the source region of the Yellow River in the Tibetan Plateau. In order to estimate erosion rates in terms of the main factors affecting soil loss, samples were collected taking into account the slope and vegetation cover along six selected transects within the Dari County catchment. The reference inventory for the area was established at a stable, well-preserved, site of small thickness (value of 2324 Bqm- 2). All the sampling sites had been eroded and 137Cs inventories varied widely in the topsoil (14.87-25.56 Bqkg- 1). The effective soil loss values were also highly variable (11.03-28.35 tkm- 1yr- 1) in line with the vegetation cover change. The radiometric approach was useful in quantifying soil erosion rates and examining patterns of soil movement.

Wang, Yibo; Niu, Fujun; Wu, Qingbai; Gao, Zeyong

2014-05-01

45

New Sakmarian ages for the Rio Bonito formation (Paran Basin, southern Brazil) based on LA-ICP-MS U-Pb radiometric dating of zircons crystals  

NASA Astrophysics Data System (ADS)

Two ash fall beds (tonstein) sampled from the post-glacial Permian deposits of the Paran Basin have provided new U-Pb radiometric age constraints for this stratigraphic interval. The zircon grains were recovered from tonstein layers interbedded with fine-grained and carbonaceous lithologies in the middle portion of the Rio Bonito Formation. In both samples, the dominant population is interpreted as generated by explosive volcanism, as having formed immediately before the eruption. Based on 238U/206Pb, the selected zircon grains from the dominant population have weighted mean ages of 290.62.8Ma and 281.73.2Ma, corresponding to the Sakmarian and Kungurian ages in the Cisuralian epoch, respectively. These ages constrain the time of the deposition of the tonstein horizons and have important stratigraphic implications for the Late Paleozoic evolution of both the Paran Basin and the southwestern region of Gondwana. The results presented here and the radiometric data already published suggest that deposition of the post-glacial coal-bearing deposits of the Rio Bonito Formation was probably initiated before the Early Permian. Thus, we infer that the climate had already ameliorated by this period in order to allow for the formation and accumulation of peat in this region of Gondwana.

Cagliari, Joice; Lavina, Ernesto Luiz Correa; Philipp, Ruy Paulo; Tognoli, Francisco Manoel Wohnrath; Basei, Miguel Angelo Stipp; Faccini, Ubiratan Ferrucio

2014-12-01

46

Ferricretes in New Caledonia: synthesis of age constraints by paleomagnetic and radiometric techniques. Implication on the morphogenesis of `Grande Terre'  

E-print Network

techniques. Implication on the morphogenesis of `Grande Terre' Caroline RICORDEL-PROGNON 1 , Brice SEVIN 2 being recorded in between. These data allowto constrain the post-obduction morphogenesis of New

Paris-Sud XI, Universit de

47

Paleomagnetic Secular Variation (PSV), 137Cs, and Hg dating techniques  

E-print Network

Portland State University Department of Geology #12;Hg-Mercury contamination dating http://sierranevadaairstreams.org/destinations/washoe/washoelake/index.html · First use: Roman era · Developed industrially in 1554 to remove gold and silver from ore bearing bodies

Fountain, Andrew G.

48

U-series dating of impure carbonates: An isochron technique using total-sample dissolution  

Microsoft Academic Search

U-series dating is a well-established technique for age determination of Late Quaternary carbonates. Materials of sufficient purity for nominal dating, however, are not as common as materials with mechanically inseparable aluminosilicate detritus. Detritus contaminates the sample with extraneous Th. The authors propose that correction for contamination is best accomplished with the isochron technique using total sample dissolution (TSD). Experiments were

J. L. Bischoff; J. A. Fitzpatrick

1991-01-01

49

Radiometric instrumentation and measurements guide for photovoltaic performance testing  

SciTech Connect

The Photovoltaic Module and Systems Performance and Engineering Project at the National Renewable Energy Laboratory performs indoor and outdoor standardization, testing, and monitoring of the performance of a wide range of photovoltaic (PV) energy conversion devices and systems. The PV Radiometric Measurements and Evaluation Team (PVSRME) within that project is responsible for measurement and characterization of natural and artificial optical radiation which stimulates the PV effect. The PV manufacturing and research and development community often approaches project members for technical information and guidance. A great area of interest is radiometric instrumentation, measurement techniques, and data analysis applied to understanding and improving PV cell, module, and system performance. At the Photovoltaic Radiometric Measurements Workshop conducted by the PVSRME team in July 1995, the need to communicate knowledge of solar and optical radiometric measurements and instrumentation, gained as a result of NREL`s long-term experiences, was identified as an activity that would promote improved measurement processes and measurement quality in the PV research and manufacturing community. The purpose of this document is to address the practical and engineering need to understand optical and solar radiometric instrument performance, selection, calibration, installation, and maintenance applicable to indoor and outdoor radiometric measurements for PV calibration, performance, and testing applications. An introductory section addresses radiometric concepts and definitions. Next, concepts essential to spectral radiometric measurements are discussed. Broadband radiometric instrumentation and measurement concepts are then discussed. Each type of measurement serves as an important component of the PV cell, module, and system performance measurement and characterization process.

Myers, D.

1997-04-01

50

Unravelling the chronology and evolution of the Pleistocene-Holocene basin in the hanging-wall of the 2009 L'Aquila earthquake fault by multidisciplinary approach (paleomagnetism, palaeontology, geochemistry and radiometric dating) on a 150 m deep hole  

NASA Astrophysics Data System (ADS)

The Mw=6.1 L'Aquila earthquake struck the central Apennines (Italy), on April 6th, 2009. INSAR data showed that the maximum subsidence of ca. 15 cm was located in the continental Aterno Basin, partly controlled by the Paganica extensional fault, yielding the L'Aquila earthquake. Preliminary geological and geophysical surveys have been performed in the depocenter of the Aterno Basin to figure out the underground configuration and determine the best location for a deep hole. The drilling was performed in May-June 2013, recovering 151 m of continental Holocene and Pleistocene sediments. The upper sandy-silty sequence (41 m), interbedded with gravels, is interpreted as fluvial-alluvial origin. The lower clayey-silty sequence, interpreted as lacustrine sediments, continues downward until the bottom (disrupted by 30 m of gravels). The continuous sediment record of the hole is being processed along three stages: i) Description consists of the elaboration of stratigraphical logs, color description and photographic record of the core. The second stage consists of sampling for the different analyses. ii) Continuous samples (U-Channel) were collected from the undisturbed centre of the core for paleomagnetic measurements. Additional samples were collected in the clayey-silty fraction (10 to 25 cm spacing) for calcimetry, geochemical, palynological and ostracoda fauna analysis. Finally, individual levels rich in organic matter and charcoal were sampled for radiometric datings. Iii) The measurements include magnetic susceptibility, paleomagnetic and rock magnetic properties, content of calcium carbonate and 16/18 oxygen ratio, crumble and classification of fossils for pollens and ostracods analyses. Paleomagnetic analyses will hopefully allow us to obtain experimental constraints for dating the Holocene-Pleistocene sediments of the Aterno Basin. The presence of Carbon-14 in organic materials can yield absolute dating. Palynology, oxygen ratio and calcium carbonate content will provide information about the environmental and climatic variations and paleotemperature of the water during sedimentation. The study of ostracods will provide information about the paleonvironment (e.g. water depth variations). Geotechnical tests and diffractometric analysis will document the mechanical properties and mineralogical composition of the lacustrine deposits. All the results, along with sedimentological studies, will be integrated to evaluate the occurrence of eventual ciclicities and the degree of inter-relation between the measured parameters. The final aim is to evaluate a possible correlation between the sedimentary events and activation of local extensional structures in the geological past, observe their recurrence (if any) in recent geological times and propose a reconstruction of the Pleistocene evolution of the Aterno Basin.

Mochales, T.; Porreca, M.; Smedile, A.; Buratti, N.; Macri', P.; Di Chiara, A.; Sagnotti, L.; Speranza, F.; Amoroso, S.; Nicolosi, I.; D'ajello Caracciolo, F.; Carluccio, R.; Di Giulio, G.; Vassallo, M.; Villani, F.; Civico, R.

2013-12-01

51

Small satellite radiometric measurements  

SciTech Connect

A critical need for the Mission to Planet Earth is to provide continuous, well-calibrated radiometric data for the radiation budget. This paper describes a new, compact, flexible radiometer which will provide both spectrally integrated data and data in selected spectral bands. The radiometer design is suitable for use on small satellites, aircraft, or remotely piloted vehicles (RPVs). 12 refs., 2 figs.

Weber, P.G.

1991-01-01

52

DATE:  

Cancer.gov

DATE: February 2, 2010 TO: SIP Mentors/Sponsors/Supervisors of Minor-aged employees FROM: Dr. Randall Morin Director, EHS SUBJECT: Policies and guidance documentation on minors working at the NCI-F Every year the NCI-F welcomes new

53

Dating  

MedlinePLUS

... Kids Everyday Life Away from Home Babysitter Dating Driving Food & Fun Managing Stress and Diabetes Planes Questions to Ask Your Doctor School Serious Lows Shots & Blood Glucose Checks Sick Days Sports & Recreation Teens & Parties Telling Others donate en -- Put a Stop ...

54

RPro: radiometric data processor  

NASA Astrophysics Data System (ADS)

Indigo Systems, a division of FLIR Systems, Inc., has released a commercial off-the-shelf, PC-based software program named RPro. RPro, an optional component of Indigo's RTools Radiometric Software Toolkit, was developed for engineers and scientists to efficiently batch process and analyze data from high-end infrared focal plane array cameras, Fourier transform infrared (FTIR) spectrometers, high-speed radiometers, and imaging spectrometers. Many core radiometric calibration and data reduction algorithms already exist within RPro for the user with minimal infrared radiometry experience. For the advanced radiometry engineer, RPro provides a flexible and extensible graphical programming interface to easily develop custom radiometric calibration and data reduction algorithms. Moreover, adding the RPro component to RTools provides the radiometry engineer with the capability to quickly create a data reduction algorithm that when used in conjunction with MODTRAN will correct for atmospheric effects using range supplied time, space, and position information (TSPI). RPro was designed to integrate seamlessly with all other RTools components by utilizing the Standard Archive File (SAF) format maintained by the U.S. Air Force at Arnold Air Force Base, TN.

Cromwell, Brian K.; Wright, Timothy A.; McClure, John E.

2004-08-01

55

Radiometric cloud imaging with an uncooled microbolometer thermal infrared camera.  

PubMed

An uncooled microbolometer-array thermal infrared camera has been incorporated into a remote sensing system for radiometric sky imaging. The radiometric calibration is validated and improved through direct comparison with spectrally integrated data from the Atmospheric Emitted Radiance Interferometer (AERI). With the improved calibration, the Infrared Cloud Imager (ICI) system routinely obtains sky images with radiometric uncertainty less than 0.5 W/(m(2 )sr) for extended deployments in challenging field environments. We demonstrate the infrared cloud imaging technique with still and time-lapse imagery of clear and cloudy skies, including stratus, cirrus, and wave clouds. PMID:19498585

Shaw, Joseph; Nugent, Paul; Pust, Nathan; Thurairajah, Brentha; Mizutani, Kohei

2005-07-25

56

Basalt sills of the U reflector, Newfoundland Basin: A serendipitous dating technique  

NASA Astrophysics Data System (ADS)

High core recovery at Ocean Drilling Program (ODP) Leg 210, Site 1276, provided a high-resolution porosity-depth relationship and an equally impressive age-depth model based on first and last occurrences of microfossils. Site 1276 was drilled over transitional crust in the Newfoundland nonvolcanic margin, offshore Canada, between known continental crust on the west and apparent oceanic crust on the east as identified by seafloor-spreading magnetic anomalies M3 to M0 (Barremian Aptian, 129.8 124.8 Ma). At Site 1276, two diabase sills were drilled at depths equivalent to the U reflection, a bright reflection that overlies transitional crust interpreted from seismic reflection profiles throughout the Newfoundland Basin. The sills were emplaced within uppermost Aptian fine- to coarse-grained sediments, 100 200 m above basement as estimated from seismic reflection data. Magma emplacement occurred at shallow levels within the sediment column, as evidenced by: (1) the occurrence of vesicles in the sill, and (2) compaction-induced folding of calcite veins that were emplaced near vertically in the sediments and are assumed to be coeval with the intrusion. By calculating the degree of shortening of the calcite veins and determining the reconstructed porosity of the sediments during vein emplacement, the age of magma emplacement can be deduced. From the porosity-age curve, the age of sill emplacement is estimated to be 82.5 109.1 Ma, consistent with recent 40Ar/39Ar radiometric dating of the upper sill that gave ages of 105.95 1.78 Ma and 104.7 1.7 Ma. The source of magmatism responsible for the diabase sills is necessarily postrift, and the sills are temporally equivalent to alkali basalts dredged from the Newfoundland Seamounts. The simplest explanation for the Site 1276 diabases and the widespread distribution of the U reflection relates to the migration of the Azores, Madeira, and Canary plumes across the Newfoundland Basin between 80 and 120 Ma.

Karner, Garry D.; Shillington, Donna J.

2005-12-01

57

Developing OSL Geological Dating Techniques for Use on Future Missions to Mars  

NASA Technical Reports Server (NTRS)

The surface of Mars has been subject to aeolian, fluvial, and periglacial activity in the (relatively) recent past. Unfortunately, chronological dating of recent events on Mars is difficult as the errors associated with crater counting are comparable to younger ages (approx. 1 Ma). Consequently, techniques to quantify the ages of geological processes on Mars have become an important area of research. Optically stimulated luminescence (OSL) dating is one candidate technique for in-situ dating of the deposition of Martian surface sediments. This method can aid in developing a geological and climatic history of the last million years on Mars. The current paper addresses some of the challenges and progress associated with developing OSL as a viable in-situ dating technique for Mars. Some of the challenges include the mineral composition, the effectiveness of solar resetting under Martian conditions, the temperature regime, and determining the natural dose rate on Mars. All of these topics are currently under investigation, and some preliminary results are presented.

Blair, M. W.; Kalchgruber, R.; Deo, S.; McKeever, S. W. S.

2005-01-01

58

40Ar/39Ar technique of KAr dating: a comparison with the conventional technique  

USGS Publications Warehouse

K-Ar ages have been determined by the 40Ar/39Ar total fusion technique on 19 terrestrial samples whose conventional K-Ar ages range from 3.4 my to nearly 1700 my. Sample materials included biotite, muscovite, sanidine, adularia, plagioclase, hornblende, actinolite, alunite, dacite, and basalt. For 18 samples there are no significant differences at the 95% confidence level between the KAr ages obtained by these two techniques; for one sample the difference is 4.3% and is statistically significant. For the neutron doses used in these experiments (???4 ?? 1018 nvt) it appears that corrections for interfering Ca- and K-derived Ar isotopes can be made without significant loss of precision for samples with K/Ca > 1 as young as about 5 ?? 105 yr, and for samples with K/Ca < 1 as young as about 107 yr. For younger samples the combination of large atmospheric Ar corrections and large corrections for Ca- and K-derived Ar may make the precision of the 40Ar/39Ar technique less than that of the conventional technique unless the irradiation parameters are adjusted to minimize these corrections. ?? 1971.

Brent, Dalrymple G.; Lanphere, M.A.

1971-01-01

59

U-series dating of impure carbonates: An isochron technique using total-sample dissolution  

USGS Publications Warehouse

U-series dating is a well-established technique for age determination of Late Quaternary carbonates. Materials of sufficient purity for nominal dating, however, are not as common as materials with mechanically inseparable aluminosilicate detritus. Detritus contaminates the sample with extraneous Th. We propose that correction for contamination is best accomplished with the isochron technique using total sample dissolution (TSD). Experiments were conducted on artificial mixtures of natural detritus and carbonate and on an impure carbonate of known age. Results show that significant and unpredictable transfer of radionuclides occur from the detritus to the leachate in commonly used selective leaching procedures. The effects of correcting via leachate-residue pairs and isochron plots were assessed. Isochrons using TSD gave best results, followed by isochron plots of leachates only. ?? 1991.

Bischoff, J.L.; Fitzpatrick, J.A.

1991-01-01

60

U-series dating of impure carbonates: An isochron technique using total-sample dissolution  

SciTech Connect

U-series dating is a well-established technique for age determination of Late Quaternary carbonates. Materials of sufficient purity for nominal dating, however, are not as common as materials with mechanically inseparable aluminosilicate detritus. Detritus contaminates the sample with extraneous Th. The authors propose that correction for contamination is best accomplished with the isochron technique using total sample dissolution (TSD). Experiments were conducted on artificial mixtures of natural detritus and carbonate and on an impure carbonate of known age. Results show that significant and unpredictable transfer of radionuclides occur from the detritus to the leachate on commonly used selective leaching procedures. The effects of correcting via leachate-residue pairs and isochron plots were assessed. Isochrons using TSD gave best results, followed by isochron plots of leachates only.

Bischoff, J.L.; Fitzpatrick, J.A. (Geological Survey, Menlo Park, CA (USA))

1991-02-01

61

Landsat-5 TM reflective-band absolute radiometric calibration  

USGS Publications Warehouse

The Landsat-5 Thematic Mapper (TM) sensor provides the longest running continuous dataset of moderate spatial resolution remote sensing imagery, dating back to its launch in March 1984. Historically, the radiometric calibration procedure for this imagery used the instrument's response to the Internal Calibrator (IC) on a scene-by-scene basis to determine the gain and offset of each detector. Due to observed degradations in the IC, a new procedure was implemented for U.S.-processed data in May 2003. This new calibration procedure is based on a lifetime radiometric calibration model for the instrument's reflective bands (1-5 and 7) and is derived, in part, from the IC response without the related degradation effects and is tied to the cross calibration with the Landsat-7 Enhanced Thematic Mapper Plus. Reflective-band absolute radiometric accuracy of the instrument tends to be on the order of 7% to 10%, based on a variety of calibration methods.

Chander, G.; Helder, D.L.; Markham, B.L.; Dewald, J.D.; Kaita, E.; Thome, K.J.; Micijevic, E.; Ruggles, T.A.

2004-01-01

62

Irradiation of dates: insect disinfestation, microbial and chemical assessments, and use of thermoluminescence technique  

NASA Astrophysics Data System (ADS)

Irradiation of dates (Khalas variety) at 0.9 kGy was sufficient to eliminate single insect infestation ( Oryzaephilus surinamensis) and mixed infestation ( O. surinamensis and Tribolium castaneum), whereas 0.3 kGy was effective only in controlling single infestation. Sensory properties were not affected but irradiation contributed to some reduction in microbial counts immediately after irradiation and counts remained low till the end of 6 months storage period. All sugars were significantly reduced immediately after irradiation but they increased gradually with increasing storage time. Thermoluminescence (TL) technique was useful in discriminating between irradiated and unirradiated dates during the entire storage period but was less sensitive as far as the dose estimation is concerned.

Al-Kahtani, Hassan A.; M. Abu-Tarboush, Hamza; Al-Dryhim, Yousif N.; Ahmed, Mohamed A.; Bajaber, Adnan S.; Adam, El-Shami E.; El-Mojaddidi, Mohamed A.

1998-08-01

63

The dating of shallow faults in the Earth's crust.  

PubMed

Direct dating of ductile shear zones and calculation of uplift/exhumation rates can be done using various radiometric dating techniques. But radiometric dating of shallow crustal faulting, which occurs in the crust's brittle regime, has remained difficult because the low temperatures typical of shallow crusted faults prevent the complete syntectonic mineral recrystallization that occurs in deeper faults. Both old (detrital) and newly grown (authigenic) fine-grained phyllosilicates are thus preserved in shallow fault zones and therefore their radiometric ages reflect a mixture of both mineral populations. Also, the loss of 39Ar during neutron irradiation in dating of clay minerals can produce erroneously old ages. Here we present a method of characterizing the clay populations in fault gouge, using X-ray modelling, combined with sample encapsulation, and show how it can be used to date near-surface fault activity reliably. We examine fault gouge from the Lewis thrust of the southern Canadian Rockies, which we determine to be approximately 52 Myr old. This result requires the western North America stress regime to have changed from contraction to extension in only a few million years during the Eocene. We also estimate the uplift/exhumation age and sedimentary source of these rocks to be approximately 172 Myr. PMID:11449270

van der Pluijm, B A; Hall, C M; Vrolijk, P J; Pevear, D R; Covey, M C

2001-07-12

64

The ID-KArD technique: In-situ dating on Mars  

NASA Astrophysics Data System (ADS)

The ability to measure absolute ages on the Martian surface is crucial for understanding the planet's evolution. A detailed geological history of the Moon has been determined through analysis of returned samples from specific units, and relative ages calculated by crater counting techniques. However, without returned samples or in-situ dating analyses, we lack absolute age markers for Mars and thus cannot accurately or precisely date its well-documented surface. Instead, we have relied on an estimated Mars/Moon cratering ratio and relative crater counting techniques in an attempt to calculate surface ages and classify geological units. The use of such relative parameters diminishes the precision and accuracy for surface age calculations, and thus highlights the need for independent age determinations from returned samples or in-situ dating. In this research, we describe our technique - ID-KArD (Isotope Dilution K-Ar Dating) - intended for in-situ age dating of geological units on the Martian surface. ID-KArD resolves two challenges that have previously obstructed in-situ age dating on Mars: 1) High fusion temperatures are avoided with the use of a lithium-borate flux; 2) Sample mass measurement is not required, due to the addition of an isotope dilution doubly-spiked glass. The glass has a known 39Ar/41K ratio, which removes the need for concentration measurements. Thus, only isotope ratios are required for a K-Ar age determination. ID-KArD has the potential to address Mars chronology inaccuracies, and would be a suitable technique for consideration on future missions. In the first phase of ID-KArD proof of concept, we selected a Viluy trap basalt (K2O ~ 0.7 wt%), with concordant K-Ar and Ar-Ar ages of 354.3 3.5 and 357.7 1.4 Ma respectively (Courtillot et al., 2010). An aliquot was combined into a crucible with the flux and the spike glass for separate Ar (MAP 215:50, Caltech), followed by K (KEMS, GRC) isotopic analysis. Combining our results, we obtained an age of 351 19 Ma (Farley et al., 2013), in good agreement with the previously published ages. For the second phase, we have designed and built a single instrument, capable of analysing both Ar and K from a single sample. The instrument includes two ionisation sources for separate K (thermal) and Ar (electron impact) ionsiation, and a quadrupole mass spectrometer. In addition, we have designed a sample heating mechanism that allows degassing of flux prior to sample addition, and achieves temperatures in the range of the SAM oven on Curiosity. Thus far, the instrument has successfully measured both isotopic systems, and following further testing in the coming weeks, we will date Martian surface analogues, age standards, and finally meteoritic material.

Cartwright, J. A.; Farley, K. A.; Hurowitz, J.; Asimow, P. D.; Jacobson, N. S.

2013-12-01

65

Assessment of VIIRS radiometric performance using vicarious calibration sites  

NASA Astrophysics Data System (ADS)

Radiometric performance of satellite instruments needs to be regularly monitored to determine if there is any drift in the instrument response over time despite the calibration with the best effort. If a drift occurs, it needs to be characterized in order to keep the radiometric accuracy and stability well within the specification. Instrument gain change over time can be validated independently using many techniques such as using stable earth targets (desert, ocean, snow sites etc), inter-comparison with other well calibrated radiometers (using SNO, SNO-x), deep convective clouds (DCC), lunar observations or other methods. This study focus on using vicarious calibration sites for the assessment of radiometric performance of Suomi National Polar-Orbiting Partnership (S-NPP) Visible Infrared Imaging Radiometer Suite (VIIRS) reflective solar bands. The calibration stability is primarily analyzed by developing the top-of-atmosphere (TOA) reflectance time series over these sites. In addition, the radiometric bias relative to AQUA MODIS is estimated over these calibration sites and analyzed. The radiometric bias is quantified in terms of observed and spectral bias. The spectral characterization and bias analysis will be performed using hyperspectral measurements and radiative transfer models such as MODTRAN.

Uprety, Sirish; Cao, Changyong; Blonski, Slawomir; Wang, Wenhui

2014-09-01

66

On-orbit radiometric calibration of Earth-observing sensors using the Radiometric Calibration Test Site (RadCaTS)  

NASA Astrophysics Data System (ADS)

Vicarious techniques are used to provide supplemental radiometric calibration data for sensors with onboard calibration systems, and are increasingly important for sensors without onboard calibration systems. The Radiometric Calibration Test Site (RadCaTS) is located at Railroad Valley, Nevada. It is a facility that was developed with the goal of increasing the amount of ground-based radiometric calibration data that are collected annually while maintaining the current level of radiometric accuracy produced by traditional manned field campaigns. RadCaTS is based on the reflectance-based approach, and currently consists of a Cimel sun photometer to measure the atmosphere, a weather station to monitor meteorological conditions, and ground-viewing radiometers (GVRs) that are used the determine the surface reflectance throughout the 1 1-km area. The data from these instruments are used in MODTRAN5 to determine the at-sensor spectral radiance at the time of overpass. This work describes the RadCaTS concept, the instruments used to obtain the data, and the processing method used to determine the surface reflectance and top-of-atmosphere spectral radiance. A discussion on the design and calibration of three new eight-channel GVRs is introduced, and the surface reflectance retrievals are compared to in situ measurements. Radiometric calibration results determined using RadCaTS are compared to Landsat 7 ETM+, MODIS, and MISR.

Czapla-Myers, Jeffrey S.; Leisso, Nathan P.; Anderson, Nikolaus J.; Biggar, Stuart F.

2012-06-01

67

Erosion Rates and Debris Flow History Reconstruction: a Comparison of Carbon and Cosmogenic Nuclide Dating Techniques  

NASA Astrophysics Data System (ADS)

Hillslope scale erosion rates in landslide-dominated landscapes are difficult to measure. These small spatial scales often lack representative alluvium which is typically used to infer catchment-averaged erosion rates. Furthermore, bedrock sampling tends to underestimate true erosion rates while areas with complete preservation of eroded material and datable markers occur only under special circumstances. We seek to use cosmogenic nuclide concentrations accumulated in debris flow material to determine hillslope scale erosion rates. Two small, completely preserved fans deposited on a strath terrace of the South Fork Eel River in northern California provide an opportunity to test this technique. The debris flows, likely induced by deep-seated landsliding, are preserved in the fans as episodic mass flow events with interlaced transient, fluvial activity. We collected material for cosmogenic nuclide analysis from prescribed depth intervals in profile at the upper and lower limits of the fan. These cosmogenic erosion rates are compared with volumetrically determined rates based on carbon dating. Two charcoal samples from the upper and lower limits of the fan act to constrain deposition to a period of 5 kyr during the Holocene. The fan volumes, divided by development time and upslope drainage areas, give volumetric lowering rates of approximately 0.1 and 0.5 mm/yr. These results straddle other researchers' erosion rates obtained from modern stream sediment and strath terraces in the area using cosmogenic techniques. Similar results between our two techniques will support the use of cosmogenic nuclides in determining erosion rates in debris flow material. Such uses, not currently demonstrated, will allow local erosion rates to be derived in a variety of geomorphically active areas, ultimately helping to quantify landscape formation and evolution.

Scheingross, J. S.; Willenbring, J. K.; Dietrich, W. E.

2008-12-01

68

JACIE Radiometric Assessment of QuickBird Multispectral Imagery  

NASA Technical Reports Server (NTRS)

Radiometric calibration of commercial imaging satellite products is required to ensure that science and application communities can place confidence in the imagery they use and can fully understand its properties. Inaccurate radiometric calibrations can lead to erroneous decisions and invalid conclusions and can limit intercomparisons with other systems. To address this calibration need, the NASA Stennis Space Center (SSC) Earth Science Applications (ESA) directorate,through the Joint Agency for Commercial Imagery Evaluation (JACIE) framework, established a commercial imaging satellite radiometric calibration team consisting of two groups: 1) NASA SSC ESA, supported by South Dakota State University, and 2) the University of Arizona Remote Sensing Group. The two groups determined the absolute radiometric calibration coefficients of the Digital Globe 4-band, 2.4-m QuickBird multispectral product covering the visible through near-infrared spectral region. For a 2-year period beginning in 2002, both groups employed some variant of a reflectance-based vicarious calibration approach, which required ground-based measurements coincident with QuickBird image acquisitions and radiative transfer calculations. The groups chose several study sites throughout the United States that covered nearly the entire dynamic range of the QuickBird sensor. QuickBird at-sensor radiance values were compared with those estimated by the two independent groups to determine the QuickBird sensor's radiometric accuracy. Approximately 20 at-sensor radiance estimates were vicariously determined each year. The estimates were combined to provide a high-precision radiometric gain calibration coefficient. The results of this evaluation provide the user community with an independent assessment of the QuickBird sensor's absolute calibration and stability over the 2-year period. While the techniques and method described reflect those developed at the NASA SSC, the results of both JACIE team groups are included in this paper.

Pagnutti, Mary; Carver, David; Holekamp, Kara; Knowlton, Kelly; Ryan, Robert; Zanoni, Vicki; Thome, Kurtis; Aaron, David

2004-01-01

69

Influence of Lossy Compressed DEM on Radiometric Correction for Land Cover Classification of Remote Sensing Images  

NASA Astrophysics Data System (ADS)

World coverage Digital Elevation Models (DEM) have progressively increased their spatial resolution (e.g., ETOPO, SRTM, or Aster GDEM) and, consequently, their storage requirements. On the other hand, lossy data compression facilitates accessing, sharing and transmitting large spatial datasets in environments with limited storage. However, since lossy compression modifies the original information, rigorous studies are needed to understand its effects and consequences. The present work analyzes the influence of DEM quality -modified by lossy compression-, on the radiometric correction of remote sensing imagery, and the eventual propagation of the uncertainty in the resulting land cover classification. Radiometric correction is usually composed of two parts: atmospheric correction and topographical correction. For topographical correction, DEM provides the altimetry information that allows modeling the incidence radiation on terrain surface (cast shadows, self shadows, etc). To quantify the effects of the DEM lossy compression on the radiometric correction, we use radiometrically corrected images for classification purposes, and compare the accuracy of two standard coding techniques for a wide range of compression ratios. The DEM has been obtained by resampling the DEM v.2 of Catalonia (ICC), originally having 15 m resolution, to the Landsat TM resolution. The Aster DEM has been used to fill the gaps beyond the administrative limits of Catalonia. The DEM has been lossy compressed with two coding standards at compression ratios 5:1, 10:1, 20:1, 100:1 and 200:1. The employed coding standards have been JPEG2000 and CCSDS-IDC; the former is an international ISO/ITU-T standard for almost any type of images, while the latter is a recommendation of the CCSDS consortium for mono-component remote sensing images. Both techniques are wavelet-based followed by an entropy-coding stage. Also, for large compression ratios, both techniques need a post processing for correctly delimiting coastline, avoiding the confusion between elevation and no-data values. Six (from March 2005 to May 2007) geometrically corrected Landsat-5 images on the path-row 197-031 have been used. The six optical bands and the NDVI for each date have been introduced in a powerful hybrid classification process. The training areas and the ground truth have been obtained from the Mapa de Cobertes del Sl de Catalunya (v. 3), a land cover map created by photointerpretation of 0.5 m orthophotomaps acquired between 2005 and 2007 and covering all the extension of Catalonia. The legend has been reduced from 233 categories to 21. Preliminary results have shown that the effect on land cover classification of applying lossy compression to the DEM used in the radiometric correction is small (lower than 1%) even for compression ratios up to 200:1. Comparing classification performance after a compression of 5:1 and and a compression of 200:1 with both coding standards showed that: a) the percentage of correctly classified image was 73%; b) 20% was wrongly classified; c) 3.5% was wrongly classified at compression ratio 5:1; and d) also 3.5% was wrongly classified at compression ratio 200:1. These results are the first in the literature to analyze the effect of DEM lossy compressing when DEM are employed for radiometric correction.

Mor, G.; Pesquer, L.; Blanes, I.; Serra-Sagrist, J.; Pons, X.

2012-12-01

70

Application of the 40Ar/39Ar technique to date the Minoan Tuff, Santorini  

NASA Astrophysics Data System (ADS)

The age of the catastrophic eruption of the volcano of Santorini during the Bronze Age is well established from 14C dating at 3344.9 7.5 a1 (uncertainties quoted as 1-?). Application of the 40Ar/39Ar technique to products from this eruption is used here to (1) investigate the limits of the technique using conventional single collector mass spectrometry on a MAP215-50 instrument, (2) analyse sources of uncertainty to identify major contributing factors for the uncertainty of young 40Ar/39Ar ages, and (3) provide 40Ar/39Ar ages for a sample that has been previously dated via 14C and dendrochronology to further investigate issues with the accuracy of 40Ar/39Ar dating in the late Quaternary. We have separated the plagioclase fraction from the lower Minoan Tuff that immediately overlies the Cape Riva (rp6) tuff in a bay on the west coast of Thira, NW of the town of Oia. Using the calibration of 40Ar/36Ar of Lee et al.2, the decay constant recommended by Min at al.3, and the FCs age of Kuiper et al.4, we calculate an inverse isochron age of 3.7 1.6 ka and a trapped 40Ar/36Ar intercept of 299.8 1.2, slightly higher than the ratio for atmospheric argon of 298.56 0.31, when all steps with ages > 50 ka are included in the regression. Enrichment in radiogenic 40Ar in the steps used for the isochron is extremely low, given the low concentration of K2O in plagioclase and the extremely young age. The stepwise heating approach proved useful because in all 5 replicate experiments unexpectedly high ages showed up at higher step temperatures, suggesting that in each separate some older contaminant was present. The plateaus of each of the replicate experiments had quite reproducible ages, however, and a pooled age was calculated for 23 out of 48 individual steps. The pooled age for the plateau was 17.6 4.1 ka, which is high due to the slight component of excess 40Ar in the non-radiogenic component, as revealed from regression analysis. refs: 1SW Manning et al. (2006) Chronology for the Aegean Late Bronze Age 1700-1400 B.C., Science 312, 565 - 569. 2Lee J-Y, et al. (2006), A redetermination of the isotopic abundances of atmospheric Ar. Geochimica et Cosmochimica Acta 70, 4507-4512 3Min K, et al. (2001), Call for an improved set of decay constants for geochronological use. Geochimica et Cosmochimica Acta 65, 111 - 121. 4Kuiper et al. (2008), Synchronizing rock clocks of Earth History. Science 320, 500 - 504.

Wijbrans, J. R.; Kuiper, K.; Morgan, L. E.; Klaver, M.; Vroon, P. Z.

2012-12-01

71

Deep Springs fault, Inyo County, California: An example of the use of relative-dating techniques  

SciTech Connect

This article summarizes faulting in the Deep Springs Valley area, which was studied as part of a systematic evaluation of potentially active faults throughout California by the Division of Mines and Geology. Evaluation of surface fault-rupture hazard is authorized by the Alquist-Priolo Special Studies Zones Act of 1972. This act requires the State Geologist to delineate regulatory zones for faults that are well defined and show that displacement occurred during the last 11,000 years. Fault evaluations for the Division of Mines and Geology Fault Evaluation and Zoning Project are conducted at a detailed reconnaissance level. Evaluations are mainly based on aerial photographic interpretation in which ephemeral fault-produced landforms are identified and mapped. Young alluvial deposits and geomorphic surfaces are identified as either offset or not offset by faults. Field mapping is conducted to verify fault-related geomorphic features and to estimate ages of faulted and unfaulted deposits. The section on scarp degradation and relative dating techniques provides a brief survey of methods used in studies of the Basin and Range province. In these investigations geomorphic evidence is applied to determine the recency of faulting.

Bryant, W.A.

1989-11-01

72

Modeling radiometric effects on airborne multispectral videography  

NASA Astrophysics Data System (ADS)

Observing the Earth through remote technologies allows for the extraction of synoptic data that is difficult to match with ground-based measurements. Over time, remote sensing instruments and associated processing algorithms have improved in both spectral and spatial resolution. Currently, commercial spaceborne and airborne imaging systems are capable of producing data at one-meter spatial resolution. To fully utilize these improved data sources, it is critical that processing and analysis algorithms keep pace with instrument advances. This dissertation describes models and algorithms used to correct high spatial resolution airborne imagery for radiometric effects. These radiometric effects include topography and view-angle (also termed bidirectional reflectance). Also studied were radiometric and geometric calibration issues. The sensor used for this study was a four camera off-the-shelf system which is capable of collecting imagery in the visible through near-infrared (0.4-1.0 ?m) spectral region. Three topographic correction models were applied to one- meter spatial resolution imagery collected over Fort Huachuca, Arizona, in October 1998. The model proposed by Ekstrand (1996) was successful in reducing topographic effects found in the semidesert grassland and Madrean forest communities. Spectral signature coefficient of variation, histogram range, and histogram normality all showed improvement after correction for both classes. Additionally, the optimal spatial resolution of the supporting Digital Elevation Model (DEM) was found to be 40 meters. This disagrees with previous research stating that the imagery to be corrected and the supporting DEM should be the same spatial resolution. Two bidirectional reflectance models were applied to 1.5 meter spatial resolution imagery collected over Parramore Island, Virginia, in May 1999. A modified version of a model proposed by Irons et al. (1991) was found to substantially reduce bidirectional reflectance effects over four vegetation communities. Spectral signature coefficient of variation and overlap pixel difference showed improvement after correction. Additionally, an unsupervised technique was developed to generate training data for model coefficient generation. This technique produces a large amount of training points, is relatively free of user bias, and can be used as a masking procedure to apply the correction models to the appropriate land- cover classes. Finally, the computational aspects of mosaic construction and sensor orientation calculation were examined. A distributed approach for pass-point generation was developed utilizing off-the-shelf hardware and software. The use of six processors was found to improve performance by a factor of 5.2 (measured by calculation time) when compared to a single processor. Products developed as part of the computational process are discussed. These included orthomosaics, anaglyphs, and digital elevation models. The radiometric correction models studied should be extendable to any high spatial resolution (airborne or spaceborne) multispectral or hyperspectral system. The end-to-end processing routines developed as part of this study will substantially increase the data throughput of digital multispectral videography systems.

Fischer, Robert L., Jr.

73

Age validation of canary rockfish (Sebastes pinniger) using two independent otolith techniques: lead-radium and bomb radiocarbon dating.  

SciTech Connect

Canary rockfish (Sebastes pinniger) have long been an important part of recreational and commercial rockfish fishing from southeast Alaska to southern California, but localized stock abundances have declined considerably. Based on age estimates from otoliths and other structures, lifespan estimates vary from about 20 years to over 80 years. For the purpose of monitoring stocks, age composition is routinely estimated by counting growth zones in otoliths; however, age estimation procedures and lifespan estimates remain largely unvalidated. Typical age validation techniques have limited application for canary rockfish because they are deep dwelling and may be long lived. In this study, the unaged otolith of the pair from fish aged at the Department of Fisheries and Oceans Canada was used in one of two age validation techniques: (1) lead-radium dating and (2) bomb radiocarbon ({sup 14}C) dating. Age estimate accuracy and the validity of age estimation procedures were validated based on the results from each technique. Lead-radium dating proved successful in determining a minimum estimate of lifespan was 53 years and provided support for age estimation procedures up to about 50-60 years. These findings were further supported by {Delta}{sup 14}C data, which indicated a minimum estimate of lifespan was 44 {+-} 3 years. Both techniques validate, to differing degrees, age estimation procedures and provide support for inferring that canary rockfish can live more than 80 years.

Andrews, A H; Kerr, L A; Cailliet, G M; Brown, T A; Lundstrom, C C; Stanley, R D

2007-11-04

74

Changes in the Radiometric Sensitivity of SeaWiFS  

NASA Technical Reports Server (NTRS)

We report on the lunar and solar measurements used to determine the changes in the radiometric sensitivity of the Sea-viewing Wide Field-of-view Sensor (SeaWiFS). Radiometric sensitivity is defined as the output from the instrument (or from one of the instrument bands) per unit spectral radiance at the instrument's input aperture. Knowledge of the long-term repeatability of the SeaWiFS measurements is crucial to maintaining the quality of the ocean scenes derived from measurements by the instrument. For SeaWiFS bands 1 through 6 (412 nm through 670 rim), the change in radiometric sensitivity is less than 0.2% for the period from November 1997 through November 1998. For band 7 (765 nm), the change is about 1.5%, and for band 8 (865 nm) about 5%. The rates of change of bands 7 and 8, which were linear with time for the first eight months of lunar measurements, are now slowing. The scatter in the data points about the trend lines in this analysis is less than 0.3% for all eight SeaWiFS bands. These results are based on monthly measurements of the moon. Daily solar measurements using an onboard diffuser show that the radiometric sensitivities of the SeaWiFS bands have changed smoothly during the time intervals between lunar measurements. Since SeaWiFS measurements have continued past November 1998, the results presented here are considered as a snapshot of the instrument performance as of that date.

McClain, Charles R.; Barnes, Robert A.; Eplee, Robert E., Jr.; Patt, Frederick S.

1998-01-01

75

GPUs for parallel on-board hyperspectral image radiometric normalization  

NASA Astrophysics Data System (ADS)

This paper proposed a GPU-based implementation of radiometric normalization algorithms, which is used as a representative case study of on-board data processing techniques for hyperspectral image. Three algorithms of radiometric normalization based on the column average and standard deviation of raw image statistical characteristics were implemented and applied to real hyperspectral images for evaluating their performance. These algorithms have been implemented using the compute device unified architecture (CUDA), and tested on the NVidia Tesla C2075 architecture. The airborne Pushbroom Hyperspectral Imager (PHI) was flown to acquire the spectrally contiguous images as experimental datasets. The results show that MN worked best among the three methods and the speedups achieved by the GPU implementation over their CPU counterparts are outstanding.

Wu, Yuanfeng; Zhang, Bing; Zhao, Haina; Gao, Jianwei; Ni, Li; Yang, Wei

2013-05-01

76

Small satellite radiometric measurement system  

SciTech Connect

A critical need for the US Global Change Research Program is to provide continuous, well-calibrated radiometric data for the earth's radiation budget. This paper describes a new, compact, relatively light-weight, adaptable radiometer which will provide both spectrally integrated measurements and data in selected spectral bands. The radiometer design is suitable for use on small satellites, aircraft, or remotely piloted aircraft (RPAs). An example of the implementation of this radiometer on a small satellite is given. Significant benefits derive from simultaneous measurements of specific narrow (in wavelength) spectral features; such data may be obtained by combining LARI with a compact spectrometer on the same platform. Well-chosen satellite orbits allow one to use data from other satellites (e.g. DMSP) to enhance the data product, or to provide superior coverage of specific locations. 23 refs.

Weber, P.G.

1992-01-01

77

Small satellite radiometric measurement system  

SciTech Connect

A critical need for the US Global Change Research Program is to provide continuous, well-calibrated radiometric data for the earth`s radiation budget. This paper describes a new, compact, relatively light-weight, adaptable radiometer which will provide both spectrally integrated measurements and data in selected spectral bands. The radiometer design is suitable for use on small satellites, aircraft, or remotely piloted aircraft (RPAs). An example of the implementation of this radiometer on a small satellite is given. Significant benefits derive from simultaneous measurements of specific narrow (in wavelength) spectral features; such data may be obtained by combining LARI with a compact spectrometer on the same platform. Well-chosen satellite orbits allow one to use data from other satellites (e.g. DMSP) to enhance the data product, or to provide superior coverage of specific locations. 23 refs.

Weber, P.G.

1992-01-01

78

Radiometric correction of LANDSAT data  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. The six independent sensors of the multispectral band scanner are supposed to be identical; however, in actual practice, they may have different gain settings and offset factors, which result in the effect known as stripping (black lines at regular intervals) of the imagery. A simple two parameter method to correct the gain settings and offset factors of each of the sensors with respect to one sensor, taken as reference, was developed. This method assumes: (1) the response of a detector varies linearly with the radiance of radiation received, and (2) the means, as well as the standard deviations, of a reasonably large number of pixels, in a given wavelength band, are equal for each of the detectors for the radiometrically corrected data.

Dejesusparada, N.; Kumar, R. (principal investigator); Cavalcanti, L. A.

1977-01-01

79

Monazite Age Domain Boundary Characterization Using High Resolution Transmission Electron Microscope Techniques  

Microsoft Academic Search

Monazite (mnz) geochronology is rapidly becoming the technique of choice for unraveling local and regional polyphase thermotectonic histories. High retention of radiogenic Pb makes monazite ideal for various in-situ radiometric dating methods including techniques such as electron microprobe (EMP) and ion microprobe (IMP, especially SHRIMP). Recent studies have shown the validity of total Th-U-Pb chemical ages (EMP) by reproducing U-Pb

C. W. Loehn; R. J. Tracy

2006-01-01

80

Retrieval of Geophysical Parameters From Radiometric Data  

NASA Technical Reports Server (NTRS)

Rapid linear algorithm retrieves meteorological parameters from microwave radiometric data. Versatile 2-step, multiple-linear-regression algorithm examines all possible subsets of available channels and selects optimum subset for retrieving given geophysical or meteorological parameter.

Pandey, P. C.; Kakar, R. K.

1985-01-01

81

Results of magnetic HGI and radiometric surveys in W. Canada  

SciTech Connect

This article presents four case histories in which ground-based magnetic horizontal gradient intensity (HGI) and radiometric surveys were used in Western Canada for cost-effective geochemical exploration for hydrocarbons. The authors has developed these two surface exploration techniques from published studies and adapted them for use on the prairies the past 7 years. These surveys are used in conjunction with the usual geologic and seismic studies for: (1) evaluating prospects and land; (2) verifying seismic anomalies and inexpensively locating areas for conducting expensive 3D seismic surveys. Occasionally, as in two of the case histories discussed, these surveys were used successfully as stand-alone exploration methods where seismic exploration is not effective. The HGI and radiometric surveys measure, by geophysical methods, those effects associated with geochemical alterations due to vertical microseepage of hydrocarbons. The total cost, including permitting, data acquisition, data processing, and interpretation of the combination HGI and radiometric surveys is about 15% the total cost of a 3D seismic survey. Because of this, the author finds them an attractive and rapid survey adjunct to traditional exploration. They substantially reduce finding costs and significantly raise the probability of financial success.

LeSchack, L.A. [Topaz Energy Exploration Ltd., Calgary, Alberta (Canada)

1997-05-19

82

Comparison of SAR techniques for luminescence dating of sediments derived from volcanic tuff  

Microsoft Academic Search

In this investigation we evaluate several proposed optically stimulated luminescence single-aliquot regeneration (OSL SAR) procedures to determine which technique has the greatest potential to yield accurate ages for samples collected from tuff-derived alluvial sediments within the narrow, sharply incised canyon systems of the Pajarito Plateau of northern New Mexico. The SAR data collection methods evaluated are: infrared-stimulated luminescence (IRSL), post-IR

Kenneth Lepper; Cathy Wilson; Jamie Gardner; Steven Reneau; Alexis Lavine

2003-01-01

83

Radiometric surveys in underground environment  

NASA Astrophysics Data System (ADS)

Due to their ability to travel through the air for several metres, gamma-rays emitted from natural radioactive elements can be successfully used in surveys carried out both with airborne and ground equipments. Besides the concentration of the radio-elements contained in rocks and soils and the intrinsic characteristics of the gamma-ray detector, the detected count rate depends on the solid angle around the spectrometer. On a flat outcrop, ground spectrometry detects the radiation ideally produced by a cylindrical mass of rock of about two metres in diameter and thickness of about half a meter. Under these geometrical conditions, the natural radioactivity can be easily evaluated. With operating conditions different from the standard ones, such as at the edge of an escarpment, the count rate halves because of the missing material, whereas in the vicinity of a rock wall the count rate will increase. In underground environment, the recorded count rate may even double and the in situ assessment of the concentration of radio-elements may be rather difficult, even if the ratios between the different radio-elements may not be affected. We tested the applicability of gamma-ray spectrometry for rapid assessment of the potential hazard levels related to radon and radiation dose rate in underground environment. A mine shaft, located in a zone of uranium enrichment in Liguria (Italy), has been investigated. A preliminary ground radiometric survey was carried out to define the extent of the ore deposit. Then, the radiometric investigation was focussed on the mine shaft. Due to rock mass above the shaft vault, the background gamma radiation can be considered of negligible influence on measurements. In underground surveys, besides deviations from a flat geometry, factors controlling radon exhalation, emanation and stagnation, such as fractures, water leakage and the presence of ventilation, should be carefully examined. We attempted to evaluate these control factors and collected a set of rock samples along the mine shaft to compare in situ results with high resolution gamma-ray analysis in the laboratory. The comparison points to a systematic overestimation (on the average, by a factor of two) of the uranium, thorium and potassium concentrations obtained with the portable apparatus. The bias between laboratory and field is slightly smaller for potassium and could be due only to deviation from standard geometric conditions. The largest differences occur in uranium concentrations, probably due also to the influence of the activity deriving from radon stagnation. The calculated radon flux depends on the radium specific activity, which, under the assumption of secular radioactive equilibrium, can be easily inferred from the uranium concentration, and the specific exhalation coefficient. Measurements of specific exhalation coefficient are difficult and only few studies have examined unaltered rocks in details. We estimated the values of this parameter by considering the degree of fracturing, width of fissures and evidence of percolating groundwater. In general, the coefficient increases from the entrance, where rocks are more massive, towards the shaft bottom, where closely spaced open fissures, often filled with percolating groundwater, might boost exhalation. As a whole, both potential radon flux and radiation dose values are relevant to radio protection rules.

Bochiolo, Massimo; Chiozzi, Paolo; Verdoya, Massimo; Pasquale, Vincenzo

2010-05-01

84

Radiation-induced signals of gypsum crystals analysed by ESR and TL techniques applied to dating  

NASA Astrophysics Data System (ADS)

Natural crystals of terrestrial gypsum were investigated concerning the radiation effects on Electron spin resonance (ESR) and Thermoluminescence (TL) properties and their application for geological dating. ESR signals of Fe 3+, Mn 2+, G1 ( SO3-, g = 2.003) and G2 ( SO4-, g?=2.018g?=2.009) centers were observed. The thermal stability and dose response of the ESR signals were found to be suitable for an age determination using a signal at g = 2.009. The intensity of this center increased with ?-radiation and the additive dose method for this ESR center yielded accumulated dose GD of 67.4 10.1 Gy. Using U, Th and K contents plus the cosmic-ray contribution, a dose rate of 1.92 0.22 mGy/year has been obtained. We have determined the ESR age of the gypsums to be (35 4) 10 3 years. TL peaks at 157 and 278 C were observed. By using initial rise method the thermal activation energy of 278 C TL peak was found to be underestimated, probably due to the thermal quenching. Activation energies and frequency factors obtained by the method of varying the heating rate indicate lifetime of 4.09 10 7 years (at 15 C) for 278 C peak. The additive dose method applied to this TL peak yielded GD of 75 11 Gy. The corresponding TL age using the 278 C TL peak was found to be (39 5) 10 3 years for gypsum sample. The TL age of this sample is consistent with the ESR age within experimental error limits. The obtained ESR and TL ages are not consistent with the expectations of geologists. This contradiction is probably due to the repeatedly recrystallisation of gypsum samples under the environmental conditions after their formation in the upper Miocene-Pliocene Epoch.

Ayda?, Canan; Engin, Birol; Ayd?n, Talat

2011-02-01

85

Chemical Principles Revisited: Archaeological Dating.  

ERIC Educational Resources Information Center

Discusses methods used to date archaeological artifacts and other remains. They include: (1) nuclear dating techniques (radiocarbon dating, accelerator radiocarbon dating, thermoluminescence, and others); (2) chemical dating techniques (amino acid racemization, obsidian hydration dating, elemental content changes, and thermal analysis dating); and

Rowe, M. W.

