Estimation of surface soil moisture and roughness from multi-angular ASAR imagery in the Watershed Allied Telemetry Experimental Research (WATER)

NASA Astrophysics Data System (ADS)

Wang, S. G.; Li, X.; Han, X. J.; Jin, R.

2011-05-01

Radar remote sensing has demonstrated its applicability to the retrieval of basin-scale soil moisture. The mechanism of radar backscattering from soils is complicated and strongly influenced by surface roughness. Additionally, retrieval of soil moisture using AIEM (advanced integrated equation model)-like models is a classic example of underdetermined problem due to a lack of credible known soil roughness distributions at a regional scale. Characterization of this roughness is therefore crucial for an accurate derivation of soil moisture based on backscattering models. This study aims to simultaneously obtain surface roughness parameters (standard deviation of surface height σ and correlation length cl) along with soil moisture from multi-angular ASAR images by using a two-step retrieval scheme based on the AIEM. The method firstly used a semi-empirical relationship that relates the roughness slope, Zs (Zs = σ2/cl) and the difference in backscattering coefficient (Δσ) from two ASAR images acquired with different incidence angles. Meanwhile, by using an experimental statistical relationship between σ and cl, both these parameters can be estimated. Then, the deduced roughness parameters were used for the retrieval of soil moisture in association with the AIEM. An evaluation of the proposed method was performed in an experimental area in the middle stream of the Heihe River Basin, where the Watershed Allied Telemetry Experimental Research (WATER) was taken place. It is demonstrated that the proposed method is feasible to achieve reliable estimation of soil water content. The key challenge is the presence of vegetation cover, which significantly impacts the estimates of surface roughness and soil moisture.

A new method to calibrate Lagrangian model with ASAR images for oil slick trajectory.

PubMed

Tian, Siyu; Huang, Xiaoxia; Li, Hongga

2017-03-15

Since Lagrangian model coefficients vary with different conditions, it is necessary to calibrate the model to obtain optimal coefficient combination for special oil spill accident. This paper focuses on proposing a new method to calibrate Lagrangian model with time series of Envisat ASAR images. Oil slicks extracted from time series images form a detected trajectory of special oil slick. Lagrangian model is calibrated by minimizing the difference between simulated trajectory and detected trajectory. mean center position distance difference (MCPD) and rotation difference (RD) of Oil slicks' or particles' standard deviational ellipses (SDEs) are calculated as two evaluations. The two parameters are taken to evaluate the performance of Lagrangian transport model with different coefficient combinations. This method is applied to Penglai 19-3 oil spill accident. The simulation result with calibrated model agrees well with related satellite observations. It is suggested the new method is effective to calibrate Lagrangian model. Copyright © 2016 Elsevier Ltd. All rights reserved.

Archaeological prospection of cultural heritage in the Nasca region, Peru, by coupling ENVISAT ASAR 2003-2007 and optical-VHR time series

NASA Astrophysics Data System (ADS)

Tapete, Deodato; Cigna, Francesca; Masini, Nicola; Lasaponara, Rosa

2013-04-01

We present the radar-interpretation of a 4year-long stack of ENVISAT ASAR imagery, integrated and cross-validated with optical-Very High Resolution (VHR) data from QuickBird2, GeoEye and WorldView-1/2, and carried out over the cultural and natural heritage of the Nasca region in Southern Peru. This research is performed thanks to the provision of free-access archive SAR data from the European Space Agency (ESA) through the Cat-1 project 11073, and is supporting the activities of the Italian mission of heritage Conservation and Archaeogeophysics (ITACA), which directly involve researchers from the Institute for Archaeological and Monumental Heritage (IBAM) and the Institute of Methodologies for Environmental Analysis (IMAA), National Research Council (CNR) of Italy. The whole ENVISAT ASAR imagery archive, consisting of 8 ASAR IS2 scenes acquired in descending mode between 04/02/2003 and 15/11/2005 and 5 images in ascending mode between 24/07/2005 and 11/11/2007, was processed by exploiting and analyzing SAR amplitude information and change detection to reconstruct the temporal evolution of radar signatures and related backscattering coefficient (σ0) of the targets on the ground in the monitoring period 2003-2007. The selection of a SAR amplitude-based change detection method was made to explore its actual potentials for archaeological prospection and monitoring purposes, complementarily to approaches of interferometric coherence used by other scholars over the same region of investigation. The novel contribution to heritage studies over Nasca includes remote sensing insights into the renowned UNESCO-WHL Nasca geoglyphs and archaeological mounds of the adobe Ceremonial Centre of Cahuachi, as well as the ancient puquios within the Rio Grande drainage basin. The latter are prehispanic underground aqueducts, and nowadays represent not only important cultural features to preserve, but also a potential driver to revitalize waterways and oases in such a dry region

Analysis of ASAR Wide Swath Mode time series for the retrieval of soil moisture in mountainous areas

NASA Astrophysics Data System (ADS)

Greifeneder, Felix; Notarnicola, Claudia; Cuozzo, Giovanni; Spindler, Nadine; Bertoldi, Giacomo; Della Chiesa, Stefano; Niedrist, Georg; Stamenkovic, Jelena; Wagner, Wolgang

2014-05-01

Soil moisture is a key element in the global cycles of water, energy, and carbon. Knowledge on the spatial and temporal distribution of the soil moisture content (SMC) is therefore essential for a number of hydrological applications as well as earth sciences like meteorology or climatology (Heathman et al., 2003). In the last few years there has been an increasing interest towards the estimation of SMC at local scales using active microwave sensors (Barret et al., 2009). Compared to passive microwave sensors, SAR offers the potential to provide data at high spatial resolution (modern sensors can acquire images with up to approximately 1 m), which is particularly important in mountainous areas. So far, these areas have been considered only marginally in research and only pioneer studies can be found in the literature (Brocca et al., 2012; Bertoldi et al. 2013). In this work we analyzed the temporal and spatial dynamics of the surface SMC (0 - 5 cm depth) on the basis of ground data collected by fixed meteorological stations located in the emerging Long-Term Ecological Research (LTER) site Mazia Valley (Province of Bolzano, South Tyrol, Italy), SAR data from ENVISATs ASAR sensor, wide swath (WS) mode (acquired between 2005 and 2012), and SMC estimates from the hydrological model GEOtop (Endrizzi et al., 2013). The SMC retrieval process was based on the support vector regression (SVR) method introduced by Pasolli et al. (2011). The training of the algorithm was based on data acquired in 2010. Furthermore, the SAR backscatter and derived SMC have been compared with time-series derived from the distributed hydrological model GEOtop. The differences in terms of temporal and spatial dynamic have been analyzed. The main goal of this work is to evaluate the spatial and temporal patterns of SAR derived SMC at field scale and to correlate them with ground information. This is a preparatory study to establish a methodology for the retrieval of SMC with high spatial and

Impact of Soil Moisture Dynamics on ASAR Observed Backscatters and its Spatial Variability over the Upstream of the Heihe River Basin, China

NASA Astrophysics Data System (ADS)

Wang, Shuguo

2013-01-01

The so called change detection method is a promising way to acquire soil moisture (SM) dynamics dependent on time series of radar backscatter (σ0) observations. The current study is a preceded step for using this method to carry out SM inversion at basin scale, in order to investigate the applicability of the change detection method in the Heihe River Basin, and to inspect the sensitivity of SAR signals to soil moisture variations. At the meantime, a prior knowledge of SM dynamics and land heterogeneities that may contribute to backscatter observations can be obtained. The impact of land surface states on spatial and temporal σ0 variability measured by ASAR has been evaluated in the upstream of the Heihe River Basin, which was one of the foci experimental areas (FEAs) in Watershed Allied Telemetry Experimental Research (WATER). Based on the in situ measurements provided by an automatic meteorological station (AMS) established at the A’rou site and time series of ASAR observations focused on a 1 km2 area, the relationships between the temporal dynamics of σ0 with in situ SM variations, and land heterogeneities of the study area according to the characteristics of spatial variability of σ0, were identified. The in situ measurements of soil moisture and temperature show a very clear seasonal freeze/thaw cycle in the study site. The temporal σ0 evolvement is basically coherent with ground measurements.

Reduction of atmospheric disturbances in PSInSAR measure technique based on ENVISAT ASAR data for Erta Ale Ridge

NASA Astrophysics Data System (ADS)

Kopeć, Anna

2018-01-01

The interferometric synthetic aperture radar (InSAR) is becoming more and more popular to investigate surface deformation, associated with volcanism, earthquakes, landslides, and post-mining surface subsidence. The measuring accuracy depends on many factors: surface, time and geometric decorrelation, orbit errors, however the largest challenges are the tropospheric delays. The spatial and temporal variations in temperature, pressure, and relative humidity are responsible for tropospheric delays. So far, many methods have been developed, but researchers are still searching for the one, that will allow to correct interferograms consistently in different regions and times. The article focuses on examining the methods based on empirical phase-based methods, spectrometer measurements and weather model. These methods were applied to the ENVISAT ASAR data for the Erta Ale Ridge in the Afar Depression, East Africa

ASAR images a diverse set of deformation patterns at Kilauea volcano, Hawai'i

USGS Publications Warehouse

Poland, Michael P.

2007-01-01

Since 2003, 27 independent look angles have been acquired by ENVISAT’s Advanced Synthetic Aperture Radar (ASAR) instrument over the island of Hawai`i, allowing for the formation of thousands of interferograms showing deformation of the ground surface. On Kīlauea volcano, a transition from minor to broad-scale summit inflation was observed by interferograms that span 2003 to 2006. In addition, radar interferometry (InSAR) observations of Kīlauea led to the discovery of several previously unknown areas of localized subsidence in the caldera and along the volcano’s east rift zone. These features are probably caused by the cooling and contraction of accumulated lavas. After November 2005, a surface instability near the point that lava entered the ocean on the south flank of Kīlauea was observed in interferograms. The motion is most likely a result of unbuttressing of a portion of the coast following the collapse of a large lava delta in November 2005. InSAR data can also be used to map lava flow development over time, providing ~30 m spatial resolution maps at approximately monthly intervals. Future applications of InSAR to Kīlauea will probably result in more discoveries and insights, both as the style of volcano deformation changes and as data from new instruments are acquired.

Two scales of inflation at Lastarria-Cordon del Azufre volcanic complex, central Andes, revealed from ASAR-ENVISAT interferometric data

NASA Astrophysics Data System (ADS)

Froger, J.-L.; Remy, D.; Bonvalot, S.; Legrand, D.

2007-03-01

ASAR-ENVISAT Interferometric Synthetic Aperture Radar (InSAR) data collected over the Lastarria-Cordon del Azufre complex (Chile-Argentina) between March 2003 and May 2005 show the persistence of the large wavelength ground inflation revealed by Pritchard and Simons in 2002 from the analysis of ERS InSAR data [Nature 418 (2002) 167-170]. After reducing the tropospheric contribution in the interferograms using a combination of data network adjustment and analysis of MODIS images, we produced an accurate interferometric time series showing a 2 yr long temporal evolution of the ground displacements patterns. Two distinct inflating signals are detected. The main signal covers an elliptical area with a 45 km NNE-SSW major axis and a 37 km minor axis. It is correlated with a regional topographic dome. We estimated its maximum inflation rate to ˜ 2.5 cm yr - 1 . We inverted the InSAR data for a range of source geometries (spherical, prolate ellipsoids, penny-shaped cracks). The inferred source parameters for 2003-2005 period are consistent with an over-pressured reservoir at shallow to intermediate crustal depths (7-15 km), with an average volumetric rate of inflation of about 14 × 10 6 m 3 yr - 1 . In addition to this main signal a new feature highlighted by the ASAR data is short wavelength inflation (6 km wide) at the location of Lastarria volcano on the northern margin of the large wavelength signal. We explain this short wavelength signal by a spherical over-pressured source lying 1000 m below the summit of Lastarria volcano. We estimate the average volumetric rate of inflation during the observation period to be ˜ 35 × 10 3 m 3 yr - 1 . It is remarkable that both volumetric variations for the large and small inflations exhibit the same evolution during the 2003-2005 period, suggesting that both processes could be related. On the basis of the inversion results and of arguments provided by field evidences and a morpho-structural analysis of the Digital Elevation

PALSAR/ALOS Interferometry in the Gulf of Corinth and Patras (Greece) Comparison with ASAR/ Envisat

NASA Astrophysics Data System (ADS)

Elias, Panagiotis; Briole, Pierre; Sykioti, Olga

2008-11-01

In the western part of the Gulf of Corinth (Greece), nineteen PALSAR/ALOS images were acquired, processed and compared thematically with C-band ASAR/ENVISAT data. The rift of Corinth has been long identified as a site of major importance due to its intense geophysical activity. It is one of the world's most rapidly extending continental regions and it has one of the highest seismicity rates in the euro-Mediterranean region. Specifically, around the Gulf of Patras, the deformation field is less well known, and we hope to improve this knowledge by exploiting L-band data. This is also important for acquiring a better understanding of the ground deformation around the city of Patras, which is the third biggest city in Greece. The target area includes the E-W oriented Gulf of Patras, separating the north from the south part of Greece. For this reason, the two parts are examined each part separately in order to exclude the sea in the stage of cross-correlation between master and slave image. Interferograms from the Patras frame used for the detection of ground deformation due to June 8th, 2008 Andravida earththquake, showed no co-seismic and post-seismic signal. Finally, we conclude that L-band inteferograms present better coherence compared with C-band interferograms in this area.