1986-01-01

86

Earth Observing-1 Advanced Land Imager: Radiometric Response Calibration  

NASA Technical Reports Server (NTRS)

The Advanced Land Imager (ALI) is one of three instruments to be flown on the first Earth Observing mission (EO-1) under NASA's New Millennium Program (NMP). ALI contains a number of innovative features, including a wide field of view optical design, compact multispectral focal plane arrays, non-cryogenic HgCdTe detectors for the short wave infrared bands, and silicon carbide optics. This document outlines the techniques adopted during ground calibration of the radiometric response of the Advanced Land Imager. Results from system level measurements of the instrument response, signal-to-noise ratio, saturation radiance, and dynamic range for all detectors of every spectral band are also presented.

Mendenhall, J. A.; Lencioni, D. E.; Evans, J. B.

2000-01-01

87

Correction function in the Lidar equation and the solution techniques for CO2 Lidar date reduction  

NASA Technical Reports Server (NTRS)

For lidar systems with long laser pulses the unusual behavior of the near-range signals causes serious difficulties and large errors in reduction. The commonly used lidar equation is no longer applicable since the convolution of the laser pulse with the atmospheric parameter distributions should be taken into account. It is important to give more insight into this problem and find the solution techniques. Starting from the original equation, a general form is suggested for the single scattering lidar equation where a correction function Cr is introduced. The correction Function Cr(R) derived from the original equation indicates the departure from the normal lidar equation. Examples of Cr(R) for a coaxial CO2 lidar system are presented. The Differential Absorption Lidar (DIAL) errors caused by the differences of Cr(R) for H2O measurements are plotted against height.

Zhao, Y.; Lea, T. K.; Schotland, R. M.

1986-01-01

88

Comparing OSL and CN techniques for dating fluvial terraces and estimating surface process rates in Pamir  

NASA Astrophysics Data System (ADS)

The quantification of surface process rates is crucial for understanding the topographic evolution of high mountains. Spatial and temporal variations in fluvial incision and basin-wide erosion enable to decipher the role of tectonic and climatic drivers. The Pamir is peculiar in both aspects because of its location at the western end of the India-Asia collision zone, and its position at the edge of two atmospheric circulation systems, the Westerlies and the Indian Summer Monsoon. The architecture of the Panj river network indicates prominent variations across the main tectonic structures of the Pamir. The trunk stream, deflects from the predominantly westward river orientation and cuts across the southern and central Pamir domes before doubling back to the west and leaving the orogen. Optically stimulated luminescence (OSL) dating of fluvial terraces reveals short-term sedimentation along the trunk stream during the last ~25 kyr. The agreement of OSL results to new exposure ages based on the cosmogenic nuclide (CN) 10Be confirms accurate terrace age modelling and treatment of incomplete bleaching. The consistent terrace sedimentation and exposure ages suggest also fast terrace abandonment and rapid onset of incision. Considerable differences in terrace heights reflect high spatial variations of fluvial incision, independent of time interval, change in rock type or catchment increase. Highest rates of (5.9 1.1) mm/yr to (10.0 2.0) mm/yr describe the fluvial dynamic across the Shakhdara Dome and that related to the Darvaz Fault Zone. Lower rates of (3.9 0.6) mm/yr to (4.5 0.7) mm/yr indicate a transient stage north of the Yazgulom Dome. Fluvial incision decreases to rates ranging from (1.7 0.3) mm/yr to (3.9 0.7) mm/yr in graded river reaches associated to southern dome boundaries. The pattern agrees to the interpretation of successive upstream river captures across the southern and central Pamir domes inferred from morphometric analyses of river and valley profiles. Basin-wide erosion rates based on 10Be concentrations in modern fluvial sediments yield relatively consistent rates between (0.61 0.1) mm/yr and (0.75 0.14) mm/yr along the Panj. The increasing Panj catchment averages variations of tributary basins, but minor variations in erosion rates of along-stream sub-basins resemble the pattern of OSL-based incision rates. In contrast, basin-wide erosion rates of tributary basins clearly differentiate between plateau-related sub-basins of (0.05 0.01) mm/yr to (0.17 0.03) mm/yr, and plateau margin-related sub-basins of (0.38 0.06) mm/yr to (1.43 0.26) mm/yr. The differentiation in plateau-related and marginal sub-basins and the northward increase in erosion rates correlate with the 75-percentile of the slope distribution within respective basins and to a minor degree to cumulative annual precipitation.

Fuchs, Margret; Gloaguen, Richard; Pohl, Eric; Sulaymonova, Vasila; Merchel, Silke; Rugel, Georg

2014-05-01

89

Comparison of SAR techniques for luminescence dating of sediments derived from volcanic tuff  

NASA Astrophysics Data System (ADS)

In this investigation we evaluate several proposed optically stimulated luminescence single-aliquot regeneration (OSL SAR) procedures to determine which technique has the greatest potential to yield accurate ages for samples collected from tuff-derived alluvial sediments within the narrow, sharply incised canyon systems of the Pajarito Plateau of northern New Mexico. The SAR data collection methods evaluated are: infrared-stimulated luminescence (IRSL), post-IR blue-OSL, IRSL with TL annealing cycles on polymineral fine-grains, and blue-OSL on quartz fine sand. A single-grain laser luminescence (SGLL) procedure for quartz sand is also evaluated. Age estimates obtained from these methods are compared with radiocarbon, soil PDI (profile development index), and IRSL multi-aliquot additive dose (MAAD) age constraints. Our results indicate that the modal De of quartz sand SGLL dose distributions yield ages that are consistent with radiocarbon and PDI age constraints for the tuff derived sediments in this investigation and appears to be the most promising method for studies in this area. Additionally, two fine-grained polymineral methods, IRSL SAR and traditional IRSL MAAD, produced ages that were generally in agreement with the SGLL ages and with available 14C and PDI age constraints. At the present stage of research, we advocate using quartz sand SGLL in conjunction with IRSL SAR or even IRSL MAAD for polymineral fine-grains to provide the most robust and reliable luminescence age data sets for tuff-derived sediments.

Lepper, Kenneth; Wilson, Cathy; Gardner, Jamie; Reneau, Steven; Lavine, Alexis

2003-05-01

90

The absolute radiometric calibration of the Landsat 8 Operational Land Imager using the reflectance-based approach and the Radiometric Calibration Test Site (RadCaTS)  

NASA Astrophysics Data System (ADS)

Landsat 8 was launched on 11 February 2013 as the newest platform in the Landsat program. It contains two Earthobserving instruments, one of which is the Operational Land Imager (OLI). OLI includes an onboard radiometric calibration system that is used to monitor changes in its responsivity throughout the mission lifetime, and it consists of Spectralon solar diffuser panels as well as tungsten lamp assemblies. External techniques are used to monitor both OLI and its calibration system, and they include lunar views, side slither maneuvers of the satellite, and ground-based vicarious calibration. This work presents the absolute radiometric calibration results for Landsat 8 OLI that were obtained using two ground-based measurement techniques. The first is the reflectance-based approach, where measurements of atmospheric and surface properties are made during a Landsat 8 overpass, and it requires personnel to be on site during the time of measurement. The second uses the Radiometric Calibration Test Site (RadCaTS), which was developed by the Remote Sensing Group in the College of Optical Sciences at the University of Arizona so that radiometric calibration data can be collected without the requirement of on-site personnel. It allows more data to be collected annually, which increases the temporal sampling of trending results.

Czapla-Myers, Jeffrey; Anderson, Nikolaus; Thome, Kurtis; Biggar, Stuart

2014-10-01

91

MODIS Cloud Optical Property Retrieval Uncertainties Derived from Pixel-Level VNIR/SWIR Radiometric Uncertainties  

NASA Technical Reports Server (NTRS)

Moderate Resolution Imaging Spectroradiometer (MODIS) retrievals of optical thickness and effective particle radius for liquid water and ice phase clouds employ a well-known VNIR/ SWIR solar reflectance technique. For this type of algorithm, we evaluate the quantitative uncertainty in simultaneous retrievals of these two cloud parameters to pixel-level radiometric calibration estimates and other fundamental (and tractable) error sources.

Platnick, S.; Wind, G.; Xiong, X.

2011-01-01

92

MODIS Cloud Optical Property Retrieval Uncertainties Derived from Pixel-Level Radiometric Error Estimates  

NASA Technical Reports Server (NTRS)

MODIS retrievals of cloud optical thickness and effective particle radius employ a well-known VNIR/SWIR solar reflectance technique. For this type of algorithm, we evaluate the uncertainty in simultaneous retrievals of these two parameters to pixel-level (scene-dependent) radiometric error estimates as well as other tractable error sources.

Platnick, Steven; Wind, Galina; Xiong, Xiaoxiong

2011-01-01

93

Reduction of radiometric miscalibration--applications to pushbroom sensors.  

PubMed

The analysis of hyperspectral images is an important task in Remote Sensing. Foregoing radiometric calibration results in the assignment of incident electromagnetic radiation to digital numbers and reduces the striping caused by slightly different responses of the pixel detectors. However, due to uncertainties in the calibration some striping remains. This publication presents a new reduction framework that efficiently reduces linear and nonlinear miscalibrations by an image-driven, radiometric recalibration and rescaling. The proposed framework-Reduction Of Miscalibration Effects (ROME)-considering spectral and spatial probability distributions, is constrained by specific minimisation and maximisation principles and incorporates image processing techniques such as Minkowski metrics and convolution. To objectively evaluate the performance of the new approach, the technique was applied to a variety of commonly used image examples and to one simulated and miscalibrated EnMAP (Environmental Mapping and Analysis Program) scene. Other examples consist of miscalibrated AISA/Eagle VNIR (Visible and Near Infrared) and Hawk SWIR (Short Wave Infrared) scenes of rural areas of the region Fichtwald in Germany and Hyperion scenes of the Jalal-Abad district in Southern Kyrgyzstan. Recovery rates of approximately 97% for linear and approximately 94% for nonlinear miscalibrated data were achieved, clearly demonstrating the benefits of the new approach and its potential for broad applicability to miscalibrated pushbroom sensor data. PMID:22163960

Rogass, Christian; Spengler, Daniel; Bochow, Mathias; Segl, Karl; Lausch, Angela; Doktor, Daniel; Roessner, Sigrid; Behling, Robert; Wetzel, Hans-Ulrich; Kaufmann, Hermann

2011-01-01

94

Reduction of Radiometric MiscalibrationApplications to Pushbroom Sensors  

PubMed Central

The analysis of hyperspectral images is an important task in Remote Sensing. Foregoing radiometric calibration results in the assignment of incident electromagnetic radiation to digital numbers and reduces the striping caused by slightly different responses of the pixel detectors. However, due to uncertainties in the calibration some striping remains. This publication presents a new reduction framework that efficiently reduces linear and nonlinear miscalibrations by an image-driven, radiometric recalibration and rescaling. The proposed frameworkReduction Of Miscalibration Effects (ROME)considering spectral and spatial probability distributions, is constrained by specific minimisation and maximisation principles and incorporates image processing techniques such as Minkowski metrics and convolution. To objectively evaluate the performance of the new approach, the technique was applied to a variety of commonly used image examples and to one simulated and miscalibrated EnMAP (Environmental Mapping and Analysis Program) scene. Other examples consist of miscalibrated AISA/Eagle VNIR (Visible and Near Infrared) and Hawk SWIR (Short Wave Infrared) scenes of rural areas of the region Fichtwald in Germany and Hyperion scenes of the Jalal-Abad district in Southern Kyrgyzstan. Recovery rates of approximately 97% for linear and approximately 94% for nonlinear miscalibrated data were achieved, clearly demonstrating the benefits of the new approach and its potential for broad applicability to miscalibrated pushbroom sensor data. PMID:22163960

Roga, Christian; Spengler, Daniel; Bochow, Mathias; Segl, Karl; Lausch, Angela; Doktor, Daniel; Roessner, Sigrid; Behling, Robert; Wetzel, Hans-Ulrich; Kaufmann, Hermann

2011-01-01

95

Radiometric surface temperature components for row crops  

Technology Transfer Automated Retrieval System (TEKTRAN)

Land surface temperature is a boundary condition often used in assessing soil moisture status and energy exchange from the soil-vegetation-atmosphere interface. For row crops having incomplete canopy cover, the radiometric surface temperature is a composite of sunlit and shaded vegetation and substr...

96

Dating Techniques Irka Hajdas  

E-print Network

___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ ___________________________________ Slide 5 Method Age range (years) Archive/Material 210 Pb 0- 200 Recent sediments Dendrochronology 0 12

Gilli, Adrian

97

SPOT5: first in-flight radiometric image quality results  

NASA Astrophysics Data System (ADS)

The SPOT5 remote sensing satellite was launched in May 2002. It provides SPOT service continuity above and beyond SPOT4 operation but the SPOT5 system also significantly improves the SPOT service with the new characteristics of its two HRG (High Resolution Geometry) cameras and its HRS (High Resolution Stereo) camera. SPOT5's first two months of life in orbit were dedicated to instrument calibration and the assessment of image quality performances. During this period, the CNES team used specific target programming to compute image correction parameters and estimate the performance of the image processing chain, at system level. This paper focuses on the relative radiometric performances of the different spectral bands for the three instruments, deduced from in-flight measurements. For each spectral band, a radiometric model gives the ratio between detector response and input radiance. This model takes the architecture of the onboard image chain into account. Calibration provides the normalisation parameters (dark currents and relative inter-detector sensitivities) used to correct the images. The quality of the corrected images is quantified through several signal-to-noise ratio measurements based on different techniques. These methods are presented and their accuracy is discussed. Finally, a comparison is given between flight measurements and ground measurements.

Pascal, Veronique; Lebegue, Laurent; Meygret, Aime; Laubies, Marie-Christine; Hourcastagnou, Jean-Noel; Hillairet, Emmanuel

2003-04-01

98

Principal Component Noise Filtering for NAST-I Radiometric Calibration  

NASA Technical Reports Server (NTRS)

The National Polar-orbiting Operational Environmental Satellite System (NPOESS) Airborne Sounder Testbed- Interferometer (NAST-I) instrument is a high-resolution scanning interferometer that measures emitted thermal radiation between 3.3 and 18 microns. The NAST-I radiometric calibration is achieved using internal blackbody calibration references at ambient and hot temperatures. In this paper, we introduce a refined calibration technique that utilizes a principal component (PC) noise filter to compensate for instrument distortions and artifacts, therefore, further improve the absolute radiometric calibration accuracy. To test the procedure and estimate the PC filter noise performance, we form dependent and independent test samples using odd and even sets of blackbody spectra. To determine the optimal number of eigenvectors, the PC filter algorithm is applied to both dependent and independent blackbody spectra with a varying number of eigenvectors. The optimal number of PCs is selected so that the total root-mean-square (RMS) error is minimized. To estimate the filter noise performance, we examine four different scenarios: apply PC filtering to both dependent and independent datasets, apply PC filtering to dependent calibration data only, apply PC filtering to independent data only, and no PC filters. The independent blackbody radiances are predicted for each case and comparisons are made. The results show significant reduction in noise in the final calibrated radiances with the implementation of the PC filtering algorithm.

Tian, Jialin; Smith, William L., Sr.

2011-01-01

99

Radiometric tests on wet and dry antenna reflector surface panels  

NASA Technical Reports Server (NTRS)

The results of X-band noise temperature tests on two types of antenna surface panels are presented. The first type tested was a solid antenna panel, while the second type was a perforated panel with 3/16-in.-diameter holes. Measurements were made at 8.45 GHz using an X-band radiometric system. Included in this article are measured noise temperature contributions from: (1) thermal diffusive white paint on solid and perforated panels, and (2) water sprayed on both painted and unpainted perforated panels. Experiments on perforated panels were restricted to the 3/16-in.-diameter hole panels formerly used on Deep Space Network 64-m antennas. Rigorous calibration equations, applicable to a variety of antenna panel and dichroic plate test configurations, are presented. It was demonstrated that an accurate, stable radiometric measurement system of the type used for the results of this research makes it possible to obtain information that would be much more difficult to obtain using other techniques.

Otoshi, T. Y.; Franco, M. M.

1990-01-01

100

NASA IKONOS Multispectral Radiometric Calibration and 3-Year Temporal Stability Assessment  

NASA Technical Reports Server (NTRS)

Radiometric calibration of commercial imaging satellite products is required to ensure that science and application communities can place confidence in the imagery they use and can fully understand its properties. Inaccurate radiometric calibrations can lead to erroneous decisions and invalid conclusions and can limit intercomparisons with other system. In addition, the user community has little or no insight into the design and operation of commercial sensors or into the methods involved in generating commercial products. To address this calibration need, the NASA Stennis Space Center (SSC) Earth Science Applications (ESA) Directorate established a commercial satellite imaging radiometric calibration team consisting of three independent groups: NASA, SSC,ESA, the University of Arizona Remote Sensing Group, and South Dacota State University. Each group determined the absolute radiometric calibration coefficients of the Space Imaging IKONOS 4-band, 4 m multispectral product covering the visible through near-infrared spectral region. For a three year period beginning in 2000, each team employed some variant of a reflectance-based vicarious calibration approach, requiring ground-based measurements coincident with IKONOS image acquisitions and radiative transfer calculations. Several study sites throughout the United States were employed that covered nearly the entire dynamic range of the IKONOS sensor. IKONOS at-sensor radiance values were compared to those estimated by each independent group to determine the IKONOS sensor's radiometric accuracy and stability. Over 10 individual vicariously determined at-sensor radiance estimates were used each year. When combined, these estimates provided a high-precision radiometric gain calibration coefficient. No significant calibration offset was observed. The results of this evaluation provide the scientific community with an independent assessment of the IKONOS sensor's absolute calibration and temporal stability over the 3-year period. While the techniques and method described in this paper reflect those developed at the NASA SSC, the results of the entire team are included.

Pagnutti, Mary; Carver, David; Holekamp, Kara; Ryan, Robert; Zanoni, Vicki; Thome, Kurtis; Schiller, Stephen; Aaran, David

2003-01-01

101

Radiometric analysis of infrared sensor performance.  

PubMed

The performance of IR sensors for target detection is analyzed with model SENSAT. The model calculates the radiometric relations for passive IR sensors with up to three homogeneous objects in the instantaneous field of view. For the atmospheric part, the computer code LOwTRAN-6 is used within SENSAT. The sensor model has been improved by introducing a noise model for quantum detectors. It takes into account photon noise, thermal detector/preamplifier noise, and g-r and 1/f noise. In combination with a spectral band optimization with respect to the SNR an efficient tool for the radiometric analysis of IR sensor performance is presented. The comparison of model calculations in the 3-5-micro and 8-14-microm bands with experimental measurements yields excellent agreement. PMID:20539648

Richter, R; Fries, J

1988-11-15

102

Climate change and sounder radiometric stability  

NASA Astrophysics Data System (ADS)

Satellite instrument radiometric stability is critical for climate studies. The Atmospheric Infrared Sounder (AIRS) radiances are of sufficient stability and accuracy to serve as a climate data record as evidenced by comparisons with the global network of buoys. In this paper we examine the sensitivity of derived geophysical products to potential instrument radiometric stability issues due to diurnal, orbital and seasonal variations. Our method is to perturb the AIRS radiances and examine the impact to retrieved parameters. Results show that instability in retrieved temperature products will be on the same order of the brightness temperature error in the radiances and follow the same time dependences. AIRS excellent stability makes it ideal for examining impacts of instabilities of future systems on geophysical parameter performance.

Pagano, Thomas S.; Aumann, Hartmut H.; Manning, Evan

2009-08-01

103

DATING SAFETY DATING VIOLENCE  

E-print Network

at the beginning of the relationship, such as a sexual assault or "date rape". 1 Although dating violence may across Canada, 28% of females reported to have been a victim of sexual assault or "date rape" in the past or taking advantage of someone who is intoxicated or use of a "Date Rape" drug. Unwanted kissing, touching

Lennard, William N.

104

A radiometric antenna gain calibration method  

Microsoft Academic Search

A radiometric method is presented for measuring the power gain of a microwave antenna. It is particularly applicable to horns with gains in the range 20-45 dB, and an absolute uncertainty (3sigma) of less than 0.1 dB is achievable in favorable cases. An absorbing screen with a circular aperture is placed in the far-field of the test antenna. The diameter

B. Ulich; P. E. Mantey; L. J. Griffiths; B. B. Goode

1977-01-01

105

Revised landsat-5 thematic mapper radiometric calibration  

USGS Publications Warehouse

Effective April 2, 2007, the radiometric calibration of Landsat-5 (L5) Thematic Mapper (TM) data that are processed and distributed by the U.S. Geological Survey (USGS) Center for Earth Resources Observation and Science (EROS) will be updated. The lifetime gain model that was implemented on May 5, 2003, for the reflective bands (1-5, 7) will be replaced by a new lifetime radiometric-calibration curve that is derived from the instrument's response to pseudoinvariant desert sites and from cross calibration with the Landsat-7 (L7) Enhanced TM Plus (ETM+). Although this calibration update applies to all archived and future L5 TM data, the principal improvements in the calibration are for the data acquired during the first eight years of the mission (1984-1991), where the changes in the instrument-gain values are as much as 15%. The radiometric scaling coefficients for bands 1 and 2 for approximately the first eight years of the mission have also been changed. Users will need to apply these new coefficients to convert the calibrated data product digital numbers to radiance. The scaling coefficients for the other bands have not changed. ?? 2007 IEEE.

Chander, G.; Markham, B.L.; Barsi, J.A.

2007-01-01

106

Reconstruction of contaminant trends in a salt wedge estuary with sediment cores dated using a multiple proxy approach.  

PubMed

The Taunton River is a partially mixed tidal estuary in southeastern Massachusetts (USA) which has received significant contaminant inputs, yet little information exists on the history of discharge and the subsequent fate of these contaminants. Three sediment cores taken along a transect were analyzed, reconstructing the spatial and temporal trends of pollution in the estuary. A combination of radiometric dating, contaminant markers, and storm layers from major hurricanes were used to establish age models and sedimentation rates. Age estimates obtained from the different dating methods compared well, establishing an accurate history of contaminant release to the estuary. Polycyclic aromatic hydrocarbons (PAHs) were present in one core at depths corresponding to the early 1860s, earlier than previously established dates of introduction. Temporal and spatial trends of Cr, Cu, Hg and Pb indicated multiple sources of varying input to the river. Polychlorinated biphenyls (PCBs) were present in each of the cores from the 1930s onward, with elevated levels still present in surficial sediments at several sites. A unique organic compound, Topanol, which was produced locally was used as a tracer to track contaminant transport in the river. Tracer data indicates that contaminants are still being transported and deposited to surficial sediments at high concentrations well after their discharge. This reconstruction demonstrates the utility of using multiple dating proxies where often the sole use of radiometric dating techniques is not an option and provides insights into the fate of contaminants discharged decades ago but continue to represent environmental risks. PMID:17328947

Cantwell, Mark G; King, John W; Burgess, Robert M; Appleby, Peter G

2007-08-01

107

Accuracy of Radiocarbon Dates  

Microsoft Academic Search

The accuracy of dates obtained by the radiocarbon technique is discussed. ; Apparent discrepancies are examined for geophysical significance and for a ; general principle of correction. Assay methods are reviewed and data are ; tabulated showing dates obtained from organic materials found in sites for which ; the most reliable historical dates are available. Dates obtained using a half-;

W. F. Libby

1963-01-01

108

The Specular Array Radiometric Calibration (SPARC) method: a new approach for absolute vicarious calibration in the solar reflective spectrum  

NASA Astrophysics Data System (ADS)

Physics-based exploitation of image data from Earth observing sensors requires knowledge of the accuracy, stability and repeatability of a sensor's radiometric response within its in-flight environment. Vicarious radiometric calibration techniques, using terrestrial targets, provide an effective approach to obtaining this knowledge by measuring system performance under actual operational conditions. This paper introduces a new capability for performing the vicarious radiometric calibration of high spatial resolution sensors. The SPecular Array Radiometric Calibration (SPARC) method employs convex mirrors to create two arrays of calibration targets for deriving absolute calibration coefficients of Earth remote sensing systems in the solar reflective spectrum. The first is an array of single mirrors used to oversample the sensor's point spread function (PSF) providing necessary spatial quality information needed to perform the radiometric calibration of a sensor when viewing small targets. The second is a set of panels consisting of multiple mirrors designed to stimulate detector response with known at-sensor irradiance traceable to the exo-atmospheric solar spectral constant. The outcome is improved radiometric performance knowledge compared to other in-flight vicarious techniques through reduced uncertainties in target reflectance, atmospheric effects, and temporal variability. The only ground truth needed is the measurement of atmospheric transmittance. In addition, the simplification of calibration targets and ground truth collection in the SPARC method makes the deployment more cost effective and portable, thus creating the opportunity to imbed spectral, spatial and radiometric targets at a study site providing references that improve a sensor's interactivity as a phenomenological tool. A demonstration of the SPARC method is presented based on data collected with the IKONOS satellite operated by GeoEye. A SPARC measurement of absolute calibration coefficients for the IKONOS multispectral bands is compared to coefficients derived from the established reflectance-based vicarious calibration method.

Schiller, Stephen J.; Silny, John

2010-08-01

109

Enhanced radiometric detection of Mycobacterium paratuberculosis by using filter-concentrated bovine fecal specimens  

SciTech Connect

A commercial radiometric medium, BACTEC 12B, was modified by addition of mycobactin, egg yolk suspension, and antibiotics (vancomycin, amphotericin B, and nalidixic acid). Decontaminated bovine fecal specimens were filter concentrated by using 3-microns-pore-size, 13-mm-diameter polycarbonate filters, and the entire filter was placed into the radiometric broth. Comparison of the radiometric technique with conventional methods on 603 cattle from 9 Mycobacterium paratuberculosis-infected herds found that of 75 positive specimens, the radiometric technique detected 92% while conventional methods detected 60% (P less than 0.0005). Only 3.9% of radiometric cultures were contaminated. To measure the effect of filter concentration of specimens on the detection rate, 5 cattle with minimal and 5 with moderate ileum histopathology were sampled weekly for 3 weeks. M. paratuberculosis was detected in 33.3% of nonfiltered specimens and 76.7% of filtered specimens (P less than 0.005). Detection rates were directly correlated with the severity of disease, and the advantage of specimen concentration was greatest on fecal specimens from cattle with low-grade infections. Detection times were also correlated with infection severity: 13.4 +/- 5.9 days with smear-positive specimens, 27.9 +/- 8.7 days with feces from cows with typical subclinical infections, and 38.7 +/- 3.8 days with fecal specimens from cows with low-grade infections. Use of a cocktail of vancomycin, amphotericin B, and nalidixic acid for selective suppression of nonmycobacterial contaminants was better than the commercial product PANTA (Becton Dickinson Microbiologic Systems, Towson, Md.) only when specimens contained very low numbers of M. paratuberculosis.

Collins, M.T.; Kenefick, K.B.; Sockett, D.C.; Lambrecht, R.S.; McDonald, J.; Jorgensen, J.B. (Univ. of Wisconsin, Madison (USA))

1990-11-01

110

40Ar/(39)Ar dating of the Kapthurin Formation, Baringo, Kenya.  

PubMed

The(40)Ar/(39)Ar radiometric dating technique has been applied to tuffs and lavas of the Kapthurin Formation in the Tugen Hills, Kenya Rift Valley. Two variants of the(40)Ar/(39)Ar technique, single-crystal total fusion (SCTF) and laser incremental heating (LIH) have been employed to date five marker horizons within the formation: near the base, the Kasurein Basalt at 0.61+/-0.04 Ma; the Pumice Tuff at 0.543+/-0.004 Ma; the Upper Kasurein Basalt at 0.552+/-0.015 Ma; the Grey Tuff at 0.509+/-0.009 Ma; and within the upper part of the formation, the Bedded Tuff at 0.284+/-0.012 Ma. The new, precise radiometric age determination for the Pumice Tuff also provides an age for the widespread Lake Baringo Trachyte, since the Pumice Tuff is the early pyroclastic phase of this voluminous trachyte eruption. These results establish the age of fossil hominids KNM-BK 63-67 and KNM-BK 8518 at approximately 0.510-0.512 Ma, a significant finding given that few Middle Pleistocene hominids are radiometrically dated. The Kapthurin hominids are thus the near contemporaries of those from Bodo, Ethiopia and Tanzania. A flake and core industry from lacustrine sediments in the lower part of the formation is constrained by new dates of 0.55-0.52 Ma, a period during which the Acheulian industry, characterized by handaxes, is known throughout East Africa. Points, typical of the Middle Stone Age (MSA), are found in Kapthurin Formation sediments now shown to date to between 0.509+/-0.009 Ma and 0.284+/-0.012 Ma. This date exceeds previous estimates for the age of the MSA elsewhere in East Africa by 49 ka, and establishes the age of Acheulian to MSA transition for the region. Evidence of the use of the Levallois technique for the manufacture of both small flakes and biface preforms, the systematic production of blades, and the use and processing of red ochre also occurs in this interval. The presence of blades and red ochre at this depth is important as blades signify a high degree of technical competence and red ochre suggests symbolic behavior. PMID:11795974

Deino, Alan L; McBrearty, Sally

2002-01-01

111

Reconstruction of the Late Quaternary Glaciation of the Macha Khola valley (Gorkha Himal, Nepal) using relative and absolute ( 14C, 10Be, dendrochronology) dating techniques  

Microsoft Academic Search

Late Quaternary glacier fluctuations in the Macha Khola valley (Gorkha Himal, Nepal) were reconstructed using relative and absolute dating techniques. Our results indicate that younger moraine complexes were left by Late Holocene (<1.7cal.ka BP), mid-Holocene (ca 3cal.ka BP), and Lateglacial (ca 13cal.ka BP) ice advances. Older Late Quaternary glacier advances occurred during Marine Oxygen Isotope Stages (MIS) 2 and 34.

W. Zech; B. Glaser; U. Abramowski; C. Dittmar; P. W. Kubik

2003-01-01

112

Development of a radiometric measuring system for high porous vacuum plasma sprayed titanium coatings  

NASA Astrophysics Data System (ADS)

Photothermal measurement techniques offer an unique suitability for the non-destructive and noncontact evaluation of coatings. Herein, we describe in detail the development of a radiometric measuring system for industrial application in NDE. This instrument is capable to determine the thickness and the porosity of high porous vacuum plasma sprayed (VPS) titanium coatings. Results for both, layer thickness and porosity, will be presented. Now, the system works properly for quality assurance purposes in the company AESCULAP, Tuttlingen, DE.

Ritter, R.; Schmitz, B.

1999-03-01

113

Age of Barrier Canyon-style rock art constrained by cross-cutting relations and luminescence dating techniques  

PubMed Central

Rock art compels interest from both researchers and a broader public, inspiring many hypotheses about its cultural origin and meaning, but it is notoriously difficult to date numerically. Barrier Canyon-style (BCS) pictographs of the Colorado Plateau are among the most debated examples; hypotheses about its age span the entire Holocene epoch and previous attempts at direct radiocarbon dating have failed. We provide multiple age constraints through the use of cross-cutting relations and new and broadly applicable approaches in optically stimulated luminescence dating at the Great Gallery panel, the type section of BCS art in Canyonlands National Park, southeastern Utah. Alluvial chronostratigraphy constrains the burial and exhumation of the alcove containing the panel, and limits are also set by our related research dating both a rockfall that removed some figures and the rocks exposure duration before that time. Results provide a maximum possible age, a minimum age, and an exposure time window for the creation of the Great Gallery panel, respectively. The only prior hypothesis not disproven is a late Archaic origin for BCS rock art, although our age result of A.D. ?11100 coincides better with the transition to and rise of the subsequent Fremont culture. This chronology is for the type locality only, and variability in the age of other sites is likely. Nevertheless, results suggest that BCS rock art represents an artistic tradition that spanned cultures and the transition from foraging to farming in the region. PMID:25157162

Pederson, Joel L.; Chapot, Melissa S.; Simms, Steven R.; Sohbati, Reza; Rittenour, Tammy M.; Murray, Andrew S.; Cox, Gary

2014-01-01

114

Age of Barrier Canyon-style rock art constrained by cross-cutting relations and luminescence dating techniques.  

PubMed

Rock art compels interest from both researchers and a broader public, inspiring many hypotheses about its cultural origin and meaning, but it is notoriously difficult to date numerically. Barrier Canyon-style (BCS) pictographs of the Colorado Plateau are among the most debated examples; hypotheses about its age span the entire Holocene epoch and previous attempts at direct radiocarbon dating have failed. We provide multiple age constraints through the use of cross-cutting relations and new and broadly applicable approaches in optically stimulated luminescence dating at the Great Gallery panel, the type section of BCS art in Canyonlands National Park, southeastern Utah. Alluvial chronostratigraphy constrains the burial and exhumation of the alcove containing the panel, and limits are also set by our related research dating both a rockfall that removed some figures and the rock's exposure duration before that time. Results provide a maximum possible age, a minimum age, and an exposure time window for the creation of the Great Gallery panel, respectively. The only prior hypothesis not disproven is a late Archaic origin for BCS rock art, although our age result of A.D. ? 1-1100 coincides better with the transition to and rise of the subsequent Fremont culture. This chronology is for the type locality only, and variability in the age of other sites is likely. Nevertheless, results suggest that BCS rock art represents an artistic tradition that spanned cultures and the transition from foraging to farming in the region. PMID:25157162

Pederson, Joel L; Chapot, Melissa S; Simms, Steven R; Sohbati, Reza; Rittenour, Tammy M; Murray, Andrew S; Cox, Gary

2014-09-01

115

Relative radiometric calibration of LANDSAT TM reflective bands  

NASA Technical Reports Server (NTRS)

A common scientific methodology and terminology is outlined for characterizing the radiometry of both TM sensors. The magnitude of the most significant sources of radiometric variability are discussed and methods are recommended for achieving the exceptional potential inherent in the radiometric precision and accuracy of the TM sensors.

Barker, J. L.

1984-01-01

116

Digital correction of geometric and radiometric errors in ERTS data.  

NASA Technical Reports Server (NTRS)

The sensor systems of the ERTS-A satellite are discussed and sources of geometric and radiometric errors in the received images are identified. Digital algorithms are presented for detection of reseau and ground control points, for rapid implementation of geometric corrections, and for radiometric correction of errors caused by shading, image motion, modulation transfer function, and quantum and systematic noise.

Bakis, R.; Wesley, M. A.; Will, P. M.

1971-01-01

117

Radiometric Quality Evaluation of INSAT-3D Imager Data  

NASA Astrophysics Data System (ADS)

INSAT-3D is an advanced meteorological satellite of ISRO which acquires imagery in optical and infra-red (IR) channels for study of weather dynamics in Indian sub-continent region. In this paper, methodology of radiometric quality evaluation for Level-1 products of Imager, one of the payloads onboard INSAT-3D, is described. Firstly, overall visual quality of scene in terms of dynamic range, edge sharpness or modulation transfer function (MTF), presence of striping and other image artefacts is computed. Uniform targets in Desert and Sea region are identified for which detailed radiometric performance evaluation for IR channels is carried out. Mean brightness temperature (BT) of targets is computed and validated with independently generated radiometric references. Further, diurnal/seasonal trends in target BT values and radiometric uncertainty or sensor noise are studied. Results of radiometric quality evaluation over duration of eight months (January to August 2014) and comparison of radiometric consistency pre/post yaw flip of satellite are presented. Radiometric Analysis indicates that INSAT-3D images have high contrast (MTF > 0.2) and low striping effects. A bias of <4K is observed in the brightness temperature values of TIR-1 channel measured during January-August 2014 indicating consistent radiometric calibration. Diurnal and seasonal analysis shows that Noise equivalent differential temperature (NEdT) for IR channels is consistent and well within specifications.

Prakash, S.; Jindal, D.; Badal, N.; Kartikeyan, B.; Gopala Krishna, B.

2014-11-01

118

Radiometric resolution enhancement by lossy compression as compared to truncation followed by lossless compression  

NASA Technical Reports Server (NTRS)

Recent advances in imaging technology make it possible to obtain imagery data of the Earth at high spatial, spectral and radiometric resolutions from Earth orbiting satellites. The rate at which the data is collected from these satellites can far exceed the channel capacity of the data downlink. Reducing the data rate to within the channel capacity can often require painful trade-offs in which certain scientific returns are sacrificed for the sake of others. In this paper we model the radiometric version of this form of lossy compression by dropping a specified number of least significant bits from each data pixel and compressing the remaining bits using an appropriate lossless compression technique. We call this approach 'truncation followed by lossless compression' or TLLC. We compare the TLLC approach with applying a lossy compression technique to the data for reducing the data rate to the channel capacity, and demonstrate that each of three different lossy compression techniques (JPEG/DCT, VQ and Model-Based VQ) give a better effective radiometric resolution than TLLC for a given channel rate.

Tilton, James C.; Manohar, Mareboyana

1994-01-01

119

Faint Young Sun, Radiocarbon dating  

NSDL National Science Digital Library

The first problem in this assignment is the culmination of the unit on energy balance and greenhouse gases. The students have already calculated blackbody temperatures as a function of albedo, sun's luminosity and distance from sun. They have also already calculated the magnitude of the greenhouse effect (optical thickness) of the modern atmosphere. In this first problem, the students apply these same calculations to the Faint Young Sun hypothesis and infer what can account for the geological evidence for liquid water on earth since 4.3 Ga. The second problem follows an introductory lecture on radiometric decay and radiometric dating. The students have seen the decay equation and learned what are decay constants and stable versus radioactive isotopes. In this problem, the students apply these concepts to radiocarbon.

Mea Cook

120

Amino acid racemization dating of Upper Pleistocene - Holocene terrestrial gastropods from a Mediterranean region (Murcia, SE Spain)  

NASA Astrophysics Data System (ADS)

The amino acid racemization method has become a widely used geochronological tool for dating Quaternary deposits. The method is based on the fact that living organisms contain only L-amino acids which gradually racemize into D-amino acids after death. Thus, the D/L ratio increases with time after death until it is equal to 1, that is, when equilibrium is reached. Gastropod shells are particularly useful for amino acid racemization dating. Because the amino acid racemization method is not a numerical dating method in isolation, it needs to be calibrated, mainly with radiometric dating methods. The racemization process is genus- and temperature-dependent. In this work we present a preliminary analysis that compares the radiometric age estimated from different dating methods of a number of gastropods recovered in localities from Murcia (Southeastern Spain), with the age obtained through the amino acid racemization method. Taking advantage of recent paleoseismological research in the Murcia region (SE Spain), 28 gastropods specimens were collected from different trenches dug in young Quaternary alluvial deposits. The specimens were subsequently classified and then analyzed according to the standards protocols of the Biomolecular Stratigraphy Laboratory (UPM, Madrid School of Mines). The species found were Otala lactea, Iberus gualterianus, Sphincterochila candidissima and Theba pisana. The D/L ratios of aspartic acid, leucine, phenylalanine and glutamic acid were determined, and the corresponding average age of each specimen was calculated introducing the D/L values in the age calculation algorithm of Torres et al. (1997) for gastropods of central and southern Spain. The racemization age for each locality was then compared to the radiometric age of the deposit where the specimens were collected. To this respect, the samples were classified in different groups considering the reliability on the age control method. The most reliable sample consists only on dates obtained by the radiocarbon method applied to pieces of charcoal found in the same sedimentary unit as the gastropod. The other subsets consider dates, or bracketed dates, obtained from other dating techniques (TL, OSL, Uranium series) or even stratigraphic criteria. Preliminary results show that Torres et al. (1997) calibration algorithm estimates ages as much as ten times older than the most likely one. We think that this result is due to a strong bias on the way the algorithm was obtained, based mostly in Lower Pleistocene/Pliocene samples. Hence, the new data presented here could be used to constraint better the Torres et al. (1997) function towards Upper Pleistocene and Holocene dates. This type of calibration model would be very valuable in determining ages of recent deposits in the Murcia Region, a matter that is critical in paleoseismological research.

Garcia-Mayordomo, Julian; Ortiz, Jose E.; Torres, Trinidad; Insua-Arevalo, Juan M.; Martinez-Diaz, Jose J.; Altolaguirre, Yul; Canales-Fernandez, Maria L.; Martin-Banda, Raquel

2014-05-01

121

Radiocarbon dates on bones of extinct birds from Hawaii  

SciTech Connect

Bones from a stratified sedimentary deposit in the Puu Naio Cave site on Maui, Hawaiian Islands, reveal the late Holocene extinction of 19 species of birds. The age of the sediment and associated fauna was determined by direct radiocarbon dating (tandem particle accelerator-mass spectrometer; TAMS) of amino acids extracted from bones weighing as little as 450 mg. The /sup 14/C dates indicate that sediment has been accumulating in the lava tube for at least the last 7750 years, a suitable time frame for testing the hypothesis that Holocene extinction on islands began after human colonization. Despite growing evidence that a worldwide wave of extinctions coincided with human colonization of oceanic islands, little radiometric data have been available to date the extinction of most small fossil vertebrates on islands. The TAMS technique of dating purified collagen from the bones of small vertebrates could lead to vastly improved chronologies of extinction for oceanic islands where catastrophic mid- to late-Holocene extinction is expected or known to have occurred. Chronologies derived from nonarcheological sites that show continuous sedimentation, such as the Puu Naio Cave deposit, may also yield key evidence on the timing of earliest human settlement of Oceania.

James, H.F.; Stafford, T.W. Jr.; Steadman, D.W.; Olson, S.L.; Martin, P.S.; Jull, A.J.; McCoy, P.C.

1987-04-01

122

Radiocarbon dates on bones of extinct birds from Hawaii.  

PubMed Central

Bones from a stratified sedimentary deposit in the Puu Naio Cave site on Maui, Hawaiian Islands, reveal the late Holocene extinction of 19 species of birds. The age of the sediment and associated fauna was determined by direct radiocarbon dating (tandem particle accelerator-mass spectrometer; TAMS) of amino acids extracted from bones weighing as little as 450 mg. The 14C dates indicate that sediment has been accumulating in the lava tube for at least the last 7750 years, a suitable time frame for testing the hypothesis that Holocene extinction on islands began after human colonization. Despite growing evidence that a worldwide wave of extinctions coincided with human colonization of oceanic islands, little radiometric data have been available to date the extinction of most small fossil vertebrates on islands. The TAMS technique of dating purified collagen from the bones of small vertebrates could lead to vastly improved chronologies of extinction for oceanic islands where catastrophic mid- to late-Holocene extinction is expected or known to have occurred. Chronologies derived from nonarcheological sites that show continuous sedimentation, such as the Puu Naio Cave deposit, may also yield key evidence on the timing of earliest human settlement of Oceania. Images PMID:3470800

James, H F; Stafford, T W; Steadman, D W; Olson, S L; Martin, P S; Jull, A J; McCoy, P C

1987-01-01

123

Building on previous OSL dating techniques for gypsum: a case study from Salt Basin playa, New Mexico and Texas  

USGS Publications Warehouse

The long term stability and reliability of the luminescence signal for gypsum has not been well documented or systematically measured until just recently. A review of the current literature for luminescence dating of gypsum is compiled here along with original efforts at dating an intact and in-situ bed of selenite gypsum at Salt Basin Playa, New Mexico and Texas. This effort differs from other documented luminescence dating efforts because the gypsum is not powdery or redistributed from its original growth patterns within the playa basin but is instead of a crystalline form. Sixteen ages from eight cores were ultimately produced with seven of the ages coming from rare detrital quartz encased in or with the gypsum crystals while the remaining ages are from the crystalline gypsum. As far as can be ascertained, the quartz was measured separately from the gypsum and no contaminants were noted in any of the aliquots. Some basic and preliminary tests of signal stability were measured and found to be mitigated by lessening of pre-heat protocols. Ages ranged from 8 ka to 10 ka in the shallow cores and 16 ka to 22 ka in the deeper cores. These ages will be useful in determining rates of gypsum growth within a sequence of evaporates which, in turn, will help to better document historic rates of evaporation and thus estimate, with more precision, the corresponding annual evaporation rates.

Mahan, Shannon; Kay, John

2012-01-01

124

Landsat-7 ETM+ radiometric stability and absolute calibration  

USGS Publications Warehouse

Launched in April 1999, the Landsat-7 ETM+ instrument is in its fourth year of operation. The quality of the acquired calibrated imagery continues to be high, especially with respect to its three most important radiometric performance parameters: reflective band instrument stability to better than ??1%, reflective band absolute calibration to better than ??5%, and thermal band absolute calibration to better than ??0.6 K. The ETM+ instrument has been the most stable of any of the Landsat instruments, in both the reflective and thermal channels. To date, the best on-board calibration source for the reflective bands has been the Full Aperture Solar Calibrator, which has indicated changes of at most -1.8% to -2.0% (95% C.I.) change per year in the ETM+ gain (band 4). However, this change is believed to be caused by changes in the solar diffuser panel, as opposed to a change in the instrument's gain. This belief is based partially on ground observations, which bound the changes in gain in band 4 at -0.7% to +1.5%. Also, ETM+ stability is indicated by the monitoring of desert targets. These image-based results for four Saharan and Arabian sites, for a collection of 35 scenes over the three years since launch, bound the gain change at -0.7% to +0.5% in band 4. Thermal calibration from ground observations revealed an offset error of +0.31 W/m 2 sr um soon after launch. This offset was corrected within the U. S. ground processing system at EROS Data Center on 21-Dec-00, and since then, the band 6 on-board calibration has indicated changes of at most +0.02% to +0.04% (95% C.I.) per year. The latest ground observations have detected no remaining offset error with an RMS error of ??0.6 K. The stability and absolute calibration of the Landsat-7 ETM+ sensor make it an ideal candidate to be used as a reference source for radiometric cross-calibrating to other land remote sensing satellite systems.

Markham, B.L.; Barker, J.L.; Barsi, J.A.; Kaita, E.; Thome, K.J.; Helder, D.L.; Palluconi, F.D.; Schott, J.R.; Scaramuzza, P.

2002-01-01

125

Radiometric responsivity determination for Feature Identification and Location Experiment (FILE) flown on space shuttle mission  

NASA Technical Reports Server (NTRS)

A procedure was developed to obtain the radiometric (radiance) responsivity of the Feature Identification and Local Experiment (FILE) instrument in preparation for its flight on Space Shuttle Mission 41-G (November 1984). This instrument was designed to obtain Earth feature radiance data in spectral bands centered at 0.65 and 0.85 microns, along with corroborative color and color-infrared photographs, and to collect data to evaluate a technique for in-orbit autonomous classification of the Earth's primary features. The calibration process incorporated both solar radiance measurements and radiative transfer model predictions in estimating expected radiance inputs to the FILE on the Shuttle. The measured data are compared with the model predictions, and the differences observed are discussed. Application of the calibration procedure to the FILE over an 18-month period indicated a constant responsivity characteristic. This report documents the calibration procedure and the associated radiometric measurements and predictions that were part of the instrument preparation for flight.

Wilson, R. G.; Davis, R. E.; Wright, R. E., Jr.; Sivertson, W. E., Jr.; Bullock, G. F.

1986-01-01

126

Errors in radiometric remote sensing of sea-surface temperature and salinity  

NASA Technical Reports Server (NTRS)

Techniques for remote measurement of sea-surface physical temperature and salinity using radiometric measurements from aircraft or satellite are reviewed. Studies have been conducted to determine the sensitivity of the errors in surface temperature and salinity to errors in the measured brightness temperatures using combinations of UHF, L, S, and C-band measurements. These investigations were made using values of conductivity, static dielectric constant, and relaxation time derived from the regression equations of Klein and Swift (1977). Results of the error sensitivity study are presented in the form of error contour plots which permit the calculation of errors in the estimation of the physical parameters for given errors in the raw radiometric measurements.

Britt, C. L., Jr.

1984-01-01

127

Absolute radiometric calibration of the Thematic Mapper  

NASA Technical Reports Server (NTRS)

Calibration data for the solar reflective bands of the Landsat-5 TM obtained from five in-flight absolute radiometric calibrations from July 1984-November 1985 at White Sands, New Mexico are presented and analyzed. Ground reflectance and atmospheric data were utilized to predict the spectral radiance at the entrance pupil of the TM and the average number of digital counts in each TM band. The calibration of each of the TM solar reflective bands was calculated in terms of average digital counts/unit spectral radiance for each band. It is observed that for the 12 reflectance-based measurements the rms variation from the means as a percentage of the mean is + or - 1.9 percent; for the 11 measurements in the IR bands, it is + or - 3.4 percent; and the rms variation for all 23 measurements is + or - 2.8 percent.

Slater, P. N.; Biggar, S. F.; Holm, R. G.; Jackson, R. D.; Mao, Y.

1986-01-01

128

Absolute Radiometric Calibration of EUNIS-06  

NASA Technical Reports Server (NTRS)

The Extreme-Ultraviolet Normal-Incidence Spectrometer (EUNIS) is a soundingrocket payload that obtains imaged high-resolution spectra of individual solar features, providing information about the Sun's corona and upper transition region. Shortly after its successful initial flight last year, a complete end-to-end calibration was carried out to determine the instrument's absolute radiometric response over its Longwave bandpass of 300 - 370A. The measurements were done at the Rutherford-Appleton Laboratory (RAL) in England, using the same vacuum facility and EUV radiation source used in the pre-flight calibrations of both SOHO/CDS and Hinode/EIS, as well as in three post-flight calibrations of our SERTS sounding rocket payload, the precursor to EUNIS. The unique radiation source provided by the Physikalisch-Technische Bundesanstalt (PTB) had been calibrated to an absolute accuracy of 7% (l-sigma) at 12 wavelengths covering our bandpass directly against the Berlin electron storage ring BESSY, which is itself a primary radiometric source standard. Scans of the EUNIS aperture were made to determine the instrument's absolute spectral sensitivity to +- 25%, considering all sources of error, and demonstrate that EUNIS-06 was the most sensitive solar E W spectrometer yet flown. The results will be matched against prior calibrations which relied on combining measurements of individual optical components, and on comparisons with theoretically predicted 'insensitive' line ratios. Coordinated observations were made during the EUNIS-06 flight by SOHO/CDS and EIT that will allow re-calibrations of those instruments as well. In addition, future EUNIS flights will provide similar calibration updates for TRACE, Hinode/EIS, and STEREO/SECCHI/EUVI.

Thomas, R. J.; Rabin, D. M.; Kent, B. J.; Paustian, W.

2007-01-01

129

Thermoluminescence (TL) dating  

NSDL National Science Digital Library

Thermoluminescence (TL) dating is an important technique used to determine the ages of some ancient earth materials; in this case, sediments and certain ancient artifacts. TL energy is stored in the form of trapped electrons and quartz sand is the most commonly used mineral employed in the dating process. Topics which are discussed include basic principles of TL dating, sampling techniques and strategies, sample processing, dateable material, cost and turnaround time, other applications, and associated literature.

David Price

1997-10-15

130

Fission track dating of kimberlitic zircons  

USGS Publications Warehouse

The only reliable method for dating kimberlites at present is the lengthy and specialized hydrothermal procedure that extracts 206Pb and 238U from low-uranium zircons. This paper describes a second successful method by fission track dating of large single-crystal zircons, 1.0-1.5 cm in dimension. The use of large crystals overcomes the limitations imposed in conventional fission track analysis which utilizes crushed fragments. Low track densities, optical track dispersion, and the random orientation of polished surfaces in the etch and irradiation cycle are effectively overcome. Fission track ages of zircons from five African kimberlites are reported, from the Kimberley Pool (90.3 ?? 6.5 m.y.), Orapa (87.4 ?? 5.7 and 92.4 ?? 6.1 m.y.), Nzega (51.1 ?? 3.8 m.y.), Koffiefontein (90.0 ?? 8.2 m.y.), and Val do Queve (133.4 ?? 11.5 m.y.). In addition we report the first radiometric ages (707.9 ?? 59.6 and 705.5 ?? 61.0 m.y.) of crustal zircons from kimberlites in northwest Liberia. The fission track ages agree well with earlier age estimates. Most of the zircons examined in this study are zoned with respect to uranium but linear correlations are established (by regression analysis) between zones of variable uranium content, and within zones of constant uranium content (by analysis of variance). Concordance between the fission track method and the U/Pb technique is established and we concluded that track fading from thermal annealing has not taken place. Kimberlitic zircons dated in this study, therefore, record the time of eruption. ?? 1983.

Haggerty, S.E.; Raber, E.; Naeser, C.W.

1983-01-01

131

Comparison of radiometric and chemical detection sensitivities for heterodyne and direct detection DIAL  

NASA Astrophysics Data System (ADS)

A high repetition rate, wavelength agile CO2 laser has been developed at the Air Force Research Laboratory for use as a local oscillator in a heterodyne detection receiver. Rapid wavelength selection is required for measurements of airborne chemical vapors using the differential absorption lidar (DIAL) technique. Acousto-optic modulators are used in the local oscillator to tune between different wavelengths at high speeds (greater than 100 Hz) without the need for moving mechanical parts. Other advantages obtained by the use of acousto-optic modulators are laser output power control per wavelength and rugged packaging for field applications. A series of experiments to simultaneously characterize the radiometric and chemical detection sensitivities of heterodyne and direct detection DIAL systems is being performed at Kirtland AFB, NM, and will be described. The wavelength agile local oscillator (WALO) has been incorporated into a heterodyne receiver, with the Laser Airborne Remote Sensing (LARS) system providing the laser transmitter and direct detection receiver. The experiment series is studying radiometric issues, spread spectrum operation, the effects of target-induced speckle, and the influence of atmospheric turbulence for both detection mechanisms. Measurements are being performed over a horizontal path at standoff ranges of 4 to 15 km, using both natural and man-made targets. Comparisons of the heterodyne and direct detection radiometric and chemometric results will be presented, and contrasted with predictions from simulations and models. The results will also be discussed in terms of the implications for fielding operational DIAL systems.

Senft, Daniel C.; Pierrottet, Diego F.

2004-02-01

132

Impact of the cameras radiometric resolution on the accuracy of determining spectral reflectance coefficients  

NASA Astrophysics Data System (ADS)

Nowadays remote sensing plays a very important role in many different study fields, i.e. environmental studies, hydrology, mineralogy, ecosystem studies, etc. One of the key areas of remote sensing applications is water quality monitoring. Understanding and monitoring of the water quality parameters and detecting different water contaminants is an important issue in water management and protection of whole environment and especially the water ecosystem. There are many remote sensing methods to monitor water quality and detect water pollutants. One of the most widely used method for substance detection with remote sensing techniques is based on usage of spectral reflectance coefficients. They are usually acquired using discrete methods such as spectrometric measurements. These however can be very time consuming, therefore image-based methods are used more and more often. In order to work out the proper methodology of obtaining spectral reflectance coefficients from hyperspectral and multispectral images, it is necessary to verify the impact of cameras radiometric resolution on the accuracy of determination of them. This paper presents laboratory experiments that were conducted using two monochromatic XEVA video sensors (400-1700 nm spectral data registration) with two different radiometric resolutions (12 and 14 bits). In view of determining spectral characteristics from images, the research team used set of interferometric filters. All data collected with multispectral digital video cameras were compared with spectral reflectance coefficients obtained with spectroradiometer. The objective of this research is to find the impact of cameras radiometric resolution on reflectance values in chosen wavelength. The main topic of this study is the analysis of accuracy of spectral coefficients from sensors with different radiometric resolution. By comparing values collected from images acquired with XEVA sensors and with the curves obtained with spectroradiometer it's possible to determine accuracy of imagebased spectral reflectance coefficients and decide which sensor will be more accurate to determine them for protection of water aquatic environment purpose.

Orych, A.; Walczykowski, P.; Jenerowicz, A.; Zdunek, Z.

2014-11-01

133

Laboratory radiometric calibration for the convex grating imaging spectrometer  

NASA Astrophysics Data System (ADS)

The radiometric calibration of imaging spectrometer plays an import role for scientific application of spectral data. The radiometric calibration accuracy is influenced by many factors, such as the stability and uniformity of light source, the transfer precision of radiation standard and so on. But the deviation from the linear response mode and the polarization effect of the imaging spectrometer are always neglected. In this paper, the linear radiometric calibration model is constructed and the radiometric linear response capacity is test by adjusting electric gain, exposure time and radiance level. The linear polarizer and the sine function fitting algorithm are utilized to measure polarization effect. The integrating sphere calibration system is constructed in our Lab and its spectral radiance is calibrated by a well-characterized and extremely stable NIST traceable transfer spectroradiometer. Our manufactured convex grating imaging spectrometer is relative and absolute calibrated based on the integrating sphere calibration system. The relative radiometric calibration data is used to remove or reduce the radiometric response non-uniformity every pixel of imaging spectrometer while the absolute radiometric calibration is used to construct the relationship between the physical radiant of the scene and the digital number of the image. The calibration coefficients are acquired at ten radiance levels. The diffraction noise in the images can be corrected by the calibration coefficients and the uniform radiance image can be got. The calibration result shows that our manufactured imaging spectrometer with convex grating has 3.0% degree of polarization and the uncertainties of the relative and absolute radiometric calibrations are 2.4% and 5.6% respectively.

Zhou, Jiankang; Chen, Xinhua; Chen, Yuheng; Ji, Yiqun; Shen, Weimin

2014-09-01

134

Radiometric sensitivity comparisons of multispectral imaging systems  

NASA Technical Reports Server (NTRS)

Multispectral imaging systems provide much of the basic data used by the land and ocean civilian remote-sensing community. There are numerous multispectral imaging systems which have been and are being developed. A common way to compare the radiometric performance of these systems is to examine their noise-equivalent change in reflectance, NE Delta-rho. The NE Delta-rho of a system is the reflectance difference that is equal to the noise in the recorded signal. A comparison is made of the noise equivalent change in reflectance of seven different multispectral imaging systems (AVHRR, AVIRIS, ETM, HIRIS, MODIS-N, SPOT-1, HRV, and TM) for a set of three atmospheric conditions (continental aerosol with 23-km visibility, continental aerosol with 5-km visibility, and a Rayleigh atmosphere), five values of ground reflectance (0.01, 0.10, 0.25, 0.50, and 1.00), a nadir viewing angle, and a solar zenith angle of 45 deg.

Lu, Nadine C.; Slater, Philip N.

1989-01-01

135

Blast investigation by fast multispectral radiometric analysis  

NASA Astrophysics Data System (ADS)

Knowledge regarding the processes involved in blasts and detonations is required in various applications, e.g. missile interception, blasts of high-explosive materials, final ballistics and IED identification. Blasts release large amount of energy in short time duration. Some part of this energy is released as intense radiation in the optical spectral bands. This paper proposes to measure the blast radiation by a fast multispectral radiometer. The measurement is made, simultaneously, in appropriately chosen spectral bands. These spectral bands provide extensive information on the physical and chemical processes that govern the blast through the time-dependence of the molecular and aerosol contributions to the detonation products. Multi-spectral blast measurements are performed in the visible, SWIR and MWIR spectral bands. Analysis of the cross-correlation between the measured multi-spectral signals gives the time dependence of the temperature, aerosol and gas composition of the blast. Farther analysis of the development of these quantities in time may indicate on the order of the detonation and amount and type of explosive materials. Examples of analysis of measured explosions are presented to demonstrate the power of the suggested fast multispectral radiometric analysis approach.

Devir, A. D.; Bushlin, Y.; Mendelewicz, I.; Lessin, A. B.; Engel, M.

2011-06-01

136

Transportable high sensitivity small sample radiometric calorimeter  

SciTech Connect

A new small-sample, high-sensitivity transportable radiometric calorimeter, which can be operated in different modes, contains an electrical calibration method, and can be used to develop secondary standards, will be described in this presentation. The data taken from preliminary tests will be presented to indicate the precision and accuracy of the instrument. The calorimeter and temperature-controlled bath, at present, require only a 30-in. by 20-in. tabletop area. The calorimeter is operated from a laptop computer system using unique measurement module capable of monitoring all necessary calorimeter signals. The calorimeter can be operated in the normal calorimeter equilibration mode, as a comparison instrument, using twin chambers and an external electrical calibration method. The sample chamber is 0.75 in (1.9 cm) in diameter by 2.5 in. (6.35 cm) long. This size will accommodate most {sup 238}Pu heat standards manufactured in the past. The power range runs from 0.001 W to <20 W. The high end is only limited by sample size.

Wetzel, J.R.; Biddle, R.S.; Cordova, B.S.; Sampson, T.E.; Dye, H.R.; McDow, J.G.

1998-12-31

137

The Radiometric Bode's Law and Extrasolar Planets  

E-print Network

We predict the radio flux densities of the extrasolar planets in the current census, making use of an empirical relation--the radiometric Bode's Law--determined from the five ``magnetic'' planets in the solar system (Earth and the four gas giants). Radio emission from these planets results from solar-wind powered electron currents depositing energy in the magnetic polar regions. We find that most of the known extrasolar planets should emit in the frequency range 10--1000 MHz and, under favorable circumstances, have typical flux densities as large as 1 mJy. We also describe an initial, systematic effort to search for radio emission in low radio frequency images acquired with the Very Large Array. The limits set by the VLA images (~ 300 mJy) are consistent with, but do not provide strong constraints on, the predictions of the model. Future radio telescopes, such as the Low Frequency Array (LOFAR) and the Square Kilometer Array (SKA), should be able to detect the known extrasolar planets or place austere limits on their radio emission. Planets with masses much lower than those in the current census will probably radiate below 10 MHz and will require a space-based array.

Joseph Lazio; W. M. Farrell; Jill Dietrick; Elizabeth Greenlees; Emily Hogan; Christopher Jones; L. A. Hennig

2004-05-18

138

Absolute Radiometric Calibration of Narrow-Swath Imaging Sensors with Reference to Non-Coincident Wide-Swath Sensors  

NASA Technical Reports Server (NTRS)

An inter-calibration method is developed to provide absolute radiometric calibration of narrow-swath imaging sensors with reference to non-coincident wide-swath sensors. The method predicts at-sensor radiance using non-coincident imagery from the reference sensor and knowledge of spectral reflectance of the test site. The imagery of the reference sensor is restricted to acquisitions that provide similar view and solar illumination geometry to reduce uncertainties due to directional reflectance effects. Spectral reflectance of the test site is found with a simple iterative radiative transfer method using radiance values of a well-understood wide-swath sensor and spectral shape information based on historical ground-based measurements. At-sensor radiance is calculated for the narrow-swath sensor using this spectral reflectance and atmospheric parameters that are also based on historical in situ measurements. Results of the inter-calibration method show agreement on the 2 5 percent level in most spectral regions with the vicarious calibration technique relying on coincident ground-based measurements referred to as the reflectance-based approach. While the variability of the inter-calibration method based on non-coincident image pairs is significantly larger, results are consistent with techniques relying on in situ measurements. The method is also insensitive to spectral differences between the sensors by transferring to surface spectral reflectance prior to prediction of at-sensor radiance. The utility of this inter-calibration method is made clear by its flexibility to utilize image pairings with acquisition dates differing in excess of 30 days allowing frequent absolute calibration comparisons between wide- and narrow-swath sensors.

McCorkel, Joel; Thome, Kurtis; Lockwood, Ronald

2012-01-01

139

Dendrochemical Dating of Tephra Layers  

Microsoft Academic Search

Dating eruptions in the past 1000 years can be difficult with 14C, as production rates have varied. Tree-ring dating has been used, with eruptions presumably causing thin rings. We are developing a dendrochemical dating technique that may give more confidence to such dates. When a tephra is deposited, soil chemistry may change and many components of the glassy matrix are

M. H. Ort; P. R. Sheppard; J. Speakman; K. A. Anderson; M. D. Elson; C. Siebe G

2004-01-01

140

Date: _________________________ From: ____________________________________________  

E-print Network

06/21/13 Date: _________________________ From: ____________________________________________ Via information apply: Business name & address Daily rate Hotel tax Date from Date for an online booking hotel receipt." This form may not be used for lost online booking receipts. (b) Other. I

141

A Kalman Approach to Lunar Surface Navigation using Radiometric and Inertial Measurements  

NASA Technical Reports Server (NTRS)

Future lunar missions supporting the NASA Vision for Space Exploration will rely on a surface navigation system to determine astronaut position, guide exploration, and return safely to the lunar habitat. In this report, we investigate one potential architecture for surface navigation, using an extended Kalman filter to integrate radiometric and inertial measurements. We present a possible infrastructure to support this technique, and we examine an approach to simulating navigational accuracy based on several different system configurations. The results show that position error can be reduced to 1 m after 5 min of processing, given two satellites, one surface communication terminal, and knowledge of the starting position to within 100 m.

Chelmins, David T.; Welch, Bryan W.; Sands, O. Scott; Nguyen, Binh V.

2009-01-01

142

A double-spike method for K-Ar measurement: A technique for high precision in situ dating on Mars and other planetary surfaces  

NASA Astrophysics Data System (ADS)

A new method for K-Ar dating using a double isotope dilution technique is proposed and demonstrated. The method is designed to eliminate known difficulties facing in situ dating on planetary surfaces, especially instrument complexity and power availability. It may also have applicability in some terrestrial dating applications. Key to the method is the use of a solid tracer spike enriched in both 39Ar and 41K. When mixed with lithium borate flux in a Knudsen effusion cell, this tracer spike and a sample to be dated can be successfully fused and degassed of Ar at <1000 C. The evolved 40Ar?/39Ar ratio can be measured to high precision using noble gas mass spectrometry. After argon measurement the sample melt is heated to a slightly higher temperature (1030 C) to volatilize potassium, and the evolved 39K/41K ratio measured by Knudsen effusion mass spectrometry. Combined with the known composition of the tracer spike, these two ratios define the K-Ar age using a single sample aliquot and without the need for extreme temperature or a mass determination. In principle the method can be implemented using a single mass spectrometer. Experiments indicate that quantitative extraction of argon from a basalt sample occurs at a sufficiently low temperature that potassium loss in this step is unimportant. Similarly, potassium isotope ratios measured in the Knudsen apparatus indicate good sample-spike equilibration and acceptably small isotopic fractionation. When applied to a flood basalt from the Viluy Traps, Siberia, a K-Ar age of 351 19 Ma was obtained, a result within 1% of the independently known age. For practical reasons this measurement was made on two separate mass spectrometers, but a scheme for combining the measurements in a single analytical instrument is described. Because both parent and daughter are determined by isotope dilution, the precision on K-Ar ages obtained by the double isotope dilution method should routinely approach that of a pair of isotope ratio determinations, likely better than 5%.

Farley, K. A.; Hurowitz, J. A.; Asimow, P. D.; Jacobson, N. S.; Cartwright, J. A.

2013-06-01

143

Earthtime Lesson Plan for U/Pb Dating (grade 8-12)  

NSDL National Science Digital Library

The Earthtime Lesson Plan is a complete description of a radiometric dating module taught to high school students at MIT. U/Pd dating and it's uses, teacher background, materials needed, time frame and National Science Standards are all provided as well as worksheets with teacher solutions. This module, consisting of three activities, is initially designed for a 90min period.

144

Oxygen isotope studies and compilation of isotopic dates from Antarctica  

SciTech Connect

The Quaternary Isotope Laboratory, alone or in collaboration with other investigators, is currently involved in a number of oxygen-isotope studies mainly in Antarctica. Studies of a drill core from the South Pole, seasonal oxygen-18 signals preserved in the Dominion Range, isotope dating of the Ross Ice Shelf, oxygen-18 profiles of the Siple Coast, McMurdo Ice Shelf sampling, and a data compilation of radiometric dates from Antarctica are discussed.

Grootes, P.M.; Stuiver, M.

1986-01-01

145

Radiometric Measurement Comparisons Using Transfer Radiometers in Support of the Calibration of NASA's Earth Observing System (EOS) Sensors  

NASA Technical Reports Server (NTRS)

EOS satellite instruments operating in the visible through the shortwave infrared wavelength regions (from 0.4 micrometers to 2.5 micrometers) are calibrated prior to flight for radiance response using integrating spheres at a number of instrument builder facilities. The traceability of the radiance produced by these spheres with respect to international standards is the responsibility of the instrument builder, and different calibration techniques are employed by those builders. The National Aeronautics and Space Administration's (NASA's) Earth Observing System (EOS) Project Science Office, realizing the importance of preflight calibration and cross-calibration, has sponsored a number of radiometric measurement comparisons, the main purpose of which is to validate the radiometric scale assigned to the integrating spheres by the instrument builders. This paper describes the radiometric measurement comparisons, the use of stable transfer radiometers to perform the measurements, and the measurement approaches and protocols used to validate integrating sphere radiances. Stable transfer radiometers from the National Institute of Standards and Technology, the University of Arizona Optical Sciences Center Remote Sensing Group, NASA's Goddard Space Flight Center, and the National Research Laboratory of Metrology in Japan, have participated in these comparisons. The approaches used in the comparisons include the measurement of multiple integrating sphere lamp levels, repeat measurements of select lamp levels, the use of the stable radiometers as external sphere monitors, and the rapid reporting of measurement results. Results from several comparisons are presented. The absolute radiometric calibration standard uncertainties required by the EOS satellite instruments are typically in the +/- 3% to +/- 5% range. Preliminary results reported during eleven radiometric measurement comparisons held between February 1995 and May 1998 have shown the radiance of integrating spheres agreed to within +/- 2.5% from the average at blue wavelengths and to within +/- 1.7% from the average at red and near infrared wavelengths. This level of agreement lends confidence in the use of the transfer radiometers in validating the radiance scales assigned by EOS instrument calibration facilities to their integrating sphere sources.

Butler, James J.; Johnson, B. Carol; Brown, Steven W.; Yoon, Howard W.; Barnes, Robert A.; Markham, Brian L.; Biggar, Stuart F.; Zalewski, Edward F.; Spyak, Paul R.; Cooper, John W.; Sakuma, Fumihiro

1999-01-01

146

In-flight absolute radiometric calibration of the Thematic Mapper  

NASA Astrophysics Data System (ADS)

The Thematic Mapper (TM) multispectral scanner system was placed into Earth orbit on July 16, 1982, as part of NASA's LANDSAT 4 payload. To determine temporal changes of the absolute radiometric calibration of the entire system in flight, spectroradiometric measurements of the ground and the atmosphere are made simultaneously with TM image acquisitions over the White Sands, New Mexico area. By entering the measured values into an atmospheric radiative transfer program, the radiance levels at the entrance pupil of the TM in four of the TM spectral bands are determined. These levels are compared to the output digital counts from the detectors that sampled the radiometrically measured ground area, thus providing an absolute radiometric calibration of the entire TM system utilizing those detectors. By reference to an adjacent, larger uniform area, the calibration is extended to all 16 detectors in each of the three bands.

Castle, K. R.; Holm, R. G.; Kastner, C. J.; Palmer, J. M.; Slater, P. N.; Dinguirard, M.; Ezra, C. E.; Jackson, D.; Savage, R. K.

1984-07-01

147

Mapping surface soil moisture with L-band radiometric measurements  

NASA Technical Reports Server (NTRS)

A NASA C-130 airborne remote sensing aircraft was used to obtain four-beam pushbroom microwave radiometric measurements over two small Kansas tall-grass prairie region watersheds, during a dry-down period after heavy rainfall in May and June, 1987. While one of the watersheds had been burned 2 months before these measurements, the other had not been burned for over a year. Surface soil-moisture data were collected at the time of the aircraft measurements and correlated with the corresponding radiometric measurements, establishing a relationship for surface soil-moisture mapping. Radiometric sensitivity to soil moisture variation is higher in the burned than in the unburned watershed; surface soil moisture loss is also faster in the burned watershed.

Wang, James R.; Shiue, James C.; Schmugge, Thomas J.; Engman, Edwin T.

1989-01-01

148

ASD FieldSpec Calibration Setup and Techniques  

NASA Technical Reports Server (NTRS)

This paper describes the Analytical Spectral Devices (ASD) Fieldspec Calibration Setup and Techniques. The topics include: 1) ASD Fieldspec FR Spectroradiometer; 2) Components of Calibration; 3) Equipment list; 4) Spectral Setup; 5) Spectral Calibration; 6) Radiometric and Linearity Setup; 7) Radiometric setup; 8) Datadets Required; 9) Data files; and 10) Field of View Measurement. This paper is in viewgraph form.

Olive, Dan

2001-01-01

149

Dating Violence  

ERIC Educational Resources Information Center

Dating violence is a form of student-on-student victimization and is a serious school safety issue. Research indicates that at a minimum, 10 percent of high school students are victims of dating violence in one form or another. Among female high school students that date, some data indicate that as many as 30 percent may be victims of dating

Stader, David L.

2011-01-01

150

Luminescence dating and palaeomagnetic age constraint on hominins from Sima de los Huesos, Atapuerca, Spain.  

PubMed

Establishing a reliable chronology on the extensive hominin remains at Sima de los Huesos is critical for an improved understanding of the complex evolutionary histories and phylogenetic relationships of the European Middle Pleistocene hominin record. In this study, we use a combination of 'extended-range' luminescence dating techniques and palaeomagnetism to provide new age constraint on sedimentary infills that are unambiguously associated with the Sima fossil assemblage. Post-infrared-infrared stimulated luminescence (pIR-IR) dating of K-feldspars and thermally transferred optically stimulated luminescence (TT-OSL) dating of individual quartz grains provide weighted mean ages of 43315ka (thousands of years) and 41619ka, respectively, for allochthonous sedimentary horizons overlying the hominin-bearing clay breccia. The six replicate luminescence ages obtained for this deposit are reproducible and provide a combined minimum age estimate of 42712ka for the underlying hominin fossils. Palaeomagnetic directions for the luminescence dated sediment horizon and underlying fossiliferous clays display exclusively normal polarities. These findings are consistent with the luminescence dating results and confirm that the hominin fossil horizon accumulated during the Brunhes Chron, i.e., within the last 780ka. The new bracketing age constraint for the Sima hominins is in broad agreement with radiometrically dated Homo heidelbergensis fossil sites, such as Mauer and Arago, and suggests that the split of the H.neanderthalensis and H.sapiens lineages took place during the early Middle Pleistocene. More widespread numerical dating of key Early and Middle Pleistocene fossil sites across Europe is needed to test and refine competing models of hominin evolution. The new luminescence chronologies presented in this study demonstrate the versatility of TT-OSL and pIR-IR techniques and the potential role they could play in helping to refine evolutionary histories over Middle Pleistocene timescales. PMID:24485349

Arnold, Lee J; Demuro, Martina; Pars, Josep M; Arsuaga, Juan Luis; Aranburu, Arantza; Bermdez de Castro, Jos Mara; Carbonell, Eudald

2014-02-01

151

Radiometric Calibration of the Earth Observing System's Imaging Sensors  

NASA Technical Reports Server (NTRS)

The work on the grant was mainly directed towards developing new, accurate, redundant methods for the in-flight, absolute radiometric calibration of satellite multispectral imaging systems and refining the accuracy of methods already in use. Initially the work was in preparation for the calibration of MODIS and HIRIS (before the development of that sensor was canceled), with the realization it would be applicable to most imaging multi- or hyper-spectral sensors provided their spatial or spectral resolutions were not too coarse. The work on the grant involved three different ground-based, in-flight calibration methods reflectance-based radiance-based and diffuse-to-global irradiance ratio used with the reflectance-based method. This continuing research had the dual advantage of: (1) developing several independent methods to create the redundancy that is essential for the identification and hopefully the elimination of systematic errors; and (2) refining the measurement techniques and algorithms that can be used not only for improving calibration accuracy but also for the reverse process of retrieving ground reflectances from calibrated remote-sensing data. The grant also provided the support necessary for us to embark on other projects such as the ratioing radiometer approach to on-board calibration (this has been further developed by SBRS as the 'solar diffuser stability monitor' and is incorporated into the most important on-board calibration system for MODIS)- another example of the work, which was a spin-off from the grant funding, was a study of solar diffuser materials. Journal citations, titles and abstracts of publications authored by faculty, staff, and students are also attached.

Slater, Philip N. (Principal Investigator)

1997-01-01

152

Prelaunch absolute radiometric calibration of LANDSAT-4 protoflight Thematic Mapper  

NASA Technical Reports Server (NTRS)

Results are summarized and analyzed from several prelaunch tests with a 122 cm integrating sphere used as part of the absolute radiometric calibration experiments for the protoflight TM sensor carried on the LANDSAT-4 satellite. The calibration procedure is presented and the radiometric sensitivity of the TM is assessed. The internal calibrator and dynamic range after calibration are considered. Tables show dynamic range after ground processing, spectral radiance to digital number and digital number to spectral radiance values for TM bands 1, 2, 3, 4, 5, 7 and for channel 4 of band 6.

Barker, J. L.; Ball, D. L.; Leung, K. C.; Walker, J. A.

1984-01-01

153

The absolute radiometric calibration of Terra imaging sensors: MODIS, MISR, and ASTER  

NASA Astrophysics Data System (ADS)

The Terra spacecraft contains five Earth-observation instruments, three of which are multispectral imaging sensors that complement each other in spectral and spatial coverage. The Moderate Resolution Imaging Spectroradiometer (MODIS) has 36 channels ranging from 0.4-14.4 ?m, with spatial resolutions of 250, 500, and 1000 m. The Multi-angle Imaging SpectroRadiometer (MISR) uses individual imaging sensors to view the earth at nine discreet angles. Each radiometer has four channels in the visible and near infrared (VNIR), and the nadir-viewing camera has a spatial resolution of 275 m. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) was designed with fourteen bands ranging from 0.5-11.6 ?m. It is the high-resolution sensor on Terra, with a spatial resolution of 15 m in the VNIR, and 30 m in the shortwave infrared (SWIR). This work describes the vicarious techniques used to perform the absolute radiometric calibration of MODIS, MISR, and ASTER in the solar-reflective region (0.4-2.5 ?m). It includes the reflectance-based approach, which uses ground-based personnel to make in situ measurements during the time of overpass. It also includes more recent results that were obtained using the University of Arizona's automated Radiometric Calibration Test Site (RadCaTS) at Railroad Valley, Nevada. In addition to the absolute radiometric calibration of Terra sensors, RadCaTS is used to perform the cross comparison of MODIS, MISR, and ASTER with Landsat 7 ETM+ and Landsat 8 OLI.

Czapla-Myers, Jeffrey; Thome, Kurtis; Anderson, Nikolaus; Biggar, Stuart

2014-10-01

154

A preliminary study of a very large space radiometric antenna  

NASA Technical Reports Server (NTRS)

An approach used to compute the size of a special radiometric reflector antenna is presented. Operating at 1 GHz, this reflector is required to produce 200 simultaneous contiguous beams, each with a 3 dB footprint of 1 km from an assumed satellite height of 650 km. The overall beam efficiency for each beam is required to be more than 90%.

Agrawal, P. K.

1979-01-01

155

Radiometric Calibration of Osmi Imagery Using Solar Calibration  

NASA Astrophysics Data System (ADS)

OSMI (Ocean Scanning Multi-Spectral Imager) raw image data (Level 0) were acquired and radiometrically corrected. We have applied two methods, using solar & dark calibration data from OSMI sensor and comparing with the SeaWiFS data, to the radiometric correction of OSMI raw image data. First, we could get the values of the gain and the offset for each pixel and each band from comparing the solar & dark calibration data with the solar input radiance values, calculated from the transmittance, BRDF (Bidirectional Reflectance Distribution Function) and the solar incidence angle (,) of OSMI sensor. Applying this calibration data to OSMI raw image data, we got the two odd results, the lower value of the radiometric corrected image data than the expected value, and the Venetian Blind Effect in the radiometric corrected image data. Second, we could get the reasonable results from comparing OSMI raw image data with the SeaWiFS data, and get a new problem of OSMI sensor.

Lee, Dong-Han; Kim, Yong-Seung

2000-12-01

156

Dating Violence  

MedlinePLUS

... of Dating Violence, You Might Think it's your fault. Feel angry, sad, lonely, depressed, or confused. Feel ... a victim of dating violence is not your fault. Nothing you say, wear, or do gives anyone ...

157

Radiocarbon Dating  

SciTech Connect

Radiocarbon dating can be used to determine the age of objects that contain components that were once alive. In the case of human remains, a radiocarbon date can distinguish between a crime scene and an archeological site. Documents, museum artifacts and art objects can be dated to determine if their age is correct for the historical context. A radiocarbon date does not confirm authenticity, but it can help identify a forgery.

Buchholz, B A

2007-12-20

158

DATE PALM  

Technology Transfer Automated Retrieval System (TEKTRAN)

This book chapter reviews date palm biology and cultivation. Date palm (Phoenix dactylifera L.) is one of the oldest fruit crops grown in the arid regions of the Arabian Peninsula, North Africa, and the Middle East. The exact origin of the date palm is unknown but most probably the area of origin w...

159

Radiometric and spectral calibrations of the Geostationary Imaging Fourier Transform Spectrometer (GIFTS) using principle component analysis  

NASA Astrophysics Data System (ADS)

The ultimate remote sensing benefits of the high resolution Infrared radiance spectrometers will be realized with their geostationary satellite implementation in the form of imaging spectrometers. This will enable dynamic features of the atmosphere's thermodynamic fields and pollutant and greenhouse gas constituents to be observed for revolutionary improvements in weather forecasts and more accurate air quality and climate predictions. As an important step toward realizing this application objective, the Geostationary Imaging Fourier Transform Spectrometer (GIFTS) Engineering Demonstration Unit (EDU) was successfully developed under the NASA New Millennium Program, 2000-2006. The GIFTS-EDU instrument employs three focal plane arrays (FPAs), which gather measurements across the long-wave IR (LWIR), short/mid-wave IR (SMWIR), and visible spectral bands. The raw GIFTS interferogram measurements are radiometrically and spectrally calibrated to produce radiance spectra, which are further processed to obtain atmospheric profiles via retrieval algorithms. The radiometric calibration is achieved using internal blackbody calibration references at ambient (260 K) and hot (286 K) temperatures. The absolute radiometric performance of the instrument is affected by several factors including the FPA off-axis effect, detector/readout electronics induced nonlinearity distortions, and fore-optics offsets. The GIFTS-EDU, being the very first imaging spectrometer to use ultra-high speed electronics to readout its large area format focal plane array detectors, operating at wavelengths as large as 15 microns, possessed non-linearity's not easily removable in the initial calibration process. In this paper, we introduce a refined calibration technique that utilizes Principle Component (PC) analysis to compensate for instrument distortions and artifacts remaining after the initial radiometric calibration process, thus, further enhance the absolute calibration accuracy. This method is applied to data collected during an atmospheric measurement experiment with the GIFTS, together with simultaneous observations by the accurately calibrated AERI (Atmospheric Emitted Radiance Interferometer), both simultaneously zenith viewing the sky through the same external scene mirror at ten-minute intervals throughout a cloudless day at Logan Utah on September 13, 2006. The PC vectors of the calibrated radiance spectra are defined from the AERI observations and regression matrices relating the initial GIFTS radiance PC scores to the AERI radiance PC scores are calculated using the least squares inverse method. A new set of accurately calibrated GIFTS radiances are produced using the first four PC scores in the regression model. Temperature and moisture profiles retrieved from the PC-calibrated GIFTS radiances are verified against radiosonde measurements collected throughout the GIFTS sky measurement period.

Tian, Jialin; Smith, William L.; Gazarik, Michael J.

2008-10-01

160

Radiometric stability of the Multi-angle Imaging SpectroRadiometer (MISR) following 15 years on-orbit  

NASA Astrophysics Data System (ADS)

The Multi-angle Imaging SpectroRadiometer (MISR) has successfully operated on the EOS/ Terra spacecraft since 1999. It consists of nine cameras pointing from nadir to 70.5 view angle with four spectral channels per camera. Specifications call for a radiometric uncertainty of 3% absolute and 1% relative to the other cameras. To accomplish this, MISR utilizes an on-board calibrator (OBC) to measure camera response changes. Once every two months the two Spectralon panels are deployed to direct solar-light into the cameras. Six photodiode sets measure the illumination level that are compared to MISR raw digital numbers, thus determining the radiometric gain coefficients used in Level 1 data processing. Although panel stability is not required, there has been little detectable change in panel reflectance, attributed to careful preflight handling techniques. The cameras themselves have degraded in radiometric response by 10% since launch, but calibration updates using the detector-based scheme has compensated for these drifts and allowed the radiance products to meet accuracy requirements. Validation using Sahara desert observations show that there has been a drift of ~1% in the reported nadir-view radiance over a decade, common to all spectral bands.

Bruegge, Carol J.; Val, Sebastian; Diner, David J.; Jovanovic, Veljko; Gray, Ellyn; Di Girolamo, Larry; Zhao, Guangyu

2014-09-01

161

Rapid radiometric method for detection of Salmonella in foods  

SciTech Connect

A radiometric method for the detection of Salmonella in foods has been developed which is based on Salmonella poly H agglutinating serum preventing Salmonella from producing 14CO2 from (14C) dulcitol. The method will detect the presence or absence of Salmonella in a product within 30 h compared to 4 to 5 days by routine culture methods. The method has been evaluated against a routine culture method using 58 samples of food. The overall agreement was 91%. Five samples negative for Salmonella by the routine method were positive by the radiometric method. These may have been false positives. However, the routine method may have failed to detect Salmonella due to the presence of large numbers of lactose-fermenting bacteria which hindered isolation of Salmonella colonies on the selective agar plates.

Stewart, B.J.; Eyles, M.J.; Murrell, W.G.

1980-08-01

162

The OLI Radiometric Scale Realization Round Robin Measurement Campaign  

NASA Technical Reports Server (NTRS)

A round robin radiometric scale realization was performed at the Ball Aerospace Radiometric Calibration Laboratory in January/February 2011 in support of the Operational Land Imager (OLI) Program. Participants included Ball Aerospace, NIST, NASA Goddard Space Flight Center, and the University of Arizona. The eight day campaign included multiple observations of three integrating sphere sources by nine radiometers. The objective of the campaign was to validate the radiance calibration uncertainty ascribed to the integrating sphere used to calibrate the OLI instrument. The instrument level calibration source uncertainty was validated by quatnifying: (1) the long term stability of the NIST calibrated radiance artifact, (2) the responsivity scale of the Ball Aerospace transfer radiometer and (3) the operational characteristics of the large integrating sphere.

Cutlip, Hansford; Cole,Jerold; Johnson, B. Carol; Maxwell, Stephen; Markham, Brian; Ong, Lawrence; Hom, Milton; Biggar, Stuart

2011-01-01

163

Radiometric calibration of the Scripps Earth Polychromatic Imaging Camera  

NASA Astrophysics Data System (ADS)

As part of the Triana mission, the Scripps Earth Polychromatic Imaging Camera (Scripps-EPIC) will view the full sunlit side of Earth from the Lagrange-1 point. The National Institute of Standards and Technology and the Scripps Institution of Oceanography, in collaboration with the contractor, Lockheed-Martin, planned the radiometric calibration of Scripps-EPIC. The measurements for this radiometric calibration were selected based upon the optical characteristics of Scripps-EPIC, the measurement equation relating signal to spectral radiance, and the available optical sources and calibrated radiometers. The guiding principle for the calibration was to perform separate, controlled measurements for each parameter in the measurement equation, namely dark signal, linearity, exposure time, and spectral radiance responsivity.

Early, Edward A.; Bush, Brett C.; Brown, Steven W.; Allen, David W.; Johnson, B. Carol

2002-01-01

164

Characterization of radiometric calibration of LANDSAT-4 TM reflective bands  

NASA Technical Reports Server (NTRS)

Prelaunch and postlaunch internal calibrator, image, and background data is to characterize the radiometric performance of the LANDSAT-4 TM and to recommend improved procedures for radiometric calibration. All but two channels (band 2, channel 4; band 5, channel 3) behave normally. Gain changes relative to a postlaunch reference for channels within a band vary within 0.5 percent as a group. Instrument gain for channels in the cold focal plane oscillates. Noise in background and image data ranges from 0.5 to 1.7 counts. Average differences in forward and reverse image data indicate a need for separate calibration processing of forward and reverse scans. Precision is improved by increasing the pulse integration width from 31 to 41 minor frames, depending on the band.

Barker, J. L.; Abrams, R. B.; Ball, D. L.; Leung, K. C.

1984-01-01

165

Issues in Absolute Spectral Radiometric Calibration: Intercomparison of Eight Sources  

NASA Technical Reports Server (NTRS)

The application of atmospheric models to AVIRIS and other spectral imaging data to derive surface reflectance requires that the sensor output be calibrated to absolute radiance. Uncertainties in absolute calibration are to be expected, and claims of 92% accuracy have been published. Measurements of accurate surface albedos and cloud absorption to be used in radiative balance calculations depend critically on knowing the absolute spectral-radiometric response of the sensor. The Earth Observing System project is implementing a rigorous program of absolute radiometric calibration for all optical sensors. Since a number of imaging instruments that provide output in terms of absolute radiance are calibrated at different sites, it is important to determine the errors that can be expected among calibration sites. Another question exists about the errors in the absolute knowledge of the exoatmospheric spectral solar irradiance.

Goetz, Alexander F. H.; Kindel, Bruce; Pilewskie, Peter

1998-01-01

166

The 90 GHz radiometric imaging. [for terrain analysis  

NASA Technical Reports Server (NTRS)

A 90-GHz (3 mm wavelength) radiometer with a noise output fluctuation of 0.22 K (RMS), with a scanning antenna beam mirror, and the data processing system are described. Real-time radiometric imaging of terrain and man-made objects are shown. Flying at an altitude of 1500 ft a radiometer antenna with a 2 degrees halfpower beamwidth can distinguish landforms, waterways, roads, runways, bridges, ships at sea and their wakes, aircraft on runways, and athletic fields. A flight taken at an altitude of 3000 ft with approximately 2000 ft of clouds below the radiometer demonstrates the ability to distinguish bridges, rivers, marshland and other landforms even though the clouds are optically opaque. The radiometric images of a few representative scenes along with photographs of the corresponding scenes are presented to demonstrate the resolution of the imager system.

King, H. E.; White, J. D.; Wilson, W. J.; Mori, T. T.; Hollinger, J. P.; Troy, B. E.; Kenney, J. E.; Mcgoogan, J. T.

1976-01-01

167

BOREAS TE-18, 60-m, Radiometrically Rectified Landsat TM Imagery  

NASA Technical Reports Server (NTRS)

The BOREAS TE-18 team used a radiometric rectification process to produce standardized DN values for a series of Landsat TM images of the BOREAS SSA and NSA in order to compare images that were collected under different atmospheric conditions. The images for each study area were referenced to an image that had very clear atmospheric qualities. The reference image for the SSA was collected on 02-Sep-1994, while the reference image for the NSA was collected on 2 1 Jun-1995. The 23 rectified images cover the period of 07-Jul-1985 to 18-Sep-1994 in the SSA and 22-Jun-1984 to 09-Jun-1994 in the NSA. Each of the reference scenes had coincident atmospheric optical thickness measurements made by RSS-11. The radiometric rectification process is described in more detail by Hall et al. (1991). The original Landsat TM data were received from CCRS for use in the BOREAS project. Due to the nature of the radiometric rectification process and copyright issues, the full-resolution (30-m) images may not be publicly distributed. However, this spatially degraded 60-m resolution version of the images may be openly distributed and is available on the BOREAS CD-ROM series. After the radiometric rectification processing, the original data were degraded to a 60-m pixel size from the original 30-m pixel size by averaging the data over a 2- by 2-pixel window. The data are stored in binary image-format files. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Activity Archive Center (DAAC).

Hall, Forrest G. (Editor); Knapp, David

2000-01-01

168

Radiometric characterization of diode-array field spectroradiometers  

Microsoft Academic Search

A study was conducted to evaluate the radiometric performance of two commercially available diode-array field spectroradiometers: the Spectron Engineering (SE) Model 590 that has been on the market for some 10 years and the several-year-old Analytical Spectral Devices (ASD) Personal Spectrometer (PS) 2. Both of these instruments provide rapid acquisition (?1 s) of a spectrum in the visible to near-infrared

Brian L. Markham; Darrel L. Williams; John R. Schafer; Frank Wood; Moon S. Kim

1995-01-01

169

Radiometric observations of the nucleus of Comet Halley  

NASA Technical Reports Server (NTRS)

Images obtained by the Halley multicolor camera (HMC) were used to determine the surface brightness of the nucleus. Radiometric values of jet-free areas of the surface are presented and a range of possible surface brightness values are derived. These direct measures are compared with brightnesses derived from the size of the nucleus, as determined from HMC images, and ground-based observations obtained before the onset of coma activity.

Delamere, W. A.; Reitsema, H. J.; Huebner, W. F.; Schmidt, H. U.; Keller, H. U.; Schmidt, W. K. H.; Wilhelm, K.; Whipple, Fred L.

1986-01-01

170

On-orbit radiometric calibration using a solar diffuser  

NASA Astrophysics Data System (ADS)

Radiometric calibration of spacecraft sensors using an on-board diffuser has become an accepted method in recent years for sensors operating in the solar-reflective portion of the spectrum. In many of these approaches, the radiance from a sunlit diffuser is used to illuminate the full aperture and full optical path of the sensor. If both the bi-directional reflectance distribution function (BRDF) of the diffuser and the incident solar irradiance are known, the absolute radiance from the diffuser can be used to determine the absolute radiometric calibration of the sensor. In this work, a method for the absolute radiometric calibration using a diffuser made of S13G/LO paint for a silicon-based detector sensor with spectral bands similar to Landsat-7 ETM+ is discussed. The spectral BRDF of a witness sample of the diffuser was measured with the goniometric facility at the Remote Sensing Group of the Optical Sciences Center at the University of Arizona. A measured solar spectral irradiance spectra is used to model the radiance at the sensor entrance pupil. Also presented is a sensitivity analysis of the diffuser-leaving radiance as a function of sensor view and incident solar angle. This sensitivity analysis is used to provide an error estimate for the calibration of the sensor using a diffuser based on the S13G/LO paint.

Krause, Keith S.; Biggar, Stuart F.; Thome, Kurtis J.; Eagen, Jim; Kenyon, Dave

2002-01-01

171

A Preliminary Analysis of LANDSAT-4 Thematic Mapper Radiometric Performance  

NASA Technical Reports Server (NTRS)

The NASA raw (BT) product, the radiometrically corrected (AT) product, and the radiometrically and geometrically corrected (PT) product of a TM scene were analyzed examine the frequency distribution of the digital data; the statistical correlation between the bands; and the variability between the detectors within a band. The analyses were performed on a series of image subsets from the full scence. Results are presented from one 1024 c 1024 pixel subset of Realfoot Lake, Tennessee which displayed a representative range of ground conditions and cover types occurring within the full frame image. From this cursory examination of one of the first seven channel TM data sets, it would appear that the radiometric performance of the system is most satisfactory and largely meets pre-launch specifications. Problems were noted with Band 5 Detector 3 and Band 2 Detector 4. Differences were observed between forward and reverse scan detector responses both for the BT and AT products. No systematic variations were observed between odd and even detectors.

Justice, C.; Fusco, L.; Mehl, W.

1985-01-01

172

UPb dating of detrital zircons for sediment provenance studiesa comparison of laser ablation ICPMS and SIMS techniques  

Microsoft Academic Search

New developments in UPb dating of zircons by laser ablation (LA) ICPMS are described and, for the first time, a direct comparison of detrital zircons dated by LA ICPMS and SIMS methods is presented. True real-time mass bias correction is made by aspirating a Tl\\/U tracer at the same time as laser ablation. The method is similar to that described

Jan Koler; Hege Fonneland; Paul Sylvester; Mike Tubrett; Rolf-Birger Pedersen

2002-01-01

173

Microwave and Millimeter-Wave Radiometric Studies of Temperature, Water Vapor and Clouds  

SciTech Connect

The importance of accurate measurements of column amounts of water vapor and cloud liquid has been well documented by scientists within the Atmospheric Radiation Measurement (ARM) Program. At the North Slope of Alaska (NSA), both microwave radiometers (MWR) and the MWRProfiler (MWRP), been used operationally by ARM for passive retrievals of the quantities: Precipitable Water Vapor (PWV) and Liquid Water Path (LWP). However, it has been convincingly shown that these instruments are inadequate to measure low amounts of PWV and LWP. In the case of water vapor, this is especially important during the Arctic winter, when PWV is frequently less than 2 mm. For low amounts of LWP (< 50 g/m{sup 2}), the MWR and MWRP retrievals have an accuracy that is also not acceptable. To address some of these needs, in March-April 2004, NOAA and ARM conducted the NSA Arctic Winter Radiometric Experiment - Water Vapor Intensive Operational Period at the ARM NSA/Adjacent Arctic Ocean (NSA/AAO) site. After this experiment, the radiometer group at NOAA moved to the Center for Environmental Technology (CET) of the Department of Electrical and Computer Engineering of the University of Colorado at Boulder. During this 2004 experiment, a total of 220 radiosondes were launched, and radiometric data from 22.235 to 380 GHz were obtained. Primary instruments included the ARM MWR and MWRP, a Global Positioning System (GPS), as well as the CET Ground-based Scanning Radiometer (GSR). We have analyzed data from these instruments to answer several questions of importance to ARM, including: (a) techniques for improved water vapor measurements; (b) improved calibration techniques during cloudy conditions; (c) the spectral response of radiometers to a variety of conditions: clear, liquid, ice, and mixed phase clouds; and (d) forward modeling of microwave and millimeter wave brightness temperatures from 22 to 380 GHz. Many of these results have been published in the open literature. During the third year of this contract, we participated in another ARM-sponsored experiment at the NSA during February-March 2007. This experiment is called the Radiative Heating in Underexplored Bands Campaign (RHUBC) and the GSR was operated successfully for the duration of the campaign. One of the principal goals of the experiment was to provide retrievals of water vapor during PWV amounts less than 2 mm and to compare GSR data with ARM radiometers and radiosondes. A secondary goal was to compare the radiometric response of the microwave and millimeter wavelength radiometers to water and ice clouds. In this final report, we will include the separate progress reports for each of the three years of the project and follow with a section on major accomplishments of the project.

Westwater, Edgeworth

2011-05-06

174

In situ radiometric and exposure age dating of the martian surface.  

PubMed

We determined radiogenic and cosmogenic noble gases in a mudstone on the floor of Gale Crater. A K-Ar age of 4.21 0.35 billion years represents a mixture of detrital and authigenic components and confirms the expected antiquity of rocks comprising the crater rim. Cosmic-ray-produced (3)He, (21)Ne, and (36)Ar yield concordant surface exposure ages of 78 30 million years. Surface exposure occurred mainly in the present geomorphic setting rather than during primary erosion and transport. Our observations are consistent with mudstone deposition shortly after the Gale impact or possibly in a later event of rapid erosion and deposition. The mudstone remained buried until recent exposure by wind-driven scarp retreat. Sedimentary rocks exposed by this mechanism may thus offer the best potential for organic biomarker preservation against destruction by cosmic radiation. PMID:24324273

Farley, K A; Malespin, C; Mahaffy, P; Grotzinger, J P; Vasconcelos, P M; Milliken, R E; Malin, M; Edgett, K S; Pavlov, A A; Hurowitz, J A; Grant, J A; Miller, H B; Arvidson, R; Beegle, L; Calef, F; Conrad, P G; Dietrich, W E; Eigenbrode, J; Gellert, R; Gupta, S; Hamilton, V; Hassler, D M; Lewis, K W; McLennan, S M; Ming, D; Navarro-Gonzlez, R; Schwenzer, S P; Steele, A; Stolper, E M; Sumner, D Y; Vaniman, D; Vasavada, A; Williford, K; Wimmer-Schweingruber, R F

2014-01-24

175

In Situ Radiometric and Exposure Age Dating of the Martian Surface  

NASA Astrophysics Data System (ADS)

We determined radiogenic and cosmogenic noble gases in a mudstone on the floor of Gale Crater. A K-Ar age of 4.21 0.35 billion years represents a mixture of detrital and authigenic components and confirms the expected antiquity of rocks comprising the crater rim. Cosmic-ray-produced 3He, 21Ne, and 36Ar yield concordant surface exposure ages of 78 30 million years. Surface exposure occurred mainly in the present geomorphic setting rather than during primary erosion and transport. Our observations are consistent with mudstone deposition shortly after the Gale impact or possibly in a later event of rapid erosion and deposition. The mudstone remained buried until recent exposure by wind-driven scarp retreat. Sedimentary rocks exposed by this mechanism may thus offer the best potential for organic biomarker preservation against destruction by cosmic radiation.