Temporal Stability of Soil Moisture and Radar Backscatter Observed by the Advanced Synthetic Aperture Radar (ASAR)

PubMed Central

Wagner, Wolfgang; Pathe, Carsten; Doubkova, Marcela; Sabel, Daniel; Bartsch, Annett; Hasenauer, Stefan; Blöschl, Günter; Scipal, Klaus; Martínez-Fernández, José; Löw, Alexander

2008-01-01

The high spatio-temporal variability of soil moisture is the result of atmospheric forcing and redistribution processes related to terrain, soil, and vegetation characteristics. Despite this high variability, many field studies have shown that in the temporal domain soil moisture measured at specific locations is correlated to the mean soil moisture content over an area. Since the measurements taken by Synthetic Aperture Radar (SAR) instruments are very sensitive to soil moisture it is hypothesized that the temporally stable soil moisture patterns are reflected in the radar backscatter measurements. To verify this hypothesis 73 Wide Swath (WS) images have been acquired by the ENVISAT Advanced Synthetic Aperture Radar (ASAR) over the REMEDHUS soil moisture network located in the Duero basin, Spain. It is found that a time-invariant linear relationship is well suited for relating local scale (pixel) and regional scale (50 km) backscatter. The observed linear model coefficients can be estimated by considering the scattering properties of the terrain and vegetation and the soil moisture scaling properties. For both linear model coefficients, the relative error between observed and modelled values is less than 5 % and the coefficient of determination (R2) is 86 %. The results are of relevance for interpreting and downscaling coarse resolution soil moisture data retrieved from active (METOP ASCAT) and passive (SMOS, AMSR-E) instruments. PMID:27879759

Land cover in the Guayas Basin using SAR images from low resolution ASAR Global mode to high resolution Sentinel-1 images

NASA Astrophysics Data System (ADS)

Bourrel, Luc; Brodu, Nicolas; Frappart, Frédéric

2016-04-01

Remotely sensed images allow a frequent monitoring of land cover variations at regional and global scale. Recently launched Sentinel-1 satellite offers a global cover of land areas at an unprecedented spatial (20 m) and temporal (6 days at the Equator). We propose here to compare the performances of commonly used supervised classification techniques (i.e., k-nearest neighbors, linear and Gaussian support vector machines, naive Bayes, linear and quadratic discriminant analyzes, adaptative boosting, loggit regression, ridge regression with one-vs-one voting, random forest, extremely randomized trees) for land cover applications in the Guayas Basin, the largest river basin of the Pacific coast of Ecuator (area ~32,000 km²). The reason of this choice is the importance of this region in Ecuatorian economy as its watershed represents 13% of the total area of Ecuador where 40% of the Ecuadorian population lives. It also corresponds to the most productive region of Ecuador for agriculture and aquaculture. Fifty percents of the country shrimp farming production comes from this watershed, and represents with agriculture the largest source of revenue of the country. Similar comparisons are also performed using ENVISAT ASAR images acquired in global mode (1 km of spatial resolution). Accuracy of the results will be achieved using land cover map derived from multi-spectral images.

Subway Subsidence Monitoring and Analysis in Beijing through Envisat-Asar and Terrasar-X DATA

NASA Astrophysics Data System (ADS)

Duan, G.; Gong, H.; Chen, B.; Li, X.

2014-12-01

Subway plays a significant role in public transport in Beijing, China. The safe operation of such underground rail transports are serious threatened by ground subsidence that mainly caused by groundwater over-exploitation. It is necessary to carry out a continuous observation and analysis of the surface deformation along the newly built rails. The paper mainly studied four subways which were built in different periods(see attachment). Envisat-ASAR and Terrasar-X images of the study area were selected to measure the ground deformation. Interferometric Point Target Analysis method was gathered to process the SAR data. The method is developed based on the idea of the Permanent Scatterers SAR Interferometry method which can overcome the decorrelation and atmospheric effect to gain more precise estimation of the ground deformation. The master image can be selected according to the perpendicular, Doppler and temporal baselines to minimize the potential decorrelation. After the registration of all slave images to the master image, the PS candidates would be detected on the basis of the scattering properties of the images. A complex operation of the PSs was conducted to obtain the interferometric phase which was composed of terrain phase, atmospheric phase, deformation phase and noise. A model used for the evaluation of the contribution of each component was built by means of the least squares method. The deformation phase would be the remaining of the interferometric phase minus disturbance terms. Deformation information that came from two different kinds of data was jointly analyzed to reveal the temporal character of the rails before, during and after they were built. The regional LOS(line-of-sight) velocity around a special subway station shows that the rail has suffered from a serious uneven settlement along the rail during the observation period. In addition, time series data revealed the characteristic stages of each PS point. There is a clear accelerating trend of

POLARIZATION OF NEUTRONS BY THE STRIPPING REACTION C$sup 12$(d,n)N$sup 1$$sup 3$ (in French)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Budzanowski, A.; Grotowski, K.; Niewodniczanski, H.

1960-05-01

The polarization of neutrcns emitted from the stripping reaction C/sup 12/(d,n)N/sup 13/ hns been investigated at the reaction angle was / sub lab/ = 15 tained and deuteron energy E/sub d/ = 12.9 Mev. The polarization of neutrons connected with the 3.56 Mev energy level in N/sup 13/ nucleus was found to be --(0.39 combination rat 0.11). Also some general remarks concerning the preliminary results of the polarization of neutrons at the reaction angles 30 tained , 45 tained , and 60 tained are given. (auth)

Interseismic strain accumulation across the Ashkabad fault (NE Iran) from MERIS-corrected ASAR data

NASA Astrophysics Data System (ADS)

Walters, R. J.; Elliott, J. R.; Li, Z.; Parsons, B. E.

2011-12-01

The right-lateral Ashkabad Fault separates deforming NE Iran from the stable Turkmenistan platform to the north, and also facilitates the north-westwards extrusion of the South Caspian block (along with the left-lateral Shahrud fault zone). The fault represents the northernmost boundary of significant deformation of the Arabia-Eurasia collision in NE Iran. The 1948 M 7.3 Ashkabad earthquake, which killed around 110,000 people and was the deadliest earthquake to hit Europe or the Middle East in the 20th Century, also possibly occurred on this fault. However, the slip rate and therefore the seismic hazard that the Ashkabad fault represents are not well known. GPS data in NE Iran are sparse, and there are no direct geological or quaternary rates for the main strand of the fault. We use Envisat ASAR data acquired between 2003 and 2010 to measure interseismic strain accumulation across the fault, and hence estimate the slip rate across it. Due to the proximity of this region to the Caspian Sea and the presence of highly variable weather systems, we use data from Envisat's Medium Resolution Imaging Spectrometer (MERIS) instrument, as well as modelled weather data from the European Centre for Medium-Range Weather Forecasting (ECMWF), to correct interferograms for differences in water vapour and atmospheric pressure. We mitigate the effects of remaining noise by summing the 13 corrected interferograms that cover the fault, effectively creating a 30 year interferogram with improved signal-to-noise ratio, and we empirically correct for orbital errors. Our measurements of rates of displacement are consistent with an interseismic model for the Ashkabad fault where deformation occurs at depth on a narrow shear zone below a layer in which the fault is locked. We invert the data to solve for best fitting model parameters, estimating both the slip rate and the depth to which the fault is locked. Our measurements show that the Ashkabad fault is accumulating strain at a rate of 9 mm

Coastal flood inundation monitoring with Satellite C-band and L-band Synthetic Aperture Radar data

USGS Publications Warehouse

Ramsey, Elijah W.; Rangoonwala, Amina; Bannister, Terri

2013-01-01

Satellite Synthetic Aperture Radar (SAR) was evaluated as a method to operationally monitor the occurrence and distribution of storm- and tidal-related flooding of spatially extensive coastal marshes within the north-central Gulf of Mexico. Maps representing the occurrence of marsh surface inundation were created from available Advanced Land Observation Satellite (ALOS) Phased Array type L-Band SAR (PALSAR) (L-band) (21 scenes with HH polarizations in Wide Beam [100 m]) data and Environmental Satellite (ENVISAT) Advanced SAR (ASAR) (C-band) data (24 scenes with VV and HH polarizations in Wide Swath [150 m]) during 2006-2009 covering 500 km of the Louisiana coastal zone. Mapping was primarily based on a decrease in backscatter between reference and target scenes, and as an extension of previous studies, the flood inundation mapping performance was assessed by the degree of correspondence between inundation mapping and inland water levels. Both PALSAR- and ASAR-based mapping at times were based on suboptimal reference scenes; however, ASAR performance seemed more sensitive to reference-scene quality and other types of scene variability. Related to water depth, PALSAR and ASAR mapping accuracies tended to be lower when water depths were shallow and increased as water levels decreased below or increased above the ground surface, but this pattern was more pronounced with ASAR. Overall, PALSAR-based inundation accuracies averaged 84% (n = 160), while ASAR-based mapping accuracies averaged 62% (n = 245).

PHASE DIAGRAM FOR THE SYSTEM TITANIUM-TIN (in Russian)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kornilov, I.I.; Nartova, T.T.

1960-03-01

Differential thermal analysis, microstructural analyses, and determinations of hardness values and electric resistance were used to construct a diagram of state for the binary system Ti-Sn up to the composition of the compound Ti/sub 3/Sn (from 0 to 25 at.% Sn). Analyses of the thermograms showed that all conversions proceeding with the absorption of heat could be detected on the heating curves. Tin lowers the temperature of conversion of titunium with 5.0 at.% tin first to a minimum at 860 tained C which then increases to 890 tained C at higher tin contents. A peritectoid reaction ( alpha / submore » 2/ were ob ore resistant t + ) takes place with a conversion temperature at 890 tained C. A HF-HNO/sub 3/-glycerin etch showed a single-phase homogeneous structure of an alpha -solid solution with alloys containing up to 9 at.% Q. The amount of a second -phase increases with increasing tin content until a single-phase structure of a -solid solution of the compound Ti/sub 3/Sn is noted with alloys containing 23 to 25 at.% Sn. Alloys containing 8 to 22.5 at.% Sn undergo a peritectoid reaction, at a temperature of 890 tained C as shown by thermal analyses and by microstructural analyses of samples quenched frorn above and below the conversion temperature. A study of the microstructure of quenched alloys showed that the solubility of tin in ore resistant t -titanium increases from 8 at.% Sn at 890 tained C to 10.5 at.% Sn at 1100 tained C. X-ray analyses of annealed samples of alloy showed only the lines of an alpha solid solution for 5, 8, 9 at.% Sn, a -solid solution for 23 at.% Sn (close to the composition Ti/sub 3/Sn), and an alpha and mixed phase for a 15 at.% Sn. Vickers hardness numbers were determined with a diamond pyramid at a loading of 10 kg. The hardness increases smoothly with increasing tin content to a maximum at the saturation solubility of the tin in the alpha - or ore resistant t -solid solution. The hardness decreases smoothly with the appearance of

Three-dimensional slum urban reconstruction in Envisat and Google Earth Egypt

NASA Astrophysics Data System (ADS)

Marghany, M.; Genderen, J. v.

2014-02-01

This study aims to aim to investigate the capability of ENVISAT ASAR satellite and Google Earth data for three-dimensional (3-D) slum urban reconstruction in developed country such as Egypt. The main objective of this work is to utilize 3-D automatic detection algorithm for urban slum in ENVISAT ASAR and Google Erath images were acquired in Cairo, Egypt using Fuzzy B-spline algorithm. The results show that fuzzy algorithm is the best indicator for chaotic urban slum as it can discriminate them from its surrounding environment. The combination of Fuzzy and B-spline then used to reconstruct 3-D of urban slam. The results show that urban slums, road network, and infrastructures are perfectly discriminated. It can therefore be concluded that fuzzy algorithm is an appropriate algorithm for chaotic urban slum automatic detection in ENVSIAT ASAR and Google Earth data.

Rice Crop Monitoring Using Microwave and Optical Remotely Sensed Image Data

NASA Astrophysics Data System (ADS)

Suga, Y.; Konishi, T.; Takeuchi, S.; Kitano, Y.; Ito, S.

Hiroshima Institute of Technology HIT is operating the direct down-links of microwave and optical satellite data in Japan This study focuses on the validation for rice crop monitoring using microwave and optical remotely sensed image data acquired by satellites referring to ground truth data such as height of crop ratio of crop vegetation cover and leaf area index in the test sites of Japan ENVISAT-1 ASAR data has a capability to capture regularly and to monitor during the rice growing cycle by alternating cross polarization mode images However ASAR data is influenced by several parameters such as landcover structure direction and alignment of rice crop fields in the test sites In this study the validation was carried out combined with microwave and optical satellite image data and ground truth data regarding rice crop fields to investigate the above parameters Multi-temporal multi-direction descending and ascending and multi-angle ASAR alternating cross polarization mode images were used to investigate rice crop growing cycle LANDSAT data were used to detect landcover structure direction and alignment of rice crop fields corresponding to the backscatter of ASAR As the result of this study it was indicated that rice crop growth can be precisely monitored using multiple remotely sensed data and ground truth data considering with spatial spectral temporal and radiometric resolutions

An Automated Temperature Controller for the Advanced Hall Effect Experimental Data Acquisition System.

DTIC Science & Technology

1982-03-01

ENTRY: ACCA CONTAINS THE CHARACTER EXIT: ACCA CONTAINS THE CHARACTER DISPLAY TAilLE UPDATKD DISPLAY POINTER INCREMENTED VOLATILE RECISTERS: B...OUTPUTS THE RIC11T HALF-BYTE OF THE HEX NUMBER CON- TAINED IN ACCA TO THE DISPLAY. ENTRY: ACCA CONTAINS THE HEX NUMBER EXIT: ACCA CONTAINS THE HEX...OUTPUTS THE LEFT HALF-BYTE OF THE HEX NUMBER CON- TAINED IN ACCA TO THE DISPLAY. ENTRY: ACCA CONTAINS THE HEX NUMBER EXIT: ACCA CONTAINS THE HEX

Pneumatic Control Device for the Pershing 2 Adaption Kit

DTIC Science & Technology

1979-03-14

forward force to main- tain a pressure seal (this, versus an-I6-to 25 pound maximum reverse .force component due to pressure). In all probability, initial...stem forward force to main- tain a pressure seal (this, versus an 48-to-25-pound maximum " reverse.force, component due-topressue). In-all probability...PII Li L! Ramn Eniern Inc Contrato . 2960635 GAS GENERATOR COMPATIBILITY U TEST REPORT 1.j Requirement s The requirements for the Pershing II, Phase I

[Accuracy improvement of spectral classification of crop using microwave backscatter data].

PubMed

Jia, Kun; Li, Qiang-Zi; Tian, Yi-Chen; Wu, Bing-Fang; Zhang, Fei-Fei; Meng, Ji-Hua

2011-02-01

In the present study, VV polarization microwave backscatter data used for improving accuracies of spectral classification of crop is investigated. Classification accuracy using different classifiers based on the fusion data of HJ satellite multi-spectral and Envisat ASAR VV backscatter data are compared. The results indicate that fusion data can take full advantage of spectral information of HJ multi-spectral data and the structure sensitivity feature of ASAR VV polarization data. The fusion data enlarges the spectral difference among different classifications and improves crop classification accuracy. The classification accuracy using fusion data can be increased by 5 percent compared to the single HJ data. Furthermore, ASAR VV polarization data is sensitive to non-agrarian area of planted field, and VV polarization data joined classification can effectively distinguish the field border. VV polarization data associating with multi-spectral data used in crop classification enlarges the application of satellite data and has the potential of spread in the domain of agriculture.

PHYSICOCHEMICAL INTERACTION OF MANGANESE WITH NIOBIUM (in Russian)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Savitskii, E.M.; Kopetskii, Ch.V.

1960-03-01

Microstructural, x-ray phase, and thermal analyses as well as hardness and microhardness determinations were performed on different manganese alloys containing 2.26, with a small Nb content have a two-phase structure characteristic of a eutectic. With increasing Nb content, an increasing amount of an intermetallic compound is formed. With a 2.98 wt.% Nb alloy interference lines of only alpha -Mn with a lattice parameter a = 8.892 kX in the annealed state or of ore resistant t -Mn with a lattice parameter a = 6.290 kX in the molten state can be detected by x-ray analysis. With 5.64 wt.% Nb, linesmore » of a new phase can be detected whose intensities increase with increasing Nb content. This new phase is an intermetallic compound Mn/sub 2/Nb Laves phase with a structure of the MgZn/sub 2/ type. The lattice parameters of the Mn/sub 2/Nb phase are: a = 4.881 kX, c = 7.953 kX, c/a = 1.629. With increasing niobium content the hardness values fall from 900 to 950 hg/mm/sup 2/ for pure manganese to 650 to 700 kg/mm/sup 2/ for the 29.85 wt.% niobium alloy. The hardness of the intermetallic compound is less than the hardness of the alpha -Mn. Thermal analysis showed that additions of niobium to manganese significantly increased the temperature of the alpha = ore resistant t transition which is shifted from 727 tained C for pure manganese to 800 tained C for the alloys. A ore resistant t transition takes place at 1135 tained C by a peritectic reaction. Fusion of a eutectic mixture of -Mn and Mn/sub 2/ Nb occurs at 1220 tained C. The intermetallic compound MnNb melts at 1500 tained C. A phase diagram for the Mn-Nb system is constructed on the basis of these resuits. (TTT) Iodide-derived titanium (99.97%) and neodymium (99.8%) were fused in an electric arc furnace in a helium atmosphere to prepare nine alloys with a necdymium content of 0 to 10%. Smelted and forged samples were annealed in evacuated quartz ampoules for 25 hours at 1000 tained C and 100 hours at 850 tained C

Evaluation of the predicted error of the soil moisture retrieval from C-band SAR by comparison against modelled soil moisture estimates over Australia

PubMed Central

Doubková, Marcela; Van Dijk, Albert I.J.M.; Sabel, Daniel; Wagner, Wolfgang; Blöschl, Günter

2012-01-01

The Sentinel-1 will carry onboard a C-band radar instrument that will map the European continent once every four days and the global land surface at least once every twelve days with finest 5 × 20 m spatial resolution. The high temporal sampling rate and operational configuration make Sentinel-1 of interest for operational soil moisture monitoring. Currently, updated soil moisture data are made available at 1 km spatial resolution as a demonstration service using Global Mode (GM) measurements from the Advanced Synthetic Aperture Radar (ASAR) onboard ENVISAT. The service demonstrates the potential of the C-band observations to monitor variations in soil moisture. Importantly, a retrieval error estimate is also available; these are needed to assimilate observations into models. The retrieval error is estimated by propagating sensor errors through the retrieval model. In this work, the existing ASAR GM retrieval error product is evaluated using independent top soil moisture estimates produced by the grid-based landscape hydrological model (AWRA-L) developed within the Australian Water Resources Assessment system (AWRA). The ASAR GM retrieval error estimate, an assumed prior AWRA-L error estimate and the variance in the respective datasets were used to spatially predict the root mean square error (RMSE) and the Pearson's correlation coefficient R between the two datasets. These were compared with the RMSE calculated directly from the two datasets. The predicted and computed RMSE showed a very high level of agreement in spatial patterns as well as good quantitative agreement; the RMSE was predicted within accuracy of 4% of saturated soil moisture over 89% of the Australian land mass. Predicted and calculated R maps corresponded within accuracy of 10% over 61% of the continent. The strong correspondence between the predicted and calculated RMSE and R builds confidence in the retrieval error model and derived ASAR GM error estimates. The ASAR GM and Sentinel-1 have

Synergy of ASAR and RADARSAT-2 ultra-fine acquisitions for ground deformation monitoring by means of DInSAR and PSI

NASA Astrophysics Data System (ADS)

Elias, Panagiotis; Briole, Pierre; Sykioti, Olga

2010-05-01

consideration the raised seismisity of the area. The Psathopyrgos fault zone as well as the Rion-Patras transfer fault zone are investigated for any detectable ground deformations that could be indications/precursors or inter-seismic accumulation processes before a main event. The city of Patras are investigated for any detectable ground/buildings deformation due to human interventions or geophysical processes. The potential of Rion-Antirion bridge monitoring for any detectable deformation as well as the surrounding ground on the two edges of it, are also investigated and assessed. The study area presents major difficulties for DInSAR/PSI applications, due to its intense vegetation coverage and high topography presenting various facets, varying high slopes and shadowing effects. Moreover its intense topography in conjunction with its location between Aegean and Ionian seas is leading to high precipitation rates and extend cloud coverage. All these characteristics of the study area contribute to high decorrelation of the interferometric products. For the estimation of the ocuured deformations a series of ASAR/ENVISAT (image swath 2) data are processed by means of PSI and DInSAR techniques, but RADARSAT-2 (ultra-fine beam mode) data are processed only by means of DInSAR technique due to its lack of historical data. The processing will be carried out exploiting commercial and in-house software. The medium and high ground resolution added value products of the acquired data are combined in the thematic level.

Flowable composites for bonding orthodontic retainers.

PubMed

Tabrizi, Sama; Salemis, Elio; Usumez, Serdar

2010-01-01

To test the null hypothesis that there are no statistically significant differences between flowables and an orthodontic adhesive tested in terms of shear bond strength (SBS) and pullout resistance. To test the SBS of Light Bond, FlowTain, Filtek Supreme, and Tetric Flow were applied to the enamel surfaces of 15 teeth. Using matrices for application, each composite material was cured for 40 seconds and subjected to SBS testing. To test pullout resistance, 15 samples were prepared for each composite in which a wire was embedded; then the composite was cured for 40 seconds. Later, the ends of the wire were drawn up and tensile stress was applied until the resin failed. Findings were analyzed using an ANOVA and a Tukey HSD test. The SBS values for Light Bond, FlowTain, Filtek Supreme, and Tetric Flow were 19.0 +/- 10.9, 14.7 +/- 9.3, 22.4 +/- 16.3, and 16.8 +/- 11.8 MPa, respectively, and mean pullout values were 42.2 +/- 13.0, 24.0 +/- 6.9, 26.3 +/- 9.4, and 33.8 +/- 18.0 N, respectively. No statistically significant differences were found among the groups in terms of SBS (P > .05). On the other hand, Light Bond yielded significantly higher pullout values compared with the flowables Filtek Supreme and Flow-Tain (P < .01). However, there were no significant differences among the pullout values of flowables, nor between Light Bond and Tetric Flow (P > .05). The hypothesis is rejected. Light Bond yielded significantly higher pullout values compared with the flowables Filtek Supreme and FlowTain. However, flowable composites provided satisfactory SBS and wire pullout values, comparable to a standard orthodontic resin, and therefore can be used as an alternative for direct bonding of lingual retainers.

Fuzzy B-spline optimization for urban slum three-dimensional reconstruction using ENVISAT satellite data

NASA Astrophysics Data System (ADS)

Marghany, Maged

2014-06-01

A critical challenges in urban aeras is slums. In fact, they are considered a source of crime and disease due to poor-quality housing, unsanitary conditions, poor infrastructures and occupancy security. The poor in the dense urban slums are the most vulnerable to infection due to (i) inadequate and restricted access to safety, drinking water and sufficient quantities of water for personal hygiene; (ii) the lack of removal and treatment of excreta; and (iii) the lack of removal of solid waste. This study aims to investigate the capability of ENVISAT ASAR satellite and Google Earth data for three-dimensional (3-D) slum urban reconstruction in developed countries such as Egypt. The main objective of this work is to utilize some 3-D automatic detection algorithm for urban slum in ENVISAT ASAR and Google Erath images were acquired in Cairo, Egypt using Fuzzy B-spline algorithm. The results show that the fuzzy algorithm is the best indicator for chaotic urban slum as it can discriminate between them from its surrounding environment. The combination of Fuzzy and B-spline then used to reconstruct 3-D of urban slum. The results show that urban slums, road network, and infrastructures are perfectly discriminated. It can therefore be concluded that the fuzzy algorithm is an appropriate algorithm for chaotic urban slum automatic detection in ENVSIAT ASAR and Google Earth data.

Classification of Active Microwave and Passive Optical Data Based on Bayesian Theory and Mrf

NASA Astrophysics Data System (ADS)

Yu, F.; Li, H. T.; Han, Y. S.; Gu, H. Y.

2012-08-01

A classifier based on Bayesian theory and Markov random field (MRF) is presented to classify the active microwave and passive optical remote sensing data, which have demonstrated their respective advantages in inversion of surface soil moisture content. In the method, the VV, VH polarization of ASAR and all the 7 TM bands are taken as the input of the classifier to get the class labels of each pixel of the images. And the model is validated for the necessities of integration of TM and ASAR, it shows that, the total precision of classification in this paper is 89.4%. Comparing with the classification with single TM, the accuracy increase 11.5%, illustrating that synthesis of active and passive optical remote sensing data is efficient and potential in classification.

Action Planning for Prevention and Recovery: A Self-Help Guide

MedlinePlus

... everything, from really easily accessible things, like taking deep breaths, to things you only do once in ... self-help books that help you relax through deep breathing and focusing your attention on cer- tain ...

Fault source modeling of October 28, 2008 earthquake sequence in Baluchistan, Pakistan, on the basis of ALOS/PALSAR InSAR data

NASA Astrophysics Data System (ADS)

Usman, M.; Furuya, M.

2014-12-01

The Quetta Syntaxis in the western Baluchistan, Pakistan, serves as a junction for different thrust faults. As this area also lays close to the left lateral strike slip Chaman fault, which is supposed to be marking the boundary between Indian and Eurasian plate, thus the resulting seismological behavior of this regime becomes much more complex. In the region of Quetta Syntaxis, below the fold and thrust belt of Suleiman and Kirthar ranges and on 28 October 2008, there stroke an earthquake of magnitude 6.4 (Mw) which was followed by a doublet on the very next day. In association with these major events, there have been four more shocks, one foreshock and three aftershocks that have moment magnitude greater than 5. On the basis of seismological, GPS and ENVISAT/ASAR InSAR data many researchers tried to explain the source of this sequence. The latest source modeling results, on the basis of ENVISAT/ASAR data has provided an insight about the complexity of tectonics in the study area. However, in comparison to ALOS/PALSAR InSAR data, ENVISAT/ASAR has lacked signals near the epicentral area because of the low coherence. Probably, it has led to different interpretations by different researchers even on the basis of same satellite data. By using ALOS/PALSAR data, we have suggested a four faults model, two left laterals and two right laterals, which also retains the most desirable features of previous models.

U.S. EPA, Pesticide Product Label, , 12/02/1982

EPA Pesticide Factsheets

2011-04-21

... DISPOSAL, TAINE INTO "ftft"'-. AaOVE 32° f. ."., I •• H ••• r rift ..... th.t c-",,_, Ia. u .. ,tI .cco,~ ... _I hu .... etf ..... It. 4h ..... of .cc.rtllnlil .. .,.lIc."'. FMerel. ...