Farley, K. A.; Malespin, C.; Mahaffy, P.; Grotzinger, J. P.; Vasconcelos, P. M.; Milliken, R. E.; Malin, M.; Edgett, K. S.; Pavlov, A. A.; Hurowitz, J. A.; Grant, J. A.; Miller, H. B.; Arvidson, R.; Beegle, L.; Calef, F.; Conrad, P. G.; Dietrich, W. E.; Eigenbrode, J.; Gellert, R.; Gupta, S.; Hamilton, V.; Hassler, D. M.; Lewis, K. W.; McLennan, S. M.; Ming, D.; Navarro-Gonzlez, R.; Schwenzer, S. P.; Steele, A.; Stolper, E. M.; Sumner, D. Y.; Vaniman, D.; Vasavada, A.; Williford, K.; Wimmer-Schweingruber, R. F.; Blake, David F.; Bristow, Thomas; DesMarais, David; Edwards, Laurence; Haberle, Robert; Hoehler, Tori; Hollingsworth, Jeff; Kahre, Melinda; Keely, Leslie; McKay, Christopher; Wilhelm, Mary Beth; Bleacher, Lora; Brinckerhoff, William; Choi, David; Dworkin, Jason P.; Floyd, Melissa; Freissinet, Caroline; Garvin, James; Glavin, Daniel; Harpold, Daniel; Martin, David K.; McAdam, Amy; Raaen, Eric; Smith, Michael D.; Stern, Jennifer; Tan, Florence; Trainer, Melissa; Meyer, Michael; Posner, Arik; Voytek, Mary; Anderson, Robert C.; Aubrey, Andrew; Behar, Alberto; Blaney, Diana; Brinza, David; Christensen, Lance; Crisp, Joy A.; DeFlores, Lauren; Feldman, Jason; Feldman, Sabrina; Flesch, Gregory; Hurowitz, Joel; Jun, Insoo; Keymeulen, Didier; Maki, Justin; Mischna, Michael; Morookian, John Michael; Parker, Timothy; Pavri, Betina; Schoppers, Marcel; Sengstacken, Aaron; Simmonds, John J.; Spanovich, Nicole; Juarez, Manuel de la Torre; Webster, Christopher R.; Yen, Albert; Archer, Paul Douglas; Cucinotta, Francis; Jones, John H.; Morris, Richard V.; Niles, Paul; Rampe, Elizabeth; Nolan, Thomas; Fisk, Martin; Radziemski, Leon; Barraclough, Bruce; Bender, Steve; Berman, Daniel; Dobrea, Eldar Noe; Tokar, Robert; Williams, Rebecca M. E.; Yingst, Aileen; Leshin, Laurie; Cleghorn, Timothy; Huntress, Wesley; Manhs, Grard; Hudgins, Judy; Olson, Timothy; Stewart, Noel; Sarrazin, Philippe; Vicenzi, Edward; Wilson, Sharon A.; Bullock, Mark; Ehresmann, Bent; Peterson, Joseph; Rafkin, Scot; Zeitlin, Cary; Fedosov, Fedor; Golovin, Dmitry; Karpushkina, Natalya; Kozyrev, Alexander; Litvak, Maxim; Malakhov, Alexey; Mitrofanov, Igor; Mokrousov, Maxim; Nikiforov, Sergey; Prokhorov, Vasily; Sanin, Anton; Tretyakov, Vladislav; Varenikov, Alexey; Vostrukhin, Andrey; Kuzmin, Ruslan; Clark, Benton; Wolff, Michael; Botta, Oliver; Drake, Darrell; Bean, Keri; Lemmon, Mark; Anderson, Ryan B.; Herkenhoff, Kenneth; Lee, Ella Mae; Sucharski, Robert; Hernndez, Miguel ngel de Pablo; valos, Juan Jos Blanco; Ramos, Miguel; Kim, Myung-Hee; Plante, Ianik; Muller, Jan-Peter; Ewing, Ryan; Boynton, William; Downs, Robert; Fitzgibbon, Mike; Harshman, Karl; Morrison, Shaunna; Kortmann, Onno; Palucis, Marisa; Williams, Amy; Lugmair, Gnter; Wilson, Michael A.; Rubin, David; Jakosky, Bruce; Balic-Zunic, Tonci; Frydenvang, Jens; Jensen, Jaqueline Klvgaard; Kinch, Kjartan; Koefoed, Asmus; Madsen, Morten Bo; Stipp, Susan Louise Svane; Boyd, Nick; Campbell, John L.; Perrett, Glynis; Pradler, Irina; VanBommel, Scott; Jacob, Samantha; Owen, Tobias; Rowland, Scott; Savijrvi, Hannu; Boehm, Eckart; Bttcher, Stephan; Burmeister, Snke; Guo, Jingnan; Khler, Jan; Garca, Csar Martn; Mueller-Mellin, Reinhold; Bridges, John C.; McConnochie, Timothy; Benna, Mehdi; Franz, Heather; Bower, Hannah; Brunner, Anna; Blau, Hannah; Boucher, Thomas; Carmosino, Marco; Atreya, Sushil; Elliott, Harvey; Halleaux, Douglas; Renn, Nilton; Wong, Michael; Pepin, Robert; Elliott, Beverley; Spray, John; Thompson, Lucy; Gordon, Suzanne; Newsom, Horton; Ollila, Ann; Williams, Joshua; Bentz, Jennifer; Nealson, Kenneth; Popa, Radu; Kah, Linda C.; Moersch, Jeffrey; Tate, Christopher; Day, Mackenzie; Kocurek, Gary; Hallet, Bernard; Sletten, Ronald; Francis, Raymond; McCullough, Emily; Cloutis, Ed; ten Kate, Inge Loes; Kuzmin, Ruslan; Fraeman, Abigail; Scholes, Daniel; Slavney, Susan; Stein, Thomas; Ward, Jennifer; Berger, Jeffrey; Moores, John E.

2014-01-01

176

In Situ Radiometric Dating of Aqueously Formed Carbonates in Sutter's Mill  

NASA Astrophysics Data System (ADS)

We report Manganese-Chromium systematics for dolomite grains in the Sutter's Mill meteorite, section SM-51. Measurements yield a well-defined isochron with aqueous alteration ages comparable to CM and CI chondrites.

Jilly, C. E.; Huss, G. R.; Nagashima, K.; Yin, Q.-Z.; Sugiura, N.; Krot, A. N.

2013-09-01

177

Radiometric culture of Mycobacterium avium paratuberculosis from the feces of tule elk.  

PubMed

To determine if Mycobacterium avium paratuberculosis has persisted in tule elk (Cervus elaphus nannodes) at Point Reyes National Seashore (California, USA), 100 fresh fecal samples were collected. Feces were cultured on a modified BACTEC 12B radiometric medium for detection of M. avium paratuberculosis. Four samples, coming from two separate groups of elk tested positive for M. avium paratuberculosis. Thus, a noninvasive technique was used to document the continued presence of M. avium paratuberculosis in elk at Point Reyes National Seashore. These findings document persistence of this organism for a period of at least 13 yr in a free ranging herd of elk, with a 6 yr absence of observed clinical signs. PMID:9249713

Cook, W E; Cornish, T E; Shideler, S; Lasley, B; Collins, M T

1997-07-01

178

Novel Hyperspectral Sun Photometer for Satellite Remote Sensing Data Radiometric Calibration and Atmospheric Aerosol Studies  

NASA Technical Reports Server (NTRS)

A simple and cost-effective, hyperspectral sun photometer for radiometric vicarious remote sensing system calibration, air quality monitoring, and potentially in-situ planetary climatological studies, was developed. The device was constructed solely from off the shelf components and was designed to be easily deployable for support of short-term verification and validation data collects. This sun photometer not only provides the same data products as existing multi-band sun photometers, this device requires a simpler setup, less data acquisition time and allows for a more direct calibration approach. Fielding this instrument has also enabled Stennis Space Center (SSC) Applied Sciences Directorate personnel to cross calibrate existing sun photometers. This innovative research will position SSC personnel to perform air quality assessments in support of the NASA Applied Sciences Program's National Applications program element as well as to develop techniques to evaluate aerosols in a Martian or other planetary atmosphere.

Pagnutti, Mary; Ryan, Robert E.; Holekamp, Kara; Harrington, Gary; Frisbie, Troy

2006-01-01

179

Virtual Dating  

NSDL National Science Digital Library

This is an interactive exercise about Geologic Time. It focuses on how geologists and archaeologists determine the ages of rocks and ancient artifacts. This is a beta release of an instructional activity still under development. Virtual Dating contains two modules as well as a demonstration version. One module is Virtual Dating Isochron for rocks and minerals and the other is Virtual Dating Radiocarbon (Carbon-14). The interactive modules involve the students in exploring data and background information and answering questions as they move through the activity. An answer checking and feedback function is employed. There is also a Virtual Dating Demo if you want to do a quick run-through of the activity without answer checking enabled.

Gary Novak

180

Automatic and improved radiometric correction of Landsat imagery using reference values from MODIS surface reflectance images  

NASA Astrophysics Data System (ADS)

Radiometric correction is a prerequisite for generating high-quality scientific data, making it possible to discriminate between product artefacts and real changes in Earth processes as well as accurately produce land cover maps and detect changes. This work contributes to the automatic generation of surface reflectance products for Landsat satellite series. Surface reflectances are generated by a new approach developed from a previous simplified radiometric (atmospheric + topographic) correction model. The proposed model keeps the core of the old model (incidence angles and cast-shadows through a digital elevation model [DEM], Earth-Sun distance, etc.) and adds new characteristics to enhance and automatize ground reflectance retrieval. The new model includes the following new features: (1) A fitting model based on reference values from pseudoinvariant areas that have been automatically extracted from existing reflectance products (Terra MODIS MOD09GA) that were selected also automatically by applying quality criteria that include a geostatistical pattern model. This guarantees the consistency of the internal and external series, making it unnecessary to provide extra atmospheric data for the acquisition date and time, dark objects or dense vegetation. (2) A spatial model for atmospheric optical depth that uses detailed DEM and MODTRAN simulations. (3) It is designed so that large time-series of images can be processed automatically to produce consistent Landsat surface reflectance time-series. (4) The approach can handle most images, acquired now or in the past, regardless of the processing system, with the exception of those with extremely high cloud coverage. The new methodology has been successfully applied to a series of near 300 images of the same area including MSS, TM and ETM+ imagery as well as to different formats and processing systems (LPGS and NLAPS from the USGS; CEOS from ESA) for different degrees of cloud coverage (up to 60%) and SLC-off. Reflectance products have been validated with some example applications: time series robustness (for a pixel in a pseudoinvariant area, deviations are only 1.04% on average along the series), spectral signatures generation (visually coherent with the MODIS ones, but more similar between dates), and classification (up to 4 percent points better than those obtained with the original manual method or the CDR products). In conclusion, this new approach, that could also be applied to other sensors with similar band configurations, offers a fully automatic and reasonably good procedure for the new era of long time-series of spatially detailed global remote sensing data.

Pons, X.; Pesquer, L.; Cristbal, J.; Gonzlez-Guerrero, O.

2014-12-01

181

BOREAS TE-18, 30-m, Radiometrically Rectified Landsat TM Imagery  

NASA Technical Reports Server (NTRS)

The BOREAS TE-18 team used a radiometric rectification process to produce standardized DN values for a series of Landsat TM images of the BOREAS SSA and NSA in order to compare images that were collected under different atmospheric conditions. The images for each study area were referenced to an image that had very clear atmospheric qualities. The reference image for the SSA was collected on 02-Sep-1994, while the reference image for the NSA was collected on 21-Jun-1995. the 23 rectified images cover the period of 07-Jul-1985 to 18 Sep-1994 in the SSA and from 22-Jun-1984 to 09-Jun-1994 in the NSA. Each of the reference scenes had coincident atmospheric optical thickness measurements made by RSS-11. The radiometric rectification process is described in more detail by Hall et al. (199 1). The original Landsat TM data were received from CCRS for use in the BOREAS project. The data are stored in binary image-format files. Due to the nature of the radiometric rectification process and copyright issues, these full-resolution images may not be publicly distributed. However, a spatially degraded 60-m resolution version of the images is available on the BOREAS CD-ROM series. See Sections 15 and 16 for information about how to possibly acquire the full resolution data. Information about the full-resolution images is provided in an inventory listing on the CD-ROMs. The data files are available on a CD-ROM (see document number 20010000884), or from the Oak Ridge National Laboratory (ORNL) Distributed Activity Archive Center (DAAC).

Hall, Forrest G. (Editor); Knapp, David

2000-01-01

182

Radiometric calibration of the Landsat MSS sensor series  

USGS Publications Warehouse

Multispectral remote sensing of the Earth using Landsat sensors was ushered on July 23, 1972, with the launch of Landsat-1. Following that success, four more Landsat satellites were launched, and each of these carried the Multispectral Scanner System (MSS). These five sensors provided the only consistent multispectral space-based imagery of the Earth's surface from 1972 to 1982. This work focuses on developing both a consistent and absolute radiometric calibration of this sensor system. Cross-calibration of the MSS was performed through the use of pseudoinvariant calibration sites (PICSs). Since these sites have been shown to be stable for long periods of time, changes in MSS observations of these sites were attributed to changes in the sensors themselves. In addition, simultaneous data collections were available for some MSS sensor pairs, and these were also used for cross-calibration. Results indicated substantial differences existed between instruments, up to 16%, and these were reduced to 5% or less across all MSS sensors and bands. Lastly, this paper takes the calibration through the final step and places the MSS sensors on an absolute radiometric scale. The methodology used to achieve this was based on simultaneous data collections by the Landsat-5 MSS and Thematic Mapper (TM) instruments. Through analysis of image data from a PICS location and through compensating for the spectral differences between the two instruments, the Landsat-5 MSS sensor was placed on an absolute radiometric scale based on the Landsat-5 TM sensor. Uncertainties associated with this calibration are considered to be less than 5%.

Helder, Dennis L.; Karki, Sadhana; Bhatt, Rajendra; Micijevik, Esad; Aaron, David; Jasinski, Benjamin

2012-01-01

183

Onboard radiometric photography of EXCEDE SPECTRAL's ejected-electron beam  

NASA Astrophysics Data System (ADS)

The details of a wide-angle camera system used in the EXCEDE SPECTRAL experiment to determine spatial distributions of energy deposition are discussed, along with the camera calibrating and film data reduction procedures. The measured column emission rate distributions within a few tens of meters from the rocket between 123 and 83 km are presented and compared wit the predictions of an independent particle transport model. Spatial distributions of emission can be assessed with the aid of unfolds from the radiometrically calibrated photographs.

Kofsky, I. L.; Sluder, R. B.; Villanucci, D. P.

1982-10-01

184

A radiometric interpretive legend for Landsat digital thematic maps  

USGS Publications Warehouse

A legend is suggested for use with computer-generated thematic maps made from Landsat digital data that designates some of the radiometric characteristics of each thematic map unit as well as the described terrain attributes of each map unit. The relationship between spectral band and radiance for each map unit is shown by a two-dimensional polygon with the four Landsat multispectral scanner bands plotted on the ordinate and radiance levels on the abscissa. The resulting shape is colored to correspond with the map unit color, thus facilitating the recognition and understanding of the computer-generated map units.

Robinove, Charles J.

1977-01-01

185

Evaluation of S190A radiometric exposure test data  

NASA Technical Reports Server (NTRS)

The S190A preflight radiometric exposure test data generated as part of preflight and system test of KM-002 Sequence 29 on flight camera S/N 002 was analyzed. The analysis was to determine camera system transmission using available data which included: (1) films exposed to a calibrated light source subject; (2) filter transmission data; (3) calibrated light source data; (4) density vs. log10 exposure curves for the films; and (5) spectral sensitometric data for the films. The procedure used is outlined, and includes the data and a transmission matrix as a function of field position for nine measured points on each station-film-filter-aperture-shutter speed combination.

Lockwood, H. E.; Goodding, R. A.

1974-01-01

186

Spectrally and Radiometrically Stable, Wideband, Onboard Calibration Source  

NASA Technical Reports Server (NTRS)

The Onboard Calibration (OBC) source incorporates a medical/scientific-grade halogen source with a precisely designed fiber coupling system, and a fiber-based intensity-monitoring feedback loop that results in radiometric and spectral stabilities to within less than 0.3 percent over a 15-hour period. The airborne imaging spectrometer systems developed at the Jet Propulsion Laboratory incorporate OBC sources to provide auxiliary in-use system calibration data. The use of the OBC source will provide a significant increase in the quantitative accuracy, reliability, and resulting utility of the spectral data collected from current and future imaging spectrometer instruments.

Coles, James B.; Richardson, Brandon S.; Eastwood, Michael L.; Sarture, Charles M.; Quetin, Gregory R.; Porter, Michael D.; Green, Robert O.; Nolte, Scott H.; Hernandez, Marco A.; Knoll, Linley A.

2013-01-01

187

Microwave radar and radiometric remote sensing measurements of lake ice  

NASA Technical Reports Server (NTRS)

Simultaneous microwave radar and spectral radiometric data were collected over Lake Erie during March 1978. A theoretical development is presented which interprets the data collected at nadir in terms of changes in the ice thickness and the electromagnetic attenuation coefficient. The theory also addresses the failure of the spectral radiometer to determine ice thickness through observations of quarter wavelength excursions in the reflectivity. Radar data collected off-nadir showed a substantially different behavior compared to that collected near nadir. This difference is attributed to a change in propagation characteristics from quasi-specular return from the ice-water interface to scattering from the rough air-ice interface.

Swift, C. T.; Jones, W. L., Jr.; Harrington, R. F.; Fedors, J. C.; Couch, R. H.; Jackson, B. L.

1980-01-01

188

Millennial-scale varnish microlamination dating of late Pleistocene geomorphic features in the drylands of western USA  

NASA Astrophysics Data System (ADS)

Varnish microlamination (VML) dating is a climate-based correlative age determination technique used to correlate and date various geomorphic features in deserts. In this study, we establish a generalized late Pleistocene (18-74 ka) millennial-scale microlamination sequence in fine-grained, fast-accumulating rock varnish for the drylands of western USA, radiometrically calibrate the sequence and correlate it with the ?18O record in the GISP2 Greenland ice core. We then use this climate-correlated varnish microstratigraphy to estimate surface exposure ages for radiometrically dated late Pleistocene geomorphic features in the study region. The VML dating of debris flow deposits on the Sehoo recessional shorelines of Lake Lahontan at the Jessup embayment of central Nevada yields a minimum-limiting age of 14.95-15.95 ka, in good agreement with a calibrated 14C age of 15.22 0.12 ka for the timing of the lake recession. The VML dating of a giant ejecta block on the rim of Meteor Crater in northern Arizona yields a minimum-limiting age of 49.15 ka, closely matching a thermoluminescence (TL) age of 49 3 ka and slightly younger than a recently updated cosmogenic 36Cl age of 56.0 2.4 ka for the meteor impact event. The VML dating of distal Q2c fan surfaces on Hanaupah Canyon alluvial fan in Death Valley, California, yields a minimum-limiting age of 73.55 ka, in accord with cosmogenic 36Cl depth-profile ages of 66 + 22/-14 ka and 72 + 24/- 20 ka for the same fan deposits. The close agreement between the VML age estimates and the independently derived radiometric ages for these geomorphic features attests to the validity and reliability of millennial-scale VML dating. To further assess its potential in desert geomorphological research, we use the VML method to study alluvial-fan responses to millennial-scale climatic changes. The VML dating of a small tributary fan in Death Valley reveals two episodes of fan aggradation, one ceasing at 73.55-86.75 ka during the dry period of the last interglacial (MIS 5a) and the other finishing at 66.15 ka during the wet period of the last glacial (MIS 4). The VML and 36Cl dating of the distal Q2c fan surfaces on Hanaupah Canyon fan reveal two episodes of large-scale fan aggradation ended at 72 + 24/- 20 ka and 73.55 ka during the wet period of MIS 4. Fanhead incision and associated within-channel or fantoe aggradation are found to take place during the relatively dry period of the glacial-to-interglacial climatic transition (12-24 ka) and the Holocene interglacial dry period (0-12 ka). These data indicate that, on the millennial to sub-Milankovitch timescale (~ 103-104 years), fan aggradation is a discrete sedimentational process under various climatic conditions. Because fan aggradation is ultimately controlled by the intensity and frequency of precipitation events - which in turn are modulated by major climatic oscillations such as Heinrich events, Dansgaard/Oeschger (DO) events, and glacial/interglacial shifts - these major climatic changes could be the pacemaker of regionally contemporaneous large-area fan segmentation.

Liu, Tanzhuo; Broecker, Wallace S.

2013-04-01

189

Absolute ages from crater statistics: Using radiometric ages of Martian samples for determining the Martian cratering chronology  

NASA Technical Reports Server (NTRS)

In the absence of dates derived from rock samples, impact crater frequencies are commonly used to date Martian surface units. All models for absolute dating rely on the lunar cratering chronology and on the validity of its extrapolation to Martian conditions. Starting from somewhat different lunar chronologies, rather different Martian cratering chronologies are found in the literature. Currently favored models are compared. The differences at old ages are significant, the differences at younger ages are considerable and give absolute ages for the same crater frequencies as different as a factor of 3. The total uncertainty could be much higher, though, since the ratio of lunar to Martian cratering rate which is of basic importance in the models is believed to be known no better than within a factor of 2. Thus, it is of crucial importance for understanding the the evolution of Mars and determining the sequence of events to establish an unambiguous Martian cratering chronology from crater statistics in combination with clean radiometric ages of returned Martian samples. For the dating goal, rocks should be as pristine as possible from a geologically simple area with a one-stage emplacement history of the local formation. A minimum of at least one highland site for old ages, two intermediate-aged sites, and one very young site is needed.

Neukum, G.

1988-01-01

190

PREDICTION OF A WHEAT CROP YIELD MAP BY USING POST-ANTHESIS RADIOMETRICAL DATA  

E-print Network

PREDICTION OF A WHEAT CROP YIELD MAP BY USING POST-ANTHESIS RADIOMETRICAL DATA B. GABRIELLE, P and radiometric mapping of green leaf area index (GLAI) after anthesis, on a 15-ha wheat-cropped field with marked of this paper was to evaluate the benefits of using GLAI data (obtained shortly after anthesis) to the CERES-Wheat

Paris-Sud XI, Universit de

191

Singular system analysis of the inversion of microwave radiometric data: applications to biological temperature retrieval  

E-print Network

Singular system analysis of the inversion of microwave radiometric data: applications to biological-370. Printed in the UK Singular system analysis of the inversion of microwave radiometric data: applications physiological and pathological processes. Infrared thermography has been considered in the past years

Bertero, Mario

192

RADIOMETRIC AND GEOMETRIC EVALUATION OF IKONOS GEO IMAGES AND THEIR USE FOR 3D BUILDING MODELLING  

Microsoft Academic Search

Investigations on the radiometric and geometric characteristics of IKONOS Geo satellite imagery and its use for orthoimage generation and 3D building reconstruction are reported. The paper first starts with an analysis of the radiometric quality of IKONOS Geo images of varying preprocessing and type, focussing on noise, edge quality and definition, and various artefacts. A noise estimation method is presented

Emmanuel Baltsavias; Maria Pateraki; Li Zhang

193

Remote Sensing Ayman F. Habib Radiometric Processing of Remote Sensing Data  

E-print Network

Remote Sensing Ayman F. Habib 1 Chapter 4 Radiometric Processing of Remote Sensing Data #12;Remote. Noise removal. Point and edge detection. Frequency domain. #12;Remote Sensing Ayman F. Habib 3 Radiometric Calibration #12;Remote Sensing Ayman F. Habib 4 Recorded Digital Numbers (DN) Recorded grey

Habib, Ayman

194

Parallel relative radiometric normalisation for remote sensing image mosaics  

NASA Astrophysics Data System (ADS)

Relative radiometric normalisation (RRN) is a vital step to achieve radiometric consistency among remote sensing images. Geo-analysis over large areas often involves mosaicking massive remote sensing images. Hence RRN becomes a data-intensive and computing-intensive task. This study implements a parallel RNN method based on the iteratively re-weighted multivariate alteration detection (IR-MAD) transformation and orthogonal regression. To parallelise the method of IR-MAD and orthogonal regression, there are two key problems: the normalisation path determination and the task dependence on normalisation coefficients calculation. In this paper, the reference image and normalisation paths are determined based on the shortest distance algorithm to reduce normalisation error. Formulas of orthogonal regression are acquired considering the effect of the normalisation path to reduce the task dependence on the calculation of coefficients. A master-slave parallel mode is proposed to implement the parallel method, and a task queue and a process queue are used for task scheduling. Experiments show that the parallel RRN method provides good normalisation results and favourable parallel speed-up, efficiency and scalability, which indicate that the parallel method can handle large volumes of remote sensing images efficiently.

Chen, Chong; Chen, Zhenjie; Li, Manchun; Liu, Yongxue; Cheng, Liang; Ren, Yibin

2014-12-01

195

Branching Ratios for The Radiometric Calibration of EUNIS-2012  

NASA Technical Reports Server (NTRS)

The Extreme Ultraviolet Normal Incidence Spectrograph (EUNIS) sounding rocket instrument is a two-channel imaging spectrograph that observes the solar corona and transition region with high spectral resolution and a rapid cadence made possible by unprecedented sensitivity. The upcoming flight will incorporate a new wavelength channel covering the range 524-630 Angstroms, the previously-flown 300-370 Angstroms channel, and the first flight demonstration of cooled active pixel sensor (APS) arrays. The new 524-630 Angstrom channel incorporates a Toroidal Varied Line Space (TVLS) grating coated with B4C/Ir, providing broad spectral coverage and a wide temperature range of 0.025 to 10 MK. Absolute radiometric calibration of the two channels is being performed using a hollow cathode discharge lamp and NIST-calibrated AXUV-100G photodiode. Laboratory observations of He I 584 Angstroms and He II 304 Angstroms provide absolute radiometric calibrations of the two channels at those two respective wavelengths by using the AXUV photodiode as a transfer standard. The spectral responsivity is being determined by observing line pairs with a common upper state in the spectra of Ne I-III and Ar II-III. Calculations of A-values for the observed branching ratios are in progress.

Daw, Adrian N.; Bhatia, A. K.; Rabin, Douglas M.

2012-01-01

196

On the observability of Mars entry navigation using radiometric measurements  

NASA Astrophysics Data System (ADS)

A thorough observability analysis of the Mars entry navigation using radiometric measurements from ground based beacons is performed. This analysis involves the evaluation of the Fisher information matrix which is derived from the maximum likelihood estimation. A series of navigation cases with multiple beacons are investigated, and both range and range-rate measurements are considered. The determinant of Fisher information matrix is used to quantify the observability of navigation system, while the trace of Fisher information matrix is used to determine the lower-bound of estimation errors. For one and two beacon cases, the navigation system is unobservable. However, the eigenvectors of Fisher information matrix give the observable and unobservable component. When three or more beacon measurements are employed, the states of entry vehicle become observable. Some valuable analytic conclusions on the relationship between the geometric configuration of beacons and observability are obtained consequently. Finally, simulation results from two navigation examples indicate that our effort is useful for understanding and assessing the observability of the Mars entry navigation using radiometric measurements.

Yu, Zhengshi; Cui, Pingyuan; Zhu, Shengying

2014-10-01

197

Radiometric infrared focal plane array imaging system for thermographic applications  

NASA Technical Reports Server (NTRS)

This document describes research performed under the Radiometric Infrared Focal Plane Array Imaging System for Thermographic Applications contract. This research investigated the feasibility of using platinum silicide (PtSi) Schottky-barrier infrared focal plane arrays (IR FPAs) for NASA Langley's specific radiometric thermal imaging requirements. The initial goal of this design was to develop a high spatial resolution radiometer with an NETD of 1 percent of the temperature reading over the range of 0 to 250 C. The proposed camera design developed during this study and described in this report provides: (1) high spatial resolution (full-TV resolution); (2) high thermal dynamic range (0 to 250 C); (3) the ability to image rapid, large thermal transients utilizing electronic exposure control (commandable dynamic range of 2,500,000:1 with exposure control latency of 33 ms); (4) high uniformity (0.5 percent nonuniformity after correction); and (5) high thermal resolution (0.1 C at 25 C background and 0.5 C at 250 C background).

Esposito, B. J.; Mccafferty, N.; Brown, R.; Tower, J. R.; Kosonocky, W. F.

1992-01-01

198

Blood culture cross contamination associated with a radiometric analyzer  

SciTech Connect

During a 9-day period in August 1980 in a New Jersey hospital, three pairs of consecutively numbered blood cultures from different patients were identified as positive for the same organism, for each pair, both cultures were positive in the same atmosphere, both organisms had the same sensitivities, and the second of each pair grew at least 2 days after the first and was the only positive blood culture obtained from the patient. When the hospital laboratory discontinued use of its radiometric culture analyzer for 15 days, no more consecutive pairs of positive cultures occurred. Subsequent use of the machine for 9 days with a new power unit but the original circuit boards resulted in one more similar consecutive pair (Staphylococcus epidermidis). After replacement of the entire power unit, there were no further such pairs. Examination of the machine by the manufacturer revealed a defective circuit board which resulted in inadequate needle sterilization. Laboratories which utilize radiometric analyzers should be aware of the potential for cross contamination. Recognition of such events requires alert microbiologists and infection control practitioners and a record system in the bacteriology laboratory designed to identify such clusters.

Griffin, M.R.; Miller, A.D.; Davis, A.C.

1982-04-01

199

Radiometric Characterization of Hyperspectral Imagers using Multispectral Sensors  

NASA Technical Reports Server (NTRS)

The Remote Sensing Group (RSG) at the University of Arizona has a long history of using ground-based test sites for the calibration of airborne and satellite based sensors. Often, ground-truth measurements at these test sites are not always successful due to weather and funding availability. Therefore, RSG has also automated ground instrument approaches and cross-calibration methods to verify the radiometric calibration of a sensor. The goal in the cross-calibration method is to transfer the calibration of a well-known sensor to that of a different sensor, This work studies the feasibility of determining the radiometric calibration of a hyperspectral imager using multispectral a imagery. The work relies on the Moderate Resolution Imaging Spectroradiometer (M0DIS) as a reference for the hyperspectral sensor Hyperion. Test sites used for comparisons are Railroad Valley in Nevada and a portion of the Libyan Desert in North Africa. Hyperion bands are compared to MODIS by band averaging Hyperion's high spectral resolution data with the relative spectral response of M0DlS. The results compare cross-calibration scenarios that differ in image acquisition coincidence, test site used for the calibration, and reference sensor. Cross-calibration results are presented that show agreement between the use of coincident and non-coincident image pairs within 2% in most brands as well as similar agreement between results that employ the different MODIS sensors as a reference.

McCorkel, Joel; Kurt, Thome; Leisso, Nathan; Anderson, Nikolaus; Czapla-Myers, Jeff

2009-01-01

200

A Preliminary Analysis of LANDSAT-4 Thematic Mapper Radiometric Performance  

NASA Technical Reports Server (NTRS)

Analysis was performed to characterize the radiometry of three Thematic Mapper (TM) digital products of a scene of Arkansas. The three digital products examined were the NASA raw (BT) product, the radiometrically corrected (AT) product and the radiometrically and geometrically corrected (PT) product. The frequency distribution of the digital data; the statistical correlation between the bands; and the variability between the detectors within a band were examined on a series of image subsets from the full scene. The results are presented from one 1024 x 1024 pixel subset of Realfoot Lake, Tennessee which displayed a representative range of ground conditions and cover types occurring within the full frame image. Bands 1, 2 and 5 of the sample area are presented. The subsets were extracted from the three digital data products to cover the same geographic area. This analysis provides the first step towards a full appraisal of the TM radiometry being performed as part of the ESA/CEC contribution to the NASA/LIDQA program.

Justice, C.; Fusco, L.; Mehl, W.

1984-01-01

201

Investigation of radiometric properties of the LANDSAT-4 multispectral scanner  

NASA Technical Reports Server (NTRS)

The radiometric data quality of the LANDSAT 4 multispectral scanner (MSS) was examined using several LANDSAT 4 frames. It was found that LANDSAT 4 MSS produces high-quality data of the caliber experienced with previous LANDSATS. For example, the detector equalization procedure worked well, leaving a residual banding effect of about 0.3 digital counts RMS, close to the theoretical minimum value of quantization error. Nevertheless, artifacts of the data were found, two of which were not experienced in previous MSS data. A low-level coherent noise effect was observed in all bands, with a magnitude of about 0.5 digital counts and a frequency of approximately 28 KHz (representing a wavelength of about 3.6 pixels); a substantial increase in processing complexity would be required to reduce this artifact in the data. Also, a substantial scan-length variation (of up to six pixels) was noted in MSS data when the TM sensor was operating; the LANDSAT 4 correction algorithms being applied routinely by the EROS Data Center to produce a p-type data should remove most of this variation. Between-satellite calibrations were examined in paired LANDSAT 3 and LANDSAT 4 MSS data sets, which were closely matched in acquisition time and place. Radiometric comparisons showed that all bands were highly linear in digital counts, and a well-determined linear transformation between the MSS's was established.

Malila, W. A. (principal investigator); Rice, D. P.

1983-01-01

202

Accurate Radiometric Calibration using Mechanically-Shuttered CCD Systems  

NASA Astrophysics Data System (ADS)

Acquiring accurate radiometric measurements is an essential part of characterizing non-resolvable satellites. For instance, temporal photometric signatures provide information on characteristic size, reflectance, and stability, spin rate, etc., and with more detailed analysis, shape and attitude. Multi-color photometric measurements provide information on material composition and the effects of space weathering. Thermal infrared radiometry provides gray-body temperatures and emissivity properties. Many of these methods rely on accurate radiometric calibration. For CCD systems, the calibration process generally entails removing bias and dark signals from the raw frames, dividing by a flat-field frame to account for non-uniformities, and applying a sensitivity factor to convert the remaining signal into photon-flux or energy-flux units. However, when using mechanically-shuttered camera systems, another effect must be accounted for to obtain accurately calibrated data: the finite time required for the mechanical shutter to open and close. Measurements for both two-bladed and iris mechanical shutters indicate that neglecting this effect can lead to calibration errors of 10% or more in short-duration exposures. We present methods for measuring this effect, either in a laboratory setting or with the instrument mounted on a telescope, and the additional steps required to calibrate CCD data.

Hall, D.; Liang, D.

203

Ar-Ar Dating of Martian Chassignites, NWA2737 and Chassigny, and Nakhlite MIL03346  

NASA Technical Reports Server (NTRS)

Until recently only three nakhlites and one chassignite had been identified among martian meteorites. These four exhibit very similar radiometric ages and cosmic ray exposure (CRE) ages, indicating that they may have derived from a common location on Mars and were ejected into space by a single impact. This situation is quite different from that of martian shergottites, which exhibit a range of radiometric ages and CRE ages (1). Recently, several new nakhlites and a new martian dunite (NWA2737) have been recognized. Here we report our results of Ar-39-Ar-40 dating for the MIL03346 nakhlite and the NWA2737 "chassignite", along with new results on Chassigny.

Bogard, D. D.; Garrison, D. H.

2006-01-01

204

Employment Counseling Action Plan Today's Date  

E-print Network

Employment Counseling Action Plan Today's Date: Action Item: Due Date: Resources: Progress: Prepare or revise resume Prepare sample cover letters Register with several staffing agencies Seek out employment opportunities Practice interviewing techniques Review internal and external job opportunities Contact employers

Myers, Lawrence C.

205

The Landsat Data Continuity Mission Operational Land Imager (OLI) Radiometric Calibration  

NASA Technical Reports Server (NTRS)

The Operational Land Imager (OLI) on the Landsat Data Continuity Mission (LDCM) has a comprehensive radiometric characterization and calibration program beginning with the instrument design, and extending through integration and test, on-orbit operations and science data processing. Key instrument design features for radiometric calibration include dual solar diffusers and multi-lamped on-board calibrators. The radiometric calibration transfer procedure from NIST standards has multiple checks on the radiometric scale throughout the process and uses a heliostat as part of the transfer to orbit of the radiometric calibration. On-orbit lunar imaging will be used to track the instruments stability and side slither maneuvers will be used in addition to the solar diffuser to flat field across the thousands of detectors per band. A Calibration Validation Team is continuously involved in the process from design to operations. This team uses an Image Assessment System (IAS), part of the ground system to characterize and calibrate the on-orbit data.

Markham, Brian L.; Dabney, Philip W.; Murphy-Morris, Jeanine E.; Knight, Edward J.; Kvaran, Geir; Barsi, Julia A.

2010-01-01

206

Date Rape  

MedlinePLUS

What Is Date Rape? When people think of rape , they might picture a stranger jumping out of a shadowy place and attacking someone. ... things that you can do: Immediately After a Rape If you're hurt, go straight to the ...

207

New U-series dates at the Caune de l'Arago, France  

USGS Publications Warehouse

In the beginning of the 1980s, the Caune de l'Arago was the focus of an interdisciplinary effort to establish the chronology of the Homo heidelbergensis (Preneandertals) fossils using a variety of techniques on bones and on speleothems. The result was a very large spread of dates particularly on bone samples. Amid the large spread of results, some radiometric data on speleothems showed a convergence in agreement with inferences from faunal studies. We present new U-series results on the stalagmitic formation located at the bottom of Unit IV (at the base of the Upper Stratigraphic Complex). Samples and splits were collaboratively analyzed in the four different laboratories with excellent interlaboratory agreement. Results show the complex sequence of this stalagmitic formation. The most ancient part is systematically at internal isotopic equilibrium (>350 ka) suggesting growth during or before isotopic stage 9, representing a minimum age for the human remains found in Unit III of the Middle Stratigraphical Complex which is stratigraphically under the basis of the studied stalagmitic formation. Overlaying parts of the speleothem date to the beginning of marine isotope stages 7 and 5. ?? 2003 Elsevier Science Ltd. All rights reserved.

Falgueres, C.; Yokoyama, Y.; Shen, G.; Bischoff, J.L.; Ku, T.-L.; de Lumley, H.

2004-01-01

208

New U-series dates at the Caune de l'Arago, France  

USGS Publications Warehouse

In the beginning of the 1980s, the Caune de l'Arago was the focus of an interdisciplinary effort to establish the chronology of the Homo heidelbergensis (Preneandertals) fossils using a variety of techniques on bones and on speleothems. The result was a very large spread of dates particularly on bone samples. Amid the large spread of results, some radiometric data on speleothems showed a convergence in agreement with inferences from faunal studies. We present new U-series results on the stalagmitic formation located at the bottom of Unit IV (at the base of the Upper Stratigraphic Complex). Samples and splits were collaboratively analyzed in the four different laboratories with excellent interlaboratory agreement. Results show the complex sequence of this stalagmitic formation. The most ancient part is systematically at internal isotopic equilibrium (>350 ka) suggesting growth during or before isotopic stage 9, representing a minimum age for the human remains found in Unit III of the Middle Stratigraphical Complex which is stratigraphically under the basis of the studied stalagmitic formation. Overlaying parts of the speleothem date to the beginning of marine isotope stages 7 and 5. ?? 2003 Elsevier Ltd. All rights reserved.

Falgueres, C.; Yokoyama, Y.; Shen, G.; Bischoff, J.L.; Ku, T.-L.; de Lumley, H.

2004-01-01

209

The importance and attainment of accurate absolute radiometric calibration  

NASA Technical Reports Server (NTRS)

The importance of accurate absolute radiometric calibration is discussed by reference to the needs of those wishing to validate or use models describing the interaction of electromagnetic radiation with the atmosphere and earth surface features. The in-flight calibration methods used for the Landsat Thematic Mapper (TM) and the Systeme Probatoire d'Observation de la Terre, Haute Resolution visible (SPOT/HRV) systems are described and their limitations discussed. The questionable stability of in-flight absolute calibration methods suggests the use of a radiative transfer program to predict the apparent radiance, at the entrance pupil of the sensor, of a ground site of measured reflectance imaged through a well characterized atmosphere. The uncertainties of such a method are discussed.

Slater, P. N.

1984-01-01

210

Directional radiometric measurements of row-crop temperatures  

NASA Technical Reports Server (NTRS)

The variability of directional sensor response for a cotton row crop in Phoenix, Arizona was measured for various solar zenith angles. The geometric structure of the canopy was described with regard to height, width, spacing, and shape of rows. In addition, radiometric temperature data were collected on four scene components: sunlit and shaded vegetation and sunlit and shaded soil. These data were used to test the predictions and assumptions of a modified version of the row crop model of Jackson et al. (1979), which predicts the thermal infrared response of a sensor as a function of sensor view angle, component temperature, and geometrical structure of the canopy. The field data showed sensor response differentials as great as 16.2 C when going from a zenith view angle of 0 deg to one of 80 deg normal to the row direction. The rms deviation between the predicted and measured sensor response for all measurement periods and view angles was 0.96 C.

Kimes, D. S.; Kirchner, J. A.

1983-01-01

211

Radiometric performance of the Viking Mars lander cameras  

NASA Technical Reports Server (NTRS)

The Viking lander cameras feature an array of 12 silicon photodiodes for electronic focus selection and multispectral imaging. Comparisons of absolute radiometric calibrations of the four cameras selected for the mission to Mars with performance predictions based on their design data revealed minor discrepancies. These discrepancies were caused primarily by the method used to calibrate the photosensor array and apparently also from light reflections internal to the array. The sensitivity and dynamic range of all camera channels are found to be sufficient for high quality pictures, providing that the commandable gains and offsets can be optimized for the scene radiance; otherwise, the quantization noise may be too high or the dynamic range too low for an adequate characterization of the scene.

Huck, F. O.; Burcher, E. E.; Taylor, E. J.; Wall, S. D.

1975-01-01

212

Radiometric measurements of snow and ice surfaces in Antartica  

NASA Astrophysics Data System (ADS)

First results of a ground radiometric campaign carried out in Antarctica during the last Italian scientific expedition in winter 1994/95 are here presented. The measurements were collected by means of a 4-channel radiometer, fitting with the MSS and first 4 TM spectral intervals. More than 100 measurements were taken in different sites, concerning three main categories: snow cover, continental ice, and marine ice. The investigation consisted in the collection of radiance information accompanied by observations of physical properties of the surfaces according to the standards by the International Glaciological Society. The reflectance values of different snow/ice covers indicate some interesting remarks to the use of these results as a method for the calibration of satellite imagery to a better understanding of this particular environment.

Zilioli, Eugenio; Cagnati, Anselmo

1995-11-01

213

Airborne Millimeter-Wave Radiometric Observations of Cirrus Clouds  

NASA Technical Reports Server (NTRS)

This paper reports the first radiometric measurements of cirrus clouds in the frequency range of 89-325 GHz from a high-altitude aircraft flight. The measurements are conducted with a Millimeter-wave Imaging Radiometer (MIR) on board the NASA ER-2 aircraft over a region in northern Oklahoma. Aboard the same aircraft are a cloud lidar system and a multichannel radiometer operating at the visible and infrared wavelengths. The instrument ensemble is well suited for identifying cirrus clouds. It is shown that the depressions in brightness temperatures associated with a few intense cirrus clouds occur at all frequency channels of the MIR. Estimates of total ice water path of the cirrus clouds are derived from comparisons of radiative transfer calculations and observed brightness depressions.

Wang, J. R.; Racette, P.

1997-01-01

214

Laboratory Measurement of Bidirectional Reflectance of Radiometric Tarps  

NASA Technical Reports Server (NTRS)

This experiment measured the reflectance of tarps with ground instruments in order to check radiometric calibration, validate atmospheric correction, and predict at-sensor radiance for satellite instruments. The procedure of this experiment is as follows: 1) Assemble laboratory apparatus to duplicate ground reference measurement geometry and satellite measurement geometry; 2) Measure spectral radiance with Optronics OL 750 double monochromator/spectroradiometer; 3) Measure radiance of NIST-calibrated Spectralon panel irradiated by collimated light at incidence angle of calibrated reflectance (20 deg, 30 deg, 40 deg, or 50 deg), viewing normal to panel surface; 4) Measure radiance of Spectralon panel irradiated at incidence angle equal to solar zenith angle at time of overpass; 5) Calculate reflectance of Spectralon panel irradiated at solar zenith angle, viewing normal to panel surface (ground geometry).

Knowlton, Kelly

2004-01-01

215

FAADE Reconstruction Using Geometric and Radiometric Point Cloud Information  

NASA Astrophysics Data System (ADS)

This paper aims at faade reconstruction for subsequent enrichment of LOD2 building models. We use point clouds from dense image matching with imagery both from Mobile Mapping systems and oblique airborne cameras. The interpretation of faade structures is based on a geometric reconstruction. For this purpose a pre-segmentation of the point cloud into faade points and non-faade points is necessary. We present an approach for point clouds with limited geometric accuracy where a geometric segmentation might fail. Our contribution is a radiometric segmentation approach. Via local point features, based on a clustering in hue space, the point cloud is segmented into faade-points and non-faade points. This way, the initial geometric reconstruction step can be bypassed and point clouds with limited accuracy can still serve as input for the faade reconstruction and modelling approach.

Tutzauer, P.; Haala, N.

2015-03-01

216

Radiometric Ages of Martian Meteorites compared to Martian Surfaces Ages  

NASA Technical Reports Server (NTRS)

The surprisingly young Rb-Sr age of the Shergotty meteorite contributed to early suggestions that it might be of martian origin. their redox state and oxygen isotopic compositions linked the shergottites to the clino-pyroxenite nakhlites and the dunite Chassigny, causing them to be grouped as SNC meteorites. These characteristics, but especially the similarity of the elemental and isotopic compositions of gases trapped in shergottites to those of the martian atmosphere, have caused the martian origin of the SNC and related meteorites to be widely accepted. Although the young ages were one of the early hints of a martian origin for the SNC meteorites, their interpretation has remained somewhat ambiguous. We will review the radiometric ages of the martian meteorites and attempt to place them into the context of martian surface ages.

Nyquist, L. E.; Shih, C.-Y.

1999-01-01

217

Experimental study of radiometric forces with comparison to computational results  

NASA Astrophysics Data System (ADS)

A study of the radiometric forces on heated plates has been conducted both experimentally and computationally. The experiments were carried out at USC in two vacuum chambers up to a maximum pressure of 6 Pa for various carrier gases. The computations were performed with both the DSMC and ES-BGK methods for a 2-D gas flow over a comparable range of pressures. It is shown that the radiometric devices provide maximum force at a Knudsen number approximating 0.1. Of the various gases tested, helium provides the largest peak force. Qualitatively, the experimental data and computational results are similar. A lack of experimental data on gas-surface accommodation and flow three-dimensionality yields up to a 40% difference in the magnitude of the measured and computed forces, but it is shown that this discrepancy can be used to predict accommodation values. Comparison of four geometric configurations has shown that the effect of the area is significant at pressures up to where the force is maximum. It is also demonstrated that the size of the chamber in which the radiometer resides is of primary importance, where the chamber dimensions are inversely related to the generated force. Finally, simulation of multi-vane configurations have shown that the optimal spacing of vanes can be tailored for specific uses; for maximum force production a tight spacing should be used, while maximum efficiency requires spacing on the order of a vane dimension. While the results so far are encouraging, they are far from complete. Further improvements would include: a new experimental setup to reduce uncertainty with highly accurate temperature control and measurement, an in situ way to prepare the surface as well as measure its cleanliness, and an in depth iterative computational study observing the impact of multiple radiometer vanes at numerous seperations.

Selden, Nathaniel P.

218

San Bernardino Cave (Italy) and the Appearance of Levallois Technology in Europe: Results of a Radiometric and Technological Reassessment  

PubMed Central

The introduction of Levallois technology in Europe marked the transition from the Lower to the early Middle Paleolithic. This new method of flake production was accompanied by significant behavioral changes in hominin populations. The emergence of this technological advance is considered homogeneous in the European archaeological record at the Marine isotopic stage (MIS) 9/MIS 8 boundary. In this paper we report a series of combined electron spin resonance/U-series dates on mammal bones and teeth recovered from the lower units of San Bernardino Cave (Italy) and the technological analyses of the lithic assemblages. The San Bernardino Cave has yielded the earliest evidence of Levallois production on the Italian Peninsula recovered to date. In addition to our results and the review of the archaeological record, we describe the chronological and geographical differences between European territories and diversities in terms of technological developments. The belated emergence of Levallois technology in Italy compared to western Europe corresponds to the late Italian Neanderthal speciation event. The new radiometric dates and the technological analyses of San Bernardino Cave raise the issue of the different roles of glacial refugia in the peopling and the spread of innovative flaking strategies in Europe during the late Middle Pleistocene. PMID:24146836

Picin, Andrea; Peresani, Marco; Falgures, Christophe; Gruppioni, Giulia; Bahain, Jean-Jacques

2013-01-01

219

South american geochronology: radiometric time scale for middle to late tertiary mammal-bearing horizons in patagonia.  

PubMed

Radiometric (potassium-argon) age determinations for basalts and tuffs associated with middle to late Tertiary mammal-bearing horizons in Patagonia, southern Argentina, permit refinement of boundaries and hiatuses between beds of Deseadan (early Oligocene) through Friasian (middle to late Miocene) age. At two localities beds of Deseadan age are overlain by basalts, which gave dates of 33.6 and 35.4 million years ago; 34.0 million years ago is tentatively accepted as a terminal date for known Deseadan. At several localities beds of Colhuehuapian age are underlain by basalts, which gave dates ranging from 28.8 to 24.3 million years ago; 25.0 million years is tentatively taken as a basal age for known Colhuehuapian. The paleontological hiatus between known Deseadan and known Colhuehuapian is thus in the order of 9.0 million years. Two tuffs from the Santa Cruz Formation (Santacrucian) gave ages of 21.7 and 18.5 million years. Plagioclase and biotite concentrates of an ignimbrite from the Colln Cur Formation (Friasian) gave ages ranging from 15.4 to 14.0 million years. PMID:17738414

Marshall, L G; Pascual, R; Curtis, G H; Drake, R E

1977-03-25

220

Concept, Simulation, and Instrumentation for Radiometric Inflight Icing Detection  

NASA Technical Reports Server (NTRS)

The multi-agency Flight in Icing Remote Sensing Team (FIRST), a consortium of the National Aeronautics and Space Administration (NASA), the Federal Aviation Administration (FAA), the National Center for Atmospheric Research (NCAR), the National Oceanographic and Atmospheric Administration (NOAA), and the Army Corps of Engineers (USACE), has developed technologies for remotely detecting hazardous inflight icing conditions. The USACE Cold Regions Research and Engineering Laboratory (CRREL) assessed the potential of onboard passive microwave radiometers for remotely detecting icing conditions ahead of aircraft. The dual wavelength system differences the brightness temperature of Space and clouds, with greater differences potentially indicating closer and higher magnitude cloud liquid water content (LWC). The Air Force RADiative TRANsfer model (RADTRAN) was enhanced to assess the flight track sensing concept, and a 'flying' RADTRAN was developed to simulate a radiometer system flying through simulated clouds. Neural network techniques were developed to invert brightness temperatures and obtain integrated cloud liquid water. In addition, a dual wavelength Direct-Detection Polarimeter Radiometer (DDPR) system was built for detecting hazardous drizzle drops. This paper reviews technology development to date and addresses initial polarimeter performance.

Ryerson, Charles; Koenig, George G.; Reehorst, Andrew L.; Scott, Forrest R.

2009-01-01

221

Ground-based radiometric measurements of slant-path attenuation in the V/W bands  

NASA Astrophysics Data System (ADS)

Ground-based radiometric techniques were applied to measure the slant-path attenuation cumulative distribution function to over 20 dB of attenuation and to less than 1% exceedance probability at the V and W band frequencies of 72.5 and 82.5 GHz. These are the first such measurements in these frequency bands. Brightness temperature measurements were collected at an elevation angle of 36 in Rome, NY, using a four-channel radiometer that included 23.8 and 31.4 GHz receivers. A model-based approach was used to invert brightness temperature to attenuation. An atmospheric model relevant to the geographic location and statistically representative of the attenuating conditions was developed for this purpose. The main assumption of the atmospheric model was that the sources of attenuation for exceedance probabilities of concern were dominated by stratiform rain. Monte Carlo solutions to the radiative transfer equation for the precipitating atmosphere were used to generate the attenuation retrieval algorithm. Sensitivity analysis showed that the attenuation retrieval algorithm was robust to uncertainties in the model parameters. Slant-path attenuation was also measured with the radiometer using the Sun as a source of radiation. Over 30 dB of attenuation dynamic range was possible with this technique. Sun-beacon measurements were used to test model predictions.

Brost, George; Magde, Kevin

2014-12-01

222

QuEChERS, a sample preparation technique that is catching on: an up-to-date interview with its inventors  

Technology Transfer Automated Retrieval System (TEKTRAN)

The technique of QuEChERS (Quick, Easy, Cheap, Effective, Rugged and Safe) is only 7 years old, yet it is revolutionizing the manner in which multiresidue, multiclass pesticide analysis (and perhaps beyond) is performed. Columnist Ron Majors sits down with inventors Steve Lehotay and Michelangelo An...

223

Mars chronology: Assessing techniques for quantifying surficial processes  

USGS Publications Warehouse

Currently, the absolute chronology of Martian rocks, deposits and events is based mainly on crater counting and remains highly imprecise with epoch boundary uncertainties in excess of 2 billion years. Answers to key questions concerning the comparative origin and evolution of Mars and Earth will not be forthcoming without a rigid Martian chronology, enabling the construction of a time scale comparable to Earth's. Priorities for exploration include calibration of the cratering rate, dating major volcanic and fluvial events and establishing chronology of the polar layered deposits. If extinct and/or extant life is discovered, the chronology of the biosphere will be of paramount importance. Many radiometric and cosmogenic techniques applicable on Earth and the Moon will apply to Mars after certain baselines (e.g. composition of the atmosphere, trace species, chemical and physical characteristics of Martian dust) are established. The high radiation regime may pose a problem for dosimetry-based techniques (e.g. luminescence). The unique isotopic composition of nitrogen in the Martian atmosphere may permit a Mars-specific chronometer for tracing the time-evolution of the atmosphere and of lithic phases with trapped atmospheric gases. Other Mars-specific chronometers include measurement of gas fluxes and accumulation of platinum group elements (PGE) in the regolith. Putting collected samples into geologic context is deemed essential, as is using multiple techniques on multiple samples. If in situ measurements are restricted to a single technique it must be shown to give consistent results on multiple samples, but in all cases, using two or more techniques (e.g. on the same lander) will reduce error. While there is no question that returned samples will yield the best ages, in situ techniques have the potential to be flown on multiple missions providing a larger data set and broader context in which to place the more accurate dates. ?? 2004 Elsevier B.V. All rights reserved.