Limitations and potential of satellite imagery to monitor environmental response to coastal flooding

USGS Publications Warehouse

Ramsey, Elijah W.; Werle, Dirk; Suzuoki, Yukihiro; Rangoonwala, Amina; Lu, Zhong

2012-01-01

Storm-surge flooding and marsh response throughout the coastal wetlands of Louisiana were mapped using several types of remote sensing data collected before and after Hurricanes Gustav and Ike in 2008. These included synthetic aperture radar (SAR) data obtained from the (1) C-band advance SAR (ASAR) aboard the Environmental Satellite, (2) phased-array type L-band SAR (PALSAR) aboard the Advanced Land Observing Satellite, and (3) optical data obtained from Thematic Mapper (TM) sensor aboard the Land Satellite (Landsat). In estuarine marshes, L-band SAR and C-band ASAR provided accurate flood extent information when depths averaged at least 80 cm, but only L-band SAR provided consistent subcanopy detection when depths averaged 50 cm or less. Low performance of inundation mapping based on C-band ASAR was attributed to an apparent inundation detection limit (>30 cm deep) in tall Spartina alterniflora marshes, a possible canopy collapse of shoreline fresh marsh exposed to repeated storm-surge inundations, wind-roughened water surfaces where water levels reached marsh canopy heights, and relatively high backscatter in the near-range portion of the SAR imagery. A TM-based vegetation index of live biomass indicated that the severity of marsh dieback was linked to differences in dominant species. The severest impacts were not necessarily caused by longer inundation but rather could be caused by repeated exposure of the palustrine marsh to elevated salinity floodwaters. Differential impacts occurred in estuarine marshes. The more brackish marshes on average suffered higher impacts than the more saline marshes, particularly the nearshore coastal marshes occupied by S. alterniflora.

Project SQUID: The Foundations of Nonequilibrium Statistical Mechanics. Volume 1

DTIC Science & Technology

1963-06-01

equations available (Boltzmann, Landau,, Bogolubov- Balescu -Lenard) are essentially exact and cannot be improved. That isv for kinetic gases (those...effects) as well as to the newly obtained kinetic equation for plasmas (8) (Bogolubov- Balescu -Lenard equation). The hope of ob- taining correctly

Wear resistance of four types of vacuum-formed retainer materials: a laboratory study.

PubMed

Raja, Taiyub A; Littlewood, Simon J; Munyombwe, Theresa; Bubb, Nigel L

2014-07-01

To investigate the resistance to wear of four different vacuum-formed retainer (VFR) materials: Essix C+, Essix ACE, Duran, and Tru-Tain. Essix C+ is a polypropylene polymer; the other materials are polyethylene co-polymers. The study was undertaken at the Leeds Dental Institute, Leeds, UK, with 26 samples in each group. The specimens were vacuum-formed according to the manufacturers' guidelines, and a custom-made wear-simulation machine was used to conduct the test. Each specimen was subjected to 1000 cycles of the wear simulation, with steatite balls as the antagonist material. The resistance to wear of the VFR materials was evaluated by measuring the maximum wear depth using noncontact, three-dimensional surface profilometry. The wear depth was given in micrometers. The median wear depth was 63.20 µm for the Essix C+ group, 7.88 µm for the Essix ACE group, 9.75 µm for the Duran group, and 12.08 µm for the Tru-Tain group. The Kruskal-Wallis test to compare the four VFR materials detected a statistically significant difference between the groups (P < .001). Comparisons of the groups using the Mann-Whitney U-test demonstrated that the Essix C+ group had significantly greater wear than the other three groups (P < .001). There was no statistically significant difference in median wear depth between the two groups with the least amount of wear-the Essix ACE and Duran groups. Under the standardized conditions of this laboratory study, the three polyethylene co-polymer materials-Essix ACE, Duran, and Tru-Tain-exhibited significantly less wear than the polypropylene material, Essix C+.

Towards Clean Diesel Engines. Second Symposium. Book of Abstracts.

DTIC Science & Technology

1998-04-06

and Mie-scattering imaging and EXCIPLEX technique, based on a fluorescence system. This last technique, even if it is able to distinguish...set of experimental data, ob- tained by a collaborative effort with researchers at the RWTH Aachen, is presented. Laser-induced exciplex fluorescence

WASTE REDUCTION PRACTICES AT TWO CHROMATED COPPER ARSENATE WOOD-TREATING PLANTS

EPA Science Inventory

Two chromated copper arsenate (CCA) wood-treating plants were assessed for their waste reduction practices. The objectives of this study were to estimate the amount of hazardous wastes that a well-designed and well-main- tained CCA treatment facility would generate and to iden- t...

The Value of Information in Distributed Decision Networks

DTIC Science & Technology

2016-03-04

formulation, and then we describe the various results at- tained. 1 Mathematical description of Distributed Decision Network un- der Information...Constraints We now define a mathematical framework for networks. Let G = (V,E) be an undirected random network (graph) drawn from a known distribution pG, 1

The Effects of Minor Constituents in Calcium Silicate Insulation on the Corrosion of Underground Heat Distribution Systems.

DTIC Science & Technology

1984-05-01

distribution systems were ob- ride content per unit weight of insulation was deter- tained from Johns - Manville , Pabco, and Owens- mined as the ratio...either adding more distilled-deionized water to the Aecomecial oraoh milly ana-yzedias-received samples of Johns - Manville . Owens-Corning, suspension, or

Enhanced tactical radar correlator (ETRAC): true interoperability of the 1990s

NASA Astrophysics Data System (ADS)

Guillen, Frank J.

1994-10-01

The enhanced tactical radar correlator (ETRAC) system is under development at Westinghouse Electric Corporation for the Army Space Program Office (ASPO). ETRAC is a real-time synthetic aperture radar (SAR) processing system that provides tactical IMINT to the corps commander. It features an open architecture comprised of ruggedized commercial-off-the-shelf (COTS), UNIX based workstations and processors. The architecture features the DoD common SAR processor (CSP), a multisensor computing platform to accommodate a variety of current and future imaging needs. ETRAC's principal functions include: (1) Mission planning and control -- ETRAC provides mission planning and control for the U-2R and ASARS-2 sensor, including capability for auto replanning, retasking, and immediate spot. (2) Image formation -- the image formation processor (IFP) provides the CPU intensive processing capability to produce real-time imagery for all ASARS imaging modes of operation. (3) Image exploitation -- two exploitation workstations are provided for first-phase image exploitation, manipulation, and annotation. Products include INTEL reports, annotated NITF SID imagery, high resolution hard copy prints and targeting data. ETRAC is transportable via two C-130 aircraft, with autonomous drive on/off capability for high mobility. Other autonomous capabilities include rapid setup/tear down, extended stand-alone support, internal environmental control units (ECUs) and power generation. ETRAC's mission is to provide the Army field commander with accurate, reliable, and timely imagery intelligence derived from collections made by the ASARS-2 sensor, located on-board the U-2R aircraft. To accomplish this mission, ETRAC receives video phase history (VPH) directly from the U-2R aircraft and converts it in real time into soft copy imagery for immediate exploitation and dissemination to the tactical users.

Ground Subsidence Along Shanghai Metro Line 6 BY PS-InSAR Method

NASA Astrophysics Data System (ADS)

Wu, J.; Liao, M.; Li, N.

2018-04-01

With the rapid development of urban economy, convenient, safe, and efficient urban rail transit has become the preferred method for people to travel. In order to ensure the safety and sustainable development of urban rail transit, the PS-InSAR technology with millimeter deformation measurement accuracy has been widely applied to monitor the deformation of urban rail transit. In this paper, 32 scenes of COSMO-SkyMed descending images and 23 scenes of Envisat ASAR images covering the Shanghai Metro Line 6 acquired from 2008 to 2010 are used to estimate the average deformation rate along line-of-sight (LOS) direction by PS-InSAR method. The experimental results show that there are two main subsidence areas along the Shanghai Metro Line 6, which are located between Wuzhou Avenue Station to Wulian Road Station and West Gaoke Road Station to Gaoqing Road Station. Between Wuzhou Avenue Station and Wulian Road Station, the maximum displacement rate in the vertical direction of COSMO-SkyMed images is -9.92 mm/year, and the maximum displacement rate in the vertical direction of Envisat ASAR images is -8.53 mm/year. From the West Gaoke Road Station to the Gaoqing Road Station, the maximum displacement rate in the vertical direction of COSMO-SkyMed images is -15.53 mm/year, and the maximum displacement rate in the vertical direction of Envisat ASAR images is -17.9 mm/year. The results show that the ground deformation rates obtained by two SAR platforms with different wavelengths, different sensors and different incident angles have good consistence with each other, and also that of spirit leveling.

General McClellan and the Politicians Revisited

DTIC Science & Technology

2012-01-01

in late December, McClellan fell ill with typhoid fever . He endeavored to main- tain an active engagement with the president in the weeks that...so much to one man were vividly illustrated during McClellan’s bout with typhoid . From a Huntingtonian viewpoint, Lincoln’s subsequent management

Low Efficiency Control Measures for Jet Engine Test Cells

DTIC Science & Technology

1978-09-01

replacement cost was based upon filter cost data ob- tained from Mr. Roland Langlois, Owens - Corning Fiberglas Inc., Technical Cen- ter, Granville, Ohio. 3...Torgeson’s theory was used to calculate the collection efficiency of three commercial glass fiber filter media samples obtained from Owens - Corning Fiberglas

Propulsion and Energetics Panel Working Group 11 on Aircraft Fire Safety. Volume 2. Main Report

DTIC Science & Technology

1979-11-01

which make burning metal particles a potent igni- tion source and extinguishment of bulk metal fires a difficult task. In the latter case, the difficulty...aircraft to fires induced by uncon- tained engine failures and internal engine metal fires . With respect to the uncontained engine failure current engine

Bibliography on Cold Regions Science and Technology, Volume 53, Part 1

DTIC Science & Technology

1999-12-01

Greenland t80/ tain regions: the case study of the Ritigraben tor-Chepyzhenko, V.I., Lautin, L.M., 160 ice core records and North Atlantic foramin - rent...recent planktic foramin - models, Computerized simulation 53-1858 ifera and water mass properties in the western 53-1851 Antarctic Treaty exchange of

Formal Specification and Verification of Concurrent Programs

DTIC Science & Technology

1993-02-01

of examples from the emerging theory of This book describes operating systems in general programming languages. via the construction of MINIX , a UNIX...look-alike that runs on IBM-PC compatibles. The book con- Wegner72 tains a complete MINIX manual and a complete Wegnerflisting of its C codie. egner

Protecting Commercial Aviation Against the Shoulder-Fired Missile Threat

DTIC Science & Technology

2005-01-01

to reestablish the Caliphate. To those not in thrall to radical Muslim ideology, no meaningful connection between these millennial goals and specific...According to prosecutors, Lakhani agreed to deliver an SA-18 missile to U.S. agents posing as buyers after he ob- tained it from Russian agents posing as

Forecasting Trafficability of Soils. Report Number 4. Information for Predicting Moisture in the Surface Foot of Various Soils

DTIC Science & Technology

1957-02-01

this report is acknowledged: Northeastern Forest Experiment Station, Southeastern Forest and Range Experiment Station, and California Forest Sand Range...Washington ........... ................. .... A7 Tanbark Flat, California ....... ................. .... A8 Madera County, California ...Mississippi, Pennsylvania, California , South Carolina, South Dakota, Nebraska, and Indiana were ob- tained and analyzed. 8. The method developed for prediction

The 1980-81 AFOSR-HTTM-Stanford Conference on Complex Turbulent Flows: Comparison of Computation & Experiment.

DTIC Science & Technology

1982-02-01

1968, 1969 and 1972 Confereaces. Zec -tain items at. the list delineate problems needing research (reattachment zones, *iv/bou j.Azy layer interactions...viscous energy equation--each in unaveraged form. As Peter Bradshaw has put it, God gave us one good model. Why should there be another model that is

Investigation of Heat Transfer in Straight and Curved Rectangular Ducts.

DTIC Science & Technology

1980-09-01

theoretical explanation of the heat transfer effects required that all non-linear terms be re- tained in the flow equations. R. Kahawita and R...112, February 1370. 2’. Kahawita , R. and Meroney, R., "The Inffluence of Heating on the Stability of Laminar Boundary Layers Along Con- cave Curved

Cardiac Isoenzyme Values after Total Joint Arthroplasty Number 240: March 1989

DTIC Science & Technology

1989-05-01

tion, postoperative myocardial infarction for myocardium. Galen8ŝ reported that its can be painless in up to 50% of patients.7 presence in the serum is...plasty of the hip and knee. organs including myocardium, brain, kid- tained between 18 and 24 hours after infarc- ney, lung, thyroid , bladder, uterus

Remote sensing for mapping soil moisture and drainage potential in semi-arid regions: Applications to the Campidano plain of Sardinia, Italy.

PubMed

Filion, Rébecca; Bernier, Monique; Paniconi, Claudio; Chokmani, Karem; Melis, Massimo; Soddu, Antonino; Talazac, Manon; Lafortune, Francois-Xavier

2016-02-01

The aim of this study is to investigate the potential of radar (ENVISAT ASAR and RADARSAT-2) and LANDSAT data to generate reliable soil moisture maps to support water management and agricultural practice in Mediterranean regions, particularly during dry seasons. The study is based on extensive field surveys conducted from 2005 to 2009 in the Campidano plain of Sardinia, Italy. A total of 12 small bare soil fields were sampled for moisture, surface roughness, and texture values. From field scale analysis with ENVISAT ASAR (C-band, VV polarized, descending mode, incidence angle from 15.0° to 31.4°), an empirical model for estimating bare soil moisture was established, with a coefficient of determination (R(2)) of 0.85. LANDSAT TM5 images were also used for soil moisture estimation using the TVX slope (temperature/vegetation index), and in this case the best linear relationship had an R(2) of 0.81. A cross-validation on the two empirical models demonstrated the potential of C-band SAR data for estimation of surface moisture, with and R(2) of 0.76 (bias +0.3% and RMSE 7%) for ENVISAT ASAR and 0.54 (bias +1.3% and RMSE 5%) for LANDSAT TM5. The two models developed at plot level were then applied over the Campidano plain and assessed via multitemporal and spatial analyses, in the latter case against soil permeability data from a pedological map of Sardinia. Encouraging estimated soil moisture (ESM) maps were obtained for the SAR-based model, whereas the LANDSAT-based model would require a better field data set for validation, including ground data collected on vegetated fields. ESM maps showed sensitivity to soil drainage qualities or drainage potential, which could be useful in irrigation management and other agricultural applications. Copyright © 2015 Elsevier B.V. All rights reserved.

Korean Affairs Report

DTIC Science & Technology

1985-04-11

mobilization of units in the puppet army, a large number of tanks, armoured vehicles, howitzers and helicopters. They are now desperately inciting a war...cupied by the Chinese at around 7:20 a.m. to take breakfast orders, the cur- tains of the rooms were draped with one policeman for each room standing

Using the CREW Method to Enhance Public and School Library Collections

ERIC Educational Resources Information Center

Boon, Belinda

2009-01-01

Now, more than ever, public and school libraries struggle to main- tain their relevance in the age of instant access, electronic databases, and Google. While print collections continue to grow, many collections are drowning in obsolete, unused, and unwanted materials. And while most libraries keep up with deselection in an intelligent manner, many…

A Periplasmic Polymer Curves Vibrio cholerae and Promotes Pathogenesis.

PubMed

Bartlett, Thomas M; Bratton, Benjamin P; Duvshani, Amit; Miguel, Amanda; Sheng, Ying; Martin, Nicholas R; Nguyen, Jeffrey P; Persat, Alexandre; Desmarais, Samantha M; VanNieuwenhze, Michael S; Huang, Kerwyn Casey; Zhu, Jun; Shaevitz, Joshua W; Gitai, Zemer

2017-01-12

Pathogenic Vibrio cholerae remains a major human health concern. V. cholerae has a characteristic curved rod morphology, with a longer outer face and a shorter inner face. The mechanism and function of this curvature were previously unknown. Here, we identify and characterize CrvA, the first curvature determinant in V. cholerae. CrvA self-assembles into filaments at the inner face of cell curvature. Unlike traditional cytoskeletons, CrvA localizes to the periplasm and thus can be considered a periskeletal element. To quantify how curvature forms, we developed QuASAR (quantitative analysis of sacculus architecture remodeling), which measures subcellular peptidoglycan dynamics. QuASAR reveals that CrvA asymmetrically patterns peptidoglycan insertion rather than removal, causing more material insertions into the outer face than the inner face. Furthermore, crvA is quorum regulated, and CrvA-dependent curvature increases at high cell density. Finally, we demonstrate that CrvA promotes motility in hydrogels and confers an advantage in host colonization and pathogenesis. Copyright © 2017 Elsevier Inc. All rights reserved.

When contemporary aminoacyl-tRNA synthetases invent their cognate amino acid metabolism

PubMed Central

Roy, Hervé; Becker, Hubert Dominique; Reinbolt, Joseph; Kern, Daniel

2003-01-01

Faithful protein synthesis relies on a family of essential enzymes called aminoacyl-tRNA synthetases, assembled in a piecewise fashion. Analysis of the completed archaeal genomes reveals that all archaea that possess asparaginyl-tRNA synthetase (AsnRS) also display a second ORF encoding an AsnRS truncated from its anticodon binding-domain (AsnRS2). We show herein that Pyrococcus abyssi AsnRS2, in contrast to AsnRS, does not sustain asparaginyl-tRNAAsn synthesis but is instead capable of converting aspartic acid into asparagine. Functional analysis and complementation of an Escherichia coli asparagine auxotrophic strain show that AsnRS2 constitutes the archaeal homologue of the bacterial ammonia-dependent asparagine synthetase A (AS-A), therefore named archaeal asparagine synthetase A (AS-AR). Primary sequence- and 3D-based phylogeny shows that an archaeal AspRS ancestor originated AS-AR, which was subsequently transferred into bacteria by lateral gene transfer in which it underwent structural changes producing AS-A. This study provides evidence that a contemporary aminoacyl-tRNA synthetase can be recruited to sustain amino acid metabolism. PMID:12874385

Sustaining Service Members and Their Families: Exploring Opportunities for Efficiency and Joint Provision of Services Using Nonappropriated Funds

DTIC Science & Technology

2016-05-31

do not necessarily reflect the opinions of its research clients and sponsors. Support RAND Make a tax -deductible charitable contribution at...This report con- tains the results of that analysis, looking at the areas of NAF accounting and NAF employee benefits in terms of best practices in...5 CHAPTER TWO Program Area Descriptions: NAF Accounting

Remote Sensing and GIS for Landuse/Landcover Classification and Water Quality in the Northern Ireland

NASA Astrophysics Data System (ADS)

Amer, R.; Ofterdinger, U.; Ruffell, A.; Donald, A.

2012-04-01

This study presents landuse/landcover (LULC) classifications of Northern Ireland in order to quantify land-use types driving chemical loading in the surface water bodies. The major LULC classes are agricultural land, bare land (mountainous areas), forest, urban areas, and water bodies. Three ENVISAT ASAR multi-look precision images acquired in 2011 and two Enhanced Thematic Mapper Plus (ETM+) acquired in 2003 were used for classification. The ASAR digital numbers were converted to backscattering coefficient (sigma nought) and enhanced using adaptive Gamma filter and Gaussian stretch. Supervised classifications of Maximum Likelihood, Mahalanobils Distance, Minimum Distance, Spectral Angel Mapper, Parallelepiped, and Winner Tercat were applied on ETM+ and ASAR images. A confusion matrix was used to evaluate the classification accuracy; the best results of ETM+ and ASAR were given by the winner classification (82.9 and 73.6 %), and maximum likelihood (81.7 and 72.5 %), respectively. Change detection was applied to identify the areas of significant changes in landuse/landcover over the last eight years. The Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) digital elevation model was processed to extract the drainage systems and watersheds. Water quality data of the first and second order streams were extracted from 2005 survey by Geological Survey of Northern Ireland. GIS spatially distributed modelling generated maps showing the distribution of phosphorus (P), nitrate (NO3), dissolved organic carbon (DOC), and some of the trace elements including fluoride (F), calcium (Ca), aluminium (Al), iron (Fe), copper (Cu), lead (Pb), zinc (Zn), and arsenic (As) across the watersheds of the Northern Ireland were generated. The distribution of these elements was evaluated against the LULC classes and bed rock geology. Concentration of these elements was classified into normal (safe level), moderate, high, and very high based on the World Health Organization

Aircrew Automated Escape Systems (AAES) In-Service Usage Data Analyses. Volume 1. Papers Presented at the Annual SAFE Symposium (21st), San Antonio, Texas, 5,6,7,8 November 1983.

DTIC Science & Technology

1983-11-05

NECK INJURIES, ANTHROPOMETRY . MAINTENANCE, AIRCREW LIFE SUPPORT SYSTEMS, EJECTION INJURIES, FLIGHT SURGEON’S REPORT I ABSTRACT (Continue en reverse...AND TUMBLE: fACTORS INFLUENCING FREQUENCY AND SEVERITY OF NECK INJURIES SUS- TAINED BY EJECTEES; JFISNAP AIMCREW ANTHROPOMETRY ANALYSIS AND SCREENING...1979 ....................................... 1-281 U.S. Navy Aviation Mishap Aircrew Anthropometry ; 1 January 1969 through 31 December 1979

Large-scale effects of timber harvesting on stream systems in the Ouachita Mountains, Arkansas, USA

Treesearch

Lance R. Williams; Christopher M. Taylor; Melvin L. Warren; J. Alan Clingenpeel

2002-01-01

Using Basin Area Stream Survey (BASS) data from the USDA Forest Service, we evaluated how tim-ber harvesting influenced patterns of variation in physical stream features and regional fish and macroinvertebrate as-semblages. Data were collected for three years (1990-1992) from six hydrologically variable streams in the Ouachita Moun-tains, AR, USA that were paired by...

Large-Diameter InGaAs/AlGaAs Vertical-Cavity Surface-Emitting Lasers with Low Threshold Current Density Fabricated Using a Simple Chemical Etch Process

DTIC Science & Technology

1994-03-01

Epitaxial structure of vertical cavity surface - emitting laser ( VCSEL ...diameter (75 tum < d< 150 prm) vertical - cavity surface - emitting lasers fabricated from an epitaxial structure containing a single In0 .2Ga 8.,As quantum...development of vertical - cavity surface - emitting lasers ( VCSELs ) [1] has enabled III-V semiconductor technology to be applied to cer- tain optical

The p53-Deficient Mouse as a Breast Cancer Model

DTIC Science & Technology

1995-10-01

M.A. Gryka , F.Z. Bischoff, M.A. Tain- Halachmi, R.T. Bronson, and R.A. Weinberg. 1994. Tumor sky, and S.H. Friend. 1990. Germ line p53 mutations in a...J. Kassel, M.A. Gryka , F.Z. Bischoff, Weaver-Feldhaus, W. Ding, Z. Gholami, P. Soderkvist, L. M.A. Tainsky, and S.H. Friend. 1990. Germ line p53

Tests of Several Model Nacelle-Propeller Arrangements in Front of a Wing

DTIC Science & Technology

1939-09-01

uso in sub- sequent annl7scs 1 similar tosts vera made ot.tho wine alone. A second series ot tosts vas made ot each combination with the propeller...tained from tho toata of nacelles alo ~o (reference 2). ----------··-· ····---- ___ , ____ . • 14 !he maximum value of ~· has alread7 been shown to be

State and Local Intelligence in the War on Terrorism

DTIC Science & Technology

2005-01-01

the Los Angeles Police Department . Santa Monica, Calif.: RAND Corporation, MR-1745- LAPD , 2003. Global Justice Information Sharing Initiative. Law... Police Profes- sionalism for the Los Angeles Police Department , Russell W. Glenn, Barbara R. Panitch, Dionne Barnes-Proby, Elizabeth F. Williams, John...Mike McClary and Cap- tain Kathy Suey of the Las Vegas Metropolitan Police Department , Captain Gary Williams of the

A Guide to Ordinary High Water Mark (OHWM) Delineation for Non-Perennial Streams in the Western Mountains, Valleys, and Coast Region of the United States

DTIC Science & Technology

2014-08-01

in vegetation characteristics. This guide addresses the underlying hydrologic and geomorphic concepts per- taining to the OHWM and the field...temporally varying hydrologic and geomorphic processes .............................. 12 4 The distribution of rankings for each of the three primary...define, amend, or replace any existing regulations, laws , or legal guidance related to the OHWM or to the regulation of WoUS. Furthermore, determining

Naval Audit Service: Effectiveness of Navy’s Internal Audit Organization is Limited.

DTIC Science & Technology

1988-02-24

reports were inaccurate or incomplete in reporting audit findings. Additionally, summary reports on multilocation audits con- tained findings not reported... Audit Reports 29 Deficiencies in Multilocation Audits 30 ; Deficiencies in Supervision 32 Conclusions 34 " Recommendations 34 Agency Comments and Our...Congress, the Sec- retary of the Navy, or the general public. After multilocation audits , NAS headquarters issues summary reports which consolidate the

Review of Laboratory Program on Degradation Mechanisms in Soil of Wastewater From Nitroguanidine Manufacture

DTIC Science & Technology

1987-03-01

in./hr) (3). Nutrients (organic nitrogen, ammonia-nitrogen, nitrate/I nitrite-nitrogen, potassium , and phosphorus) in SFAAP soils are generally...A mixture con- taining equal portions of these was diluted with 0.085 percent potassium chloride. The 30 percent solution was filtered and the...01 L (d) Cyanamide - Spectrophotometric determination after complexation with pentacyanoamine ferrate reagent. Detection limit was approximately 100

Chinese HJ-1C SAR And Its Wind Mapping Capability

NASA Astrophysics Data System (ADS)

Huang, Weigen; Chen, Fengfeng; Yang, Jingsong; Fu, Bin; Chen, Peng; Zhang, Chan

2010-04-01

Chinese Huan Jing (HJ)-1C synthetic aperture radar (SAR) satellite has been planed to be launched in 2010. HJ-1C satellite will fly in a sun-synchronous polar orbit of 500-km altitude. SAR will be the only sensor on board the satellite. It operates in S band with VV polarization. Its image mode has the incidence angles 25°and 47°at the near and far sides of the swath respectively. There are two selectable SAR modes of operation, which are fine resolution beams and standard beams respectively. The sea surface wind mapping capability of the SAR has been examined using M4S radar imaging model developed by Romeiser. The model is based on Bragg scattering theory in a composite surface model expansion. It accounts for contributions of the full ocean wave spectrum to the radar backscatter from ocean surface. The model reproduces absolute normalized radar cross section (NRCS) values for wide ranges of wind speeds. The model results of HJ-1C SAR have been compared with the model results of Envisat ASAR. It shows that HJ-1C SAR is as good as Envisat ASAR at sea surface wind mapping.

Exploring the capacity of radar remote sensing to estimate wetland marshes water storage.

PubMed

Grings, F; Salvia, M; Karszenbaum, H; Ferrazzoli, P; Kandus, P; Perna, P

2009-05-01

This paper focuses on the use of radar remote sensing for water storage estimation in wetland marshes of the Paraná River Delta in Argentina. The approach followed is based on the analysis of a temporal set of ENVISAT ASAR data which includes images acquired under different polarizations and incidence angles as well as different environmental conditions (water level, precipitation, and vegetation condition). Two marsh species, named junco and cortadera, were monitored. This overall data set gave us the possibility of studying and understanding the basic interactions between the radar, the soil under different flood conditions, and the vegetation structure. The comprehension of the observed features was addressed through electromagnetic models developed for these ecosystems. The procedure used in this work to estimate water level within marshes combines a direct electromagnetic model, field work data specifically obtained to feed the model, the actual ASAR measurements and a well known retrieval scheme based on a cost function. Results are validated with water level evaluations at specific points. A map showing an estimation of the water storage capacity and its error in junco and cortadera areas for the date where the investigation was done is also presented.