Doran, P.T.; Clifford, S.M.; Forman, S.L.; Nyquist, L.; Papanastassiou, D.A.; Stewart, B.W.; Sturchio, N.C.; Swindle, T.D.; Cerling, T.; Kargel, J.; McDonald, G.; Nishiizumi, K.; Poreda, R.; Rice, J.W.; Tanaka, K.

2004-01-01

224

Comparative evaluation of radiometric tryptic soy broth versus radiometric tryptic soy broth with 10% sucrose for detection of bacteremia and fungemia in pediatric patients.  

PubMed Central

We compared BACTEC radiometric blood culture media with (8B) and without (6B) 10% sucrose for the detection of bacteremia and fungemia in pediatric patients at four university teaching hospitals that used identical methods for obtaining and processing specimens. Overall, the yields of microorganisms from 5,714 blood culture sets were no different in the two media, although a trend was noted favoring 6B for the detection of pneumococci. Speed of detection of positive results was faster in the 6B than in the 8B medium (P less than 0.05), largely due to the faster detection of Staphylococcus aureus in the 6B medium. We conclude that, overall, with pediatric patients the hypertonic 8B radiometric medium has no advantage and that it possibly has a modest disadvantage, compared with isotonic 6B radiometric medium. PMID:2681248

Weinstein, M P; Reller, L B; Mirrett, S; Stratton, C W; Paisley, J W; Lauer, B A

1989-01-01

225

Flight Technology Improvement. [spaceborne optical radiometric instruments, attitude control, and electromechanical and power subsystems  

NASA Technical Reports Server (NTRS)

Shortcomings in spaceborne instrumentation technology are analyzed and recommendations are given for corrections and technology development. The technologies discussed are optical radiometric instruments and calibration, attitude control and determination, and electromechanical and power subsystems.

1979-01-01

226

Susceptibility testing of filamentous fungi to amphotericin B by a rapid radiometric method  

SciTech Connect

A rapid, radiometric method was developed to determine the susceptibility of filamentous fungi to amphotericin B. The rapid, radiometric method depended on measurement of the inhibition of /sup 24/CO/sub 2/ production in the presence of amphotericin B. Thirty isolates of filamentous fungi were tested by the rapid, radiometric method and a reference agar dilution method. There was 93% agreement between the two methods when an 80% or greater decrease in CO/sub 2/ production was used to calculate the minimal inhibitory concentration with the rapid, radiometric method. Minimal inhibitory concentrations, based on 80% decrease of CO/sub 2/ production, were achieved within 24 h of incubation with all of the fungi tested.

Merz, W.G.; Fay, D.; Thumar, B.; Dixon, D.

1984-01-01

227

Intra-annual NDVI validation of the Landsat 5 TM radiometric calibration  

USGS Publications Warehouse

Multispectral data from the Landsat 5 (L5) Thematic Mapper (TM) sensor provide the backbone of the extensive archive of moderate-resolution Earth imagery. Even after more than 24 years of service, the L5 TM is still operational. Given the longevity of the satellite, the detectors have aged and the sensor's radiometric characteristics have changed since launch. The calibration procedures and parameters in the National Land Archive Production System (NLAPS) have also changed with time. Revised radiometric calibrations in 2003 and 2007 have improved the radiometric accuracy of recently processed data. This letter uses the Normalized Difference Vegetation Index (NDVI) as a metric to evaluate the radiometric calibration. The calibration change has improved absolute calibration accuracy, consistency over time, and consistency with Landsat 7 (L7) Enhanced Thematic radiometry and will provide the basis for continued long-term studies of the Earth's land surfaces.

Chander, G.; Groeneveld, D.P.

2009-01-01

228

COMPARISON OF LAND SURFACE EMISSIVITY AND RADIOMETRIC TEMPERATURE DERIVED FROM MODIS AND ASTER SENSORS  

Technology Transfer Automated Retrieval System (TEKTRAN)

This study compares surface emissivity and radiometric temperature products derived using data collected with the MODerate resolution Imaging Spectroradiometer (MODIS) and Advanced Spaceborne Thermal Emission Reflectance Radiometer (ASTER) sensors, on the Earth Observation System (EOS) - Terra satel...

229

Radioisotope dating with a cyclotron.  

PubMed

By considering radioisotope dating as a problem in trace element detection, and by using the cyclotron as a high-energy mass spectrometer for this purpose, we have shown that one can greatly increase the maximum age that can be determined while simultaneously reducing the size of the sample required. The cyclotron can be used to detect atoms or simple molecules that are present at the 10(-16) level or greater. For (14)C dating one should be able to go back 40,000 to 100,000 years with 1- to 100-mg carbon samples; for (10)Be dating, 10 to 30 million years with 1-mm(3) to 10-cm(3) rock samples; for tritium dating, 160 years with a 1-liter water sample. The feasibility of the technique has been demonstrated experimentally by measuring the tritium/deuterium ratio in a sample 24 years old. For samples many half-lives old, the fractional error in the age is small even if rates of production or deposition of the isotopes. Although cyclotrons are expensive to build, their operating costs are relatively low. If several samples are dated per hour the cost per date may not be substantially higher than it is today for decay dating. There are already more than 50 cyclotrons in operation which have the potential to do radioisotope dating, and their application to important problems of dating and trace element analysis should prove very fruitful. PMID:17837065

Muller, R A

1977-04-29

230

Study of Spectral/Radiometric Characteristics of the Thematic Mapper for Land Use Applications  

NASA Technical Reports Server (NTRS)

An investigation conducted in support of the LANDSAT 4/5 Image Data Quality Analysis (LIDQA) Program is discussed. Results of engineering analyses of radiometric, spatial, spectral, and geometric properties of the Thematic Mapper systems are summarized; major emphasis is placed on the radiometric analysis. Details of the analyses are presented in appendices, which contain three of the eight technical papers produced during this investigation; these three, together, describe the major activities and results of the investigation.

Malila, W. A. (principal investigator); Metzler, M. D. (principal investigator)

1985-01-01

231

The Landsat Data Continuity Mission Operational Land Imager: Radiometric Performance  

NASA Technical Reports Server (NTRS)

The Operational Land Imager (OLI) is one of two instruments to fly on the Landsat Data Continuity Mission (LDCM), which is scheduled to launch in December 2012 to become the 8th in the series of Landsat satellites. The OLI images in the solar reflective part of the spectrum, with bands similar to bands 1-5, 7 and the panchromatic band on the Landsat-7 ETM+ instrument. In addition, it has a 20 nm bandpass spectral band at 443 nm for coastal and aerosol studies and a 30 nm band at 1375 nm to aid in cirrus cloud detection. Like ETM+, spatial resolution is 30 m in the all but the panchromatic band, which is 15 meters. OLI is a pushbroom radiometer with approximately 6000 detectors per 30 meter band as opposed to the 16 detectors per band on the whiskbroom ETM+. Data are quantized to 12 bits on OLI as opposed to 8 bits on ETM+ to take advantage of the improved signal to noise ratio provided by the pushbroom design. The saturation radiances are higher on OLI than ETM+ to effectively eliminate saturation issues over bright Earth targets. OLI includes dual solar diffusers for on-orbit absolute and relative (detector to detector) radiometric calibration. Additionally, OLI has 3 sets of on-board lamps that illuminate the OLI focal plane through the full optical system, providing additional checks on the OLI's response[l]. OLI has been designed and built by Ball Aerospace & Technology Corp. (BATC) and is currently undergoing testing and calibration in preparation for delivery in Spring 2011. Final pre-launch performance results should be available in time for presentation at the conference. Preliminary results will be presented below. These results are based on the performance of the Engineering Development Unit (EDU) that was radiometrically tested at the integrated instrument level in 2010 and assembly level measurements made on the flight unit. Signal-to-Noise (SNR) performance: One of the advantages of a pushbroom system is the increased dwell time of the detectors allowing for significantly higher SNR than equivalent aperture whiskbroom systems. OLI performance based on the EDU at the "typical" radiance level as specified in the OLI requirements document are about 10 times better than ETM+ performance and 2-3 times better than the requirements for OLI (Table 1).

Markham, Brian; Dabney, Philip; Pedelty, Jeffrey

2011-01-01

232

Radioactive Dating: A Method for Geochronology.  

ERIC Educational Resources Information Center

Gives historical background on the discovery of natural radiation and discusses various techniques for using knowledge of radiochemistry in geochronological studies. Indicates that of these radioactive techniques, Potassium-40/Argon-40 dating is used most often. (JN)

Rowe, M. W.

1985-01-01

233

A multi-channel radiometric profiler of temperature, humidity and cloud liquid.  

SciTech Connect

A microwave radiometer is described that provides continuous thermodynamic (temperature, water vapor, and moisture) soundings during clear and cloudy conditions. The radiometric profiler observes radiation intensity at 12 microwave frequencies, along with zenith infrared and surface meteorological measurements. Historical radiosonde and neural network or regression methods are used for profile retrieval. We compare radiometric, radiosonde, and forecast soundings and evaluate the accuracy of radiometric temperature and water vapor soundings on the basis of statistical comparison with radiosonde soundings. We find that radiometric soundings are equivalent in accuracy to radiosonde soundings when used in numerical weather forecasting. A case study is described that demonstrates improved fog forecasting on the basis of variational assimilation of radiometric soundings. The accuracy of radiometric cloud liquid soundings is evaluated by comparison with cloud liquid sensors carried by radiosondes. Accurate high-resolution three-dimensional water vapor and wind analysis is described on the basis of assimilation of simulated thermodynamic and wind soundings along with GPS slant delays. Examples of mobile thermodynamic and wind profilers are shown. Thermodynamic profiling, particularly when combined with wind profiling and slant GPS, provides continuous atmospheric soundings for improved weather and dispersion forecasting.

Ware, R.; Carpenter, R.; Guldner, J.; Liljegren, J.; Nehrkorn, T.; Solheim, F.; Vandenberghe, F.; Environmental Research; Radiometrics Corp.; Univ. Corp. for Atmospheric Research; Weather Decision Technologies Inc.; Atmospheric and Environmental Research Inc.; National Center for Atmospheric Research

2003-07-31

234

Dating sediments using luminescence signals  

SciTech Connect

Before siting a nuclear power station or a nuclear waste repository, it is necessary to establish that the area has been free of earthquake activity for a sufficient period of time. Evidence of past earthquake activity is often provided by faults in surface sediments. Age limits for fault formation can be set by obtaining the depositional ages of the sediment unit in which the fault was formed and the overlying sediment. A useful technique would be one that dating could be applied to the mineral grains that make up the sediments and that would give the time that has passed since the grains were blown or washed into position. Luminescence dating techniques, of which the most well known is thermo-luminescence (TL), provide such information. This approach has been successful in dating movement on the Wasatch Fault in Utah. A combination of TL and radiocarbon dates indicated that three faulting events had occurred within the past 5000 years. 2 refs., 1 fig.

Wintle, A. (Univ. of Wales, Aberystwyth (United Kingdom))

1993-05-01

235

Radiometric analysis of the longwave infrared channel of the Thematic Mapper on LANDSAT 4 and 5  

NASA Technical Reports Server (NTRS)

The first objective was to evaluate the postlaunch radiometric calibration of the LANDSAT Thematic Mapper (TM) band 6 data. The second objective was to determine to what extent surface temperatures could be computed from the TM and 6 data using atmospheric propagation models. To accomplish this, ground truth data were compared to a single TM-4 band 6 data set. This comparison indicated satisfactory agreement over a narrow temperature range. The atmospheric propagation model (modified LOWTRAN 5A) was used to predict surface temperature values based on the radiance at the spacecraft. The aircraft data were calibrated using a multi-altitude profile calibration technique which had been extensively tested in previous studies. This aircraft calibration permitted measurement of surface temperatures based on the radiance reaching the aircraft. When these temperature values are evaluated, an error in the satellite's ability to predict surface temperatures can be estimated. This study indicated that by carefully accounting for various sensor calibration and atmospheric propagation effects, and expected error (1 standard deviation) in surface temperature would be 0.9 K. This assumes no error in surface emissivity and no sampling error due to target location. These results indicate that the satellite calibration is within nominal limits to within this study's ability to measure error.

Schott, John R.; Volchok, William J.; Biegel, Joseph D.

1986-01-01

236

Radiometric calibration of the in-flight blackbody calibration system of the GLORIA interferometer  

NASA Astrophysics Data System (ADS)

GLORIA (Gimballed Limb Observer for Radiance Imaging of the Atmosphere) is an airborne, imaging, infrared Fourier transform spectrometer that applies the limb-imaging technique to perform trace gas and temperature measurements in the Earth's atmosphere with three-dimensional resolution. To ensure the traceability of these measurements to the International Temperature Scale and thereby to an absolute radiance scale, GLORIA carries an on-board calibration system. Basically, it consists of two identical large-area and high-emissivity infrared radiators, which can be continuously and independently operated at two adjustable temperatures in a range from -50 C to 0 C during flight. Here we describe the radiometric and thermometric characterization and calibration of the in-flight calibration system at the Reduced Background Calibration Facility of the Physikalisch-Technische Bundesanstalt. This was performed with a standard uncertainty of less than 110 mK. Extensive investigations of the system concerning its absolute radiation temperature and spectral radiance, its temperature homogeneity and its short- and long-term stability are discussed. The traceability chain of these measurements is presented.

Monte, C.; Gutschwager, B.; Adibekyan, A.; Kehrt, M.; Ebersoldt, A.; Olschewski, F.; Hollandt, J.

2014-01-01

237

In-flight radiometric calibration of the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS)  

NASA Technical Reports Server (NTRS)

A reflectance-based method was used to provide an analysis of the in-flight radiometric performance of AVIRIS. Field spectral reflectance measurements of the surface and extinction measurements of the atmosphere using solar radiation were used as input to atmospheric radiative transfer calculations. Five separate codes were used in the analysis. Four include multiple scattering, and the computed radiances from these for flight conditions were in good agreement. Code-generated radiances were compared with AVIRIS-predicted radiances based on two laboratory calibrations (pre- and post-season of flight) for a uniform highly reflecting natural dry lake target. For one spectrometer (C), the pre- and post-season calibration factors were found to give identical results, and to be in agreement with the atmospheric models that include multiple scattering. This positive result validates the field and laboratory calibration technique. Results for the other spectrometers (A, B and D) were widely at variance with the models no matter which calibration factors were used. Potential causes of these discrepancies are discussed.

Conel, James E.; Green, Robert O.; Alley, Ronald E.; Bruegge, Carol J.; Carrere, Veronique; Margolis, Jack S.; Vane, Gregg; Chrien, Thomas G.; Slater, Philip N.; Biggard, Stuart F.

1988-01-01

238

Radiometric errors caused by diffraction from circular apertures: edge effects.  

PubMed

The diffraction corrections associated with a circular aperture are calculated for the case of a point source and a detector aperture having a diameter approximately equal to that of the illuminated region. This investigation is made for monochromatic and complex (tungsten) radiation; two types of detectors are considered: a typical silicon diode and a neutral detector. The intensity distribution near the edge is calculated for the same cases. Some experimental results are also presented to corroborate the calculations and to suggest the behavior with extended sources. We show that strong diffraction effects are present close to the shadow edge even with a source-detector combination having a very extended wavelength band. In radiometric measurements, a suitable compromise between diffraction effects, stray light, and vignetting effects can be achieved by having the detector aperture diameter approximately half that of the illuminated region. An extended source will reduce diffraction effects. Finally, some suggestions are made with respect to making diffraction corrections for a series of apertures. PMID:20168496

Boivin, L P

1977-02-01

239

NERO: General concept of a NEO radiometric observatory  

NASA Astrophysics Data System (ADS)

NERO (Near-Earth Objects Radiometric Observatory) is one of the six studies for possible missions dedicated to near-Earth objects, that were funded by the ESA in 2002-2003. NERO is a further development of previous studies already submitted to ESA (Sysiphos,Spaceguard-1). The general concept is that a small satellite equipped with both a CCD for visible wavelengths and an array for thermal IR measurements around 10 microns would be an ideal platform for simultaneously obtaining two of the major objectives of current NEO science, namely the physical characterization of the objects and the discovery of NEOs which are difficult to detect because they have orbits entirely or partly interior to the Earth's orbit. The NERO study included a comprehensive analysis of the advantages and drawbacks of different orbital options for the satellite (including L2 of Earth and L2 of Venus) and a preliminary simulation of the effectiveness in deriving reliable orbits of the newly detected objects. The main results of this study, including also a preliminary design of the payload (optics, detectors, cooling system, etc.) are briefly summarized.

Cellino, A.; Somma, R.; Tommasi, L.; Paolinetti, R.; Muinonen, K.; Virtanen, J.; Tedesco, E. F.

240

A hyperspectral imager for high radiometric accuracy Earth climate studies  

NASA Astrophysics Data System (ADS)

We demonstrate a visible and near-infrared prototype pushbroom hyperspectral imager for Earth climate studies that is capable of using direct solar viewing for on-orbit cross calibration and degradation tracking. Direct calibration to solar spectral irradiances allow the Earth-viewing instrument to achieve required climate-driven absolute radiometric accuracies of <0.2% (1?). A solar calibration requires viewing scenes having radiances 105 higher than typical Earth scenes. To facilitate this calibration, the instrument features an attenuation system that uses an optimized combination of different precision aperture sizes, neutral density filters, and variable integration timing for Earth and solar viewing. The optical system consists of a three-mirror anastigmat telescope and an Offner spectrometer. The as-built system has a 12.2 cross track field of view with 3 arcmin spatial resolution and covers a 350-1050 nm spectral range with 10 nm resolution. A polarization compensated configuration using the Offner in an out of plane alignment is demonstrated as a viable approach to minimizing polarization sensitivity. The mechanical design takes advantage of relaxed tolerances in the optical design by using rigid, non-adjustable diamond-turned tabs for optical mount locating surfaces. We show that this approach achieves the required optical performance. A prototype spaceflight unit is also demonstrated to prove the applicability of these solar cross calibration methods to on-orbit environments. This unit is evaluated for optical performance prior to and after GEVS shake, thermal vacuum, and lifecycle tests.

Espejo, Joey; Drake, Ginger; Heuerman, Karl; Kopp, Greg; Lieber, Alex; Smith, Paul; Vermeer, Bill

2011-10-01

241

Advanced radiometric and interferometric milimeter-wave scene simulations  

NASA Technical Reports Server (NTRS)

Smart munitions and weapons utilize various imaging sensors (including passive IR, active and passive millimeter-wave, and visible wavebands) to detect/identify targets at short standoff ranges and in varied terrain backgrounds. In order to design and evaluate these sensors under a variety of conditions, a high-fidelity scene simulation capability is necessary. Such a capability for passive millimeter-wave scene simulation exists at TRW. TRW's Advanced Radiometric Millimeter-Wave Scene Simulation (ARMSS) code is a rigorous, benchmarked, end-to-end passive millimeter-wave scene simulation code for interpreting millimeter-wave data, establishing scene signatures and evaluating sensor performance. In passive millimeter-wave imaging, resolution is limited due to wavelength and aperture size. Where high resolution is required, the utility of passive millimeter-wave imaging is confined to short ranges. Recent developments in interferometry have made possible high resolution applications on military platforms. Interferometry or synthetic aperture radiometry allows the creation of a high resolution image with a sparsely filled aperture. Borrowing from research work in radio astronomy, we have developed and tested at TRW scene reconstruction algorithms that allow the recovery of the scene from a relatively small number of spatial frequency components. In this paper, the TRW modeling capability is described and numerical results are presented.

Hauss, B. I.; Moffa, P. J.; Steele, W. G.; Agravante, H.; Davidheiser, R.; Samec, T.; Young, S. K.

1993-01-01

242

Investigation of Aerodynamic and Aerodynamic and Radiometric Land Surface Temperatures  

NASA Technical Reports Server (NTRS)

The overall goal of the project was to reconcile the difference between T(sub s,r) and T(sub aero), while maintaining consistency within models and with theory and data. The project involved collaboration between researchers at Bucknell University, Boston University, University of mode Island, and the USDNARS Hydrology Laboratory. This report focuses on the work done at Bucknell, which used an analytical continuous-source flux model developed by Crago (1998), based on work by Brutsaert and Sugita (1996) to generate fluxes at all levels of the canopy. Named ALARM [Analytical Land- Atmosphere-Radiometer Model] by Suleiman and Crago (2002), the model assumes the foliage has an exponential vertical temperature profile. The same profile is felt by the within-canopy turbulence and 'seen" by a radiometer viewing the surface from any zenith view angle. ALARM converts radiometric surface temperatures taken from any view angle into a clearly-defined version of Taero called the equivalent isothermal surface temperature T(sub s,j), and then calculates the sensible heat flux H using Monin-Obukhov similarity theory. This allows remotely sensed Ts,r measurements to be used to produce high quality sensible and latent heat flux estimates, or to validate or update the surface temperature produced by SVATs in climate or mesoscale models.

Crago, Richard D.; Friedl, Mark; Kustas, William; Wang, Ye-Qiao

2003-01-01

243

Robust Multiscale Stereo Matching from Fundus Images with Radiometric Differences  

PubMed Central

A robust multiscale stereo matching algorithm is proposed to find reliable correspondences between low contrast and weakly textured retinal image pairs with radiometric differences. Existing algorithms designed to deal with piecewise planar surfaces with distinct features and Lambertian reflectance do not apply in applications such as 3D reconstruction of medical images including stereo retinal images. In this paper, robust pixel feature vectors are formulated to extract discriminative features in the presence of noise in scale space, through which the response of low-frequency mechanisms alter and interact with the response of high-frequency mechanisms. The deep structures of the scene are represented with the evolution of disparity estimates in scale space, which distributes the matching ambiguity along the scale dimension to obtain globally coherent reconstructions. The performance is verified both qualitatively by face validity and quantitatively on our collection of stereo fundus image sets with ground truth, which have been made publicly available as an extension of standard test images for performance evaluation. PMID:21464502

Tang, Li; Garvin, Mona K.; Lee, Kyungmoo; Alward, Wallace L.M.; Kwon, Young H.; Abrmoff, Michael D.

2013-01-01

244

Combined Geometric/radiometric Point Cloud Matching for Shear Analysis  

NASA Astrophysics Data System (ADS)

In the recent past, dense image matching methods such as Semi-Global Matching (SGM) became popular for many applications. The SGM approach has been adapted to and implemented for Leica ADS line-scanner data by North West Geomatics (North West) in co-operation with Leica Geosystems; it is used in North West's production workflow. One of the advantages of ADS imagery is the calibrated color information (RGB and near infrared), extending SGM-derived point clouds to dense "image point clouds" or, more general, information clouds (info clouds). With the goal of automating the quality control of ADS data, info clouds are utilized for Shear Analysis: Three-dimensional offsets of adjacent ADS image strips are determined from a pattern of info cloud pairs in strip overlaps by point cloud matching. The presented approach integrates geometry (height) and radiometry (intensity) information; matching is based on local point-to-plane distances for all points in a given cloud. The offset is derived in a least squares adjustment by applying it to each individual distance computation equation. Using intensities in addition to heights greatly benefits the offset computation, because intensity gradients tend to occur more frequently than height gradients. They can provide or complement the required information for the derivation of planimetric offset components. The paper details the combined geometric/radiometric point cloud matching approach and verifies the results against manual measurements.

Gehrke, S.

2012-07-01

245

Design, manufacture, and calibration of infrared radiometric blackbody sources  

SciTech Connect

A Radiometric Calibration Station (RCS) is being assembled at the Los Alamos National Laboratories (LANL) which will allow for calibration of sensors with detector arrays having spectral capability from about 0.4-15 {mu}m. The configuration of the LANL RCS. Two blackbody sources have been designed to cover the spectral range from about 3-15 {mu}m, operating at temperatures ranging from about 180-350 K within a vacuum environment. The sources are designed to present a uniform spectral radiance over a large area to the sensor unit under test. The thermal uniformity requirement of the blackbody cavities has been one of the key factors of the design, requiring less than 50 mK variation over the entire blackbody surface to attain effective emissivity values of about 0.999. Once the two units are built and verified to the level of about 100 mK at LANL, they will be sent to the National Institute of Standards and Technology (NIST), where at least a factor of two improvement will be calibrated into the blackbody control system. The physical size of these assemblies will require modifications of the existing NIST Low Background Infrared (LBIR) Facility. LANL has constructed a bolt-on addition to the LBIR facility that will allow calibration of our large aperture sources. Methodology for attaining the two blackbody sources at calibrated levels of performance equivalent to present state of the art will be explained in the following.

Byrd, D.A.; Michaud, F.D.; Bender, S.C. [and others

1996-04-01

246

Date and Date Processing: A Review  

Microsoft Academic Search

Date fruit is an important product in the world and plays a significant role in the economic and political life in date growing regions. Date palm (Phoenix dactylifera L.) is a monocotyledon plant that goes through the stages of hababauk, kimri, khalal, rutab, and tamer during ripening. The main constituents of date include water, sugar, protein, fat, pectin, ash, crude

Zahra Ashraf; Zohreh Hamidi-Esfahani

2011-01-01

247

Laser photothermal radiometric instrumentation for fast in-line industrial steel hardness inspection and case depth measurements  

SciTech Connect

A contact-free, nondestructive laser photothermal radiometric instrumentation technique was developed to meet industrial demand for on-line steel hardness inspection and quality control. A series of industrial steel samples, flat or curvilinear, with different effective hardness case depths ranging between 0.21 and 1.78 mm were measured. The results demonstrated that three measurement parameters (metrics) extracted from fast swept-sine photothermal excitation and measurements, namely, the phase minimum frequency fmin, the peak or trough frequency width W, and the area S, are complementary for evaluating widely different ranges of hardness case depth: fmin is most suitable for large case depths, and W and S for small case depths. It was also found that laser beam angular inclination with respect to the surface plane of the sample strongly affects hardness measurement resolution and that the phase frequency maximum is more reliable than the amplitude maximum for laser beam focusing on the sample surface.

Guo Xinxin; Sivagurunathan, Konesh; Garcia, Jose; Mandelis, Andreas; Giunta, Salvatore; Milletari, Salvatore

2009-03-01

248

English/Russian terminology on radiometric calibration of space-borne optoelectronic sensors  

NASA Astrophysics Data System (ADS)

The efficient use of data acquired through exo-atmospheric observations of the Earth within the framework of existing and newly planned programs requires a unique understanding of respective terms and definitions. Yet, the last large-scale document on the subject - The International Electrotechnical Vocabulary - had been published 18 years ago. This lack of a proper document, which would reflect the changes that had occurred in the area since that time, is especially detrimental to the developing international efforts aimed at global observations of the Earth from space such as the Global Earth Observations Program proposed by the U.S.A. at the 2003 WMO Congress. To cover this gap at least partially, a bi-lingual explanatory dictionary of terms and definitions in the area of radiometric calibration of space-borne IR sensors is developed. The objectives are to produce a uniform terminology for the global space-borne observations of the Earth, establish a unique understanding of terms and definitions by the radiometric communities, including a correspondence between the Russian and American terms and definitions, and to develop a formal English/Russian reference dictionary for use by scientists and engineers involved in radiometric observations of the Earth from space. The dictionary includes close to 400 items covering basic concepts of geometric, wave and corpuscular optics, remote sensing technologies, and ground-based calibration as well as more detailed treatment of terms and definitions in the areas of radiometric quantities, symbols and units, optical phenomena and optical properties of objects and media, and radiometric systems and their properties. The dictionary contains six chapters: Basic Concepts, Quantities, Symbols, and Units, Optical phenomena, Optical characteristics of surfaces and media, Components of Radiometric Systems, Characteristics of radiometric system components, plus English/Russian and Russian/Inglish indices.

Privalsky, V.; Zakharenkov, V.; Humpherys, T.; Sapritsky, V.; Datla, R.

249

Microwave and Millimeter Wave Forward Modeling Results from the 2004 North Slope of Alaska Arctic Winter Radiometric Experiment  

SciTech Connect

The 2004 Arctic Winter Radiometric Experiment was conducted at the North Slope of Alaska (NSA) Atmospheric Radiation Measurement (ARM) Program field site near Barrow, Alaska from March 9 to April 9, 2004. The goals of the experiment were: to study the microwave and millimeter wave radiometric response to water vapor and clouds during cold and dry conditions; to obtain data for forward model studies at frequencies ranging from 22.235 to 400 GHz, to demonstrate new Environmental Technology Laboratory's (ETL) radiometric receiver and calibration technology and to compare both radiometric and in situ measurements of water vapor.

Westwater, E.R.; Cimini, D.; Klein, M.; Leuski, V.; Mattioli, V.; Gasiewski, A.J.; Dowlatshahi, S.; Liljegren, J.S.; Lesht, B.M.; Shaw, J.A.

2005-03-18

250

Radiometric calibration of a polarization-sensitive sensor  

NASA Technical Reports Server (NTRS)

The radiometric accuracy of a sensor is adversely affected by scene polarization if its optical system is sensitive to polarization. Tests performed on the reflective bands of the NS001 Thematic Mapper simulator, an aircraft multispectral scanner, show that it is very sensitive to the polarization state of the incoming radiations. For 100 percent linearly polarized light, errors in the measured intensity vary from -40 to +40 percent, depending on the scan angle and spectral band. To estimate polarization-induced errors in the intensity measured at aircraft level, the intensity and polarization of the atmospheric radiances were simulated using a realistic earth-atmosphere radiative transfer model. For the polarization of atmospheric radiances in the solar meridian plane over a vegetated target, intensity errors may range from -10 to + 10 percent. The polarization-induced errors are highest in the shortest NS001 spectral band (0.450-0.525 microns) because of large atmospheric polarizations contributed by Rayleigh particles and small diluting effects caused by the small contributions of weakly polarized radiations coming from aerosols and the surface. Depending on the illumination and view angles, the errors in derived surface reflectance due to the radiance errors can be very large. In particular, for large off-nadir view angles in the forward scattered direction when the sun is low, the relative errors in the derived surface reflectance can be as large as 4 to 5 times the relative error in the radiances. Polarization sensitivity errors cannot be neglected for the shorter wavelengths when the surface reflectance contribution to atmospheric radiances is very small.

Ahmad, Suraiya P.; Markham, Brian L.

1992-01-01

251

Wafer-level radiometric performance testing of uncooled microbolometer arrays  

NASA Astrophysics Data System (ADS)

A turn-key semi-automated test system was constructed to perform on-wafer testing of microbolometer arrays. The system allows for testing of several performance characteristics of ROIC-fabricated microbolometer arrays including NETD, SiTF, ROIC functionality, noise and matrix operability, both before and after microbolometer fabrication. The system accepts wafers up to 8 inches in diameter and performs automated wafer die mapping using a microscope camera. Once wafer mapping is completed, a custom-designed quick insertion 8-12 ?m AR-coated Germanium viewport is placed and the chamber is pumped down to below 10-5 Torr, allowing for the evaluation of package-level focal plane array (FPA) performance. The probe card is electrically connected to an INO IRXCAM camera core, a versatile system that can be adapted to many types of ROICs using custom-built interface printed circuit boards (PCBs). We currently have the capability for testing 384x288, 35 ?m pixel size and 160x120, 52 ?m pixel size FPAs. For accurate NETD measurements, the system is designed to provide an F/1 view of two rail-mounted blackbodies seen through the Germanium window by the die under test. A master control computer automates the alignment of the probe card to the dies, the positioning of the blackbodies, FPA image frame acquisition using IRXCAM, as well as data analysis and storage. Radiometric measurement precision has been validated by packaging dies measured by the automated probing system and re-measuring the SiTF and Noise using INO's pre-existing benchtop system.

Dufour, Denis G.; Topart, Patrice; Tremblay, Bruno; Julien, Christian; Martin, Louis; Vachon, Carl

2014-03-01

252

The Eurosdr Project "RADIOMETRIC Aspects of Digital Photogrammetric IMAGES" - Results of the Empirical Phase  

NASA Astrophysics Data System (ADS)

This article presents the empirical research carried out in the context of the multi-site EuroSDR project "Radiometric aspects of digital photogrammetric images" and provides highlights of the results. The investigations have considered the vicarious radiometric and spatial resolution validation and calibration of the sensor system, radiometric processing of the image blocks either by performing relative radiometric block equalization or into absolutely reflectance calibrated products, and finally aspects of practical applications on NDVI layer generation and tree species classification. The data sets were provided by Leica Geosystems ADS40 and Intergraph DMC and the participants represented stakeholders in National Mapping Authorities, software development and research. The investigations proved the stability and quality of evaluated imaging systems with respect to radiometry and optical system. The first new-generation methods for reflectance calibration and equalization of photogrammetric image block data provided promising accuracy and were also functional from the productivity and usability points of view. The reflectance calibration methods provided up to 5% accuracy without any ground reference. Application oriented results indicated that automatic interpretation methods will benefit from the optimal use of radiometrically accurate multi-view photogrammetric imagery.

Honkavaara, E.; Arbiol, R.; Markelin, L.; Martnez, L.; Bovet, S.; Bredif, M.; Chandelier, L.; Heikkinen, V.; Korpela, I.; Lelegard, L.; Prez, F.; Schlpfer, D.; Tokola, T.

2011-09-01

253

Radiometric Characterization Results for the IKONOS, Quickbird, and OrbView-3 Sensor  

NASA Technical Reports Server (NTRS)

Radiometric calibration of commercial imaging satellite products is required to ensure that science and application communities better understand commercial imaging satellite properties. Inaccurate radiometric calibrations can lead to erroneous decisions and invalid conclusions and can limit intercomparisons with other systems. To address this calibration need, the NASA Applied Sciences Directorate (ASD) at Stennis Space Center established a commercial satellite imaging radiometric calibration team consisting of three independent groups: NASA ASD, the University of Arizona Remote Sensing Group, and South Dakota State University. Each group independently determined the absolute radiometric calibration coefficients of available high-spatial-resolution commercial 4-band multispectral products, in the visible though near-infrared spectrum, from GeoEye(tradeMark) (formerly SpaceImaging(Registered TradeMark)) IKONOS, DigitalGlobe(Regitered TradeMark) QuickBird, and GeoEye (formerly ORBIMAGE(Registered TradeMark) OrbView. Each team member employed some variant of reflectance-based vicarious calibration approach, requiring ground-based measurements coincident with image acquisitions and radiative transfer calculations. Several study sites throughout the United States that covered a significant portion of the sensor's dynamic range were employed. Satellite at-sensor radiance values were compared to those estimated by each independent team member to evaluate the sensor's radiometric accuracy. The combined results of this evaluation provide the user community with an independent assessment of these sensors' absolute calibration values.

Holekamp, Kara; Aaron, David; Thome, Kurtis

2006-01-01

254

Radiometric calibration and noise estimation of acousto-optic tunable filter hyperspectral imaging systems.  

PubMed

The accuracy of the radiometric response of acousto-optic tunable filter (AOTF) hyperspectral imaging systems is crucial for obtaining reliable measurements. It is therefore important to know the radiometric response and noise characteristics of the hyperspectral imaging system used. A radiometric model of an AOTF hyperspectral imaging system composed of an imaging sensor radiometric model (CCD, CMOS, and sCMOS) and an AOTF light transmission model is proposed. Using the radiometric model, a method for obtaining the fixed pattern noise (FPN) of the imaging system by displacing and imaging an illuminated reference target is developed. Methods for estimating the temporal noise of the imaging system, using the photon transfer method, and for correcting FPN are also presented. Noise estimation and image restoration methods were tested on an AOTF hyperspectral imaging system. The results indicate that the developed methods can accurately calculate temporal and FPN, and can effectively correct the acquired images. After correction, the signal-to-noise ratio of the acquired images was shown to increase by 26%. PMID:23736239

Katranik, Jaka; Pernu, Franjo; Likar, Botjan

2013-05-20

255

PRESCHOOL APPLICATION Current Date_______________________ Desired Admission Date ____________________________________  

E-print Network

____________________________ Child's food allergies _______________________________ Other allergies-to-date Immunizations __ Allergy Form __Signed General Permission Form__ Signed Research Permission Form ___ Preschool

256

210Pb dating  

USGS Publications Warehouse

Roughly fifty years ago, a small group of scientists from Belgium and the United States, trying to better constrain ice sheet accumulation rates, attempted to apply what was then know about environmental lead as a potential geochronometer. Thus Goldberg (1963) developed the first principles of the 210Pb dating method, which was soon followed by a paper by Crozaz et al. (1964), who examined accumulation history of Antarctic snow using 210Pb. Shortly thereafter, Koide et al. (1972, 1973) adapted this technique to unravel sediment deposition and accumulation records in deep-sea environments. Serendipitously, they chose to work in a deep basin off California, where an independent and robust age model had already been developed. Krishanswami et al. (1971) extended the use of this technique to lacustrine deposits to reconstruct depositional histories of lake sediment, and maybe more importantly, contaminant inputs and burial. Thus, the powerful tool for dating recent (up to about one century old) sediment deposits was established and soon widely adopted. Today almost all oceanographic or limnologic studies that address recent depositional reconstructions employ 210Pb as one of several possible geochronometers (Andrews et al., 2009; Gale, 2009; Baskaran, 2011; Persson and Helms, 2011). This paper presents a short overview of the principles of 210Pb dating and provides a few examples that illustrate the utility of this tracer in contrasting depositional systems. Potential caveats and uncertainties (Appleby et al., 1986; Binford, 1990; Binford et al., 1993; Smith, 2001; Hancock et al., 2002) inherent to the use and interpretation of 210Pb-derived age-models are also introduced. Recommendations as to best practices for most reliable uses and reporting are presented in the summary.

Swarzenski, Peter W.

2014-01-01

257

Chronological information and uncertainty Radiocarbon dating & calibration -Paula Reimer  

E-print Network

SUPRA-net: Chronological information and uncertainty Radiocarbon dating & calibration - Paula Austin et al. 1995 #12;https://cams.llnl.gov/ Radiocarbon dating & calibration uncertainties ·Sampling Tephrochronology ­ David Lowe U series dating ­ David Richards* Combining multiple dating techniques ­ Andrew

Sengun, Mehmet Haluk

258

ADVANCES IN SURFACE LUMINESCENCE DATING: NEW DATA FROM SELECTED MONUMENTS  

Microsoft Academic Search

In the present study, an attempt is being made to date samples from three archaeological sites in the Mediterranean using surface luminescence dating techniques. The methods are well established and this study is an effort to apply it to monuments that have not being dated with these methods before. Megalithic structures are eligible for absolute dating using OSL approaches in

I. Liritzis; A. Vafiadou; N. Zacharias; G. S. Polymeris; R. G Bednarik

2013-01-01

259

Dendrochronologically Dated Ottoman Monuments  

E-print Network

Dendrochronologically Dated Ottoman Monuments Peter Ian Kuniholm #12;Dendrochronologically Dated 4 Ottoman Monuments Peter Ian Kuniholm INTRODUCTION Dendrochronology or tree-ring dating has been carried history, no matter PETERIANKUNMOLMl Aegean Dendrochronology Project, Department of the History of Art

Manning, Sturt

260

Investigation of radiometric combustion monitoring techniques for coal-fired stoker boilers. Final report  

Microsoft Academic Search

Fuel-ash bed disturbances are costly problems often encountered in operating coal-fired, mechanical-stoker boilers in military heat plants. In traveling grate, mechanical-stoker boilers, all or most of the coal burns on the traveling grate, so proper control of combustion grate fuel-ash bed thickness is critical for cost-effective, high-availability operation. In these plants, operators must adjust combustion equipment as the coal enters

F. V. Karlson; T. H. Parsons; M. J. Savoie; W. B. Scholten

1993-01-01

261

Radiometric correction techniques and accuracy assessment for Landsat TM data in remote  

E-print Network

, illumination geometry, ground reference data of pseudo-invariant features (PIFs), and satellite calibration reference data, climate data, or the subjective selection of PIFs were assessed for these images rfrence au sol des attributs pseudo-invariants (PIF) ainsi que les donnes d'talonnage du satellite. La

Northern British Columbia, University of

262

Microwave radiometric measurements of soil moisture in Italy Hydrology and Earth System Sciences, 7(6), 937948 (2003) EGU  

E-print Network

Sciences, 7(6), 937948 (2003) © EGU Microwave radiometric measurements of soil moisture in Italy GMicrowave radiometric measurements of soil moisture in Italy 937 Hydrology and Earth System GHz). The aim of the experiments was to collect soil moisture and vegetation biomass information

Paris-Sud XI, Université de

263

Comparison of diverse methods for the correction of atmospheric effects on LANDSAT and SKYLAB images. [radiometric correction in Brazil  

NASA Technical Reports Server (NTRS)

Earth's atmosphere reduces a sensors ability in currently discriminating targets. Using radiometric correction to reduce the atmospheric effects may improve considerably the performance of an automatic image interpreter. Several methods for radiometric correction from the open literature are compared leading to the development of an atmospheric correction system.

Parada, N. D. J. (principal investigator); Camara, G.; Dias, L. A. V.; Mascarenhas, N. D. D.; Desouza, R. C. M.; Pereira, A. E. C.

1982-01-01

264

Geometric and radiometric performance evaluation methods for Marine Observation Satellite-1 (MOS-1) verification program (MVP)  

NASA Astrophysics Data System (ADS)

The airborne verification experiment designed to develop algorithms for the data processing facility of MOS-1 and to assess geometric and radiometric performance evaluation methods for the MOS-1 verification program (MVP) is described. The geometric and radiometric performance evaluation methods described include the evaluation of the S/N and gain change effect, brooming evaluation, sensor alignment evaluation, and spatial resolution evaluation for the MESSR; the spatial resolution evaluation for the VTIR; and the S/N evaluation and spatial resolution evaluation for the MSR.

Maeda, K.; Azuma, Y.; Kojima, M.

1986-10-01

265

Magnetostratigraphic and radiometric constraints on salt formation in the Qaidam Basin, NE Tibetan Plateau  

NASA Astrophysics Data System (ADS)

The Qaidam Basin is the largest Cenozoic intermontane basin within the northeast (NE) Tibetan Plateau. It contains large amounts of nonmarine evaporite deposits formed during the Pliocene-Quaternary. Even at present, extensive salt deposits dominated by halite and potash are formed by solar-driven concentration of brine water in the basin interior, making it the most important industrial base for potash exploitation in China. The formation of salt required an arid climatic, appropriate hydrological and tectonic setting through geologic times and will do so in the future. Studying the salt formation in the Qaidam Basin will enhance our understanding of processes driven by saline lake evolution, regional climate change, and tectonic movements, not only for the setting of the Tibetan Plateau. Reliable dating is crucial for assessing the time of salt formation in Qaidam Basin and the accumulation process, yet no comprehensive scientific studies have been reported on this important issue until now. In this paper, we critically review and compile magnetostratigraphic and radiometric studies of the salt-bearing strata within seven depressions of the basin. We find that the ages of salt formation are very different in these depressions: for the Dalangtan, Yiliping, Chahansilatu, and Kunteyi depressions, first salt deposits occurred at >3.900.02Ma, 2.880.04Ma, 2.240.01Ma and 1.180.02Ma, respectively. For the Mahai, Gasikule, and Qarhan, the ages of earliest salt formation are much younger i.e., 30256ka, 60838ka, and 54-24ka, respectively. However, the result from Mahai has to be considered with caution. The variability of ages suggests an older salt-forming stage in the center of the western basin and a younger salt accumulation period along the basin margin. In a regional view, previous results from stratigraphy, sedimentology, geomorphology, and tectonic history allow us to conclude that the salt formation in the Qaidam Basin was probably controlled by pulsed intrabasinal tectonic movements and the distribution and migration of paleo-rivers during the Pliocene-Quaternary. However, the climatic shift towards drier and colder conditions in the Asian interior during this time also promoted salt formation.

Wang, Jiuyi; Fang, Xiaomin; Appel, Erwin; Zhang, Weilin

2013-10-01

266

A Sounding Rocket Mission Concept to Acquire High-Resolution Radiometric Spectra Spanning the 9 nm - 31 nm Wavelength Range  

NASA Technical Reports Server (NTRS)

When studying Solar Extreme Ultraviolet (EUV) emissions, both single-wavelength, two- dimensional (2D) spectroheliograms and multi-wavelength, one-dimensional (1D) line spectra are important, especially for a thorough understanding of the complex processes in the solar magnetized plasma from the base of the chromosphere through the corona. 2D image data are required for a detailed study of spatial structures, whereas radiometric (i.e., spectral) data provide information on relevant atomic excitation/ionization state densities (and thus temperature). Using both imaging and radiometric techniques, several satellite missions presently study solar dynamics in the EUV, including the Solar Dynamics Observatory (SDO), Hinode, and the Solar-Terrestrial Relations Observatory (STEREO). The EUV wavelengths of interest typically span 9 nm to 31 nm, with the shorter wavelengths being associated with the hottest features (e.g., intense flares and bright points) and the longer wavelengths associated with cooler features (e.g., coronal holes and filaments). Because the optical components of satellite instruments degrade over time, it is not uncommon to conduct sounding rocket underflights for calibration purposes. The authors have designed a radiometric sounding rocket payload that could serve as both a calibration underflight for and a complementary scientific mission to the upcoming Solar Ultraviolet Imager (SUVI) mission aboard the GOES-R satellite (scheduled for a 2015 launch). The challenge to provide quality radiometric line spectra over the 9-31 nm range covered by SUVI was driven by the multilayer coatings required to make the optical components, including mirrors and gratings, reflective over the entire range. Typically, these multilayers provide useful EUV reflectances over bandwidths of a few nm. Our solution to this problem was to employ a three-telescope system in which the optical components were coated with multilayers that spanned three wavelength ranges to cover the three pairs of SUVI bands. The complete system was designed to fit within the Black Brandt-IX 22.-diameter payload skin envelope. The basic optical path is that of a simple parabolic telescope in which EUV light is focused onto a slit and shutter assembly and imaged onto a normal-incidence diffraction grating, which then disperses the light onto a 2048 2048 CCD sensor. The CCD thus records 1D spatial information along one axis and spectral information along the other. The slit spans 40 arc-minutes in length, thus covering a solar diameter out to +/- 1.3 solar radii. Our operations concept includes imaging at three distinct positions: the north-south meridian, the northeast-southwest diagonal, and real-time pointing at an active region. Six 10-second images will be obtained at each position. Fine pointing is provided by the SPARCS-VII attitude control system typically employed on Black Brandt solar missions. Both before and after launch, all three telescopes will be calibrated with the EUV line emission source and monochromater system at NASA's Stray Light Facility at Marshall Spaceflight Center. Details of the payload design, operations concept, and data application will be presented.

Krause, L. Habash; Cirtain, Jonathan; McGuirck, Michael; Pavelitz, Steven; Weber, Ed.; Winebarger, Amy

2012-01-01

267

Research paper Constraining the age of rock art by dating a rockfall event using sediment and  

E-print Network

dating techniques, dendrochronology and lichenometry, are indirect measurements requiring the presence of specific species of organisms (Lang et al., 1999). Dendrochronology is a useful method for dating rockfall

Pederson, Joel L.

268

Amino acid racemization dating of fossil bones  

Microsoft Academic Search

The development of amino acid racemization as a dating technique holds considerable promise for resolving questions of human evolution and culture histories. The advantages of this method are: fossil bone can be directly dated; only gram quantities are needed for analysis; and the range extends beyond that of radiocarbon. Amino acid racemization rates are dependent upon both time and temperature.

Jeffrey L. Bada; Patricia Masters Helfman

1975-01-01

269

Airborne lidar and radiometric observations of PBL- and low clouds  

NASA Technical Reports Server (NTRS)

Boundary layer- and low altitude clouds over open ocean and continent areas have been studied during several field campaigns since mid-1990 using the French airborne backscatter lidar LEANDRE in conjunction with on-board IR and visible radiometers. LEANDRE is an automatic system, and a modification of the instrumental parameters, when airborne, is computer controlled through an operator keyboard. The vertical range squared lidar signals and instrument status are displayed in real time on two dedicated monitors. The lidar is used either down- or up-looking while the aircraft is flying above or below clouds. A switching of the viewing configuration takes about a minute. The lidar measurements provide a high resolution description of cloud morphology and holes in cloud layers. The flights were conducted during various meteorological conditions on single or multilayer stratocumulus and cumulus decks. Analysis on a single shot basis of cloud top (or bottom) altitude and a plot of the corresponding histogram allows one to determine a probability density function (PDF). The preliminary results show the PDFs for cloud top are not Gaussian and symmetric about the mean value. The skewness varies with atmospheric conditions. An example of results recorded over the Atlantic ocean near Biarritz is displayed, showing: (1) the range squared lidar signals as a function of time (here 100 s corresponds to about 8 km, 60 shots are averaged on horizontal); the Planetary Boundary Layer (PBL) - up to 600 m - is observed at the beginning of the leg as well as on surface returns, giving an indication of the porosity; (2) the cloud top altitude variation between 2.4 to 2.8 km during the 150 to 320 s section; and (3) the corresponding PDF. Similar results are obtained on stratocumulus over land. Single shot measurements can be used also to determine an optical porosity at a small scale as well as a fractional cloudiness at a larger scale. A comparison of cloud top altitude retrieved from lidar and narrowbeam IR radiometer is conducted to study the scale integration problem. A good agreement within less than 100 m relies on spatial uniformity and an optically thick layer. In the presence of holes, a discrepancy is observed. This is illustrated in figure 2, displaying as a function of time (1) the lidar signals; (2) the target temperature (either clouds or sea surface) retreived from a narrowbeam IR radiometer, 17 C is the sea surface temperature on that day; and (3) the visible flux, linked to cloud albedo, measured by a pyranometer. In preparation of ASTEX, down- and up-looking measurements where conducted on stratocumulus clouds over the Atlantic Ocean near Quimper in Brittany. Depending on the flight pattern orientation with respect to the wind, the top and bottom cloud morphologies are different. Preliminary results are given on cloud morphology, cloud top PDFs, optical porosity, fractional cloudiness, and comparison of lidar and radiometric measurements.

Flamant, P. H.; Valentin, R.; Pelon, J.

1992-01-01

270

Adjustments to the MODIS Terra Radiometric Calibration and Polarization Sensitivity in the 2010 Reprocessing  

NASA Technical Reports Server (NTRS)

The Moderate-Resolution Imaging Spectroradiometer (MODIS) on NASA s Earth Observing System (EOS) satellite Terra provides global coverage of top-of-atmosphere (TOA) radiances that have been successfully used for terrestrial and atmospheric research. The MODIS Terra ocean color products, however, have been compromised by an inadequate radiometric calibration at the short wavelengths. The Ocean Biology Processing Group (OBPG) at NASA has derived radiometric corrections using ocean color products from the SeaWiFS sensor as truth fields. In the R2010.0 reprocessing, these corrections have been applied to the whole mission life span of 10 years. This paper presents the corrections to the radiometric gains and to the instrument polarization sensitivity, demonstrates the improvement to the Terra ocean color products, and discusses issues that need further investigation. Although the global averages of MODIS Terra ocean color products are now in excellent agreement with those of SeaWiFS and MODIS Aqua, and image quality has been significantly improved, the large corrections applied to the radiometric calibration and polarization sensitivity require additional caution when using the data.

Meister, Gerhard; Franz, Bryan A.