Engineering Design Handbook. Army Weapon Systems Analysis. Part 2

DTIC Science & Technology

1979-10-01

EXPERIMENTAL DESIGN ............................... ............ 41-3 41-5 RESULTS OF THE ASARS lIX SIMULATIONS ........................... 41-4 41-6 LATIN...sciences and human factors engineering fields utilizing experimental methodology and multi-variable statistical techniques drawn from experimental ...randomly to grenades for the test design . The nine experimental types of hand grenades (first’ nine in Table 33-2) had a "pip" on their spherical

Investigation of Coherent and Incoherent Change Detection Algorithms

DTIC Science & Technology

2017-12-01

Office of Management and Budget, Paperwork Reduction Project (0704-0188) Washington DC 20503. 1. AGENCY USE ONLY (Leave blank) 2. REPORT DATE December...Data Management System (SDMS) in order to compare the various change detection techniques. These change detection methods include the following: a...SAR) is presented in this thesis. This investigation utilizes data gathered from the Air Force Research Laboratory (AFRL) Sensor Data Management

CrossTalk: The Journal of Defense Software Engineering. Volume 19, Number 7

DTIC Science & Technology

2006-07-01

public key certificates and cryptographic keys for crypto - graphic devices. In an environment where enterprise protection relies on an array of IA-enabled...allowing for greater accuracy, currency , and relevance of the information con- tained in the satellite communications data- base will be evaluated...JWPO). The purpose of the JWPO is to define, develop, validate, and evolve the JTRS SCA; acquire wave- form software applications; acquire Crypto

Finding Multiple Lanes in Urban Road Networks with Vision and Lidar

DTIC Science & Technology

2009-03-24

drawbacks. First, the cost of updating and main- taining millions of kilometers of roadway is prohibitive. Second, the danger of autonomous vehicles perceiving... autonomous vehicles . We propose that a data infrastructure is useful for topological information and sparse geometry, but reject relying upon it for dense...Throughout the race, approximately 50 human- driven and autonomous vehicles were simultaneously active, thus providing realistic traffic scenarios. Our most

Conjunctive Faith: A Critique and Analysis from an Evangelical Perspective

DTIC Science & Technology

1990-06-01

Fowler regards those who practice radical monotheism as valuers of an inclusive, global community, practicing a type of universal faith that eclipses...Stages of Faith, 20. * 24 think. ,23 Niebuhr’s second type of faith relationship, which Fowler endorses, is henotheism. Niebuhr clothes henotheism...could sus- tain. In doing so, I failed to take seriously enough certain indications, which faith development categories actually make quite clear

Heat Recovery at Army Materiel Command (AMC) Facilities

DTIC Science & Technology

1988-06-01

industrial complexes and somewhat smaller commercial/ HVAC ** systems, a portion of this waste heat can be recovered, improving energy efficiency. Heat...devices are used in sequence. Other shell-and-tube applications include heat transfer from process liquids, condensates, and cooling water. Two...pipe consists of a sealed element involving an annular capillary wick con- tained inside the full length of the tube, with an appropriate entrained

Value Engineering Synergies with Lean Six Sigma

DTIC Science & Technology

2010-09-01

understanding the problem, developing solutions, and evalu- ating pros and cons of the solutions. The paramount considerations are getting enough facts and...parts or labor operations. Functions are defined for every element of the product or process that con - sumes resources. The functions are typically...shoot bullets, detect movement, and so forth). A work function establishes quantitative statements. Functional definitions con - taining a verb and a

Initial Single Event Effects Testing of the Xilinx Virtex-4 Field Programmable Gate Array

NASA Technical Reports Server (NTRS)

Allen, Gregory R.; Swift, Gary M.; Carmichael, C.; Tseng, C.

2007-01-01

We present initial results for the thin epitaxial Xilinx Virtex-4 Fie ld Programmable Gate Array (FPGA), and compare to previous results ob tained for the Virtex-II and Virtex-II Pro. The data presented was a cquired through a consortium based effort with the common goal of pr oviding the space community with data and mitigation methods for the use of Xilinx FPGAs in space.

The Impact of the AT&T (American Telephone and Telegraph) Divestiture on the Strategic Air Command.

DTIC Science & Technology

1984-01-01

the corporate tel- ecommunications manager, think of the impact on the military communicator. For a corporation, poorly planned, installed, and main...tained telecommunications equipment and services may mean increased cost or lost profits. For the military communicator, the same prob- lems can mean ...effective telecommunications systems available, even if it means turning our backs on past methods and relationships with vendors. I 4 NOTES -CHAPTER

MATILDA Version 2: Rough Earth TIALD Model for Laser Probabilistic Risk Assessment in Hilly Terrain - Part I

DTIC Science & Technology

2017-03-13

support of airborne laser designator use during test and training exercises on military ranges. The initial MATILDA tool, MATILDA PRO Version-1.6.1...was based on the 2007 PRA model developed to perform range safety clearances for the UK Thermal Imaging Airborne Laser Designator (TIALD) system...AFRL Technical Reports. This Technical Report, designated Part I, con- tains documentation of the computational procedures for probabilistic fault

Promoter and Cofactor Requirements for SERM-ER Activity

DTIC Science & Technology

2007-05-01

was seen in the no- digestion control or no-ligation control. We performed the same experiment using thedesigned against the intergenic region between...estrogen, and the fixed chromatin was digested with a specific restriction taining an SV40 promoter and transfected these vec- tors into hormone...Enhancer Domains and Transcriptional Activity of En- hancer Regions (A) Chromosome capture assay was per- formed after digesting fixed chromatin from

A Business Process Analysis of the Surface Navys Depot Maintenance Program

DTIC Science & Technology

2015-12-01

In this section, I provide a breakdown of the levels of maintenance and the ways in which the Navy employs these types of maintenance to accomplish...of inefficiencies to ensure there is no wasted movement. Toyota , Honda, and their Japanese counterparts championed the lean process and served as...are another way trust is built, because they cultivate the relationships necessary for process improvement and innovation. JSPs have career

Duty Module Validation for Accomplishing Taining Feedback. Volume 1. System Design for Training Feedback

DTIC Science & Technology

1977-11-14

job element for developing PCCs for the measurement of an officer’s performance capability. As a result of the work already done on Duty Modules, new...exercise is ended. Recent studies to evaluate the effect on unit mission performance as a result of assign- ing varying numbers of women soldiers to...Passes driver’s test and demonstrates ability to perform effectively in all crew positions of track vehicles in his TOE. Radios, Telephones

Congressional Report on Defense Business Operations

DTIC Science & Technology

2010-03-15

by more than 1,700 users and used to store approximately 250 submissions a month. Each month, more than 2,000 documents are accessed and downloaded . 6...that is stored, managed and main- tained centrally. Data includes Geographic Information Systems ( GIS ) and Computer Aided Design and Drafting (CADD...Office FTP File Transfer Protocol FY Fiscal Year GAO Government Accountability Office GFEBS General Fund Enterprise Business System GIS Geographic

Operation REDWING. Technical Summary of Military Effects. Programs 1-9

DTIC Science & Technology

1981-05-15

study chorioretinal burns. The primary objective of the program on effects on aircraft structures was to ascer- tain the reliability of current weapons...other aircraft. In the program of tests on service equipment and studies of electromagnetic effects,I 4k. the emphasis was placed on studying long...range detection of nuclear explosions. An additional objective was the study of the effects of nuclear detonations on the ionosphere and microwave

CrossTalk: The Journal of Defense Software Engineering. Volume 18, Number 11

DTIC Science & Technology

2005-11-01

languages. Our discipline of software engineering has really experienced phenomenal growth right before our eyes. A sign that software design has...approach on a high level of abstraction. The main emphasis is on the identification and allocation of a needed functionality (e.g., a target tracker ), rather...messaging software that is the backbone of teenage culture. As increasing security constraints will increase the cost of developing and main- taining any

Filmwise Condensation on Low Integral-Fin Tubes of Different Diameter

DTIC Science & Technology

1988-12-01

the prime mover of condensate . Therefore, the Nusselt analysis was not valid for finned tubes. They therefore divided the finned tube into two regions...the objectives of this thesis. Prior to these modifications, cooling water to the secondary condenser was con- tained in two helically wound coils made...temperature difference across condensate film (K), il = dynamic viscosity of condensate (N. s/m 2). By substituting the Nusselt - and the Sieder-Tate

Veterinary Laboratory Services Study - 1976.

DTIC Science & Technology

1976-09-01

rabies , equine infectious anemia and other zoonotic and animal dis— eases has actually increased or increase in this area is p lanned. Some special...functions were transferred to the Department of Chemistry in October 1975. A sheep flock is main- tained and sheep blood is supplied to clinical...since several dv~guostic procedures involving zoonotic diseases are done there. Their ciagnostic service could be considered a prototype for other Medical

Hospital Corpsman 3 + 2. Revision

DTIC Science & Technology

1981-01-01

scorpion of ) medical importance is the type called Cen-- truroides sculpturatus found in Mexico and cer- BRW-ELS tain areas of the American Southwest...Endemic centers medical officer’s supervision, exist in mountainous regions of Mexico , Central N and South America, th Bakn,.atr 1. Preventive measures...34’ CHICKENPOX-HERPES ZOSTER ( VARICELLA -SHINGLES) TREATMENT. Symptomatic treatment is normally all that is necessary. Wet compresses M. Chickenpox is an

Clinical Investigation Program Annual Progress Report

DTIC Science & Technology

1988-10-20

Presented: Interna- tional Symposium on Orthopedics, Mexico , September 1987. Publications: In preparation. 147 FAMC A.P.R. (RCS MED 300) Detail Summary...Infection: A Prospective Study. Presented: 2nd Annual Symposium of the Rocky Moun- tain Flow Cytometry Users Group, Albuquerque, New Mexico , 10-11...Podgore, COL, MC (9) Dept/ISvc: Pediatrics (10) Associate Investigators (11) Key Words: Myron J. Levin, M.D. varicella vaccine U Co. HSC (12

DESC (Defense Electronics Supply Center) Total Quality Management Plan

DTIC Science & Technology

1989-04-01

Paoerwort Reduction Proodt(0704.01 ge. Washington. DC 20S03 4. TITLE AND SUBTITLE Api598 . FUNDING NUMBERS DESC Total Quality Management Master Plan...OF PAGES TQM (Total Quality Management ), Continuous Process Improvement,_________ cTainingManagement 16. PRICE CODE 17. SECURITY CLASSIFICATION 18... QUALITY MANAGEMENT As you read the DESC Total Quality Management Plan, I ask each of you to make a commitment to continuously strive for improvement

JPRS Report, Near East & South Asia

DTIC Science & Technology

1989-03-31

character of cer- tain functions. [REVOLUTION AFRICAINE] Coordination hasn’t been the strong suit of the executive, political and legislative institutions... Westminister Bank of Britain was charged with marketing the loan provided that the nine banks participating in the loan are given equal shares. The...transitional government that would hold legislative elections to pave the way for a secular democratic regime that would bring about peace between

Bandwidth Allocation to Interactive Users in DBS-Based Hybrid Internet

DTIC Science & Technology

1998-01-01

policies 12 3.1 Framework for queuing analysis: ON/OFF source traffic model . 13 3.2 Service quality . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 14...minimizing the queuing delay. In consequence, we were interested in ob- taining improvements in the service quality , as perceived by the users. A...the service quality as per- ceived by users. The merit of this approach, first introduced in [8], is the ability to capture the characteristics of the

Characterization of Thick Glass Reinforced Composites

DTIC Science & Technology

1992-07-01

24 ounces per square yard. The matrices were different polyester resin systems from American Cyanamid and Owens Corning . Specimen thicknesses ranged...fab- ricated similar size plates using the American Cyanamid resin. The Owens Corning plates con- tained 53% volume fraction fiber while the American...thicknesses for the Owens Corning and four for the American Cyanamid. Specimens were loaded in three point bending at a displacement rate that was changed

Detection and Evaluation of Early Breast Cancer via Magnetic Resonance Imaging: Studies of Mouse Models and Clinical Implementation

DTIC Science & Technology

2009-03-01

compartment modeling on breast 3D DCE-MRI data, to relate kinetic curves to the underlying physiology of the lesions (14–18). However, for low time...classification provided high sensitivity and low specificity in diagnosing malignant lesions. The results demonstrated that the modified EMM fit the 3D...lesion localization and characterization.11 However, for low time resolution 3D DCEMRI data, the accuracy of physiological parameters ob- tained from

Novel Nonlinear Laser Diagnostic Techniques

DTIC Science & Technology

1993-07-01

a thermometric probe of reactive flows. Since the two-photon pump laser couples a Doppler broadened ground state velocity distribution to the excited...rism, and passed unfocused into an aluminum cell con- in frequency space. Regions for line fitting are found by taining 99% pure NO. The gas mixture...of ASE as a More recently, ASE has prompted interest as an thermometric probe of combustion environments optical diagnostic of combustion environments

Decision Theory: Individual Biases and Their Effect on Forecasting in an Organization.

DTIC Science & Technology

1983-12-01

has not bien a great deal written about how these biases effact decisicns in an organizational environment . The purpcse of -:his thesis is tc examine...and prospers while using fallible information to infer the stateb of his uncer- tain environment and to pr.dict future events. Experiments that have...chapters deal with data from two separate crganizati-ons in two different environments . The Judgmental processes of forecasTing future organizational

Toward Active Control of Noise from Hot Supersonic Jets

DTIC Science & Technology

2012-07-24

1.5 heated jet simulated by way of LES. spreading angles of the jet which were determined from prelimi- nary LES computations performed by CRAFT Tech...system allowed time-resolved and high dynamic range measurements to be ob- tained for a heated , supersonic jet. Each component of the system is...independently operated, temporal spacing between frames is variable and can be set in an asynchronous fashion. Such flexibility even allows eight

Projects, Products and Services: Celebrating 75 Years of Excellence

DTIC Science & Technology

2009-01-01

own war against this unyielding force of nature . The 1943 spring thaw caused eight of the Missouri’s tributaries to spill over their banks. The main...generating hydroelectricity and con- tained hydraulically-placed earthfill. Therefore, the project naturally divided itself into the dam, the... natural channel and divert its water through the newly built intake structure and tunnels. This was the first use of the hydraulic placement method

Comparison/Validation Study of Lattice Boltzmann and Navier Stokes for Various Benchmark Applications: Report 1 in Discrete Nano-Scale Mechanics and Simulations Series

DTIC Science & Technology

2014-09-15

solver, OpenFOAM version 2.1.‡ In particular, the incompressible laminar flow equations (Eq. 6-8) were solved in conjunction with the pressure im- plicit...central differencing and upwinding schemes, respectively. Since the OpenFOAM code is inherently transient, steady-state conditions were ob- tained...collaborative effort between Kitware and Los Alamos National Laboratory. ‡ OpenFOAM is a free, open-source computational fluid dynamics software developed

Army Logistician. Volume 35, Issue 5, September-October 2003

DTIC Science & Technology

2003-10-01

Report Documentation Page Form ApprovedOMB No. 0704-0188 Public reporting burden for the collection of information is estimated to average 1 hour per...and reviewing the collection of information. Send comments regarding this burden estimate or any other aspect of this collection of information...designed to deliver performance-enhancing natu- ral food elements to troops in the field. The gel con- tains a mixture of glucose and maltodextrin —a

Enzyme Polymorphism and Genetic Variability of One Colonized and Several Field Populations of Phlebotomus papatasi (Diptera: Psychodidae)

DTIC Science & Technology

1993-01-01

One Colonized and Several Field Populations of Phlebotomus papatasi (Diptera: Psychodidae) HALA A. KASSEM ,1. 2 DAVID J. FRYAUFF,1., MAGDI G, SHEHATA...were found to erations, and that selection for refractoriness to have atypical genitalia ( Kassem et al. 1988), and infection is associated with a shift... females and has been main- tained for 34 successive generations using the allndt(96) SINAI methods described by Schmid(16) Electrophoretic Techniques

U.S. Lake Erie Natural Gas Resource Development. Final Programmatic Environmental Impact Statement

DTIC Science & Technology

1982-03-01

with expensive investments by end-users in more energy efficient houses, plants and equipment. The end result of this alternative would be to post...construction of transmission systems from other sources into the Lake Erie watershed, construction of synfuel and coal gasi- fication plants and...water treatment plant and by main- taining the pit near neutral during chlorination. 1.022 If jack-up rigs, drillehips, or stimulation barges capsize

Where next for the laser?

NASA Astrophysics Data System (ADS)

2010-05-01

We all know that turbulence in the atmosphere makes stars twinkle, but it also severely blurs telescope images. Newton realized this back in 1730, when he wrote in Opticks that "the Air through which we look upon the Stars, is in perpetual Tremor... The only Remedy is a most serene and quiet Air, such as may perhaps be found on the tops of the highest Moun tains above the Grosser Clouds".

JPRS Report, China.

DTIC Science & Technology

1988-11-17

political situa- tion. The distinctive history and geographical environ- ment of the western regions not only makes the situation there a microcosm of the...our watch- words; therefore, this response is not only active, but also truly feasible. History will verify that only when reform of the western...co-existing appointment and election systems will have to be main- tained. A review of world history produces the following conclusion: Democratic

Off-Site Monitoring of Nuclear Fuel Reprocessing Plants for Nuclear Weapons Proliferation

DTIC Science & Technology

1980-01-01

of commercial nuclear power reactors by the collection of cesium and neodynium radionuclides and the use-of isotopic correlation techniques.Both...Both Goodwin (ref 1) and Clark (ref 2) investigated off-site monitoring of commercial nuclear power reactoze by the collection of cesium and neodynium...manner than that which is used for power production.Economical generation of electrical power requires a long sus- tained fission cycle whereas Pu-239

Considerations for Net Zero Waste Installations: Treatment of Municipal Solid Waste

DTIC Science & Technology

2015-09-01

plastic) containers or reusable drink containers (such as thermoses) can reduce the amount of metals in the waste stream. Foun- tain drink loyalty ...alternatives are needed to give customers outlets to safely dispose of unwanted HHHW. Periodic turn-in days can be valuable for this pur- pose... restaurants , schools, hospitals, and dining halls) and family housing areas where food waste is continually generated. ERDC/CERL TR-15-21 24

Measurement of Droplet Sizes by the Diffraction Ring Method

DTIC Science & Technology

1948-07-27

for measuring the droplet size distribution in sprays ob- tained by pressure injection of a liquid through an orifice «roby air- stream atomization...Diameter vs Injection Pressure 10 6. Distribution Curves for Spray Sample of Water Injected into Air Stream .... 11 Page ii Page Hi i^ujJa-je jii...tion in sprays obtained by pressure injection of a liquid through an orifice or by air- stream atomization. Perhaps the most widely used method

Microbial Fouling and Its Effect on Power Generation.

DTIC Science & Technology

1982-09-01

Bryers, J. D. (1980) " Dynamics of Early Biof’dm Formation in a Turbulent Flow System." Ph.D. dissertation, Rice University. Trulear, M. G. (1980...studies to date have avoided addressing fundamental questions concerning fouling in fluid flow and heat transfer systems and their effect on fluid...34clean" surface exposed to turbulent flow of a tuid con- taining dispersed microorganisms, nutrient, and organic macromolecules. Adsorption of an organic

Innovative Leader Development: Evaluation of the U.S. Army Asymmetric Warfare Adaptive Leader Program

DTIC Science & Technology

2014-01-01

weaknesses of any one method or measure with other approaches. Second, for most outcome measures, we used a pretest – posttest design and included measures of...behaviors on their jobs ( pretest ) or should do so ( posttest ). The surveys asked the same kinds of attitude questions for behaviors per- taining to...General cognitive ability was strongly and positively associated with scores on the pretest and posttest , but there was no interaction between the

Safety Engineering and Protective Technology in Support of Army Modernization Programs--Picatinny Arsenal Papers Presented at the 16th Annual Explosive Safety Seminar

DTIC Science & Technology

1975-08-01

beams with diagonal bracing. The siding and roofing were constructed of corrugated aluminum panels connected to the girts and purlins by 1/4- inch...Fig 8) . Also con- tained in this report are static and dynamic properties of steel columns and beams ; as well as recommended types of steels and...both the beams and the columns . 3. The interaction between axial loads and displacements. The computer program input data includes the modulus of

JPRS Report, China, Qiushi Seeking Truth, No. 5, 1 March 1991.

DTIC Science & Technology

1991-05-09

people, bent solely on profits and leading a exuberant vitality. More and more cultural workers are corrupt life, gradually grew more and more. Especially... irrational to adopt, on this basis, a dards of intraparty political life and the organizational negative attitude of detesting politics and to go to...We should see that the inflation in the irrational demands for housing, in cer- building industry can also make money and is an impor- tain

A Study of the Attitudes of Married Minuteman Crewmembers and Their Wives Concerning Female Minuteman Crewmembers

DTIC Science & Technology

1978-12-01

female crew. The crewmembers were about evenly split as to type of crew pairing. The author recommended using an all-female crew pairing plan when...obtained so that the respondents could be assigned to various subpopulations during the analysis. Data ob- tained provided information about: Type of...respondent is made. There are many types of correlations that can be calculated but the parti- cular one employed by SPSS is Pearson’s correlation. A

Large Eddy Simulations of Supercritical Mixing Layers for Air Force Applications

DTIC Science & Technology

2010-05-01

Taskinoglu and J. Bellan Species m( gmo \\-]) 7). (K) P,(MPa) N2 28.013 126.3 3.399 C7H16 100.205...equation is that its source term, called the irreversible en- tropy production, which is by definition is the dissipation [3|, con - tains the full extent...with sim- ilar or even larger gradient magnitudes under fully turbulent con - ditions (the experimental data was for Re = O(104) - O(105)). Thus

Journal of Special Operations Medicine, Volume 7, Edition 1

DTIC Science & Technology

2007-01-01

SOMA through www.somaonline.org or contact MSG Russell Justice at justicer@earthlink.net. SOMA pro - vides a very valuable means of obtaining SOF...battlefield. The committee now has representation from all the Serv- ices and is busy deciding which way it needs to pro - ceed. There should be a...medical lessons learned and unit after actions reports (AARs) that con - tain combat mission needs has been a discussed item; this has been

Fate of 2,4,6-Trinitrotoluene in a Simulated Compost System

DTIC Science & Technology

1994-09-01

to the NaOH solution. The insoluble material remaining after the NaOH fractionation con- tained the humin fraction as well as remaining cellulose ...insoluble) (solb) HUMIN + CELLULOSE MIBK (insoluble) (MIBK) (aqueous) ICELLULOSE HUMIN HUMIC ACID + FULVIC ACID +HCI to pH 1 (insoLuble) (soluble...0.5 N NaOH (insoluble) (soluble) HUMIN+ CELLULOSE • MIBK (insoluble) (MIBK) (aqueous) CELLULOSE HUMIN HUMIC ACID + FULVIC ACID + HUMIN +HCl to pH 1

Legislative and Regulatory Actions Needed to Deal with a Changing Domestic Telecommunications Industry.

DTIC Science & Technology

1981-09-24

procedures? GAO recommends that the Congress address these questions by amending the Communications Act of 1934 to establish the basic framework to create...concerns with rate of return/rate base regulation 198 VII Basic procedures used in establishing rates of return 201 VIII Problems regarding AT&T’s rate...prompted a critical reexamination of the basic communications policy and regulatory methods con- tained in the Communications Act of 1934 (47 U.S.C

Research and Development of Wound Dressing in Maxillofacial Trauma.

DTIC Science & Technology

1983-03-14

Lidocaine 7 Table 4 PVP-1 2 (BASF 17/12) Microcapsule Size Distribution 8 Table 5 Processing Summary of PVP-1 2 (BASF 17/12) Microencapsulation 9 Table...benzalkonium chloride (Maquat LC-12S) was also incorporated into fabrics and powders. The povidone iodine (BASF 17/12) was microencapsulated using the... microcapsules con- taining povidone iodine. At 30% polymer, 70% of the product was between :- 212-600 microns. This material gave in vitro release of

Interservice/Industry Training Systems Conference (13th) Held in Orlando, Florida on 2-5 December 1991

DTIC Science & Technology

1991-12-01

within the be able to design and implement tactile feedback, cube. These simulations range from pc-oased binaural hearing, and autosterioscopic...of the 6-per-revolution beat simulate local wind velocities near the hub. experienced by the tandem 3-blade rotor hubs of the CH46, thus minimizing the...totally -- taking inventory and main- ignored- in another. For example, the taining the security of the videotape entitled " Beating the Odds -- of the

Effects of Formulated Glyphosate and Adjuvant Tank Mixes on Atomization from Aerial Application Flat Fan Nozzles

DTIC Science & Technology

2012-01-01

Bradley K. Fritz,1 W. Clint Hoffmann,1 and W. E. Bagley2 Effects of Formulated Glyphosate and Adjuvant Tank Mixes on Atomization from Aerial...Application Flat Fan Nozzles REFERENCE: Fritz, Bradley K., Hoffmann, W. Clint, and Bagley, W. E., “Effects of Formulated Glyphosate and Adjuvant Tank Mixes on...factors. Twelve spray-solution treatments were evaluated, ten of which contained a formulated glyphosate product and nine of these con- tained an

Conduct Research on the Foraging Ecology of Beaked Whales in Hawaiian Waters

DTIC Science & Technology

2012-09-30

The M3R (Marine Mammal Monitoring on Navy Ranges) software were used to analyze the data. M3R can identify the biosonar signals from short-finned...various detections in terms of the percent of observation periods (OBSP) that con- tained biosonar clicks from the five different species (Cuvier...observation periods (OBSP) in which biosonar clicks were detected. Since each observation period is 30 seconds every 5 minutes, a total of 288 observation

A Critical Assessment of the Aluminum Cartridge Case Failure Mechanism

DTIC Science & Technology

1976-03-01

achievements of an exploratory development program at Frankford Arsenal. The program was initiated to determine the engineering parameters required for...third that of brass cases, are ideal for improving the combat load effectiveness of an infantryman, a combat vehicle or a gunship« To enable...damage sus- tained by aluminum cartridge cases during "burn-through". A more accurate method of determining the effect of "burn- through" in a

Finding The Right Way: Toward an Army Institutional Ethic

DTIC Science & Technology

2012-09-01

viewed as a collective American failure, rather than the failure of just Cap- tain Ernest Medina, Lieutenant William Calley, and the platoon.46 In the past...This is largely true. How- ever, William Deresiewicz noted that only Abu Ghraib was widely discussed, and he asked the question, “How many more of...and dispersed throughout the manual. In 2002, USAWC students Lieutenant Colonels Mark Patterson and Janet Phipps found the doctrine ethically

New York City, New York Municipal Forest Resource Analysis

Treesearch

P.J. Peper; E.G. McPherson; J.R. Simpson; S.L. Gardner; K.E. Vargas; Q. Xiao

2007-01-01

New York City, the largest city in the United States and one of the world’s major global cities, main-tains trees as an integral component of the urban infrastructure (Figure 1). Since 1995, over 120,000 trees have been planted along the streets of the city’s five boroughs. Over 592,000 street trees are managed by the New York City Department of Parks & Recreation...