2011-01-01

271

GEOMETRIC AND RADIOMETRIC MODELING OF 3D SCENES Marco Marcon, Augusto Sarti, Stefano Tubaro  

E-print Network

of a real scene) an accurate description of lighting condition and surface reflection properties of eachGEOMETRIC AND RADIOMETRIC MODELING OF 3D SCENES Marco Marcon, Augusto Sarti, Stefano Tubaro (ITALY) ABSTRACT Modeling of 3D scenes is a hot topic in Computer Vision from more that thirty years

Marcon, Marco

272

Diffusion-wave laser radiometric diagnostic quality-control technologies for materials NDE/NDT  

E-print Network

radiometric NDE metrology capable of measuring the primary photo- injected free carrier parameters in materials, well beyond the optical penetration depth of illumination sources, i.e. below the range vector, which leads to spatially heavily damped pseudo-propagation, and a frequency-dependent `skin

Mandelis, Andreas

273

Development of a five-hour radiometric serum antibacterial assay for gram-positive cocci  

SciTech Connect

A preliminary report on a 5-hr radiometric serum antibacterial assay (ABA) for Gram-positive cocci is presented. The method agreed within +- one twofold dilution with static ABA endpoints in 24/26 (92%) of the assays and with cidal ABA end-points in 23/26 (88%) of the assays performed.

Beckwith, D.G.; Guidon, P.T. Jr.

1981-03-01

274

Spectral and radiometric calibration of the Airborne Visible/Infrared Imaging Spectrometer  

NASA Technical Reports Server (NTRS)

The laboratory spectral and radiometric calibration of the AVIRIS science data collected since 1987 is described. The instrumentation and procedures used in the calibration are discussed and the accuracy achieved in the laboratory as determined by measurement and calculation is compared with the requirements. Instrument performance factors affecting radiometry are described. The paper concludes with a discussion of future plans.

Vane, Gregg; Chrien, Thomas G.; Miller, Edward A.; Reimer, John H.

1987-01-01

275

ESTIMATING SUBPIXEL SURFACE TEMPERATURES AND ENERGY FLUXES FROM THE VEGETATION INDEX-RADIOMETRIC TEMPERATURE RELATIONSHIP  

Technology Transfer Automated Retrieval System (TEKTRAN)

Routine (i.e., daily to weekly) monitoring of surface energy fluxes, particularly evapotranspiration (ET), using satellite observations of radiometric surface temperature has not been feasible at high pixel resolution because of the low frequency in satellite coverage over the region of interest (i...

276

Landsat:radiometricandtopographiccorrectionofsatelliteimagery (Rpackage)  

Technology Transfer Automated Retrieval System (TEKTRAN)

Most Geographic Information System software includes routines for atmospheric and topograhic correction of satellite imagery such as that taken by Landsat. Radiometric correction is an active area of research, and new, improved methods are rarely if ever available for testing and application. The R...

277

UTILITY OF RADIOMETRIC-AERODYNAMIC TEMPERATURE RELATIONS FOR HEAT FLUX ESTIMATION  

Technology Transfer Automated Retrieval System (TEKTRAN)

In many land surface models using bulk transfer (one-source) approaches, the application of radiometric surface temperature observations in energy flux computations has given mixed results. This is due in part to the non-unique relationship between the so-called aerodynamic temperature, which relat...

278

IMPLICATIONS OF RADIOMETRIC-AERODYNAMIC TEMPERATURE DIFFERENCES FOR HEAT FLUX ESTIMATION  

Technology Transfer Automated Retrieval System (TEKTRAN)

In the application of radiometric surface temperature observations for heat flux computations in numerical models, it is necessary to consider differences between the so-called aerodynamic temperature, which is the model-derived temperature that relates to the efficiency of heat exchange between t...

279

Radiometric calibration accuracy of GOSAT-TANSO-FTS (TIR) relating to CO2 retrieval error  

Microsoft Academic Search

Radiometric calibration accuracy of 0.3 K in Tbb is necessary to retrieve CO2 concentration profile with accuracy of 1 % in the upper atmosphere. In case of the thermal infrared (TIR) band (band 4) of GOSAT-TANSO-FTS, interferometric phase correction procedure is very important because the total transmittance of the optics at the band is about 70 % because of opacity

Ryoichi Imasu; Naoko Saitoh; Yosuke Niwa; Hiroshi Suto; Akihiko Kuze; Kei Shiomi; Masakatsu Nakajima

2008-01-01

280

In-orbit radiometric performance variations of geostationary ocean color imager  

NASA Astrophysics Data System (ADS)

Geostationary Ocean Color Imager (GOCI), a payload of the Communication, Ocean and Meteorology Satellite (COMS), is the world's first ocean color observation satellite in geostationary orbit. It was launched at Kourou Space Center in French Guiana in June 2010. The detector array in GOCI is custom CMOS Image sensor about 2 Mega-pixels, featuring rectangular pixel size to compensate for the Earth oblique projection. This satellite is being operated on geostationary orbit about 36,500km far from the earth; hence it can be more influenced by sun activities than the other on low Earth orbit. Especially, the detector is sensitive of heat and it may give rise to increasing the defective pixels. In this paper, radiometric performance variations have been analyzed through the time series analysis, using the offset parameters and detector temperature estimated in GOCI radiometric model. It is essential to monitor the overall sensitivity of GOCI sensor, and it will helpful to the radiometric calibration. In the result, we notified there was no great variation in time series of offset parameters after operating the GOCI in July 2010, but we monitored an anomaly by an operational event. One of them related to thermal electron showed slightly increasing trend and the diurnal variation by the sun energy. Although sun interferences are occurred sometimes, any significant anomaly isn't found. With these results of characterization, we find that GOCI has been carrying out stably in the aspect of radiometric performance, and expect that it will be kept during the mission life.

Lee, Sun-Ju; Cho, Seongick; Han, Hee-Jeong; Oh, Eunsong; Ryu, Joo-Hyung; Ahn, Yu-Hwan

2011-11-01

281

Research on methods of spectral calibration and radiometric calibration of the windowing Fourier transform imaging spectrometer  

NASA Astrophysics Data System (ADS)

Spectral calibration and radiometric calibration is an important part in the data processing of the windowing Fourier transform imaging spectrometer, it can ensure that the spectral curve output from spectrometer are more closely to target spectrum. The main idea of spectral calibration is using a monochromatic source whose wavelength is known, in the same way, radiometric calibration can be achieved by using radiation source whose radiation characteristic is known. In this paper, we propose a set of methods of spectral calibration and radiometric calibration. In order to carry out spectral calibration, we use monocharomator to scan several sample points near the position of every spectral channel of imaging spectrometer, and then we employ Gaussian fitting function to determine the central wavelength and bandwidth of every spectral channel. In order to carry out radiometric calibration, we employ panchromatic light source and integrating sphere, at the position of every spectral channel of imaging spectrometer, we measure the response ability of spectrometer to radiation. The calibration accuracy is carefully analyzed. Experimental results show that calibration accuracy meet the given requirements.

Zhang, Lei; Gao, Jiao Bo; Zhao, Yu Jie; Luo, Yan Ling; Xiao, Xiang Guo; Zhang, Fang

2013-08-01

282

Lifetime radiometric calibration of HJ-1A/B CCD sensor using Dunhuang Gobi site  

NASA Astrophysics Data System (ADS)

Dunhuang Gobi site, a pseudo-invariant ground target, has been extensively used to calibrate the remote sensing instruments because of its high spatial and spectral uniformity and good temporal stability. Four Charge Coupled Device (CCD) sensors onboard HUANGJING-A/B (HJ-1A/B) satellites have been running 5-years since launched in 2008, and provided important remote sensing data for land surface reflectance retrieval, bio/geophysical variables estimation and environment pollution /disaster monitoring. The radiometric performance of HJ-1A/B CCD may change after launched because of many factors, thus, we have carried out many ground measurement campaigns at a pseudo-invariant test site-Dunhuang gobi to perform radiometric calibration of these sensors. This article describes the characteristics of Dunhuang gobi site and lifetime radiometric calibration monitoring results obtained for four CCD sensors. The results indicate that the long-term changes in calibration coefficients trending exceeding the dark-noise changes are primarily due to the drifts in the CCD radiometric responsivity, and the degradations of HJ-1A/B CCD are from -2.3%/year to -9.5%/year.

Han, Qijin; Zhang, Xuewen; Liu, Li; Wang, Aichun

2014-11-01

283

Onboard Real-Time Absolute Radiometric Calibration for Thermal Infrared Channels of Chinese Geostationary Meteorological Satellites  

E-print Network

Onboard Real-Time Absolute Radiometric Calibration for Thermal Infrared Channels of Chinese and brightness temperatures with the corresponding DNs. In addition, the temperatures of onboard blackbody (OBB and temperatures of various mirrors, the transform equations from TOBB to TEBB are developed. Finally, the onboard

Dery, Stephen

284

RAW MATERIALS USED FOR THE PHOSPHATE FERTILIZER PRODUCTION IN ROMANIA -NEW RADIOMETRIC DATA  

E-print Network

RAW MATERIALS USED FOR THE PHOSPHATE FERTILIZER PRODUCTION IN ROMANIA - NEW RADIOMETRIC DATA Aurora gamma spectrometry in natural apatites used as raw materials in the phosphate fertilizer industry. The results confirmed that the phosphates of sedimentary origin (i.e. the samples from Jordan and Morocco

Paris-Sud XI, Universit de

285

Radiometric calibration of GOES7 VISSR solar channels during the GOES pathfinder benchmark period  

Microsoft Academic Search

The GOES-7 VISSR solar channels are radiometrically calibrated for the period from June 1987 through November 1988. Space, White Sands, and the Sonora Desert are used as calibration targets. Three different calibrations were performed: 1) using the stretched data (i.e., retransmitted data operationally destriped using NOAA's normalization procedure) and considering individual VISSR detectors separately; 2) using the stretched data averaged

Robert J. Frouin; James J. Simpson

1995-01-01

286

Geometric and radiometric correction of TM data of mountainous forested areas  

Microsoft Academic Search

Methodologies to improve Landsat TM (Thematic Mapper) forest classifications of alpine regions through the removal of some radiometric and geometric distortions are tested. Besides correcting for sensor and system induced errors, geometric errors are corrected using a digital elevation model. Then scene-related effects such as differences in illumination as well as the height dependent atmospheric influence and adjacency effects are

Klaus I. Itten; Peter Meyer

1993-01-01

287

Lithostratigraphy, magnetostratigraphy, and radiometric dating of the Stanislaus Group, CA, and age of the Little Walker Caldera  

E-print Network

/trachydacite) lavas and ignimbrites, provides an important marker for reconstructing the elevation history lavas at ca. 10.4 Ma and (2) ignimbrite eruptions alternating with lesser lava flow eruptions during ca of the present Sierra Nevada crest, whereas the ignimbrite eruptions formed the Little Walker Caldera. Our new

Busby, Cathy

288

Using the Dunhuang test site to monitor the radiometric stability of the ZY-3 multispectral sensor  

NASA Astrophysics Data System (ADS)

The ZY-3 satellite plays an important role in agriculture, forestry, water conservancy, ecological environment, and so on since its successfully running. In order to achieve continuity, stability and reliability of the remote sensing data, and improve quantitative application level of the ZY-3 satellite data, an accurate sensor radiometric calibration is essential. Because ZY-3 satellite doesn't have onboard calibration system, in-fight filed absolute radiometric calibration as a means to effective monitor the radiometric stability.This paper uses multi-day, multi-field at the Dunhuang test site to calibrate the ZY-3 multispectral sensor. The experiment obtained a synchronization measurement data on the August 18, 23 and 28, respectively. The two of ground surface were selected for measuring reflectance, which middling reflectance field (20%) and high reflectance field (40%). At the time of the ZY-3 overpass on the site, synchronous measure surface reflectance of ground targets, atmospheric optical characteristics parameters, such as atmospheric aerosol optical depth, atmospheric columnar water vapor content. Then use the radiative transfer model to estimate the top of atmosphere (TOA) radiance for MSS band. Radiometric calibration coefficient of MSS band was estimated by comparing the TOA radiance with average digital number of the MSS image. Based on multi-day, multi-field, and the real-time measurement at the Dunhuang site, radiometric calibration for ZY-3 MSS was successfully performed using reflectance-based method and calibration coefficients for MSS bands were obtained as well. According to contrast between in-fight calibration and the prelaunch, it was shown that the response of MSS changed at some extent after launch, especially band 1 and band 4. As a result, it was quite essential to update calibration coefficient timely and periodically in order to monitor the change of ZY-3 MSS better and to improve the quantitative application of MSS data as well.

Zhang, Xuewen; Han, Qijin; Liu, Li

2014-11-01

289

Arrival Date: Departure Date: First Last (Gender)  

E-print Network

Arrival Date: Departure Date: Name First Last (Gender) Address Telephone City/Town Postal Code rates do NOT include applicable taxes and fees (5% GST, 4% tourism Levy and 2 % Destination Marketing Town Home - 2 rooms with double beds, 2 rooms with single beds. Living area, kitchen, TV, microwave

Kadiri, Habiba

290

Adaptive least squares correlation a powerful image matching technique  

Microsoft Academic Search

The Adaptive Least Squares Correlation is a very potent and flexible technique for all kinds of data matching problems. Here its application to image matching is outlined. It allows for simultaneous radiometric corrections and local geometrical image shaping, whereby the system parameters are automatically assessed, corrected, and thus optimized during the least squares iterations. The various tools of least squares

A. W. Gruen

1985-01-01

291

Sample detection and analysis techniques for electrophoretic separation  

NASA Technical Reports Server (NTRS)

Methods for detecting and analyzing biological agents suitable for space flight operations were studied primarily by literature searches which were conducted of cell separation techniques. Detection methods discussed include: photometrometric, electric, radiometric, micrometry, ultrasonic, microscopic, and photographic. A bibliography, and a directory of vendors are included along with an index of commercial hardware.

Falb, R. D.; Hughes, K. E.; Powell, T. R.

1975-01-01

292

Dating and Marriage  

MedlinePLUS

... National HIV/AIDS and Aging Awareness Day National Gay Men's HIV/AIDS Awareness Day National Latino AIDS Awareness Day World AIDS Day Conferences 30 Years of ... Translate Text Size Print Dating and Marriage Dating ...

293

Laboratory for Radiokrypton Dating  

NASA Astrophysics Data System (ADS)

Due to its simple production and transport processes in the terrestrial environment, the long-lived noble-gas isotope 81Kr (half-life = 230 kyr) is the ideal tracer for studying old water and ice in the age range of 10^5-10^6 years, a range beyond the reach of 14C. 81Kr dating, a concept pursued in the past four decades by numerous laboratories employing a variety of techniques, is now available for the first time to the earth science community at large. This is made possible by the development of ATTA-3 (Jiang et al., GCA 91, 1-6; 2012), an efficient and selective atom counter based on the Atom Trap Trace Analysis method (Chen et al., Science 286, 1139-1141; 1999). The instrument is capable of measuring both 81Kr/Kr and 85Kr/Kr ratios of environmental samples in the range of 10^-14-10^-10. For 81Kr-dating in the age range of 150 - 1,500 kyr, the required sample size is 5 - 10 micro-L STP of krypton gas, which can be extracted from approximately 100 - 200 kg of water or 40 - 80 kg of ice. For 85Kr/Kr analysis, the required sample size is generally smaller by an order of magnitude because of the isotope's higher initial abundance in the atmosphere. The Laboratory for Radiokrypton Dating is currently equipped to analyze up to 120 samples per year. With future equipment upgrades, this limit can be increased as demand grows. In the period since November 2011, the Laboratory has measured both 81Kr/Kr and 85Kr/Kr ratios in over 50 samples that had been extracted by collaborators from six different continents. The samples were from groundwater wells in the Great Artesian Basin (Australia), Guarani Aquifer (Brazil), and Locust Grove (Maryland); from brine wells of the Waste Isolation Pilot Plant (New Mexico); from geothermal steam vents in Yellowstone National Park; from near-surface ice at Taylor Glacier, Antarctica; and from deep mines in South Africa. Sample collection and purification was performed by groups including the University of Illinois at Chicago, University of Bern, and International Atomic Energy Agency. ATTA is a laser-based atom counting method, not a mass spectrometry method. A magneto-optical trap is used to capture neutral atoms (rather than ions) of the desired isotope using laser beams. A photo-sensor detects the laser induced fluorescence emitted by the individual trapped atoms. ATTA is unique among trace analysis techniques in that it is free of interferences from any other isotopes, isobars, atomic or molecular species. In an experiment demonstrating that ATTA-3 can analyze 39Ar/Ar ratios in environmental samples, no interference from other atomic or molecular species was observed at the 1x10^-16 level (Jiang et al., Phys. Rev. Lett. 106, 103001; 2011). This work proved the feasibility of performing 39Ar dating using the ATTA method. We are supported by DOE, Office of Nuclear Physics, under contract DE-AC02-06CH11357, and by Argonne National Laboratory.

Lu, Z.; Bailey, K.; Jiang, W.; Mller, P.; O'Connor, T. P.; Zappala, J. C.

2013-12-01

294

Dating as leisure  

Microsoft Academic Search

Partner selection occurs naturally and informally, but it may also be organized through commercial intermediaries facilitating mating and dating. This paper focuses on the relationship between online dating and the business cycle . We rely on monthly data covering the period from January 2004 to August 2008 on the demand for online dating in France to study whether economic recession

Vronique Flambard; Nicolas Grard Vaillant; Franois-Charles Wolff

2010-01-01

295

Improving Ocean Color Data Products using a Purely Empirical Approach: Reducing the Requirement for Radiometric Calibration Accuracy  

NASA Technical Reports Server (NTRS)

Radiometric calibration is the foundation upon which ocean color remote sensing is built. Quality derived geophysical products, such as chlorophyll, are assumed to be critically dependent upon the quality of the radiometric calibration. Unfortunately, the goals of radiometric calibration are not typically met in global and large-scale regional analyses, and are especially deficient in coastal regions. The consequences of the uncertainty in calibration are very large in terms of global and regional ocean chlorophyll estimates. In fact, stability in global chlorophyll requires calibration uncertainty much greater than the goals, and outside of modern capabilities. Using a purely empirical approach, we show that stable and consistent global chlorophyll values can be achieved over very wide ranges of uncertainty. Furthermore, the approach yields statistically improved comparisons with in situ data, suggesting improved quality. The results suggest that accuracy requirements for radiometric calibration cab be reduced if alternative empirical approaches are used.

Gregg, Watson

2008-01-01

296

From Romance to Rocket Science: Speed Dating in Higher Education  

ERIC Educational Resources Information Center

This article is the first comprehensive review of speed dating in the tertiary sector. While speed dating has its origins as a networking technique to connect singles, it has only more recently made its way into the academy. Since 2005 universities world-wide have begun to adopt speed dating protocols as a tool for building research culture. An

Muurlink, Olav; Poyatos Matas, Cristina

2011-01-01

297

Prime candidate earth targets for the post-launch radiometric calibration of space-based optical imaging instruments  

USGS Publications Warehouse

This paper provides a comprehensive list of prime candidate terrestrial targets for consideration as benchmark sites for the post-launch radiometric calibration of space-based instruments. The key characteristics of suitable sites are outlined primarily with respect to selection criteria, spatial uniformity, and temporal stability. The establishment and utilization of such benchmark sites is considered an important element of the radiometric traceability of satellite image data products for use in the accurate monitoring of environmental change.

Teillet, P.M.; Barsi, J.A.; Chander, G.; Thome, K.J.

2007-01-01

298

A liquid-helium-cooled absolute reference cold load for long-wavelength radiometric calibration  

NASA Technical Reports Server (NTRS)

Design, radiometric and thermal performance, and operation of a large diameter (78 cm) liquid-helium-cooled blackbody absolute reference cold load (CL) for the calibration of microwave radiometers is described. CL provides an absolute calibration near the liquid-helium (LHe) boiling point, with total uncertainty in the radiometric temperature of less than 30 mK over the 2.5-23 cm wavelength operating range. CL was used at several wavelengths at the South Pole, Antarctica and the White Mountain Research Center, California. Results show that, for the instruments operated at 20-, 12-, 7.9-, and 4.0 cm wavelength at the South Pole, the total corrections to the LHe boiling-point temperature (about 3.8 K) were 48 +/-23, 18 +/-10, 10 +/-18, and 15 +/-mK.

Bensadoun, Marc; Witebsky, Chris; Smoot, George; De Amici, Giovanni; Kogut, AL; Levin, Steve

1992-01-01

299

First realisation of the Space Absolute Radiometric Reference (SARR) during the ATLAS 2 flight period  

NASA Technical Reports Server (NTRS)

A number of different solar constant observations all made from space during the ATLAS 2 mission have been gathered and compared to each other. The Sun did not have a single sunspot during several days. As eight of the radiometric channels were all within 0.1%, the mean of the observations has been used to determine a set of adjustment factors providing de facto the definition of the Space Absolute Radiometric Reference (SARR). The differential absolute radiometers of Solar Constant (SOLCON) experiment and the Solar Variability-1 (SOVA 1) experiment, as well as the SOVA 2 and Active Cavity Radiometer (ACR) radiometers that have been brought back to the Earth may, if used in the same conditions, reproduce and maintain the SARR for the future.

Crommelynck, D.; Fichot, A.; Lee, R. B., III; Romero, J.

1995-01-01

300

Landsat-8 operational land imager on-orbit radiometric calibration and stability  

NASA Astrophysics Data System (ADS)

The Operational Land Imager (OLI) on Landsat-8 has been collecting imagery on orbit for 17 months. The radiometric performance of the OLI is monitored using on-board systems (lamps and solar diffusers) as well as by reference to lunar and ground measurements and other satellite systems. Over this nearly 1 years of operation the OLI has been extremely radiometrically stable in all of its 9 spectral bands. Only the shortest wavelength band, centered at 443 nm, which has degraded about 0.8%, has changed by more than the variability among the measurements (~0.2%). This consistency between the lamps, diffusers, moon, and ground measurements lends high confidence to these statements, which is unusual for a system so early in its lifetime. Comparisons to other satellite systems and ground measurements show that the OLI is calibrated to within requirements and generally better than 3% in both radiance and reflectance.

Markham, Brian L.; Barsi, Julia A.; Kaita, Edward; Ong, Lawrence; Haque, Md. O.; Mishra, Nischal; Czapla-Myers, Jeffrey; Pahlevan, Nima; Helder, Dennis

2014-10-01

301

Real-Time EDL Navigation Performance Using Spacecraft to Spacecraft Radiometric Data  

NASA Technical Reports Server (NTRS)

A two-year task sponsored by NASA's Mars Technology Program's Advanced Entry, Descent and Landing (EDL) work area includes investigation of improvements to EDL navigation by processing spacecraft-to-spacecraft radiometric data. Spacecraft-to- spacecraft navigation will take advantage of the UHF link between two spacecraft (i.e. to an orbiter from an approaching lander for EDL telemetry relay) to build radiometric data, specifically the velocity between the two spacecraft along the radio beam, that are processed to determine position and velocity in real time. The improved onboard state knowledge provided by spacecraft-to-spacecraft navigation will improve the performance of entry guidance by providing a more accurate state estimate and ultimately reduce the landed position error. Work on the final year of this task is reported here.

Burkhart, P. Daniel; Ely, Todd; Duncan, Courtney; Lightsey, Glenn; Campbell, Todd; Mogensen, Andy

2006-01-01

302

Radiometric versus thermometric calibration of IR test systems: which is best?  

NASA Astrophysics Data System (ADS)

Radiometric calibration of military IR test equipment is an approach being explored to avoid perceived shortcomings of traditional thermometric calibration. This issue has profound impact on the testing of military systems: the lack of internally consistent calibration architecture can cost military customers millions of dollars in increased maintenance and spares costs due to test result inconsistencies. An example is presented to show that the lack of a standard spectral response definition in this region, and the difficulty in making such a definition, make the radiometric calibration approach seem questionable for the foreseeable future. Calibration errors of more than 7% (not even a worst-case scenario) can result. The best approach to assuring test accuracy and calibration consistency is to employ thermometric calibration in conjunction with intelligent test system design: high, flat spectral transmittance of the test system and high emissivity targets and sources. These are achievable today with proper application of existing materials and coatings.

Richardson, Philip I.

1991-09-01

303

Improved ground calibration results from Southwest Research Institute Ultraviolet Radiometric Calibration Facility (UV-RCF)  

NASA Astrophysics Data System (ADS)

Four compact planetary ultraviolet spectrographs have been built by Southwest Research Institute and successfully operated on different planetary missions. These spectrographs underwent a series of ground radiometric calibrations before delivery to their respective spacecraft. In three of the four cases, the in-flight measured sensitivity was approximately 50% lower than the ground measurement. Recent tests in the Southwest Research Institute Ultraviolet Radiometric Calibration Facility (UV-RCF) explain the discrepancy between ground and flight results. Revised ground calibration results are presented for the Rosetta-Alice, New Horizons-Alice, the Lunar Reconnaissance Orbiter Lyman- Alpha Mapping Project, and Juno-Ultraviolet Spectrograph (UVS) and are then compared to the original ground and flight calibrations. The improved understanding of the calibration system reported here will result in improved ground calibration of the upcoming Jupiter Icy Moons Explorer (JUICE)-UVS.

Davis, Michael W.; Greathouse, Thomas K.; Gladstone, G. Randall; Retherford, Kurt D.; Slater, David C.; Stern, S. Alan; Versteeg, Maarten H.

2014-07-01

304

Radiometric, SEM and XRD investigation of the Chituc black sands, southern Danube Delta, Romania.  

PubMed

The black sand of the Chituc marine sand bank, northern of the city of Navodari (Romania), presents anomalous high radioactivity. Field measurements recorded in some places dose rate up to 200nSv/h, significantly overpassing the average value of 4420nSv/h along the entire Southern sector of Romanian Black Sea shore. Gamma ray spectrometry performed on both Slanic-Prahova Underground Low Background Laboratory and Geological Institute of Romania Radiometric Facilities showed with clarity the dominance of (228)Ac radioisotope in the 50 microns fraction together with the (226)Ra and traces of (40)K. No significant amount of anthropogenic (137)Cs was identified. Based on radiometric as well as on SEM-EDAX and XRD determinations we come to the conclusion that the evidenced radioactivity could be attributed to both uranium and thorium series in the zircon and monazite fractions and to a lesser extent to potassium in the feldspars. PMID:25181034

Margineanu, R M; Blebea-Apostu, Ana-Maria; Celarel, Aurelia; Gomoiu, Claudia-Mariana; Costea, C; Dumitras, Delia; Ion, Adriana; Duliu, O G

2014-12-01

305

A new automatic system for angular measurement and calibration in radiometric instruments.  

PubMed

This paper puts forward the design, construction and testing of a new automatic system for angular-response measurement and calibration in radiometric instruments. Its main characteristics include precision, speed, resolution, noise immunity, easy programming and operation. The developed system calculates the cosine error of the radiometer under test by means of a virtual instrument, from the measures it takes and through a mathematical procedure, thus allowing correcting the radiometer with the aim of preventing cosine error in its measurements. PMID:22319320

Marquez, Jose Manuel Andujar; Bohrquez, Miguel ngel Martnez; Garcia, Jonathan Medina; Nieto, Francisco Jose Aguilar

2010-01-01

306

On-ground characterization of Rosetta\\/VIRTIS-M. II. Spatial and radiometric calibrations  

Microsoft Academic Search

After having considered the spectral and geometrical performances of the Rosetta\\/VIRTIS-M experiment, we complete here the analysis by evaluating quantitatively the flat-field and radiometric responses. The purpose of this work is to retrieve the flat-field matrix necessary to homogenize the focal plane response. Moreover, the most important result is the determination of the instrument transfer function that allows to convert

G. Filacchione; E. Ammannito; A. Coradini; F. Capaccioni; G. Piccioni; M. C. de Sanctis; M. Dami; A. Barbis

2006-01-01

307

Vicarious calibration campaign in Argentina for radiometric calibration of a multispectral imager onboard Sumbandila Satellite  

Microsoft Academic Search

Continuous assessment of the radiometric response of Earth Observation (EO) satellite imagers is necessary for the quality assurance of derived data products. With the launch of South Africas SumbandilaSat in September 2009, a number of vicarious calibration campaigns have been planned and executed to meet this requirement for the high-resolution multispectral imager payload. This paper describes a vicarious calibration campaign

D. J. Griffith; M. Horlent; G. Ibanez; M. D. Lysko; M. Lubbe; A. E. Mudau; S. Torrusio; V. Sivakumar; L. M. Vhengani

2011-01-01

308

Radiometric calibration of DMSP-OLS sensor using VIIRS day/night band  

NASA Astrophysics Data System (ADS)

Defense Meteorological Satellite Program (DMSP) Operational Linescan System (OLS) has been collecting global night light imaging data for more than 40 years. With the launch of Suomi-NPP satellite in 2011, the Day/Night Band (DNB) of the Visible Infrared Imaging Radiometer Suite (VIIRS) represents a major advancement in night time imaging capabilities because it surpasses DMSP-OLS in having broader radiometric measurement range, more accurate radiometric calibration, finer spatial resolution, and better geometric quality. DMSP-OLS sensor does not have on-board calibration and data is recorded as digital number (DN). Therefore, VIIRS-DNB provides opportunities to perform quantitative radiometric calibration of DMSP-OLS sensor. In this paper, vicarious radiometric calibration of DMSP-OLS at night under lunar illumination is performed. Events were selected when satellite flies above Dome C in Antarctic at night and the moon illuminates the site with lunar phase being more than quarter moon. Additional event selection criteria to limit solar and lunar zenith angle range have been applied to ensure no influence of stray light effects and adequate lunar illumination. The data from DMSP-OLS and VIIRS-DNB were analyzed to derive the characteristic radiance or DN for the region of interest. The scaling coefficient for converting DMSP-OLS DN values into radiance is determined to optimally merge the observation of DMSP-OLS into VIIRS-DNB radiance data as a function of lunar phases. Calibrating the nighttime light data collected by the DMSP-OLS sensors into radiance unit can enable applications of using both sensor data and advance the applications of night time imagery data.

Shao, Xi; Cao, Changyong; Zhang, Bin; Qiu, Shi; Elvidge, Christopher; Von Hendy, Michael

2014-11-01

309

A procedure for radiometric recalibration of Landsat 5 TM reflective-band data  

USGS Publications Warehouse

From the Landsat program's inception in 1972 to the present, the Earth science user community has been benefiting from a historical record of remotely sensed data. The multispectral data from the Landsat 5 (L5) Thematic Mapper (TM) sensor provide the backbone for this extensive archive. Historically, the radiometric calibration procedure for the L5 TM imagery used the detectors' response to the internal calibrator (IC) on a scene-by-scene basis to determine the gain and offset for each detector. The IC system degraded with time, causing radiometric calibration errors up to 20%. In May 2003, the L5 TM data processed and distributed by the U.S. Geological Survey (USGS) Earth Resources Observation and Science Center through the National Landsat Archive Production System (NLAPS) were updated to use a lifetime lookup-table (LUT) gain model to radiometrically calibrate TM data instead of using scene-specific IC gains. Further modification of the gain model was performed in 2007. The L5 TM data processed using IC prior to the calibration update do not benefit from the recent calibration revisions. A procedure has been developed to give users the ability to recalibrate their existing level-1 products. The best recalibration results are obtained if the work-order report that was included in the original standard data product delivery is available. However, if users do not have the original work-order report, the IC trends can be used for recalibration. The IC trends were generated using the radiometric gain trends recorded in the NLAPS database. This paper provides the details of the recalibration procedure for the following: 1) data processed using IC where users have the work-order file; 2) data processed using IC where users do not have the work-order file; 3) data processed using prelaunch calibration parameters; and 4) data processed using the previous version of the LUT (e.g., LUT03) that was released before April 2, 2007.

Chander, G.; Haque, M.O.; Micijevic, E.; Barsi, J.A.

2010-01-01

310

Study of spectral/radiometric characteristics of the Thematic Mapper for land use applications  

NASA Technical Reports Server (NTRS)

The radiometric characteristics of LANDSAT 5 TM data were analyzed. Effects which were found earlier and quantified in LANDSAT 4 TM data were quantified for LANDSAT-5 data as well, including: scan-direction-related signal droop and scan correlated level shifts. Coincident LANDSAT 4 and 5 fully corrected (CCT-PT) TM data were analyzed, and band-by-band relationships between the two sensors were derived in terms of both signal counts and radiance.

Malila, W. A.; Metzler, M. D. (principal investigators)

1985-01-01

311

NERO: General concept of a Near-Earth object Radiometric Observatory  

Microsoft Academic Search

Near-Earth objects Radiometric Observatory (NERO) is one of the six studies for possible missions dedicated to near-Earth objects, that were funded by the European Space Agency (ESA) in 20022003. It is a further development of some previous studies already submitted to ESA (Sysiphos, Spaceguard-1). The general concept is that a small satellite equipped with both a detector for visible wavelengths

A. Cellino; R. Somma; L. Tommasi; R. Paolinetti; K. Muinonen; J. Virtanen; E. F. Tedesco; M. Delb

2006-01-01

312

Radiometric calibration and monitoring of NOAA AVHRR data for ISCCP. [International Satellite Cloud Climatology Project  

NASA Technical Reports Server (NTRS)

The methodology developed to monitor the radiometric calibration of NOAA AVHRR data and to normalize succeeding polar orbiters for the International Satellite Cloud Project (ISCCP) is described. Results are given for NOAA-7, -8, and -9 Channel 1 (visible) data. The successful normalization of NOAA-8, and -9, to NOAA-7 permits the ISCCP calibration standard to be maintained over time. A correction for the degradation of NOAA-9 data and an absolute calibration for the entire ISCCP dataset are presented.

Brest, Christopher L.; Rossow, William B.

1992-01-01

313

Revised Landsat5 TM radiometric calibration procedures and postcalibration dynamic ranges  

Microsoft Academic Search

Effective May 5, 2003, Landsat-5 (L5) Thematic Mapper (TM) data processed and distributed by the U.S. Geological Survey (USGS) Earth Resources Observation System (EROS) Data Center (EDC) will be radiometrically calibrated using a new procedure and revised calibration parameters. This change will improve absolute calibration accuracy, consistency over time, and consistency with Landsat-7 (L7) Enhanced Thematic Mapper Plus (ETM+) data.

Gyanesh Chander; Brian Markham

2003-01-01

314

Algorithm for relative radiometric consistency process of remote sensing images based on object-oriented smoothing and contourlet transforms  

NASA Astrophysics Data System (ADS)

Traditional relative radiometric normalization methods generally depend on global statistical linear parameters, do not consider two-dimensional radiometric distribution, and do not eliminate foreground objects in an image. Thus, we present a method for relative radiometric consistency process based on object-oriented smoothing and contourlet transforms. Object-level smoothing is applied to both the reference image and the image to be normalized so as to reduce the influence of foreground objects on background radiation extraction. Then, high-frequency and low-frequency sections of an image are separated by contourlet transforms to preserve high-frequency texture information of the image to be normalized, with low-pass filtering applied to the low-frequency sections to gather the background radiation difference. Finally, contourlet reverse transforms are used to reconstruct the radiometrically normalized images. Test results show that the proposed method is effective for radiometric normalization of images with both large-scale and small-scale radiometric characteristics. The proposed method can not only normalize linear and nonlinear radiation differences at the same time, but also maximally preserve image texture information. It can improve the visual effects of normalized images and increase change detection accuracy.

Li, Wenzhuo; Sun, Kaimin; Zhang, Hongya

2014-01-01

315

Introduction to the Sentinel-2 radiometric calibration activities during commissioning phase  

NASA Astrophysics Data System (ADS)

In partnership with the European Commission and in the frame of the Copernicus program, the European Space Agency (ESA) is developing the Sentinel-2 optical imaging mission devoted to the operational monitoring of land and coastal areas. The Sentinel-2 mission is based on a satellites constellation deployed in polar sun-synchronous orbit. Sentinel-2 will offer a unique combination of global coverage with a wide field of view (290km), a high revisit (5 days with two satellites), a high spatial resolution (10m, 20m and 60m) and multi-spectral imagery (13 spectral bands in visible and shortwave infra-red domains). The first satellite is planned to be launched in mid-2015. In this context, the Centre National d'Etudes Spatiales (CNES) supports ESA to insure the calibration/validation commissioning phase during the first six months in flight. This paper provides first an overview of the Sentinel-2 system and a description of the products delivered by the ground segment associated to the main radiometric specifications to achieve. Then the paper will focus on the description of the Sentinel-2 Technical Expertise Center which is in charge of the radiometric and geometric activities during the commissioning phases of the Sentinel-2 satellites. The paper will finally address the radiometric methods and calibration sites used in this CNES image quality center to reach the specifications of the sensors, in term of absolute calibration, pixel to pixel relative sensitivity, MTF estimation and level 2 products accuracy.

Lachrade, S.; Trmas, T.; Lonjou, V.; Nosavan, J.; Petrucci, B.; Martimort, P.; Isola, C.

2014-10-01

316

High-performance field-portable imaging radiometric spectrometer technology for chemical agent detection  

NASA Astrophysics Data System (ADS)

Standoff detection, identification and quantification of chemicals in the gaseous state are fundamental needs in several fields of applications. Additional required sensor characteristics include high sensitivity, low false alarms and high-speed (ideally real-time) operation, all in a compact and robust package. The thermal infrared portion of the electromagnetic spectrum has been utilized to implement such chemical sensors, either with spectrometers (with none or moderate imaging capability) or with imagers (with moderate spectral capability). Only with the recent emergence of high-speed, large format infrared imaging arrays, has it been possible to design chemical sensors offering uncompromising performance in the spectral, spatial, as well as the temporal domain. Telops has developed a novel instrument that can not only provide an early warning for chemical agents and toxic chemicals, but also one that provides a "Chemical Map" of the field of view and is man portable. To provide to best field imaging spectroscopy instrument, Telops has developed the FIRST, Field-portable Imaging Radiometric Spectrometer Technology, instrument. This instrument is based on a modular design that includes: a high performance infrared FPA and data acquisition electronics, onboard data processing electronics, a high performance Fourier transform modulator, dual integrated radiometric calibration targets and a visible boresighted camera. These modules, assembled together in an environmentally robust structure, used in combination with Telops' proven radiometric and spectral calibration algorithms make this instrument a world-class passive standoff detection system for chemical imaging.

Vallires, Alexandre; Chamberland, Martin; Farley, Vincent; Belhumeur, Louis; Villemaire, Andr; Giroux, Jean; Legault, Jean-Franois

2005-10-01

317

High-performance field-portable imaging radiometric spectrometer technology for hyperspectral imaging applications  

NASA Astrophysics Data System (ADS)

Standoff detection, identification and quantification of chemicals in the gaseous state are fundamental needs in several fields of applications. Additional required sensor characteristics include high sensitivity, low false alarms and high-speed (ideally real-time) operation, all in a compact and robust package. The thermal infrared portion of the electromagnetic spectrum has been utilized to implement such chemical sensors, either with spectrometers (with none or moderate imaging capability) or with imagers (with moderate spectral capability). Only with the recent emergence of high-speed, large format infrared imaging arrays, has it been possible to design chemical sensors offering uncompromising performance in the spectral, spatial, as well as the temporal domain. Telops has developed a novel instrument that can not only provide an early warning for chemical agents and toxic chemicals, but also one that provides a "Chemical Map" of the field of view and is man portable. To provide to best field imaging spectroscopy instrument, Telops has developed the FIRST, Field-portable Imaging Radiometric Spectrometer Technology, instrument. This instrument is based on a modular design that includes: a high performance infrared FPA and data acquisition electronics, onboard data processing electronics, a high performance Fourier transform modulator, dual integrated radiometric calibration targets, a visible boresight camera. These modules, assembled together in an environmentally robust structure, used in combination with Telops' proven radiometric and spectral calibration algorithms make this instrument a world-class passive standoff detection system for chemical imaging.

Chamberland, Martin; Farley, Vincent; Vallires, Alexandre; Villemaire, Andr; Belhumeur, Louis; Giroux, Jean; Legault, Jean-Franois

2005-11-01

318

Simple radiometric method for accurately quantitating epitope densities of hapten-protein conjugates with sulfhydryl linkages.  

PubMed

Control of small molecule hapten epitope densities on antigenic carrier proteins is essential for development and testing of optimal conditions for vaccines. Yet, accurate determination of epitope density can be extremely difficult to accomplish, especially with the use of small haptens, large molecular weight carrier proteins, and limited amounts of protein. Here we report a simple radiometric method that uses (14)C-labeled cystine to measure hapten epitope densities during sulfhydryl conjugation of haptens to maleimide activated carrier proteins. The method was developed using a (+)-methamphetamine (METH)-like hapten with a sulfhydryl terminus, and two prototype maleimide activated carrier proteins, bovine serum albumin (BSA) and immunocyanin monomers of keyhole limpet hemocyanin. The method was validated by immunochemical analysis of the hapten-BSA conjugates, and least-squares linear regression analysis of epitope density values determined by the new radiometric method versus values determined by matrix-assisted laser desorption/ionization mass spectrometry. Results showed that radiometric epitope density values correlated extremely well with the mass spectrometrically derived values (r(2) = 0.98, y = 0.98x + 0.91). This convenient and simple method could be useful during several stages of vaccine development including the optimization and monitoring of conditions for hapten-protein conjugations, and choosing the most effective epitope densities for conjugate vaccines. PMID:25426820

Peterson, Eric C; Hambuchen, Michael D; Tawney, Rachel L; Gunnell, Melinda G; Cowell, James L; Lay, Jackson O; Blough, Bruce E; Carroll, F Ivy; Owens, S Michael

2014-12-17

319

Tritium/Helium-3 Dating  

NSDL National Science Digital Library

First, the USGS summarizes the use of tritium and helium-3 for dating geologically young groundwater (1). Researchers can find the conditions needed to solve the helium isotope mass balance as well as equations and corrections needed to obtain the age of water. The second website, provided by the Rosenstiel School of Marine and Atmospheric Sciences, discusses the presence of tritium and helium isotopes in the oceans (2). Users can find out about the Noble Gas Isotope Lab's research projects including the _Mantle 3He Distribution and Deep Circulation in the Indian Ocean_. Next, the University of Ottawa offers equations for helium and tritium concentrations and decay (3). Visitors can also learn how solubility of noble gases is affected by temperature. Fourth, the University of Waterloo describes the characteristics of the hydrogen radioisotope, tritium (4). The website explains how tritium was discovered through the work of Lord Rutherford, Sir John, Ernest Lawrence, Luis Alvarex, Willard Libby, and others. Next, the University of T'bingen furnishes a pdf file dealing with numerous dating techniques including fission track, radio carbon, and thermoluminescence dating (5). Beginning on page nine, individuals can learn about tritium formation and decay as well as its use in dating ground water. At the sixth website, the USGS describes the characteristics of the stable isotopes of helium (6). Visitors can discover how 3He is used to date geologically young ground water, whereas 4He is used to date older ground water. The seventh website, created by SAHRA (Sustainability of semi-Arid Hydrology and Riparian Areas) at the University of Arizona, illustrates the effectiveness of isotope hydrology in "understanding fundamental physical, chemical, biological, and climate forcing processes occurring in a watershed" (7). Along with the discussion of the fundamentals of age dating and sources of isotopes, visitors can learn the advantages to using tritium for water samples collected in the field. Lastly, the Victoria University of Manchester introduces its research using noble gas isotopes to better understand earth systems (8). Visitors can discover the decay rates of tritium to 3He and the rates of accumulation of 4He in older groundwater as well as many applications of dating water.

320

Opportunities to Intercalibrate Radiometric Sensors From International Space Station  

NASA Technical Reports Server (NTRS)

Highly accurate measurements of Earth's thermal infrared and reflected solar radiation are required for detecting and predicting long-term climate change. We consider the concept of using the International Space Station to test instruments and techniques that would eventually be used on a dedicated mission such as the Climate Absolute Radiance and Refractivity Observatory. In particular, a quantitative investigation is performed to determine whether it is possible to use measurements obtained with a highly accurate reflected solar radiation spectrometer to calibrate similar, less accurate instruments in other low Earth orbits. Estimates of numbers of samples useful for intercalibration are made with the aid of year-long simulations of orbital motion. We conclude that the International Space Station orbit is ideally suited for the purpose of intercalibration.

Roithmayr, C. M.; Lukashin, C.; Speth, P. W.; Thome, K. J.; Young, D. F.; Wielicki, B. A.

2012-01-01

321

Radiometric instrumentation for high-altitude balloon atmospheric measurements  

NASA Astrophysics Data System (ADS)

The Balloon Altitude Mosaic Measurements (BAMM) radiometer has a lead sulfide 4 x 4 detector array that is designed to collect earth radiation background from an altitude of 30 km. This paper describes some of the solutions to the environmental problems that were to be encountered during a flight. A detailed description is given of the radiometer characteristics and specifications, thermal, radiation and environmental considerations. It was found that the lead sulfide detectors have an enhanced detectivity at 163 K, and the intricate techniques to maintain the temperature are described. The effect of the window temperature on the signal was explored and the control of temperature variations was achieved, minimizing negative contributions. Flight testing indicates that the dewar and electronic boxes operate from sea level atmospheric pressure up to the partial pressure at 30 km. The effectiveness of the design configuration was confirmed by theoretical and experimental data.

Morse, D. E.

1980-01-01

322

Quaternary TL Surveys: A Guide to Thermoluminescence (TL) Date Measurement  

NSDL National Science Digital Library

Quaternary TL Surveys, a company that provides date measurement services to archaeologists and geologists, offers this comprehensive tutorial on archaeometric dating techniques. The tutorial contains a general overview as well as specific information on dating flint and stone, stalagmitic calcite, sediments, and methods of interpreting and using TL dates. For ease of use, portions of the guide are marked to alert users to their relative importance.

323

Trending of Suomi-NPP VIIRS radiometric performance with lunar band ratio  

NASA Astrophysics Data System (ADS)

Radiometric stability of the lunar surface and its smooth reflectance spectrum makes the moon an ideal target for calibrating satellite-based hyper/multi-band visible imagers, as demonstrated in several lunar calibration studies of satellite radiometers. Most of the lunar calibrations rely on using lunar irradiance models to calibrate satellite radiometers, which require the lunar irradiance model to be highly accurate. In this paper, we use Lunar Band Ratio (LBR) to trend satellite radiometer performance so that the usage of lunar irradiance model is not required. The LBR method is applied to monitor long term radiometric performance of VIIRS (Visible Infrared Imaging Radiometer Suite) onboard Suomi-NPP. VIIRS observes moon at nearly the same lunar phase angle through Earth view during scheduled spacecraft maneuver. Total lunar digital number are calculated for each VIIRS reflective solar bands (RSBs) from lunar observations and one of the most stable bands of VIIRS such as M4 band is chosen as the reference band for calculating the band ratio. LBRs are compared with the degradation factors derived from VIIRS operational radiometric calibration of RSBs using onboard solar diffuser. The LBR analysis reveals that M6 and M7 degrade the fastest and agree well with the trending independently determined from onboard solar diffuser. For stable bands such as M3-M4 of VIIRS, the variation range of band ratios of M2/M4 and M3/M4 are all within 0.6%, indicating the LBR can be used to reveal the sub percent band to band stability. For M11 band of VIIRS, there have been large uncertainties in verifying its radiometric performance using vicarious ground targets. LBR of M11 provides an independent and useful radiometric stability monitoring tool for verifying the relative stability of M11 band. The LBR analysis also shows that band-to-band variability in the spectrally similar band pairs such as I2 vs. M7 and I3 vs. M10 of VIIRS are consistent within 0.2%. It is demonstrated that long-term performance monitoring of VIIRS instrument using LBR is an important part of the VIIRS lunar calibration for solar bands and can effectively reveal the degradation of instruments.

Shao, Xi; Choi, Taeyoung; Cao, Changyong; Blonski, Slawomir; Wang, Wenhui; Ban, Yan

2014-11-01

324

Dating the Crucifixion  

NASA Astrophysics Data System (ADS)

The date of the Crucifixion has been debated for many years, but there has been no agreement on the year nor the day. Astronomical calculations have now been used to reconstruct the Jewish calendar in the first century AD and to date a lunar eclipse that biblical and other references suggest followed the Crucifixion. The evidence points to Friday 3 April AD 33 as the date when Jesus Christ died.

Humphreys, Colin J.; Waddington, W. G.

1983-12-01

325

Investigating the influence of radiometric calibration on tree species determination based on small footprint full-waveform airborne LiDAR  

NASA Astrophysics Data System (ADS)

Small footprint airborne LiDAR is a well-established measurement technique in forestry, where cost- and time efficient wide-area data acquisition of the vegetation structure is required. Gathering stand-based information about tree species composition is of particular interest for forestry applications. Modern LiDAR systems provide, next to the acquired 3D (i.e. geometric) information, also a quantification of the signal strength of each echo. In order to utilize this information for tree species determination independently from different overlapping LiDAR swaths, different LiDAR sensors or acquisition times, radiometric calibration is a necessity. This contribution summarises the theoretical background of radiometric LiDAR data calibration on the physical basis of the radar equation. Using LiDAR observations of reference targets with known reflectivity the so-called calibration constant is computed. It accounts for sensor specific parameters, as well as atmospheric attenuation of the laser signal. Hence the backscatter properties of the laser echoes can be determined and physical observables characterizing the reflectivity of the scanned surface can be estimated. A practical calibration workflow is demonstrated on the example of a single wavelength full-waveform LiDAR data set from a mixed woodland in Austria. Subsequently, an automated method for tree species determination that is based on the laser light scattering mechanisms in the forest canopy is applied on both (calibrated and un-calibrated) data sets. First, an edge-based segmentation approach is used to aggregate LiDAR echoes to segments representing single tree crowns. Second, metrics are computed for each tree crown describing radiometric and geometric features that are related to foliage composition. Third, these metrics are used in a knowledge-based fuzzy classification scheme for the determination of segments representing coniferous and deciduous trees. Influences of the radiometric calibration on the classification results are shown and discussed through a comparison of adjacent swaths with focus on the overlapping areas, as well as the whole study site, before and after calibration. An extensive set of forestry inventory data including information on tree height, diameter, crown height and species, is used to evaluate the quality of the different classification results with and without usage of calibrated data. We demonstrate that radiometric calibration of airborne LiDAR data produces highly homogeneous data sets throughout and across adjacent swaths. The calibrated data are rich in contrast and, on the one hand, a valuable source for visual interpretation. On the other hand, (un-) supervised classification schemes benefit from the calibrated data in terms of higher robustness in depiction of diverse tree species. It is shown that calibrated full-waveform LiDAR data are a most suitable basis for vegetation classification of large areas, with a large number of acquisition swaths and high relief energy.

Mcke, W.; Briese, C.; Hollaus, M.; Pfeifer, N.; Wagner, W.

2013-12-01

326

In Vitro Conservation of Date Palm Germplasm  

Microsoft Academic Search

\\u000a Date palm (Phoenix dactylifera L.) germplasm is difficult to conserve and store in the form of offshoots or in field collections. Tissue culture technologies\\u000a have had a major impact on the ex situ conservation of plant genetic resources. In vitro culture techniques supplement date palm conservation efforts and have been applied to germplasm collection, preservation\\u000a and rapid clonal multiplication. In

S. A. Bekheet

327

The 60 GHz radiometric local vertical sensor experiment  

NASA Technical Reports Server (NTRS)

The experiment concept involves the use of millimeter wave radiation the atmospheric oxygen to provide vertical sensing information to a satellite-borne radiometer. The radiance profile studies require the calculation of ray brightness temperature as a function of tangential altitude and atmosphere model, and the computer program developed for this purpose is discussed. Detailed calculations have been made for a total of 12 atmosphere models, including some showing severe warning conditions. The experiment system analysis investigates the effect of various design choices on system behavior. Calculated temperature profiles are presented for a wide variety of frequencies, bandwidths, and atmosphere models. System performance is determined by the convolution of the brightness temperature and an assumed antenna pattern. A compensation scheme to account for different plateau temperatures is developed and demonstrated. The millimeter wave components developed for the local vertical sensor are discussed, with emphasis on the antenna, low noise mixer, and solid state local oscillator. It was concluded that a viable sensing technique exists, useful over a wide range of altitude with an accuracy generally on the order of 0.01 degree or better.

Grauling, C. H., Jr.

1973-01-01

328

A Low Loss Microstrip Antenna for Radiometric Applications  

NASA Technical Reports Server (NTRS)

The design and analysis of a series-fed, low-loss, inverted microstrip array antenna, operating at 1.413 GHz is presented. The antenna is composed of two subarrays. Each subarray consists of an equal number of microstrip patches all connected together with microstrip lines. In the first design microstrip array for linear polarization is presented which incorporated a series feeding technique. The next design, which is capable of dual linear polarization (V-polarization and H-polarization), utilizes a corporate feed network for the V-pol and series feed arrangement for the H-pol. The first element of each subarray for H-pol is coaxially fed with a 180 deg phase difference. This approach ensures a symmetric radiation pattern on broadside in H-pol. For the V-pol two feeds are in the same phase on the two subarrays ensuring a broadside beam in V-pol. The designs presented here are simulated using the IE3D code that utilizes the method of moments. Measured results are compared with simulated results and show good agreement.

Wahid, Parveen

2000-01-01

329

Not only Chauvet: dating Aurignacian rock art in Altxerri B Cave (northern Spain).  

PubMed

The discovery and first dates of the paintings in Grotte Chauvet provoked a new debate on the origin and characteristics of the first figurative Palaeolithic art. Since then, other art ensembles in France and Italy (Aldne, Fumane, Arcy-sur-Cure and Castanet) have enlarged our knowledge of graphic activity in the early Upper Palaeolithic. This paper presents a chronological assessment of the Palaeolithic parietal ensemble in Altxerri B (northern Spain). When the study began in 2011, one of our main objectives was to determine the age of this pictorial phase in the cave. Archaeological, geological and stylistic evidence, together with radiometric dates, suggest an Aurignacian chronology for this art. The ensemble in Altxerri B can therefore be added to the small but growing number of sites dated in this period, corroborating the hypothesis of more complex and varied figurative art than had been supposed in the early Upper Palaeolithic. PMID:24012252

Gonzlez-Sainz, C; Ruiz-Redondo, A; Garate-Maidagan, D; Iriarte-Avils, E

2013-10-01

330

Structure and dating errors in the geologic time scale and periodicity in mass extinctions  

NASA Technical Reports Server (NTRS)

Structure in the geologic time scale reflects a partly paleontological origin. As a result, ages of Cenozoic and Mesozoic stage boundaries exhibit a weak 28-Myr periodicity that is similar to the strong 26-Myr periodicity detected in mass extinctions of marine life by Raup and Sepkoski. Radiometric dating errors in the geologic time scale, to which the mass extinctions are stratigraphically tied, do not necessarily lessen the likelihood of a significant periodicity in mass extinctions, but do spread the acceptable values of the period over the range 25-27 Myr for the Harland et al. time scale or 25-30 Myr for the DNAG time scale. If the Odin time scale is adopted, acceptable periods fall between 24 and 33 Myr, but are not robust against dating errors. Some indirect evidence from independently-dated flood-basalt volcanic horizons tends to favor the Odin time scale.

Stothers, Richard B.

1989-01-01

331

Pregnancy Declaration Form Date: ______________  

E-print Network

Pregnancy Declaration Form Date: ______________ To: Curtis Plotkin., Radiation Safety Officer From this pregnancy. * The NRC defines a declared pregnant woman as "a woman who has voluntarily informed her employer in writing of her pregnancy and estimated date of conception." 9/20/11 tw #12;

de Lijser, Peter

332

Landsat-8 Thermal Infrared Sensor (TIRS) Vicarious Radiometric Calibration  

NASA Technical Reports Server (NTRS)

Launched in February 2013, the Landsat-8 carries on-board the Thermal Infrared Sensor (TIRS), a two-band thermal pushbroom imager, to maintain the thermal imaging capability of the Landsat program. The TIRS bands are centered at roughly 10.9 and 12 micrometers (Bands 10 and 11 respectively). They have 100 m spatial resolution and image coincidently with the Operational Land Imager (OLI), also on-board Landsat-8. The TIRS instrument has an internal calibration system consisting of a variable temperature blackbody and a special viewport with which it can see deep space; a two point calibration can be performed twice an orbit. Immediately after launch, a rigorous vicarious calibration program was started to validate the absolute calibration of the system. The two vicarious calibration teams, NASA/Jet Propulsion Laboratory (JPL) and the Rochester Institute of Technology (RIT), both make use of buoys deployed on large water bodies as the primary monitoring technique. RIT took advantage of cross-calibration opportunity soon after launch when Landsat-8 and Landsat-7 were imaging the same targets within a few minutes of each other to perform a validation of the absolute calibration. Terra MODIS is also being used for regular monitoring of the TIRS absolute calibration. The buoy initial results showed a large error in both bands, 0.29 and 0.51 W/sq msrmicrometers or -2.1 K and -4.4 K at 300 K in Band 10 and 11 respectively, where TIRS data was too hot. A calibration update was recommended for both bands to correct for a bias error and was implemented on 3 February 2014 in the USGS/EROS processing system, but the residual variability is still larger than desired for both bands (0.12 and 0.2 W/sq msrmicrometers or 0.87 and 1.67 K at 300 K). Additional work has uncovered the source of the calibration error: out-of-field stray light. While analysis continues to characterize the stray light contribution, the vicarious calibration work proceeds. The additional data have not changed the statistical assessment but indicate that the correction (particularly in band 11) is probably only valid for a subset of data. While the stray light effect is small enough in Band 10 to make the data useful across a wide array of applications, the effect in Band 11 is larger and the vicarious results suggest that Band 11 data should not be used where absolute calibration is required.

Barsi, Julia A.; Shott, John R.; Raqueno, Nina G.; Markham, Brian L.; Radocinski, Robert G.

2014-01-01

333

Radiometric and Photometric Tests of Solar Luminosity Variation Mechanisms  

NASA Astrophysics Data System (ADS)

A variety of diagnostics has been developed to discriminate among competing physical explanations of solar luminosity variation, and to use them for new insight into magneto-convection on the sun and similar stars. The shape of spot -induced irradiance dips correlates well with changes in spot projected area, but not with growth or decay rate. This argues against storage of the spot's missing heat flux in the spot magnetic field.Efficient heat flow blocking and storage in the HCZ seems to provide the simplest mechanism.The weakness of sunspot bright rings and thermal shadows is consistent with eddy thermal diffusivities calculated from models of the HCZ. The contribution of faculae and network is still too uncertain to decide whether they account for all of the remaining variance in luminosity, after spot dimming is removed.But the correlation of irradiance variations is much higher with the difference of compensating spot and facular contributions than with total magnetic flux. This argues against "magnetic stirring" as an important factor in luminosity variation. The darkness of small flux tubes in continuum near disc center, especially near 1.63 microns,and their center - to - limb contrast variation, seems to favor their interpretation as photospheric heat leaks.This is supported by the lowered facular temperature gradient measured using two -color photometric imaging. Photometric searches for large - scale photospheric temperature inhomogeneities have yielded useful upper limits.Possible global variations in effective temperature, studied through monitoring of photospheric limb-darkening, and of temperature - sensitive Fraunhofer lines, have not revealed any convincing variations.But the percentage sensitivity to solar irradiance change is limited to about 0.2 per year, and might be improved with helioseismological techniques. The decrease in facular-to-spot area ratio observed at high solar activity levels suggests a simple explanation for the increased photometric variability of younger sun - like stars in terms of photospheric magnetism. The apparent absence of detectable solar luminosity variations outside modulation due to photospheric magnetism poses an interesting new constraint on stellar convection theory. Ongoing advances in cryogenic radiometry, thermal imaging,and helioseismology are all likely to contribute to the search for possible more subtle luminosity variations below the threshold of present measurements.

Foukal, P.

2001-05-01

334

Total ozone and aerosol optical depths inferred from radiometric measurements in the Chappuis absorption band  

NASA Technical Reports Server (NTRS)

A second-derivative smoothing technique, commonly used in inversion work, is applied to the problem of inferring total columnar ozone amounts and aerosol optical depths. The application is unique in that the unknowns may be solved for directly without employing standard inversion methods. It is shown, however, that by employing inversion constraints, better solutions are normally obtained. The method is quite versatile and able to deal with varying total ozone and various aerosol size distributions. The technique is applied first in simulation, then to 119 days of measurements taken in Tucson, Arizona, that are compared to TOMS values for the same dates. The technique is also applied to two measurements taken at Mauna Loa, Hawaii, for which Dobson ozone values are available in addition to the TOMS values, and the results agree to within 15 percent. It is also shown through simulations that additional information can be obtained from measurements outside the Chappuis band. This approach reduces the bias and spread of the estimated total ozone and is unique in that it uses measurements from both the Chappuis and Huggins absorption bands.

Flittner, D. E.; Herman, B. M.; Thome, K. J.; Simpson, J. M.; Reagan, J. A.

1993-01-01

335

A liquid-helium-cooled absolute reference cold load for long-wavelength radiometric calibration  

SciTech Connect

We describe a large (78 cm) diameter liquid-helium-cooled blackbody absolute reference cold load for the calibration of microwave radiometers. The load provides an absolute calibration near the liquid-helium (LHe) boiling point, with total uncertainty in the radiometric temperature of less than 30 mK over the 2.5--23-cm wavelength (12--1.3 GHz) operating range. Emission from those parts of the cold load not immersed in LHe is {le}25 mK and the reflection coefficient is {le}3.5{times}10{sup {minus}4}. This cold load has been used at several wavelengths at the South Pole, Antarctica and at the White Mountain Research Station, California to calibrate spectral measurements of the cosmic microwave background radiation. For the instruments operated at 20-, 12-, 7.9-, and 4.0-cm wavelength at the South Pole, the total corrections to the LHe boiling-point temperature ({similar to}3.8 K) were 48{plus minus}23, 18{plus minus}10, 10{plus minus}18, and 15{plus minus}16 mK, respectively. In operation, the average LHe loss rate was {le}4.4 l/h, allowing day-long periods of operation without a LHe fill. The boiloff rate is not strongly dependent on the radiative load at the aperture, yielding very stable operation and radiometric performance. Design considerations, radiometric and thermal performance, and operational aspects are discussed. A comparison with other LHe-cooled reference loads including the predecessor of this cold load is given.

Bensadoun, M.; Witebsky, C.; Smoot, G.; De Amici, G.; Kogut, A.; Levin, S. (Space Sciences Laboratory and Lawrence Berkeley Laboratory, University of California, Berkeley, California 94720 (United States))

1992-10-01

336

The radiometric performance of FY-3A/B MERSI reflective solar bands  

NASA Astrophysics Data System (ADS)

Medium Resolution Spectral Imager (MERSI) is a keystone instrument onboard Fengyun-3 (FY-3), the second generation of polar-orbiting meteorological satellites in China. The first unit still in operation is FY-3A which was launched on May 27, 2008 in a sun-synchronous morning orbit with a local equator-crossing time of 10:30 AM in descending node. The second unit still in operation is FY-3B which was launched on November 5, 2010, in an afternoon orbit with an equator-crossing time of 1:30 PM in ascending node. FY-3 MERSI provides global coverage on top-of-atmosphere (TOA) radiances used for a broad range of scientific studies of the Earth's system. Nineteen of the 20 MERSI spectral bands are reflective solar bands (RSBs) from 412 NM to 2130 nm, which cannot be absolutely calibrated onboard. The long-term on-orbit response changes of FY-3A/B MERSI are relatively large at visible bands. A multisite calibration tracking method has been developed to monitor the RSB radiometric response variation, revealing that the overall degradation for 412 nm of FY-3A MERSI is about 43% until June 2014. A daily calibration updating model is developed to recalibrate FY-3A/B MERSI, and the data quality is monitored using SNO targets against Aqua MODIS. This paper demonstrates the radiometric performance of FY-3A/B MERSI RSBs after recalibration accounting for the temporal variation of radiometric response. The recalibrated MERSI shows good agreement with MODIS. For FY-3B MERSI band 1 (470nm), the overall percentage difference (Mean+/-Std) is within 4%.

Sun, Ling; Xu, Na; Hu, Xiuqing; Rong, Zhiguo; Yang, Zhongdong; Lu, Naimeng

2014-11-01

337

A novel solution for car traffic control based on radiometric microwave devices  

NASA Astrophysics Data System (ADS)

The significant problem of traffic in big cities, connected with huge and building up quantity of automobile cars, demands for novel strategies, based on nonconventional solutions, in order to improve system traffic control, especially at crossroads. As well known, the usual solution is based on the time relay, which requires the installation of a fixed traffic interval (signal light switching) at a crossroad; this solution is low cost, but does not account for the actual traffic conditions. Therefore, in the recent years, attention is towards to new designs, where the monitoring of the and control of traffic is carried out by using various methods including, optical, the infrared, magnetic, radar tracking, acoustical ones. In this work, we discuss the deployment of high sensitivity radiometric systems and radiometers(sensor) in the microwave range [1, 2]. In fact, the radiometer as "sensor" can provide an always updated information about the car traffic in any weather condition and in absence or low visibility conditions. In fact, the radiometric sensor detects the cars thanks to the different behavior of the car roofs which reflect the cold sky whereas the road asphalt is visible as warm object (at around outside temperature). [1] A. G. Denisov, V. P. Gorishnyak, S. E. Kuzmin et al., "Some experiments concerning resolution of 32 sensors passive 8mm wave imaging system," in Proceedings of the International Symposium on Space Terahertz Technology (ISSTT '09), Charlottesville, Va, USA, April 2009. [2] F. Soldovieri, A. Natale, V. Gorishnyak, A. Pavluchenko, A. Denisov, and L. Chen, "Radiometric Imaging for Monitoring and Surveillance Issues," International Journal of Antennas and Propagation, vol. 2013, Article ID 272561, 8 pages, 2013. doi:10.1155/2013/272561.

Soldovieri, Francesco; Denisov, Alexander; Speziale, Victor

2014-05-01

338

Multi-point radiometric calibration method based on complex spectrum of Fourier transform spectrometer  

NASA Astrophysics Data System (ADS)

As the impact of the instrument internal error, external interference and other factors, the interferogram measured by Fourier transform spectrometer is asymmetric, result in the complex outcome after Fourier transform. Currently, most radiometric calibration method used for Fourier transform spectrometer is usually based on real spectrums, which is converted from the above complex spectrum by calculating magnitude value or make the phase correction first. Proceed from error sources and mechanisms of the Fourier transform spectrometer, we propose a multi-point radiometric calibration method based on complex spectral data to improve the processing efficiency and accuracy, which is obtained by the original interferogram via Fourier transform. We solving the instrument response function include linear gain and offset by complex spectrum above to calculate complex spectral radiance. Compared with the traditional method based on real spectrum, the present efficient method does not limited to real spectrum and the phase correction is not required. In this paper, we use BOMEM's MR304 Fourier transform infrared spectrometer and the DCN1000N3 blackbody made by HGH Infrared Systems to carry out the radiation calibration experiment in laboratory. The results show that, the amplitude of complex radiance spectrum obtained by this method has a high consistency with the theoretical value, while the extra imaginary spectrum is similar with the difference between results and theoretical value in absolute value and trends. It proved that, this multi-point radiometric calibration method by using the amplitude of complex spectral data is highly reliable; meanwhile, the imaginary spectrum can reflect the calibration error very well and offer a new technical approach for accuracy evaluation research.

He, Qian; Wang, Guangping; Wu, Jingli; Li, Junwei

2014-11-01

339

Three Years of Atmospheric Infrared Sounder Radiometric Calibration Validation using Sea Surface Temperatures  

NASA Technical Reports Server (NTRS)

This paper evaluates the absolute accuracy and stability of the radiometric calibration of the Atmospheric Infrared Sounder (AIRS) by analyzing the difference between the brightness temperatures measured at 2616 cm(exp -1) and those calculated at the top of the atmosphere (TOA), using the Real-Time Global Sea Surface Temperature (RTGSST) for cloud-free night tropical oceans between +/- 30 degrees latitude. The TOA correction is based on radiative transfer. The analysis of the first 3 years of AIRS radiances verifies the absolute calibration at 2616 cm(exp -1) to better than 200 mK, with better than 16 mK/yr stability. The AIRS radiometric calibration uses an internal full aperture wedge blackbody with the National Institute of Standards and Technology (NIST) traceable prelaunch calibration coefficients. The calibration coefficients have been unchanged since launch. The analysis uses very tight cloud filtering, which selects about 7000 cloud-free tropical ocean spectra per day, about 0.5% of the data. The absolute accuracy and stability of the radiometry demonstrated at 2616 cm(sup -1) are direct consequences of the implementation of AIRS as a thermally controlled, cooled grating-array spectrometer and meticulous attention to details. Comparable radiometric performance is inferred from the AIRS design for all 2378 channels. AIRS performance sets the benchmark for what can be achieved with a state-of-the-art hyperspectral radiometer from polar orbit and what is expected from future hyperspectral sounders. AIRS was launched into a 705 km altitude polar orbit on NASA's Earth Observation System (EOS) Aqua spacecraft on 4 May 2002. AIRS covers the 3.7-15.4 micron region of the thermal infrared spectrum with a spectral resolution of nu/Delta nu = 1200 and has returned 3.7 million spectra of the upwelling radiance each day since the start of routine data gathering in September 2002.

Aumann, H. H.; Broberg, Steve; Elliott, Denis; Gaiser, Steve; Gregorich, Dave

2006-01-01

340

L5 TM radiometric recalibration procedure using the internal calibration trends from the NLAPS trending database  

USGS Publications Warehouse

From the Landsat program's inception in 1972 to the present, the earth science user community has benefited from a historical record of remotely sensed data. The multispectral data from the Landsat 5 (L5) Thematic Mapper (TM) sensor provide the backbone for this extensive archive. Historically, the radiometric calibration procedure for this imagery used the instrument's response to the Internal Calibrator (IC) on a scene-by-scene basis to determine the gain and offset for each detector. The IC system degraded with time causing radiometric calibration errors up to 20 percent. In May 2003 the National Landsat Archive Production System (NLAPS) was updated to use a gain model rather than the scene acquisition specific IC gains to calibrate TM data processed in the United States. Further modification of the gain model was performed in 2007. L5 TM data that were processed using IC prior to the calibration update do not benefit from the recent calibration revisions. A procedure has been developed to give users the ability to recalibrate their existing Level-1 products. The best recalibration results are obtained if the work order report that was originally included in the standard data product delivery is available. However, many users may not have the original work order report. In such cases, the IC gain look-up table that was generated using the radiometric gain trends recorded in the NLAPS database can be used for recalibration. This paper discusses the procedure to recalibrate L5 TM data when the work order report originally used in processing is not available. A companion paper discusses the generation of the NLAPS IC gain and bias look-up tables required to perform the recalibration.

Chander, G.; Haque, Md. O.; Micijevic, E.; Barsi, J.A.

2008-01-01

341

Field determination of optimal dates for the discrimination of invasive wetland plant species using derivative spectral analysis  

USGS Publications Warehouse

Mapping invasive plant species in aquatic and terrestrial ecosystems helps to understand the causes of their progression, manage some of their negative consequences, and control them. In recent years, a variety of new remote-sensing techniques, like Derivative Spectral Analysis (DSA) of hyperspectral data, have been developed to facilitate this mapping. A number of questions related to these techniques remain to be addressed. This article attempts to answer one of these questions: Is the application of DSA optimal at certain times of the year? Field radiometric data gathered weekly during the summer of 1999 at selected field sites in upstate New York, populated with purple loosestrife (Lythrum salicaria L.), common reed (Phragmites australis (Cav.)) and cattail (Typha L.) are analyzed using DSA to differentiate among plant community types. First, second and higher-order derivatives of the reflectance spectra of nine field plots, varying in plant composition, are calculated and analyzed in detail to identify spectral ranges in which one or more community types have distinguishing features. On the basis of the occurrence and extent of these spectral ranges, experimental observations suggest that a satisfactory differentiation among community types was feasible on 30 August, when plants experienced characteristic phenological changes (transition from flowers to seed heads). Generally, dates in August appear optimal from the point of view of species differentiability and could be selected for image acquisitions. This observation, as well as the methodology adopted in this article, should provide a firm basis for the acquisition of hyperspectral imagery and for mapping the targeted species over a broad range of spatial scales. ?? 2005 American Society for Photogrammetry and Remote Sensing.

Laba, M.; Tsai, F.; Ogurcak, D.; Smith, S.; Richmond, M.E.

2005-01-01

342

Variations in in-flight absolute radiometric calibration. [satellite remote sensors  

NASA Technical Reports Server (NTRS)

Variations in the in-flight absolute radiometric calibration of the Coastal Zone Color Scanner and the Thematic Mapper (TM) are reviewed. At short wavelengths, the sensors show a gradual reduction in response, while in the mid-IR the TM shows oscillatory variations. One set of measurements made at White Sands, New Mexico shows anomalous results in TM bands 2 and 4. The results of a reflectance-based and a radiance-based calibration method at White Sands are described. An analysis of the radiance-based method shows the value of such measurements from helicopter altitudes for calibration.

Slater, Philip N.

1986-01-01

343

The effect of spatial, spectral and radiometric factors on classification accuracy using Thematic Mapper data  

NASA Technical Reports Server (NTRS)

An experiment of a factorial design was conducted to test the effects on classification accuracy of land cover types due to the improved spatial, spectral and radiometric characteristics of the LANDSAT Thematic Mapper (TM) in comparison to the Multispectral Scanner (MSS). High altitude aircraft scanner data from the Airborne Thematic Mapper instrument was used to simulate TM data as well as all combinations of the three characteristics for eight data sets in all. Results for the training sites (field-center pixels) show better classification accuracies for MSS spatial resolution, TM spectral bands and TM radiometry in order of importance.

Wrigley, R. C.; Acevedo, W.; Alexander, D.; Buis, J.; Card, D.

1984-01-01

344

Study of spectral/radiometric characteristics of the Thematic Mapper for land use applications  

NASA Technical Reports Server (NTRS)

Progress during the Environmental Research Institute of Michigan-ERIM's and 5 image data quality assessment program for the thematic mapper is described. Analyses of LANDSAT 5 TM radiometric characteristics were performed. Effects which had earlier been found in LANDSAT 4 TM data were found to be present in LANDSAT 5 data as well, including: (1) scan direction related signal droop; (2) scan correlated level shifts; and (3) low frequency coherent noise. Coincident LANDSAT 4 and 5 raw TM data were analyzed, and band by band relationships between the two sensors were derived. Earlier efforts which developed an information theoretic measure of multispectral information content were continued, comparing TM and MSS information content.

Malila, W. A. (principal investigator); Metzler, M. D.

1984-01-01

345

Evaluation of spatial, radiometric and spectral Thematic Mapper performance for coastal studies  

NASA Technical Reports Server (NTRS)

On 31 March 1983, the University of Delaware's Center for Remote Sensing initiated a study to evaluate the spatial, radiometric and spectral performance of the LANDSAT Thematic Mapper for coastal and estuarine studies. The investigation was supported by Contract NAS5-27580 from the NASA Goddard Space Flight Center. The research was divided into three major subprojects: (1) a comparison of LANDSAT TM to MSS imagery for detecting submerged aquatic vegetation in Chesapeake Bay; (2) remote sensing of submerged aquatic vegetation - a radiative transfer approach; and (3) remote sensing of coastal wetland biomass using Thematic Mapper wavebands.

Klemas, V.; Ackleson, S. G.; Hardisky, M. A.

1985-01-01

346

Radiometric calibration of SPOT 2 HRV - A comparison of three methods  

NASA Technical Reports Server (NTRS)

Three methods for determining an absolute radiometric calibration of a spacecraft optical sensor are compared. They are the well-known reflectance-based and radiance-based methods and a new method based on measurements of the ratio of diffuse-to-global irradiance at the ground. The latter will be described in detail and the comparison of the three approaches will be made with reference to the SPOT-2 HRV cameras for a field campaign 1990-06-19 through 1990-06-24 at the White Sands Missile Range in New Mexico.

Biggar, Stuart F.; Dinguirard, Magdeleine C.; Gellman, David I.; Henry, Patrice; Jackson, Ray D.; Moran, M. S.; Slater, Philip N.

1991-01-01

347

The effect of spatial, spectral and radiometric factors on classification accuracy using thematic mapper data  

NASA Technical Reports Server (NTRS)

An experiment of a factorial design was conducted to test the effects on classification accuracy of land cover types due to the improved spatial, spectral and radiometric characteristics of the Thematic Mapper (TM) in comparison to the Multispectral Scanner (MSS). High altitude aircraft scanner data from the Airborne Thematic Mapper instrument was acquired over central California in August, 1983 and used to simulate Thematic Mapper data as well as all combinations of the three characteristics for eight data sets in all. Results for the training sites (field center pixels) showed better classification accuracies for MSS spatial resolution, TM spectral bands and TM radiometry in order of importance.

Wrigley, R. C.; Acevedo, W.; Alexander, D.; Buis, J.; Card, D.

1984-01-01

348

StarDate Online  

NSDL National Science Digital Library

This on-line version of StarDate astronomy magazine provides current viewing information, a sky almanac, Moon phase calculator, sunrise and sunset calculator, planet viewing information, and meteor shower updates. News and Features contains information and details on the latest findings and research in the field of astronomy. Resources contains an image gallery, an astroglossary, and solar system, constellation, and star guides. The Radio section contains past radio programs by date, or searchable by subject. Also available are an archive database of past StarDate articles, and a teacher's section with ideas for teaching astronomy concepts in the classroom.

349

Determination of the in-flight spectral and radiometric characteristics of the Airborne Visible/Infrared Imaging Spectrometer (AVIRIS)  

NASA Technical Reports Server (NTRS)

AVIRIS is a science research imaging spectrometer that measures radiance in 224 channels between 400 to 2450 nm in the electromagnetic spectrum. To determine the inflight spectral and radiometric characteristics of AVIRIS a validation and calibration experiment was performed. Five data sets were acquired over a calibration site on the homogeneous playa of Rogers Dry Lake, California, U.S. Surface reflectance, atmospheric optical depths, and atmospheric water vapor measurements were acquired concurrently with the overflights. These in situ measurements were used to constrain the LOWTRAN 7 radiative transfer code to predict the total spectral radiance incident at the AVIRIS aperture. These predicted radiances and the AVIRIS measured radiances were analyzed to validate the inflight characteristics. Inflight spectral channel positions and response functions over the AVIRIS spectral range were derived. Radiometric calibration coefficients were calculated for each channel as well as radiometric accuracy, intraflight stability, and noise equivalent delta radiance.

Green, Robert O.; Conel, James E.; Carrere, Veronique; Bruegge, Carol J.; Margolis, Jack S.; Rast, Michael; Hoover, Gordon

1991-01-01

350

The Realities of Date Rape.  

ERIC Educational Resources Information Center

This poster presentation addresses the issue of date rape, specifically in the college environment. Highlighted are date rape statistics, demographics, and date rape drugs. Also discussed are date rape warnings and prevention strategies. It is concluded that college and university administrators must place the issue of date rape and acquaintance

Presley, Cara; Watson, Jennifer; Williams, Audrey R.

351

Dating the Vinland Map  

ScienceCinema

Scientists from Brookhaven National Laboratory, the University of Arizona, and the Smithsonian Institution used carbon-dating technology to determine the age of a controversial parchment that might be the first-ever map of North America.

None

2013-07-17

352

Date _____________________ Language Partner Program  

E-print Network

? ___________________________________________________________________ Are you interested in a particular language/culture Date _____________________ Language Partner Program Volunteer Application Form The purpose of the Language Partner Program is to provide English as an additional language (EAL) students

Martin, Jeff

353

Dating the Vinland Map  

SciTech Connect

Scientists from Brookhaven National Laboratory, the University of Arizona, and the Smithsonian Institution used carbon-dating technology to determine the age of a controversial parchment that might be the first-ever map of North America.

None

2013-01-04

354

Rock Dating Gallery  

NSDL National Science Digital Library

This gallery of online resources is from the Museum's Seminars on Science, a series of distance-learning courses designed to help educators meet the new national science standards. The Rock Dating Gallery, part of the Earth: Inside and Out seminar, features illustrations from the Hall of Planet Earth, which has two informative overviews: Dating Rocks with Radioactivity and Telling Time Precisely. Stillwater Gabbro, has two images of this rock from the Stillwater Complex in Montana and a video (with a printable PDF transcript) explaining how it was dated. Stillwater Gabbro: Collecting and Dating, has a Rate of Decay Graph, a Computing the Rate of Decay video (with a printable PDF transcript), and three images: Fieldwork in Montana, Collecting a Sample for the Hall, and Vials of Crushed Rock.

355

Impact of near-cloud boundaries on radiometric performance of imaging sounders: an examination of FTS and dispersive spectrometer error sources  

Microsoft Academic Search

Meteorological sounding data provided by atmospheric imaging sounders have applications in weather forecasting, atmospheric chemistry, and climate monitoring. Realistic scenes for these instruments vary in both spatial and spectral content and such variations can impact the radiometric performance of these instruments. As sounders are developed to provide climate records with demanding long-term radiometric accuracy requirements, it becomes increasingly important to

Tanya M. Ramond; Amy B. Newbury; Michelle Stephens

2011-01-01

356

A multi-frequency radiometric measurement of soil moisture content over bare and vegetated fields  

NASA Technical Reports Server (NTRS)

A USDA Beltsville Agricultural Research Center site was used for an experiment in which soil moisture remote sensing over bare, grass, and alfalfa fields was conducted over a three-month period using 0.6 GHz, 1.4 GHz, and 10.6 GHz Dicke-type microwave radiometers mounted on mobile towers. Ground truth soil moisture content and ambient air and sil temperatures were obtained concurrently with the radiometric measurements. Biomass of the vegetation cover was sampled about once a week. Soil density for each of the three fields was measured several times during the course of the experiment. Results of the radiometric masurements confirm the frequency dependence of moisture sensing sensitivity reduction reported earlier. Observations over the bare, wet field show that the measured brightness temperature is lowest at 5.0 GHz and highest of 0.6 GHz frequency, a result contrary to expectation based on the estimated dielectric permittivity of soil water mixtures and current radiative transfer model in that frequency range.

Wang, J. R.; Schmugge, T. J.; Mcmurtrey, J. E., III; Gould, W. I.; Glazar, W. S.; Fuchs, J. E. (principal investigators)

1981-01-01

357

Real-Time EDL Navigation Performance Using Spacecraft to Spacecraft Radiometric Data  

NASA Technical Reports Server (NTRS)

A two-year task sponsored by NASA's Mars Technology Program's Advanced Entry, Descent and Landing (EDL) work area includes investigation of improvements to EDL navigation by processing spacecraft-to-spacecraft radiometric data. Spacecraft-to-spacecraft navigation will take advantage of the UHF link between two spacecraft (i.e. to an orbiter from an approaching lander for EDL telemetry relay) to build radiometric data, specifically the velocity between the two spacecraft along the radio beam, that are processed to determine position and velocity in real time. The improved onboard state knowledge provided by spacecraft-to-spacecraft navigation will improve the performance of entry guidance by providing a more accurate state estimate and ultimately reduce the landed position error. A previous paper documented the progress of the first year of this task, including the spacecraft definitions, selection and documentation of the required algorithms and analysis results used to define the algorithm set. The final year of this task is reported here. Topics include modifications to the previously selected algorithm set for implementation, and performance of the implemented algorithms in a stand-alone filter, on an emulator of the target processor and finally on a breadboard processing unit.

Burkhart, P. Daniel; Ely, Todd; Duncan, Courtney; Lightsey, Glenn; Campbell, Todd; Mogensen, Andy

2006-01-01

358

Airborne lidar/radiometric measurements of cirrus cloud parameters and their application to LOWTRAN radiance evaluations  

NASA Technical Reports Server (NTRS)

SRI has assembled an airborne lidar/radiometric instrumentation suite for mapping cirrus cloud distribution and analyzing cirrus cloud optical properties. Operation of upward viewing infrared radiometers from an airborne platform provides the optimum method of measuring high altitude cold cloud radiative properties with minimum interference from the thermal emission by the earth's surface and lower atmospheric components. Airborne installed sensors can also operate over large regional areas including water, urban, and mountain surfaces and above lower atmospheric convective clouds and haze layers. Currently available sensors installed on the SRI Queen Air aircraft are illustrated. Lidar and radiometric data records are processed for real time viewing on a color video screen. A cirrus cloud data example is presented as a black and white reproduction of a color display of data at the aircraft altitude of 12,000 ft, the 8 to 14 micron atmospheric radiation background was equivalent to a blackbody temperature of about -60 C and, therefore, the radiometer did not respond strongly to low density cirrus cloud concentrations detected by the lidar. Cloud blackbody temperatures (observed by radiometer) are shown plotted against midcloud temperatures (derived from lidar observed cloud heights and supporting temperature profiles) for data collected on 30 June and 28 July.

Uthe, Edward E.

1990-01-01

359

Geometric and radiometric performance evaluation methods for marine observation satellite-1 (MOS-1) verification program (MVP)  

NASA Astrophysics Data System (ADS)

Marine Observation Satellite-1 (MOS-1) is scheduled for launch in the January and February period of 1987. Main objectives of the MOS-1 are to observe the sea, land and atmosphere by three radiometers (MESSR, VTIR and MSR) and to develop fundamental technologies for earth observation system consisting of space and ground segments. In order to accomplish these objectives NASDA is developing both MOS-1 and ground facilities, and NASDA conducted MOS-1 airborne verification experiment to develop various algorithms which were converted into MOS-1 data processing facility and then used in MOS-1 verification program (MVP). The purposes of the MVP are to evaluate and confirm the distortion correction methods and performance evaluation methods, to evaluate effectiveness of parameters of MOS-1 mission equipment and to reflect the results of the evaluation on the development and operation of the future earth observation system. Concerning radiometric performance, correction methods of deviation of CCD sensitivity for MESSR, calibration methods for VTIR and MSR have been developed and evaluation methods of S/N and dynamic range have been studied. Concerning geometric performance, geometric distortions are classified and distortion correction methods have been developed. Moreover, spatial resolution have been evaluated. In this paper, some of the geometric and radiometric performance evaluation methods are presented and evaluated.

Maeda, Korehiro; Kojima, Masahiro; Azuma, Yoshio

360

The First SIMBIOS Radiometric Intercomparison (SIMRIC-1), April-September 2001  

NASA Technical Reports Server (NTRS)

This report describes the first SIMBIOS (Sensor Intercomparison and Merger for Biological and Interdisciplinary Oceanic Studies) Radiometric Intercomparison (SIMRIC-1). The purpose of the SIMRIC-1 is to ensure a common radiometric scale of the calibration facilities that are engaged in calibrating in situ radiometers used for ocean color related research and to document the calibration procedures and protocols. SIMBIOS staff visited the seven participating laboratories for at least two days each. The SeaWiFS Transfer Radiometer SXR-II measured the calibration radiances produced in the laboratories. The measured radiances were compared with the radiances expected by the laboratories. Typically, the measured radiances were higher than the expected radiances by 0 to 2%. This level of agreement is satisfactory. Several issues were identified, where the calibration protocols need to be improved, especially the reflectance calibration of the reference plaques and the distance correction when using the irradiance standards at distances greater than the 50 cm. The responsivity of the SXR-II changed between 0.3% (channel 6) and 1.6% (channel 2) from December 2000 to December 2001. Monitoring the SXR-II with a portable light source showed a linear drift of the calibration, except for channel 1, where a 2% drop occurred in summer.

Meister, Gerhard; Abel, Peter; McClain, Charles; Barnes, Robert; Fargion, Giulietta; Cooper, John; Davis, Curtiss; Korwan, Daniel; Godin, Mike; Maffione, Robert

2002-01-01

361

A Preliminary Evaluation of LANDSAT-4 Thematic Mapper Data for Their Geometric and Radiometric Accuracies  

NASA Technical Reports Server (NTRS)

Some LANDSAT thematic mapper data collected over the eastern United States were analyzed for their whole scene geometric accuracy, band to band registration and radiometric accuracy. Band ratio images were created for a part of one scene in order to assess the capability of mapping geologic units with contrasting spectral properties. Systematic errors were found in the geometric accuracy of whole scenes, part of which were attributable to the film writing device used to record the images of film. Band to band registration showed that bands 1 through 4 were registered to within one pixel. Likewise, bands 5 and 7 also were registered to within one pixel. However, bands 5 and 7 were misregistered with bands 1 through 4 by 1 to 2 pixels. Band 6 was misregistered by 4 pixels to bands 1 through 4. Radiometric analysis indicated two kinds of banding, a modulo-16 stripping and an alternate light dark group of 16 scanlines. A color ratio composite image consisting of TM band ratios 3/4, 5/2, and 5/7 showed limonitic clay rich soils, limonitic clay poor soils, and nonlimonitic materials as distinctly different colors on the image.

Podwysocki, M. H.; Falcone, N.; Bender, L. U.; Jones, O. D.

1985-01-01

362

A preliminary evaluation of LANDSAT-4 thematic mapper data for their geometric and radiometric accuracies  

NASA Technical Reports Server (NTRS)

Some LANDSAT thematic mapper data collected over the eastern United States were analyzed for their whole scene geometric accuracy, band to band registration and radiometric accuracy. Band ratio images were created for a part of one scene in order to assess the capability of mapping geologic units with contrasting spectral properties. Systematic errors were found in the geometric accuracy of whole scenes, part of which were attributable to the film writing device used to record the images to film. Band to band registration showed that bands 1 through 4 were registered to within one pixel. Likewise, bands 5 and 7 also were registered to within one pixel. However, bands 5 and 7 were misregistered with bands 1 through 4 by 1 to 2 pixels. Band 6 was misregistered by 4 pixels to bands 1 through 4. Radiometric analysis indicated two kinds of banding, a modulo-16 stripping and an alternate light dark group of 16 scanlines. A color ratio composite image consisting of TM band ratios 3/4, 5/2, and 5/7 showed limonitic clay rich soils, limonitic clay poor soils, and nonlimonitic materials as distinctly different colors on the image.

Podwysocki, M. H.; Bender, L. U.; Falcone, N.; Jones, O. D.

1983-01-01

363

Thermal Infrared Radiometric Calibration of the Entire Landsat 4, 5, and 7 Archive (1982-2010)  

NASA Technical Reports Server (NTRS)

Landsat's continuing record of the thermal state of the earth's surface represents the only long term (1982 to the present) global record with spatial scales appropriate for human scale studies (i.e., tens of meters). Temperature drives many of the physical and biological processes that impact the global and local environment. As our knowledge of, and interest in, the role of temperature on these processes have grown, the value of Landsat data to monitor trends and process has also grown. The value of the Landsat thermal data archive will continue to grow as we develop more effective ways to study the long term processes and trends affecting the planet. However, in order to take proper advantage of the thermal data, we need to be able to convert the data to surface temperatures. A critical step in this process is to have the entire archive completely and consistently calibrated into absolute radiance so that it can be atmospherically compensated to surface leaving radiance and then to surface radiometric temperature. This paper addresses the methods and procedures that have been used to perform the radiometric calibration of the earliest sizable thermal data set in the archive (Landsat 4 data). The completion of this effort along with the updated calibration of the earlier (1985 1999) Landsat 5 data, also reported here, concludes a comprehensive calibration of the Landsat thermal archive of data from 1982 to the present

Schott, John R.; Hook, Simon J.; Barsi, Julia A.; Markham, Brian L.; Miller, Jonathan; Padula, Francis P.; Raqueno, Nina G.

2012-01-01

364

Radiometric calibration of ocean color satellite sensors using AERONET-OC data.  

PubMed

Radiometric vicarious calibration of ocean color (OC) satellite sensors is carried out through the full sunlight path radiative transfer (RT) simulations of the coupled ocean-atmosphere system based on the aerosol and water-leaving radiance data from AERONET-OC sites for the visible and near-infrared (NIR) bands. Quantitative evaluation of the potential of such approach for achieving the radiometric accuracies of OC satellite sensors is made by means of direct comparisons between simulated and satellite measured top of atmosphere (TOA) radiances. Very high correlations (R ? 0.96 for all visible channels) are achieved for the Visible Infrared Imaging Radiometer Suite (VIIRS) sensor when this approach is applied with the data from the LISCO and WaveCIS AERONET-OC sites. Vicarious calibration gain factors derived with this approach are highly consistent, with comparisons between the two sites exhibiting around 0.5% discrepancy in the blue and green parts of the spectrum, while their average temporal variability is also within 0.28% - 1.23% permitting the approach to be used, at this stage, for verification of sensor calibration performance. PMID:25321808

Hlaing, Soe; Gilerson, Alexander; Foster, Robert; Wang, Menghua; Arnone, Robert; Ahmed, Sam

2014-09-22

365

X-ray radiometric determination of lanthanides (praseodymium, neodymium, and samarium) in soils  

NASA Astrophysics Data System (ADS)

A procedure of the modified energy-dispersive X-ray fluorescence method (X-ray radiometric analysis using a 241Am radionuclide source) was developed for the identification of praseodymium, neodymium, and samarium. The procedure is based on the exclusion of the disturbing effect of barium and lanthanum on the lines of praseodymium and neodymium, as well as the effect of lanthanum and cerium on the lines of samarium. On the basis of the new method, data were obtained on the geochemistry of three lanthanides in soils of the northern taiga. Praseodymium and neodymium were detected by the X-ray radiometric method even in podzols depleted of heavy metals. The method can detect samarium at the levels of the soil clarke and higher. Positive samarium (or, wider, rare-earth) anomalies can be expected in the soils located not far from the deposits of apatite-nephelines, loparites, and phosphorites and in the soils developed on alkaline granites and carbonate weathering crusts.

Savichev, A. T.; Vodyanitskii, Yu. N.

2011-04-01

366

Initial On-Orbit Radiometric Calibration of the Suomi NPP VIIRS Reflective Solar Bands  

NASA Technical Reports Server (NTRS)

The on-orbit radiometric response calibration of the VISible/Near InfraRed (VISNIR) and the Short-Wave InfraRed (SWIR) bands of the Visible/Infrared Imager/Radiometer Suite (VIIRS) aboard the Suomi National Polar-orbiting Partnership (NPP) satellite is carried out through a Solar Diffuser (SD). The transmittance of the SD screen and the SD's Bidirectional Reflectance Distribution Function (BRDF) are measured before launch and tabulated, allowing the VIIRS sensor aperture spectral radiance to be accurately determined. The radiometric response of a detector is described by a quadratic polynomial of the detector?s digital number (dn). The coefficients were determined before launch. Once on orbit, the coefficients are assumed to change by a common factor: the F-factor. The radiance scattered from the SD allows the determination of the F-factor. In this Proceeding, we describe the methodology and the associated algorithms in the determination of the F-factors and discuss the results.

Lei, Ning; Wang, Zhipeng; Fulbright, Jon; Lee, Shihyan; McIntire, Jeff; Chiang, Vincent; Xiong, Jack

2012-01-01

367

Radiocarbon dating of ancient rock paintings  

SciTech Connect

This report presents progress made on a technique for {sup 14}C dating pictographs. A low-temperature oxygen plasma is used coupled with high-vacuum technologies to selectively remove C-containing material in the paints without contamination from inorganic carbon from rock substrates or accretions.

Ilger, W.A.; Hyman, M.; Rowe, M.W. [Texas A and M Univ., College Station, TX (United States). Dept. of Chemistry; Southon, J. [Lawrence Livermore National Lab., CA (United States)

1995-06-20

368

Identifying potentially active volcanoes in the Andes: Radiometric evidence for late Pleistocene-early Holocene eruptions at Volcn Imbabura, Ecuador  

NASA Astrophysics Data System (ADS)

Recent eruptions from volcanoes with no previously known historical activity in Chile and Indonesia have raised the importance of the early identification of potentially active centers for the purpose of hazard assessment. Here we bring radiometric evidence ( 14 C, 39Ar- 40Ar) of previously unrecognized but significant magmatic activity at partly eroded Imbabura volcano (Ecuador) in late Pleistocene to early Holocene times, on whose perimeter live more than 300,000 persons. Following an effusive stage from 50 to 30 ka with the emplacement of andesitic lava flows on different flanks of its edifice, the activity became explosive with the generation of andesitic block-and-ash flows on its eastern side, beginning at ~ 35 ka cal BP. Subsequently a flank collapse associated with a volcanic blast occurred on the volcano's SW flank at ~ 30 ka cal BP. The resulting debris avalanche and blast breccias cover an area now heavily populated around San Pablo Lake and its source was later concealed by successive dome building episodes at Huarmi which produced ~ 2.8 km 3 of silicic andesite. Renewed dome activity at the edifice's Taita summit occurred at ~ 17 ka cal BP and continued intermittently into early Holocene times, as indicated by pyroclastic flow deposits overlying a palaeosoil dated at ~ 9 ka cal BP. In summary, this study reveals an eruptive behavior characterized by a low recurrence rate but with quite large eruptions, a pattern which is also observed at other silicic volcanoes of Ecuador's Western Cordillera. It is now imperative to reconsider the origin and source of the many tephra layers catalogued in Holocene lacustrine sediments in the Imbabura area. Tephra and lava volume estimates for Imbabura volcano converted to Dense Rock Equivalent values yield a minimum magmatic output rate of 0.13 km 3/ka in the past 35,000 years, which argues for sustained magma production for this volcano in recent geological times. The Imbabura example thus raises the question of how to improve population preparedness for volcanoes with infrequent eruptions, and how to guide authorities' decisions concerning the development of urban areas and infrastructures near presently inactive but potentially highly dangerous volcanoes.

Le Pennec, J. L.; Ruiz, A. G.; Eissen, J. P.; Hall, M. L.; Fornari, M.

2011-09-01

369

78 FR 37690 - Federal Acquisition Regulation; Price Analysis Techniques  

Federal Register 2010, 2011, 2012, 2013, 2014

...9000-AM27 Federal Acquisition Regulation; Price Analysis Techniques AGENCY: Department...give a precise reference in the use of a price analysis technique in order to establish a fair and reasonable price. DATES: Effective Date: July 22,...

2013-06-21

370

Plutonium age dating reloaded  

NASA Astrophysics Data System (ADS)

Although the age determination of plutonium is and has been a pillar of nuclear forensic investigations for many years, additional research in the field of plutonium age dating is still needed and leads to new insights as the present work shows: Plutonium is commonly dated with the help of the 241Pu/241Am chronometer using gamma spectrometry; in fewer cases the 240Pu/236U chronometer has been used. The age dating results of the 239Pu/235U chronometer and the 238Pu/234U chronometer are scarcely applied in addition to the 240Pu/236U chronometer, although their results can be obtained simultaneously from the same mass spectrometric experiments as the age dating result of latter. The reliability of the result can be tested when the results of different chronometers are compared. The 242Pu/238U chronometer is normally not evaluated at all due to its sensitivity to contamination with natural uranium. This apparent 'weakness' that renders the age dating results of the 242Pu/238U chronometer almost useless for nuclear forensic investigations, however turns out to be an advantage looked at from another perspective: the 242Pu/238U chronometer can be utilized as an indicator for uranium contamination of plutonium samples and even help to identify the nature of this contamination. To illustrate this the age dating results of all four Pu/U clocks mentioned above are discussed for one plutonium sample (NBS 946) that shows no signs of uranium contamination and for three additional plutonium samples. In case the 242Pu/238U chronometer results in an older 'age' than the other Pu/U chronometers, contamination with either a small amount of enriched or with natural or depleted uranium is for example possible. If the age dating result of the 239Pu/235U chronometer is also influenced the nature of the contamination can be identified; enriched uranium is in this latter case a likely cause for the missmatch of the age dating results of the Pu/U chronometers.

Sturm, Monika; Richter, Stephan; Aregbe, Yetunde; Wellum, Roger; Mayer, Klaus; Prohaska, Thomas

2014-05-01

371

Accelerator radiocarbon dating: new applications and capabilities  

SciTech Connect

As with new advances in any field, radiocarbon dating by accelerator mass spectrometry has to be treated with some scepticism until it has proven itself against the conventional techniques. By the direct atom counting of the radioactive carbon isotope, C-14, rather than the counting of the beta particles, any background is eliminated and microgram-sized samples of a solid graphite-like target can be analyzed in a few hours instead of many days. The IsoTrace laboratory has completed a comparative analysis with materials dated by the conventional method and has shown excellent agreement, yielding an accuracy better than 1% and a precision of 0.3%. For samples less than 10,000 years old, a precision of 1.0% is routinely obtained, while, for samples less than 2000 years old, precision of 0.3% is possible. Dates can also be routinely obtained from materials up to 50,000 years old. With the small sample size and high precision, greater resolution when dating recent materials may be obtained. Materials that previously proved impossible to date due to small sample size or the nature of the material (e.g. high value, weathering etc.) may now readily be subjected to scrutiny. Fragments, rather than bulk samples, may be dated, facilitating significant stratigraphic resolution and correlation in a wide variety of situations.

Cresswell, R.G.; Beukens, R.P.; Lee, H.W.

1985-01-01

372

A Traceable Ground to On-Orbit Radiometric Calibration System for the Solar Reflective Wavelength Region  

NASA Technical Reports Server (NTRS)

This paper describes the combination of a Mie scattering spectral BSDF and BTDF albedo standard whose calibration is traceable to the NIST SIRCUS Facility or the NIST STARR II Facility. The Space-based Calibration Transfer Spectroradiometer (SCATS) sensor uses a simple, invariant optical configuration and dedicated narrow band spectral channel modules to provide very accurate, polarization-insensitive, stable measurements of earth albedo and lunar disk albedo. Optical degradation effects on calibration stability are eliminated through use of a common optical system for observations of the Sun, Earth, and Moon. The measurements from space would be traceable to SI units through preflight calibrations of radiance and irradiance at NIST's SIRCUS facility and the invariant optical system used in the sensor. Simultaneous measurements are made in multiple spectral channels covering the solar reflective wavelength range of 300 nm to 2.4 microns. The large dynamic range of signals is handled by use of single-element, highly-linear detectors, stable discrete electronic components, and a non imaging optical configuration. Up to 19 spectral modules can be mounted on a single-axis drive to give direct pointing at the Earth and at least once per orbit view of the Sun and Moon. By observing the Sun on every orbit, the most stringent stability requirements of the system are limited to short time periods. The invariant optical system for both radiance and irradiance measurements also give excellent transfer to-orbit SI traceability. Emerging instrumental requirements for remotely sensing tropospheric trace species have led to a rethinking by some of the paradigm for Systeme International d'Unites (SI) traceability of the spectral irradiance and radiance radiometric calibrations to spectral albedo (sr(exp -1)) which is not a SI unit. In the solar reflective wavelength region the spectral albedo calibrations are tied often to either the spectral albedo of a solar diffuser or the Moon. This new type of Mie scattering diffuser (MSD) is capable of withstanding high temperatures, and is more Lambertian than Spectralon(tm). It has the potential of covering the entire solar reflective wavelength region. Laboratory measurements have shown that the specular reflectance component is negligible, and indicate that internal absorption by multiple scattering is small. This MSD, a true volume diffuser, exhibits a high degree of radiometric stability which suggests that measurements at the National Institute of Standards and Technology (NIST) could provide a spectral albedo standard. Measurements have been made of its radiometric stability under a simulated space environment of high energy gamma rays, high energy protons, and UV radiation from ambient down to the vacuum ultraviolet H Lyman alpha at 121.6 nm for its eventual use in space as a solar diffuser.

Heath, Donald F.; Georgiev, Georgi

2012-01-01

373

Modelling Surface Energy Fluxes over Maize using a Two-Source Patch Model and Radiometric Soil and Canopy Temperature Observations.  

Technology Transfer Automated Retrieval System (TEKTRAN)

Models estimating surface energy fluxes over partial canopy cover with thermal remote sensing must account for significant differences between the radiometric temperatures and turbulent exchange rates associated with the soil and canopy components of the thermal pixel scene. Recent progress in separ...

374

Geometric Calibration and Radiometric Correction of LiDAR Data and Their Impact on the Quality of Derived Products  

PubMed Central

LiDAR (Light Detection And Ranging) systems are capable of providing 3D positional and spectral information (in the utilized spectrum range) of the mapped surface. Due to systematic errors in the system parameters and measurements, LiDAR systems require geometric calibration and radiometric correction of the intensity data in order to maximize the benefit from the collected positional and spectral information. This paper presents a practical approach for the geometric calibration of LiDAR systems and radiometric correction of collected intensity data while investigating their impact on the quality of the derived products. The proposed approach includes the use of a quasi-rigorous geometric calibration and the radar equation for the radiometric correction of intensity data. The proposed quasi-rigorous calibration procedure requires time-tagged point cloud and trajectory position data, which are available to most of the data users. The paper presents a methodology for evaluating the impact of the geometric calibration on the relative and absolute accuracy of the LiDAR point cloud. Furthermore, the impact of the geometric calibration and radiometric correction on land cover classification accuracy is investigated. The feasibility of the proposed methods and their impact on the derived products are demonstrated through experimental results using real data. PMID:22164121

Habib, Ayman F.; Kersting, Ana P.; Shaker, Ahmed; Yan, Wai-Yeung

2011-01-01

375

The Imaging and Slitless Spectroscopy Instrument for Surveys (ISSIS): expected radiometric performance, operation modes and data handling  

NASA Astrophysics Data System (ADS)

ISSIS is the instrument for imaging and slitless spectroscopy on-board WSO-UV. In this article, a detailed comparison between ISSIS expected radiometric performance and other ultraviolet instruments is shown. In addition, we present preliminary information on the performance verification tests and on the foreseen procedures for in-flight operation and data handling.

Gmez de Castro, Ana I.; Beln Perea, G.; Snchez, Nstor; Santiago, Javier Lpez; Chirivella, Jse; Seijas, Juan

2014-11-01

376

The spectral photon flux of the radiometric calibration spectral source for the NIRSpec instrument of the James Webb Space Telescope  

Microsoft Academic Search

The radiometric calibration spectral source (RCSS) is a very low photon flux radiation source based on an integrating sphere, operated under vacuum and cryogenic conditions, for the testing and calibration of the near infrared multiobject dispersive spectrograph (NIRSpec). NIRSpec itself is a part of the scientific instrumentation of the James Webb Space Telescope. For the traceable calibration of the photon

R. D. Taubert; C. Monte; C. Baltruschat; A. Schirmacher; B. Gutschwager; J. Hartmann; J. Hollandt; D. Kochems; C. Kchel; M. te Plate

2009-01-01

377

Radiometric calibration of IR Fourier transform spectrometers - Solution to a problem with the High-Resolution Interferometer Sounder  

Microsoft Academic Search

A calibrated Fourier transform spectrometer, known as the High-Resolution Interferometer Sounder (HIS), has been flown on the NASA U-2 research aircraft to measure the infrared emission spectrum of the earth. The primary use - atmospheric temperature and humidity sounding - requires high radiometric precision and accuracy (of the order of 0.1 and 1 C, respectively). To meet these requirements, the

Henry E. Revercomb; William L. Smith; H. Buijs; Hugh B. Howell; D. D. Laporte; L. A. Sromovsky

1988-01-01

378

Surface Dating of Dynamic Landforms: Young Boulders on Aging Moraines  

Microsoft Academic Search

The dating of landforms is crucial to understanding the evolution, history, and stability of landscapes. Cosmogenic isotope analysis has recently been used to determine quantitative exposure ages for previously undatable landform surfaces. A pioneering application of this technique to date moraines illustrated its considerable potential but suggested a chronology partially inconsistent with existing geological data. Consideration of the dynamic nature

Bernard Hallet; Jaakko Putkonen

1994-01-01

379

Sexual Coercion on Dates: It's Not Just Rape.  

ERIC Educational Resources Information Center

Contends that sexual coercion while dating falls under the umbrella of school-related violence. Discusses acquaintance and date rape, a sexual coercion continuum, and coercion victims. Concludes with a discussion of six techniques to reduce risk of sexual coercion. (CFR)

Waldner-Haugrud, Lisa

1995-01-01

380

Z .Geomorphology 29 1999 173185 Quality assurance in luminescence dating  

E-print Network

Z .Geomorphology 29 1999 173185 Quality assurance in luminescence dating Michele L. Clarke a Recent advances in luminescence dating have led to increasing application of the technique to sediments and deposition under turbid conditions. The complete zeroing of the luminescence signal, by exposure to light

Clarke, Michle

381

Biodiversity of date palm  

Technology Transfer Automated Retrieval System (TEKTRAN)

The date palm (Phoenix dactylifera) is the dominant component upon which the sustainable biophysical and socio-economic structures of the oasis ecosystem are based; a fruit tree with unique nutritional, biochemical and biophysical characteristics, a rich source of aesthetic and cultural values, and ...

382

Overtime Authorization Agreement Date __________________  

E-print Network

, ________________________________, authorize ____________________________________ Supervisor Employee to work _______ hours of overtime on _________________________. Date Employee will be compensated for these hours through Overtime pay Compensatory time. Nonexempt employees must be paid for all hours worked in excess of 40 hours (50 hours for agricultural employees

Farritor, Shane

383

The Dating Game.  

ERIC Educational Resources Information Center

Presents activities to cultivate the tendency to see special qualities in numbers that can be played on certain calendar days. Includes games on the constant of the day, Fibonacci and golden ratio dates, primes, powers, December 25, and the day of the year. (ASK)

Zerger, Monte J.

1998-01-01

384

Tecnolgico de Facts, Dates &  

E-print Network

Tecnológico de Monterrey Facts, Dates & Deadlines 2011 #12;UNDERGRADUATE AND NON BUSINESS GRADUATE. ·Final exams at Tecnológicode Monterrey are programmed according to your class schedule. You will know as early as possible. Choose one of three options for your living situation at Tecnológicode Monterrey

Petriu, Emil M.

385

Quantum Dating Market  

E-print Network

We consider the dating market decision problem under the quantum mechanics point of view. Quantum states whose associated amplitudes are modified by men strategies are used to represent women. Grover quantum search algorithm is used as a playing strategy. Success is more frequently obtained by playing quantum than playing classic.

O. G. Zabaleta; C. M. Arizmendi

2010-03-04

386

Vulcanism and radiocarbon dates  

Microsoft Academic Search

We consider whether the long term perturbation of radiocarbon dates, which is known to be approximately a sin function of period about 8000 years and amplitude of about 8% peak-to-peak, could have been caused in any major part by vulcanism. We conclude that this is not the case. On the contrary, present day volcanoes are a far less important source

L. M. Libby; W. F. Libby

1972-01-01

387

Ar-Ar Dating of Martian Meteorite, Dhofar 378: An Early Shock Event?  

NASA Technical Reports Server (NTRS)

Martian meteorite, Dhofar 378 (Dho378) is a basaltic shergottite from Oman, weighing 15 g, and possessing a black fusion crust. Chemical similarities between Dho378 and the Los Angeles 001 shergottite suggests that they might have derived from the same Mars locale. The plagioclase in other shergottites has been converted to maskelenite by shock, but Dho378 apparently experienced even more intense shock heating, estimated at 55-75 GPa. Dho378 feldspar (approximately 43 modal %) melted, partially flowed and vesiculated, and then partially recrystallized. Areas of feldspathic glass are appreciably enriched in K, whereas individual plagioclases show a range in the Or/An ratio of approximately 0.18-0.017. Radiometric dating of martian shergottites indicate variable formation times of 160-475 Myr, whereas cosmic ray exposure (CRE) ages of shergottites indicate most were ejected from Mars within the past few Myr. Most determined Ar-39-Ar-40 ages of shergottites appear older than other radiometric ages because of the presence of large amounts of martian atmosphere or interior Ar-40. Among all types of meteorites and returned lunar rocks, the impact event that initiated the CRE age very rarely reset the Ar-Ar age. This is because a minimum time and temperature is required to facilitate Ar diffusion loss. It is generally assumed that the shock-texture characteristics in martian meteorites were produced by the impact events that ejected the rocks from Mars, although the time of these shock events (as opposed to CRE ages) are not directly dated. Here we report Ar-39-Ar-40 dating of Dho378 plagioclase. We suggest that the determined age dates the intense shock heating event this meteorite experienced, but that it was not the impact that initiated the CRE age.

Park, J.; Bogard, D. D.

2006-01-01

388

Time course of radiometric detection of positive blood cultures in childhood  

SciTech Connect

We have determined the time course of radiometric detection of microbial growth in 2348 positive blood culture specimens obtained at Wyler Children's Hospital during a 5-year interval. Overall 72 and 88% of isolates were detected within 48 and 72 hours after sampling, respectively. For pathogenic organisms aerobic detection was generally more rapid and more inclusive than anaerobic detection. At 48 hours of incubation the detection of six potential pathogens (Salmonella sp., Haemophilus influenzae, Group D streptococci, Neisseria meningitidis, coagulase-negative staphylococci, Candida sp.) was significantly delayed compared with detection of other pathogenic organisms recovered from blood. At 72 hours of incubation the detection rates remained less than 95% for H. influenzae, Staphylococcus aureus, Klebsiella sp., coagulase-negative staphylococci, Group D streptococci and Candida sp. These data should assist clinical decisions regarding duration of antibiotic therapy for the presumptive diagnosis of bacteremia in children.

Meadow, W.L.; Schwartz, I.K.

1986-05-01

389

High-precision radiometric tracking for planetary approach and encounter in the inner solar system  

NASA Technical Reports Server (NTRS)

The benefits of improved radiometric tracking data have been studied for planetary approach within the inner Solar System using the Mars Rover Sample Return trajectory as a model. It was found that the benefit of improved data to approach and encounter navigation was highly dependent on the a priori uncertainties assumed for several non-estimated parameters, including those for frame-tie, Earth orientation, troposphere delay, and station locations. With these errors at their current levels, navigational performance was found to be insensitive to enhancements in data accuracy. However, when expected improvements in these errors are modeled, performance with current-accuracy data significantly improves, with substantial further improvements possible with enhancements in data accuracy.

Christensen, C. S.; Thurman, S. W.; Davidson, J. M.; Finger, M. H.; Folkner, W. M.

1989-01-01

390

Statistical and radiometric measurements of coherently illuminated, nonaugmented, low-earth-orbit satellites  

NASA Astrophysics Data System (ADS)

The US Air Force Phillips Laboratory recently completed the Floodbeam Experiment (FBE), recording the first ever spatially resolved, coherent laser returns from non-augmented (non- retroreflectors), low earth orbit satellites. The experiment broadcast a near-IR, coherent laser at a selected set of low earth orbit satellites using a beam director and visible tracking system located at the Phillips Lab Starfire Optical Range (SOR). Tracking was accomplished during terminator periods when the satellite was illuminated by the sun and the transmitting/receiving site was in darkness. Thirty eight different satel- lites were illuminated during the experiment. The reflected laser return was collected with the 1.5m telescope at the SOR and focused on a low noise IR camera. The Floodbeam experiment gathered radiometric data, data on depolarization effects, and spatially resolved coherent speckle patterns. This paper will discuss the experimental hardware and the field results.

Rider, Douglas B.; Voelz, David G.; Stone, David H.; Schulze, Kathy J.; Dean, David R.; Bush, Keith A.

1994-12-01

391

Prediction of radio frequency power generation of Neptune's magnetosphere from generalized radiometric Bode's law  

NASA Astrophysics Data System (ADS)

Magnetospheric radio frequency emission power has been shown to vary as a function of both solar wind and planetary values such as magnetic field by Kaiser and Desch. Planetary magnetic fields have been shown to scale with planetary variables such as density and angular momentum by numerous researchers. This paper combines two magnetic scaling laws (Busse's and Curtis Ness') with the radiometric law to yield "Bode's"-type laws governing planetary radio emission. Further analysis allows the reduction of variables to planetary mass and orbital distance. These generalized laws are then used to predict the power output of Neptune to be about 1.6107W; with the intensity peaking at about 3 MHz.

Millon, M. A.; Goertz, C. K.

1988-01-01

392

A Liquid-Helium-Cooled Absolute Reference Cold Load forLong-Wavelength Radiometric Calibration  

SciTech Connect

We describe a large (78-cm) diameter liquid-helium-cooled black-body absolute reference cold load for the calibration of microwave radiometers. The load provides an absolute calibration near the liquid helium (LHe) boiling point, accurate to better than 30 mK for wavelengths from 2.5 to 25 cm (12-1.2 GHz). The emission (from non-LHe temperature parts of the cold load) and reflection are small and well determined. Total corrections to the LHe boiling point temperature are {le} 50 mK over the operating range. This cold load has been used at several wavelengths at the South Pole and at the White Mountain Research Station. In operation, the average LHe loss rate was {le} 4.4 l/hr. Design considerations, radiometric and thermal performance and operational aspects are discussed. A comparison with other LHe-cooled reference loads including the predecessor of this cold load is given.

Bensadoun, M.; Witebsky, C.; Smoot, George F.; De Amici,Giovanni; Kogut, A.; Levin, S.

1990-05-01

393

Radiometric and Geometric Analysis of Hyperspectral Imagery Acquired from an Unmanned Aerial Vehicle  

SciTech Connect

In the summer of 2010, an Unmanned Aerial Vehicle (UAV) hyperspectral in-flight calibration and characterization experiment of the Resonon PIKA II imaging spectrometer was conducted at the U.S. Department of Energys Idaho National Laboratory (INL) UAV Research Park. The purpose of the experiment was to validate the radiometric calibration of the spectrometer and determine the georegistration accuracy achievable from the on-board global positioning system (GPS) and inertial navigation sensors (INS) under operational conditions. In order for low-cost hyperspectral systems to compete with larger systems flown on manned aircraft, they must be able to collect data suitable for quantitative scientific analysis. The results of the in-flight calibration experiment indicate an absolute average agreement of 96.3%, 93.7% and 85.7% for calibration tarps of 56%, 24%, and 2.5% reflectivity, respectively. The achieved planimetric accuracy was 4.6 meters (based on RMSE).

Ryan C. Hruska; Jessica J. Mitchell; Matthew O. Anderson; Nancy F. Glenn

2012-09-01

394

Radiometric calibration of an airborne multispectral scanner. [of Thematic Mapper Simulator  

NASA Technical Reports Server (NTRS)

The absolute radiometric calibration of the NS001 Thematic Mapper Simulator reflective channels was examined based on laboratory tests and in-flight comparisons to ground measurements. The NS001 data are calibrated in-flight by reference to the NS001 internal integrating sphere source. This source's power supply or monitoring circuitry exhibited greater instability in-flight during 1988-1989 than in the laboratory. Extrapolating laboratory behavior to in-flight data resulted in 7-20 percent radiance errors relative to ground measurements and atmospheric modeling. Assuming constancy in the source's output between laboraotry and in-flight resulted in generally smaller errors. Upgrades to the source's power supply and monitoring circuitry in 1990 improved its in-flight stability, though in-flight ground reflectance based calibration tests have not yet been performed.

Markham, Brian L.; Ahmad, Suraiya P.; Jackson, Ray D.; Moran, M. S.; Biggar, Stuart F.; Gellman, David I.; Slater, Philip N.

1991-01-01

395

Radiometric characterization of ultra-bright xenon short-arc discharge lamps for novel applications  

NASA Astrophysics Data System (ADS)

The latest generations of ultra-bright Xenon short-arc discharge lamps have prodigious emissions outside the visible spectrum, primarily in the near infrared. Their brightness distributions are spatially and angularly inhomogeneous due to both the pronounced non-uniformities of the plasma arc and the substantial infrared radiation from the hot electrodes. These characteristics are fortuitously favorable for applications in photonic surgery, biomedical diagnostics, high-temperature chemical reactors and furnaces: cases where the full lamp spectrum is utilizable, and the key is reconstituting the spectral power density of the optimal regions of the lamp's plasma at a remote target. The associated optical systems must be tailored to lamp radiometric properties that are not extensively available and invariably are restricted to visible light due to their widespread use in projection systems. We present experimental measurements for the spectral, spatial and angular distributions of 150 W lamps of this genre, and relate to their ramifications for broadband high-flux applications.

Nakar, Doron; Malul, Asher; Feuermann, Daniel; Gordon, Jeffrey M.

2007-09-01

396

Radiometric Quality of the MODIS Bands at 667 and 678nm  

NASA Technical Reports Server (NTRS)

The MODIS instruments on Terra and Aqua were designed to allow the measurement of chlorophyll fluorescence effects over ocean. The retrieval algorithm is based on the difference between the water-leaving radiances at 667nm and 678nm. The water-leaving radiances at these wavelengths are usually very low relative to the top-of-atmosphere radiances. The high radiometric accuracy needed to retrieve the small fluorescence signal lead to a dual gain design for the 667 and 678nm bands. This paper discusses the benefits obtained from this design choice and provides justification for the use of only one set of gains for global processing of ocean color products. Noise characteristics of the two bands and their related products are compared to other products of bands from 412nm to 2130nm. The impact of polarization on the two bands is discussed. In addition, the impact of stray light on the two bands is compared to other MODIS bands.

Meister, Gerhard; Franz, Bryan A.

2011-01-01

397

Radiometric Quality of the MODIS Bands at 667 and 678nm  

NASA Technical Reports Server (NTRS)

The MODIS instruments on Terra and Aqua were designed to allow the measurement of chlorophyll fluorescence effects over ocean. The retrieval algorithm is based on the difference between the water-leaving radiances at 667nm and 678nm. The water-leaving radiances at these wavelengths are usually very low relative to the top- of-atmosphere radiances. The high radiometric accuracy needed to retrieve the small fluorescence signal lead to a dual gain design for the 667 and 678nm bands. This paper discusses the benefits obtained from this design choice and provides justification for the use of only one set of gains for global processing of ocean color products. Noise characteristics of the two bands and their related products are compared to other products of bands from 412nm to 2130nm. The impact of polarization on the two bands is discussed. In addition, the impact of stray light on the two bands is compared to other MODIS bands.

Meister, Gerhard; Franz, Bryan A.

2010-01-01

398

Investigation of LANDSAT follow-on thematic mapper spatial, radiometric and spectral resolution  

NASA Technical Reports Server (NTRS)

The author has identified the following significant results. Fine resolution M7 multispectral scanner data collected during the Corn Blight Watch Experiment in 1971 served as the basis for this study. Different locations and times of year were studied. Definite improvement using 30-40 meter spatial resolution over present LANDSAT 1 resolution and over 50-60 meter resolution was observed, using crop area mensuration as the measure. Simulation studies carried out to extrapolate the empirical results to a range of field size distributions confirmed this effect, showing the improvement to be most pronounced for field sizes of 1-4 hectares. Radiometric sensitivity study showed significant degradation of crop classification accuracy immediately upon relaxation from the nominally specified values of 0.5% noise equivalent reflectance. This was especially the case for data which were spectrally similar such as that collected early in the growing season and also when attempting to accomplish crop stress detection.

Nalepka, R. F. (principal investigator); Morgenstern, J. P.; Kent, E. R.; Erickson, J. D.

1976-01-01

399

Radiometric surveying for the assessment of radiation dose and radon specific exhalation in underground environment  

NASA Astrophysics Data System (ADS)

We performed a radiometric survey for evaluating the natural radioactivity and the related potential hazard level both outdoor and indoor a mine tunnel. The mine is located in a zone of uranium enrichment in the Western Alps (Italy). At first, a ?-ray spectrometry survey of the area surrounding the mine was carried out to define the extent of the ore deposit. Then, spectrometric measurements were performed in the tunnel and rock samples were collected for laboratory analyses. The results point to significant heterogeneity in uranium concentration and consequently in the absorbed dose rate spatial distribution. Spectrometric results in situ and in the laboratory, together with radon air concentration measurements, were used to infer the radon specific exhalation and flow from the mine rocks. The specific exhalation is positively related to the activity concentration of uranium.

Bochiolo, M.; Verdoya, M.; Chiozzi, P.; Pasquale, V.

2012-08-01

400

Optimization of the design parameters for a wide-band radiometric system  

NASA Technical Reports Server (NTRS)

The optimun design parameters for a swept frequency wide-band radiometric antenna system for spacecraft applications are studied. Wide band antenna systems are needed to observe layered surfaces which are frequency sensitive and require multiple measurements for interpretation. The lowest frequency band of interest is between 1.4 to 2.8 Ghz. Starting with a given size reflector fed in the offset mode by a corrugated horn located at the focus of the parabola, the primary performance indexes; e.g., half power beamwidth, cross polarization level, and overall beam efficiency were calculated over a wide frequency range (two to one) for different physical horn dimensions and for different values of f/D ratio. These data are used to find the best design under given restriction of reflector size and blockage.

Agrawal, P. K.

1978-01-01

401

Evaluating Radiometric Sensitivity of LandSat 8 Over Coastal-Inland Waters  

NASA Technical Reports Server (NTRS)

The operational Land Imager (OLI) aboard Landsat 8 was launched in February 2013 to continue the Landsat's mission of monitoring earth resources at relatively high spatial resolution. Compared to Landsat heritage sensors, OLI has an additional 443-nm band (termed coastal/aerosol (CA) band), which extends its potential for mapping/monitoring water quality in coastal/inland waters. In addition, OLI's pushbroom design allows for longer integration time and, as a result, higher signal-to-noise ratio (SNR). Using a series of radiative transfer simulations, we provide insights into the radiometric sensitivity of OLI when studying coastal/inland waters. This will address how the changes in water constituents manifest at top-of-atmosphere (TOA) and whether the changes are resolvable at TOA (focal plane) relative to OLI's overall noise.

Pahlevan, Nima; Wei, Jian-Wei; Shaaf, Crystal B.; Schott, John R.

2014-01-01

402

Study of spectral/radiometric characteristics of the thematic mapper for land use applications  

NASA Technical Reports Server (NTRS)

The previous characterization of scan-related low-frequency noise was confirmed and extended through analysis of reflective-band data from another nighttime acquisition. Amplitude and phase relationships of the level shifts were determined for each detector in each of free full frames. Analysis of scan-direction-related signal droop effects in nighttime data from the reflective bands was begun with encouraging initial observations. Also, an effort to characterize high-frequency noise in the reflective bands through Fourier analysis of nighttime data was initiated. Recommendations are made relative to the choice of radiometric calibration constants in the thematic mapper image processing system for the routine processing of TM data. Non-linear (piece-wise linear) calibration curves are recommended.

Malila, W. A. (principal investigator); Metzler, M. D.

1984-01-01

403

Orbit determination of the Lunar Reconnaissance Orbiter using laser ranging and radiometric tracking data  

NASA Astrophysics Data System (ADS)

The Lunar Reconnaissance Orbiter (LRO) launched in 2009 by the National Aeronautics and Space Administration (NASA) still orbits the Moon in a polar orbit at an altitude of 50 kilometers and below. Its main objective is the detailed exploration of the Moon's surface by means of the Lunar Orbiter Laser Altimeter (LOLA) and three high resolution cameras bundled in the Lunar Reconnaissance Orbiter Camera (LROC) unit. Referring these observations to a Moon-fixed reference frame requires the computation of highly accurate and consistent orbits. For this task only Earth-based observations are available, primarily radiometric tracking data from stations in the United States, Australia and Europe. In addition, LRO is prepared for one-way laser measurements from specially adapted sites. Currently, 10 laser stations participate more or less regularly in this experiment. For operational reasons, the official LRO orbits from NASA only include radiometric data so far. In this presentation, we investigate the benefit of the laser ranging data by feeding both types of observations in an integrated orbit determination process. All computations are performed by an in-house software development based on a dynamical approach improving orbit and force parameters in an iterative way. Special attention is paid to the determination of bias parameters, in particular of timing biases between radio and laser stations and the drift and aging of the LRO spacecraft clock. The solutions from the combined data set will be compared to radio- and laser-only orbits as well as to the NASA orbits. Further results will show how recent gravity field models from the GRAIL mission can improve the accuracy of the LRO orbits.

Lcher, Anno; Kusche, Jrgen

2014-05-01

404

Radiometric, geometric, and image quality assessment of ALOS AVNIR-2 and PRISM sensors  

USGS Publications Warehouse

The Advanced Land Observing Satellite (ALOS) was launched on January 24, 2006, by a Japan Aerospace Exploration Agency (JAXA) H-IIA launcher. It carries three remote-sensing sensors: 1) the Advanced Visible and Near-Infrared Radiometer type 2 (AVNIR-2); 2) the Panchromatic Remote-Sensing Instrument for Stereo Mapping (PRISM); and 3) the Phased-Array type L-band Synthetic Aperture Radar (PALSAR). Within the framework of ALOS Data European Node, as part of the European Space Agency (ESA), the European Space Research Institute worked alongside JAXA to provide contributions to the ALOS commissioning phase plan. This paper summarizes the strategy that was adopted by ESA to define and implement a data verification plan for missions operated by external agencies; these missions are classified by the ESA as third-party missions. The ESA was supported in the design and execution of this plan by GAEL Consultant. The verification of ALOS optical data from PRISM and AVNIR-2 sensors was initiated 4 months after satellite launch, and a team of principal investigators assembled to provide technical expertise. This paper includes a description of the verification plan and summarizes the methodologies that were used for radiometric, geometric, and image quality assessment. The successful completion of the commissioning phase has led to the sensors being declared fit for operations. The consolidated measurements indicate that the radiometric calibration of the AVNIR-2 sensor is stable and agrees with the Landsat-7 Enhanced Thematic Mapper Plus and the Envisat MEdium-Resolution Imaging Spectrometer calibration. The geometrical accuracy of PRISM and AVNIR-2 products improved significantly and remains under control. The PRISM modulation transfer function is monitored for improved characterization. ?? 2006 IEEE.

Saunier, S.; Goryl, P.; Chander, G.; Santer, R.; Bouvet, M.; Collet, B.; Mambimba, A.; Kocaman, Aksakal S.

2010-01-01

405

Assessment of the Short-Term Radiometric Stability between Terra MODIS and Landsat 7 ETM+ Sensors  

NASA Technical Reports Server (NTRS)

The Landsat 7 (L7) Enhanced Thematic Mapper (ETM+) sensor was launched on April 15th, 1999 and has been in operation for over nine years. It has six reflective solar spectral bands located in the visible and shortwave infrared part of the electromagnetic spectrum (0.5 - 2.5 micron) at a spatial resolution of 30 m. The on-board calibrators are used to monitor the on-orbit sensor system changes. The ETM+ performs solar calibrations using on-board Full Aperture Solar Calibrator (FASC) and the Partial Aperture Solar Calibrator (PASC). The Internal Calibrator Lamp (IC) lamps, a blackbody and shutter optics constitute the on-orbit calibration mechanism for ETM+. On 31 May 2003, a malfunction of the scan-line corrector (SLC) mirror assembly resulted in the loss of approximately 22% of the normal scene area. The missing data affects most of the image with scan gaps varying in width from one pixel or less near the centre of the image to 14 pixels along the east and west edges of the image, creating a wedge-shaped pattern. However, the SLC failure has no impacts on the radiometric performance of the valid pixels. On December 18, 1999, the Moderate Resolution Imaging Spectroradiometer (MODIS) Proto-Flight Model (PFM) was launched on-board the NASA's EOS Terra spacecraft. Terra MODIS has 36 spectral bands with wavelengths ranging from 0.41 to 14.5 micron and collects data over a wide field of view angle (+/-55 deg) at three nadir spatial resolutions of 250 m, 500 in 1 km for bands 1 to 2, 3 to 7, and 8 to 36, respectively. It has 20 reflective solar bands (RSB) with spectral wavelengths from 0.41 to 2.1 micron. The RSB radiometric calibration is performed by using on-board solar diffuser (SD), solar diffuser stability monitor (SDSM), space-view (SV), and spectro-radiometric calibration assembly (SRCA). Through the SV port, periodic lunar observations are used to track radiometric response changes at different angles of incidence (AOI) of the scan mirror. As a part of the AM Constellation satellites, Terra MODIS flies approximately 30 minutes behind L7 ETM+ in the same orbit. The orbit of L7 is repetitive, circular, sunsynchronous, and near polar at a nominal altitude of 705 km (438 miles) at the Equator. The spacecraft crosses the Equator from north to south on a descending node between 10:00 AM and 10:15 AM. Circling the Earth at 7.5 km/sec, each orbit takes nearly 99 minutes. The spacecraft completes just over 14 orbits per day, covering the entire Earth between 81 degrees north and south latitude every 16 days. The longest continuous imaging swath that L7 sensor can collect is for a 14-minute subinterval contact period which is equivalent to 35 full WRS-2 scenes. On the other hand, Terra can provide the entire corresponding orbit with wider swath at any given ETM+ collection without contact time limitation. There are six spectral matching band pairs between MODIS (bands 3, 4, 1, 2, 6, 7) and ETM+ (bands 1, 2, 3, 4, 5, 7) sensor. MODIS has narrower spectral responses than ETM+ in all the bands. A short-term radiometric stability was evaluated using continuous ETM+ scenes within the contact period and the corresponding half orbit MODIS scenes. The near simultaneous earth observations (SNO) were limited by the smaller swath size of ETM+ (187 km) as compared to MODIS (2330 km). Two sets of continuous granules for MODIS and ETM+ were selected and mosaiced based on pixel geolocation information for non cloudy pixels over the North American continent. The Top-of- Atmosphere (TOA) reflectances were computed for the spectrally matching bands between ETM+ and MODIS over the regions of interest (ROI). The matching pixel pairs were aggregated from a finer to a coarser pixel resolution and the TOA reflectance values covering a wide dynamic range of the sensors were compared and analyzed. Considering the uncertainties of the absolute calibration of the both sensors, radiometric stability was verified for the band pairs. The Railroad Valley Playa, Nada (RVPN) was included in the path of this continuous orbit, which served as a verification poin

Choi, Taeyoung; Xiong, Xiaxiong; Chander, G.; Angal, Amit

2009-01-01

406

Spring 2014-Timeline Dates-Coop & Internships important dates to remember Spring 2014-Key Academic dates  

E-print Network

Spring 2014-Timeline Dates-Coop & Internships important dates to remember Spring 2014- Key Academic Internships December 13, 2013 Last day to turn in forms into the International Center to guarantee January 13, 2014 start date December 21, 2013 The last date to work the Fall Co-op & Internship (Work

Heller, Barbara

407

Luminescence techniques: instrumentation and methods  

Microsoft Academic Search

This paper describes techniques, instruments and methods used in luminescence dating and environmental dosimetry in many laboratories around the world. These techniques are based on two phenomena thermally stimulated luminescence and optically stimulated luminescence. The most commonly used luminescence stimulation and detection techniques are reviewed and information is given on recent developments in instrument design and on the state

Lars Btter-Jensen

1997-01-01

408

Change detection in the amazon rainforest with radiometric rotation technique RCEN multi-spectral case study: Guarayos - Bolivia  

Microsoft Academic Search

A working group of three institutions was set up to develop this study: University of Applied Sciences Eberswalde (Germany), National Institute for Space Research (INPE, Brazil) and National Institute for Amazon Research (INPA, Brazil). The main task is to apply in the Guarayos region (Bolivia), the multi- temporal change detection algorithm \\

H. Ferrufino Ugarte; T. Zawila-Niedzwiecki; J. R. Santos; F. D. Maldonado

2007-01-01

409

Dating and relationship issues  

Microsoft Academic Search

ConclusionsThe subject of dating and relationships for women with disabilities is one of those areas for which we have many more questions\\u000a than answers, more suggested tendencies than demonstrated patterns of variables. If research pursuits reflect social values,\\u000a it makes sense that a society that has long ignored or disdained the gender role of women with disabilities has invested little

Carol J. Gill

1996-01-01

410

Reconstructing level changes and assessing evidence for tectonic and glacial-rebound induced tilting of the Lake Wakatipu basin, New Zealand using novel techniques for correlating and dating paleoshorelines  

NASA Astrophysics Data System (ADS)

Glacial-rebound signals have not previously been identified or isolated from tectonic processes in the New Zealand landscape. This contrasts with other parts of the world where glacial-unloading has caused tens to hundreds of meters of uplift and increased fault activity. The aim of this research was to quantify the magnitude and timing of post-glacial lake-level changes and deformation of the Lake Wakatipu basin, New Zealand. Abandoned shorelines up to 43 m above the modern water-level had previously been suggested to be tilted. Accurate measurement of the magnitude and timing of tilting would provide a unique attempt to extract a glacial-rebound signal from the tectonically-overprinted New Zealand landscape. Paleo-shoreline profiles were surveyed along the lake using GPS and existing air-borne LiDAR datasets. The shoreline profiles were correlated based on elevation and numerically cross-correlated to assess potential progressive offset. The results reveal negligible elevation differences, in conflict with previous suggestions of shoreline tilting. The timing of lake lowering was assessed with Schmidt hammer exposure-age and optically stimulated luminescence (OSL) dating of a flight of alluvial terraces directly correlated with the shorelines. The ages suggest formation of the lake by ~17.1 +/- 2.6 ka, which is assumed to be the approximate age for initial formation of the highest and most prominent preserved shoreline. Abandonment of this high-stand shoreline is thought to have commenced at ~12 ka when lake drainage switched to a new outlet, and was followed by gradual lowering (of about 20 m in 8-10 kyr). Lowering accelerated at about 2 ka, rapidly achieving 26-29 m of lowering before then reversing by 3-6 m to attain the present-day level. Glacial-rebound induced uplift or fault activity in the last 18 kyr has not been recorded by paleo-shorelines of Lake Wakatipu. We suggest that a glacial-isostatic signal is not present in the data because either glacial rebound occurred very quickly after ice retreat, or that any uplift was uniformly distributed over the length of the lake. These results invite investigation of other glaciated areas of New Zealand to explore whether this pattern is spatially and temporally consistent.

McColl, S. T.; Stahl, T. A.; Cook, S.

2013-12-01

411

Date attachable offline electronic cash scheme.  

PubMed

Electronic cash (e-cash) is definitely one of the most popular research topics in the e-commerce field. It is very important that e-cash be able to hold the anonymity and accuracy in order to preserve the privacy and rights of customers. There are two types of e-cash in general, which are online e-cash and offline e-cash. Both systems have their own pros and cons and they can be used to construct various applications. In this paper, we pioneer to propose a provably secure and efficient offline e-cash scheme with date attachability based on the blind signature technique, where expiration date and deposit date can be embedded in an e-cash simultaneously. With the help of expiration date, the bank can manage the huge database much more easily against unlimited growth, and the deposit date cannot be forged so that users are able to calculate the amount of interests they can receive in the future correctly. Furthermore, we offer security analysis and formal proofs for all essential properties of offline e-cash, which are anonymity control, unforgeability, conditional-traceability, and no-swindling. PMID:24982931

Fan, Chun-I; Sun, Wei-Zhe; Hau, Hoi-Tung

2014-01-01

412

Date Attachable Offline Electronic Cash Scheme  

PubMed Central

Electronic cash (e-cash) is definitely one of the most popular research topics in the e-commerce field. It is very important that e-cash be able to hold the anonymity and accuracy in order to preserve the privacy and rights of customers. There are two types of e-cash in general, which are online e-cash and offline e-cash. Both systems have their own pros and cons and they can be used to construct various applications. In this paper, we pioneer to propose a provably secure and efficient offline e-cash scheme with date attachability based on the blind signature technique, where expiration date and deposit date can be embedded in an e-cash simultaneously. With the help of expiration date, the bank can manage the huge database much more easily against unlimited growth, and the deposit date cannot be forged so that users are able to calculate the amount of interests they can receive in the future correctly. Furthermore, we offer security analysis and formal proofs for all essential properties of offline e-cash, which are anonymity control, unforgeability, conditional-traceability, and no-swindling. PMID:24982931

Sun, Wei-Zhe; Hau, Hoi-Tung

2014-01-01

413

The 190Pt-186Os Decay System Applied to Dating Platinum-Group Element Mineralization in Layered Intrusions, Ophiolites and Detrital Deposits  

NASA Astrophysics Data System (ADS)

Discrete platinum-group minerals (PGM) occur as accessory phases in mafic-ultamafic intrusions and ophiolitic chromitites, as well as numerous detrital deposits globally. The 190Pt-186Os decay system, measured by laser ablation MC-ICPMS (LA-MC-ICPMS) provides a useful geochronometric tool for direct dating of PGM. Here we present two examples that verify the accuracy of the technique in geologically well constrained situations and demonstrate the potential for using the 190Pt-186Os PGM method to accurately date layered mafic intrusions, ophiolitic chromitites and detrital PGM deposits. Fifty PGM grains from three different horizons within the Bushveld complex yield a Pt-Os isochron age of 2012 47 Ma (2?, MSWD = 1.19, 186Os/188Osi = 0.119818 0.000006). This is consistent with the published U-Pb zircon age of 2054 Ma (Scoates and Friedman, 2008). The younger PGM isochron age is not likely to be a function of difference in blocking temperatures in the different systems. Pt-Os model ages are possible in high pt grains because initial 186Os/188Os can be well constrained. Using this approach we obtained Pt-Os model ages of 2113 106 Ma and 2042 102 Ma for a Bushveld Pt-Fe alloy and sperrylite respectively. Detrital PGM derived from the Meratus ophiolite, southeast Borneo yield a 190Pt-186Os isochron age of 202.5 Ma 8.3 Ma (2?, n = 260, MSWD = 0.90, 186Os/188Osi = 0.119830 0.000003), consistent with radiometric and biostratigraphic age constraints (Wakita et al., 1998). We interpret this as the age of formation of the PGM grains in during chromitite genesis in the lower oceanic lithosphere. Our combined data demonstrate the utility of the LA-MC-ICPMS method as a tool for accurate Pt-Os dating of detrital PGM as well as their igneous parent bodies. We can constrain Pt/Os fractionation at the ablation site as being < 2.5%, while within-grain heterogeneity is ultimately one of the strongest controls on isochron and single-grain ages given the partial sampling represented by laser ablation. Scoates, J.S. and Friedman, R.M. 2008. Precise age of the platiniferous Merensky reef, Bushveld Complex, South Africa, by the U-Pb zircon chemical abrasion ID-TIMS technique; Economic Geology 103, p. 465-471. Wakita, K., Miyazaki, K., Zulkarnain, I., Sopaheluwakan, J. and Sanyoto, P. 1998. Tectonic implications of new age data for the Meratus complex of south Kalimantan, Indonesia; Island Arc 7, p. 202-222.

Coggon, J. A.; Nowell, G.; Pearson, G.; Oberthr, T.; Lorand, J.; Melcher, F.; Parman, S. W.

2010-12-01

414

Employee Title Date Supervisor Dept  

E-print Network

's annual HIPAA training? Has the employee completed the University's annual safety training? Please provide the date of supervisor's last performance review training. Employee's SignaturePage 1 Employee Title Date Supervisor Dept Director Performance Review Core Values Please provide

Veiga, Pedro Manuel Barbosa

415

LAI estimation in a Mediterranean grassland by in situ radiometric measurements and MODIS satellite data  

NASA Astrophysics Data System (ADS)

Leaf Area Index (LAI) is one of a key variables in studying and understanding biogeochemical cycle mechanisms and ecosystem functionalities and, then, one of a main inputs for ecological modeling. Leaf area surface is related to the main interactions between leaves and the atmosphere as water interception, radiation extinction, energy, mass and gas exchange. Therefore LAI reduction, consequently the loss of productivity, is expression of any physiological and biochemical change of plant status due for example to summer water stress in Mediterranean areas. A good knowledge of seasonal trend and spatial variability of LAI can helps not only modelers but also local farmer to manage grasslands in a sustainable way (grazing, harvesting). In situ LAI measurements are often limited to relatively small areas whit a small number of samplings that can be sporadic, destructive and time-consuming. Nowadays an interesting alternative to estimate LAI is provided by a large variety of radiometric sensors (ground, airborne and satellite based) whit several spatial, temporal and spectral resolutions. However, few studies shown the effect of different radiometers set-up on VIs-LAI relationships that are also differently sensible to different ranges of LAI, management and to which method is used for LAI measurements. In this work, we analyzed the relations between several spectral vegetation indexes (VIs) and LAI for the Mediterranean grassland of Amplero, in the Abruzzo Region, Italy. In situ measurements were carried out in 2005 and 2006. Contemporaneously to destructive LAI measurements, radiometric measurements over the grass herbage were made by two different radiometric sensors: by hyperspectral Hand Held ASD spettroradiometer (HYS) field samplings and by broad band measurements (BNR) of incoming and outgoing global (shortwave) solar radiation components and of incident and reflected photosintetically active radiation (PAR). In addition we included in this analysis VIs calculated from MODIS Surface Reflectance (MOD-09) bands and MODIS Vegetation Indexes (MOD-13) product. Among all calculated spectral indexes, NPVI (Normalized Parabolic Vegetation Index), a new index that we proposed, showed best fit with LAI for HYS (R2 = 0.81), BNR (R2 = 0.79) and MOD-13 (R2 = 0.63) while MOD-09 correlates better with NDVI (R2 = 0.65). Moreover LAI-NPVI relationship seams not to be affected by saturation at LAI values higher than 1.5 m2 m-2 as it happens for other indexes as hyperspectral NDVI. LAI shows also a significant exponential relation with GPP (Gross Primary Production)(R2 = 0.69) saturating for LAI values higher than 1 m2 m-2. Moreover several studied vegetation indexes appear to correlate whit GPP offering thus the possibility to predict gross productivity both continuously by BNR radiometer and over a large area by MOD-09 and MOD-13 data. Finally, up-scaling the best LAI-VI relations we created LAI maps that can be helpful to local farmers to understand yield productivity and to modelers to assimilate in their models indirect estimation of leaf area index.

Balzarolo, M.; Arriga, N.; Papale, D.

2009-04-01

416

Date a Rock  

NSDL National Science Digital Library

This lesson shows students that age-dating rocks involves counting atoms and comparing the counts. Students use simulated rock samples, which show a highly magnified selection of 128 atoms, each sample with a different proportion of the atoms of two different elements: a parent radioisotope, and its daughter product. By counting the parent radioactive atoms and knowing the half-life of those atoms, students can figure the number of half-lives since the sample solidified, and therefore the age of the sample.

Karen Kalumuck

417

A method of relative radiometric correction for linear push-broom CCD Image without calibration device onboard  

NASA Astrophysics Data System (ADS)

The obvious vertical strip and chromatic aberration exist in the raw images obtained from the linear push-broom CCD, due to the different response among CCD detectors, the odd/even effect raised in signal transfer and the inconsistency of electronic link outside CCD array. In this paper, one relative radiometric correction method based on dark target image to calculate the bias coefficient and stable light target image to calculate the gain coefficient is discussed, taking the Beijing-1 small satellite panchromatic image as an example. This method is independent of the statistic characteristics of the corrected image, not only can remove the strip noise and the eliminate chromatic aberration, but also can make the color balance of the image, and is suitable for the relative radiometric calibration of linear push-broom CCD remote sensing image without calibration device onboard.

Yan, Ming; Wang, Zhiyong; He, Shaoshuai; Wu, Fei; Yu, Bingyang

2010-09-01

418

Review of Terra MODIS thermal emissive band L1B radiometric performance  

NASA Astrophysics Data System (ADS)

The MODerate-resolution Imaging Spectroradiometer (MODIS) on NASA's Earth Observing System Terra satellite, launched into orbit on 18 December 1999, will have a "first light" 15th anniversary on 24 February 2015. For nearly 15 years the MODIS instrument has provided radiances in all spectral bands. Though some detectors have fallen below SNR thresholds, the vast majority of spectral bands continue to provide high quality L1B measurements for use in L2 science algorithms supporting global climate research. Radiometric accuracy of the Terra MODIS thermal emissive bands (TEBs) in the C6 L1B product has been assessed using various approaches over the nearly 15 year Terra MODIS data record, including comparisons with instruments on the ground, in aircraft under-flights, and on other satellites. All of these approaches contribute to the understanding of the Terra MODIS radiometric L1B performance. Early in the lifetime of Terra, ground-based measurements and NASA ER-2 aircraft under-flights revealed that TEBs in the infrared window ("window" bands) are well calibrated and performing within accuracy specifications. The ER-2 under-flights also suggested that many atmospheric bands may be performing outside of specification, especially LWIR CO2 sensitive bands that are subject to optical crosstalk, although analysis uncertainties are larger for atmospheric bands. Beginning in 2007, MetOp-A IASI observations were used to evaluate Terra MODIS TEB performance through Simultaneous Nadir Overpass (SNO) comparisons. These inter-satellite comparisons largely affirm the early aircraft and ground-based evaluations, showing that all Terra MODIS window bands have small biases, minimal trending, and minor detector and mirror side striping over the 2007-2013 timeframe. Most atmospheric bands are performing satisfactorily near to specification; however, biases, striping and trending are large and significantly out of specification in the water vapor sensitive band 27 and ozone sensitive band 30 while the CO2 sensitive band 36 bias significantly exceeds specification. The investigation has found that an effective spectral shift significantly reduces biases and scene temperature dependence (but not trends) in most atmospheric bands, bringing them closer to, if not within, specification.

Moeller, Chris; Menzel, W. P.; Quinn, Greg

2014-09-01

419

On-orbit radiometric validation and field-of-view calibration of spaceborne microwave sounding instruments  

NASA Astrophysics Data System (ADS)

Two calibration/validation efforts planned for current and future spaceborne microwave sounding instruments will be presented. First, the NPOESS Aircraft Sounder Testbed-Microwave (NAST-M) airborne sensor is used to directly validate the microwave radiometers (AMSU and MHS) on several operational satellites. Comparison results for underflights of the Aqua, NOAA, and MetOp-A satellites will be shown. Second, a potential approach will be presented for on-orbit field-of-view (FOV) calibration of the Advanced Technology Microwave Sounder (ATMS). A variety of proposed spacecraft maneuvers that could facilitate the characterization of the radiometric boresight of all 22 ATMS channels will be discussed. Radiance observations from the NAST-M airborne sensor can be used to directly validate the radiometric performance of spaceborne sensors. NAST-M includes a total of four spectrometers, with three operating near the oxygen lines at 50-57, 118.75, and 424.76 GHz, and a fourth spectrometer centered on the water vapor absorption line at 183.31 GHz. All four feedhorns are co-located, have 3-dB (full-width at half-maximum) beamwidths of 7.5 (translating to 2.5-km nominal pixel diameter at nadir incidence), and are directed at a single mirror that scans cross-track beneath the aircraft with a nominal swath width of 100 km. We will present results for two recent validation efforts: 1) the Pacific THORpex (THe Observing-system Research and predictability experiment) Observing System Test (PTOST 2003, Honolulu, HI) and 2) the Joint Airborne IASI Validation Experiment (JAIVEx 2007, Houston, TX). Radiance differences between the NAST-M sensor and the Advanced Microwave Sounding Unit (AMSU) and the Microwave Humidity Sensor (MHS) were found to be less than 1K for most channels. Comparison results for ocean underflights of the Aqua, NOAA, and MetOp-A satellites are shown. We also present an approach for on-orbit FOV calibration of the ATMS satellite instrument using vicarious calibration sources with high spatial frequency content (the Earths limb, for example). The antenna beam is slowly swept across the target of interest and a constrained deconvolution approach is used to recover antenna pattern anomalies. Various proposed spacecraft maneuvers will be considered, with the intent to illustrate how each maneuver will help to identify and characterize possible FOV artifacts. Radiative transfer simulations that quantitatively assess the benefit of each satellite maneuver will also be presented.

Blackwell, William J.; Bickmeier, Laura J.; Jairam, Laura G.; Leslie, R. Vincent

2008-12-01

420

Orbit Determination and Gravity Field Estimation of the Dawn spacecraft at Vesta Using Radiometric and Image Constraints with GEODYN Software  

NASA Astrophysics Data System (ADS)

The Dawn spacecraft orbited the protoplanet Vesta from May 3, 2011 to July 25, 2012. Precise orbit determination was critical for the geophysical investigation, as well as the definition of the Vesta-fixed reference frame and the subsequent registration of datasets to the surface. GEODYN, the orbit determination and geodetic parameter estimation software of NASA Goddard Spaceflight Center, was used to compute the orbit of the Dawn spacecraft and estimate the gravity field of Vesta. GEODYN utilizes radiometric Doppler and range measurements, and was modified to process image data from Dawn's cameras. X-band radiometric measurements were acquired by the NASA Deep Space Network (DSN). The addition of the capability to process image constraints decreases position uncertainty in the along- and cross-orbit track directions because of their geometric strengths compared with radiometric measurements. This capability becomes critical for planetary missions such as Dawn due to the weak gravity environment, where non-conservative forces affect the orbit more than typical of orbits at larger planetary bodies. Radiometric measurements were fit to less than 0.1 mm/s and 5 m for Doppler and range during the Survey orbit phase (compared with measurement noise RMS of about 0.05 mm/s and 2 m for Doppler and range). Image constraint RMS was fit to less than 100 m (resolution is 5 - 150 m/pixel, depending on the spacecraft altitude). Orbits computed using GEODYN were used to estimate a 20th degree and order gravity field of Vesta. The quality of the orbit determination and estimated gravity field with and without image constraints was assessed through comparison with the spacecraft trajectory and gravity model provided by the Dawn Science Team.

Centinello, F. J.; Zuber, M. T.; Mazarico, E.

2013-12-01

421

A definitive calibration record for the Landsat-5 thematic mapper anchored to the Landsat-7 radiometric scale  

USGS Publications Warehouse

A coordinated effort on the part of several agencies has led to the specification of a definitive radiometric calibration record for the Landsat-5 thematic mapper (TM) for its lifetime since launch in 1984. The time-dependent calibration record for Landsat-5 TM has been placed on the same radiometric scale as the Landsat-7 enhanced thematic mapper plus (ETM+). It has been implemented in the National Landsat Archive Production Systems (NLAPS) in use in North America. This paper documents the results of this collaborative effort and the specifications for the related calibration processing algorithms. The specifications include (i) anchoring of the Landsat-5 TM calibration record to the Landsat-7 ETM+ absolute radiometric calibration, (ii) new time-dependent calibration processing equations and procedures applicable to raw Landsat-5 TM data, and (iii) algorithms for recalibration computations applicable to some of the existing processed datasets in the North American context. The cross-calibration between Landsat-5 TM and Landsat-7 ETM+ was achieved using image pairs from the tandem-orbit configuration period that was programmed early in the Laridsat-7 mission. The time-dependent calibration for Landsat-5 TM is based on a detailed trend analysis of data from the on-board internal calibrator. The new lifetime radiometric calibration record for Landsat-5 will overcome problems with earlier product generation owing to inadequate maintenance and documentation of the calibration over time and will facilitate the quantitative examination of a continuous, near-global dataset at 30-m scale that spans almost two decades.

Teillet, P.M.; Helder, D.L.; Ruggles, T.A.; Landry, R.; Ahern, F.J.; Higgs, N.J.; Barsi, J.; Chander, G.; Markham, B.L.; Barker, J.L.; Thome, K.J.; Schott, J.R.; Palluconi, F.D.

2004-01-01

422

Color image processing for date quality evaluation  

NASA Astrophysics Data System (ADS)

Many agricultural non-contact visual inspection applications use color image