Security of Y-00 and Similar Quantum Cryptographic Protocols

DTIC Science & Technology

2004-11-16

security of Y-00 type protocols is clarified. Key words: Quantum cryptography PACS: 03.67.Dd Anew approach to quantum cryptog- raphy called KCQ, ( keyed ...classical- noise key generation [2] or the well known BB84 quantum protocol [3]. A special case called αη (or Y-00 in Japan) has been experimentally in... quantum noise for typical op- erating parameters. It weakens both the data and key security , possibly information-theoretically and cer- tainly

JPRS Report, Soviet Union, International Affairs

DTIC Science & Technology

1989-09-11

and ethnic contradictions as well as social-class ones. In the Malaysian state bureaucracy, for example, basically Malaysian in derivation, a policy...of seeing that the share of Malaysian capital in trade and industry reaches 30 percent by 1990 is being doggedly pursued to the detri- ment of the...Chinese and Indian capital that still main- tains its sway in the country’s economy. The Malaysian origins of the traditionally honored hereditary

Software Supportability Risk Assessment in OT&E (Operational Test and Evaluation): Literature Review, Current Research Review, and Data Base Assemblage.

DTIC Science & Technology

1984-09-28

variables before simula- tion of model - Search for reality checks a, - Express uncertainty as a probability density distribution. a. H2 a, H-22 TWIF... probability that the software con- tains errors. This prior is updated as test failure data are accumulated. Only a p of 1 (software known to contain...discusssed; both parametric and nonparametric versions are presented. It is shown by the author that the bootstrap underlies the jackknife method and

A Comparison of Nonlinear Filters for Orbit Determination and Estimation

DTIC Science & Technology

1986-06-01

Com- mand uses a nonlinear least squares filter for element set maintenance for all objects orbiting the Earth (3). These objects, including active...initial state vector is the singularly averaged classical orbital element set provided by SPACECOM/DOA. The state vector in this research consists of...GSF (G) - - 26.0 36.7 GSF(A) 32.1 77.4 38.8 59.6 The Air Force Space Command is responsible for main- taining current orbital element sets for about

Translations on Eastern Europe, Political, Sociological, and Military Affairs. No. 1310

DTIC Science & Technology

1976-10-21

alone main- tain in the GDR 52 hospitals with 7,000 beds, 87 homes and institutions for the physically and mentally disabled, with room for more than...40 hospitals and 167 other church homes for social welfare purposes in the GDR. Similar statistics could also be cited for the smaller religious...or not the witness of Jesus Christ is not being told listlessly and nervously in them; —to the church executive committees, whether they take up and

Development of Composite Spectrophotometric Procedures for the Analysis of Low-Alloy Steels and of Aluminum and Its Alloys

DTIC Science & Technology

1952-11-01

COPPER lb Although copper can be determined by measurement of the blue cupric ammonia complex, the reaction is not very sensitive and is subject to...alkaline solution of the sample con- taining tartrate , provided a means of separation of copper by extraction of WADO TR 52-246 1 the copper bensoinoximate...potassium tartrate ), and sodium hydroxide solution added to ad- just the pH within the range ll3 to 12-3. After adding alpha-benzoinoxime the mixture was

Analytical Methods for Determining Nitroguanidine in Soil and Water

DTIC Science & Technology

1989-11-01

Westerdahl 1986, Manning and Maskar- inec 1987) eluted with a mobile phase that is pre- Table 2. Summary of high-performance liquid chromatographic methods...mg/L Ogle and Westerdahl (1986) 3 mL/min dominantly water. Nitroguanidine is not well re- saved using a Hewlett Packard 9114B disk drive. tained on...the ex- Ogle, E.E. and R.P. Westerdahl (1986) On-line tracts are filtered through 0.45-pm membranes. monitors for water pollutants. USA Armament Re

Precision Timing and Measurement for Inference with Laser and Vision

DTIC Science & Technology

2010-01-01

Robotics 24, 8-9 (2007), 699–722. [84] Nüchter, A., Surmann, H., Lingemann, K., and Hertzberg, J. Semantic scene analysis of scanned 3D indoor...Delaunay based triangulation can be ob- tained. Popping the points back to their 3D locations yields a feature sensitive surface mesh . Sequeira et al... texture maps acquired from cameras, the eye can be fooled into believing that the mesh quality is better than it really is. Range images are used to

Essays on Strategy VII

DTIC Science & Technology

1990-01-01

framework for a post -Cold War strategy, but rather to give examples of the elements such a strategy might con- tain, as well as some suggestions of...aspects of our national strategy. We are, for example , rcvising our conception of the Warsaw Pact nations as a single entity and our perception of...imaginatively with the issues of the post -Cold War period. One of them addresses general US strategy for the 1990s. Three focus on high-level strategic

Mechanisms in Chronic Multisymptom Illnesses

DTIC Science & Technology

2006-06-01

Psychiatry 2003;160:374–6. NEURAL ACTIVATIONS IN DEPRESSION AND CHRONIC PAIN 1583 21. Wolfe F, Ross K, Anderson J, Russell IJ. Aspects of fibromyalgia in...consequences in chronic musculoskeletal pain: a state of the art. Pain 2000;85:317–332.) S. A. MCLEAN et al. 784 Psychosomatic Medicine 67:783–790 (2005) tain...Report of the Moss International Working Group on medico-legal aspects of chronic widespread musculoskeletal pain complaints and fibromyal- gia. Scand

NMR System for a Type II Quantum Computer

DTIC Science & Technology

2007-06-01

Kevin Henry, Jr., "Coherent Control in QIP" June 2007. Please see Appendix pdf file pages 296-399. 4 Chapter 1 Introduction Recent research [1, 2, 3...can often by reduced by careful design of the time dependence of control fields. This is possible since the operators underlying the incoherence are...ob- tained by measurement. 21 1.2 Optimal Control Theory applied to Quantum Systems One of the main goals for theoretical research in quantum control

Sealane Defense: An Emerging Role for the JMSDF?

DTIC Science & Technology

1981-09-01

Constitution which is quoted below: Aspiring sincerely to an international peace based on justice and order, the Japanese people forever renounce war as a...in 1978 and 1981, showed an increase from 77 percent to 83 percent in people who favored strengthening or main- taining the SDF at present level. The ...of the ruling elite are graduates of the University of Tokyo. These ties may be likened to , but are many magnitudes greater, than those found among

YC-15 Interior Noise Measurements. Technical Discussion.

DTIC Science & Technology

1981-03-01

almost equal chord segments of the flap. The spoilers ahead of the flap are drooped as a function of flap motion to main- tain an effective slot...fan and primary exhaust air with freestream air to produce rapid temperature and velocity reduction and to spread the exhaust wake over a large span of...PRESSURESMAme Model AR- 200 Kulie Doglas14 Channel Mode XTE19010 D gital ataTape Transducer Signal Condition- INLET ACOUSTICS AND ~ odI ing Amplfiers

Integrated Parallel Processes: The Elements of Meaning in Language. Volume IV.

DTIC Science & Technology

1981-11-01

times linguistics and psychology have sought them. Religion is deeply involved, and anthropology and sociology are in important ways relevant. The...quite cir’rly. No matter what heights the human mind can at- tain, it can work only with the organs it has and the functions peculiar to them. Eyes that...is speci- fied. If a neighborhood is specified with respect to outline, colour and texture, then all objects in a sufficiently small neighborhood will

Ice Particle Charge Transfer Studies.

DTIC Science & Technology

1987-09-30

sufficient time for the rime feathers to grow . The rimed target was then exposed to the salt droplet cloud produced by a small Unicorn nebuliser. This...limited in extent, and it was possible only to grow crystals of 100 pm diameter; whereas, in nature, crystals have time to grow several hundred microns...updraft which countered ti~e terminal fall velocity of the growing crystals. The droplet supply was main- tained and the crystals grew to about 150-200

Long-Bone Injury Criteria for Use with the Articulated Total Body Model

DTIC Science & Technology

1981-01-01

bone - human, canine, bovine, etc.; condition of bone - dry, wet , embalmed , fresh; subject variations - height, weight, health, sex, age, etc; whole bone...stress strain curves ob- tained by McElhaney for various strain rates in compression. This is for embalmed human compact bone. Ultimate stress, ultimate...reported for fresh human bone of 25,000 psi (see Table 1). Recall that the McElhaney data is from embalmed subjects. If it is assumed, for lack of any real

Effect of Coadministration of Vancomycin and BMP-2 on Cocultured Staphylococcus aureus and W-20-17 Mouse Bone Marrow Stromal Cells in Vitro

DTIC Science & Technology

2012-07-01

regard to war traumas in ex- tremities, where infection of open type III fractures is all but cer- tain (10, 33). These bacterial infections complicate...healing and reduce infection . J. Orthop. Trauma 25:477– 482. 19. Gustilo RB, Anderson JT. 1976. Prevention of infection in the treatment of one...subject to a penalty for failing to comply with a collection of information if it does not display a currently valid OMB control number 1. REPORT DATE 01

Uncoupling GP1 and GP2 Expression in the Lassa Virus Glycoprotein Complex: Implications for GPI Ectodomain Shedding

DTIC Science & Technology

2008-12-23

glycoprotein precursor (GPC) signal peptide (SP) or human IgG signal sequences (s.s.). GP2 was secreted from cells only when (1) the transmembrane (TM) domain...consistent with viral TM fusion proteins [9,10]. GPC con- tains a 58 residue hydrophobic N-terminal signal peptide (SP), which directs the precursor to the...including GPC, GP1, and GP2. Various signal peptides , purification tags, and modifications to internal domains were employed for the generation and

Gaseous Electronics Conference (35th) Held at Dallas, Texas, 19-22 October 1982.

DTIC Science & Technology

1982-12-31

Hz LTE arcs con- taining mrury and metal halide additives such as Nal and Sc13 . , Using a well defined cylindrical arc vessel and a known mercury ...termination of the high pressure mercury arc will be presented. 1 F.E. Irons, J.Quant.Spect.Radiat.Transfer 22,1,(1979). 41IBLANK I- CA-3 Time Dependent...High pressure mercury lamps were. operated on a perioically pulsed supply voltage. From optically thin mercury line emission the variation of the axial

Synthetic aperture radar signal data compression using block adaptive quantization

NASA Technical Reports Server (NTRS)

Kuduvalli, Gopinath; Dutkiewicz, Melanie; Cumming, Ian

1994-01-01

This paper describes the design and testing of an on-board SAR signal data compression algorithm for ESA's ENVISAT satellite. The Block Adaptive Quantization (BAQ) algorithm was selected, and optimized for the various operational modes of the ASAR instrument. A flexible BAQ scheme was developed which allows a selection of compression ratio/image quality trade-offs. Test results show the high quality of the SAR images processed from the reconstructed signal data, and the feasibility of on-board implementation using a single ASIC.

Monitoring The Stability Of Levees With Time-Series ENVISAT ASAR Images

NASA Astrophysics Data System (ADS)

Pei, Yuanyuan; Liao, Mingsheng; Wang, Teng; Zhang, Lu

2012-01-01

Levees are constructed to protect coastal cities from typhoon, flood, and sea tide. Since the stability of levees is important, it is necessary to monitor their deformation regularly. Repeat-track space-borne SAR images are useful for environment monitoring, especially for ground deformation monitoring. Shanghai resides on the Yangtze River Delta on China’s eastern coast. Each year, the city is hit by typhoons from the Pacific Ocean and threatened by the flood of the Yangtze River. We used Persistent Scatterer Interferometry to monitor the deformation of the levees. Our experiments show that the levees around Pudong airport and Lingang town suffer from serious deformation.

Characterization of the Chemical Constitution and Profile of Pharmacological Activity of PGBx.

DTIC Science & Technology

1980-04-30

Mitochondrial Oxydative Phosphorylation System Columna Percent Activity- Comments Fractiorr 20 g 40 4g 7 50 100 slightly lower specific activity 8 115 115...amber alcoholic solution con- taining 155.6 mg of PGBx acid per ml. It was converted to the water- soluble sodium salt by us and both the freeze dried...salt and alcoholic solution were stored at 50C in a dessicator. For all biological studies, PGBx-Na was dissolved in appropriate volumes of Sorenson’s

Exercise in the Heat is Limited by a Critical Internal Temperature

DTIC Science & Technology

2000-08-01

various strains of antelope (20), the cheetah (21), dogs (24), and humans (6, 12, 14, 15). There is evidence that limitations in endurance performance in...On receipt, all rats were main- tained on a calorically restricted diet , receiving 60–63% of the diet consumed by rats fed ad libitum, as determined by...occurred when Thyp reached 42.0–42.9°C in exercising goats. Furthermore, cheetahs cease running when their core temperature reaches 40.5°C (21

Clinical Investigation Program.

DTIC Science & Technology

1987-09-30

Mexico , September 1987. Publications: None ! ~t 4, FAMC A.P.R. (RCS MED 300) Detail Summary Sheet (HSCR 40-23 as amended) (1) Date: 30 Sep 87 (2...Infection: A Prospective Study. Presented: 2nd Annual Symposium of the Rocky Moun-tain Flow Cytometry Users Group, Albuquerque, New Mexico , 10-11...COL, MC (9) Dept/Sv:Pe-at (10) Associate Tnvestigators (lI) Tey WoJr--s: Myron J. Levin, M.D. varicella vaccine U Co. HSC (12) Accumu tEve MEDCASE:* 1

Physical and Chemical Properties of Pan-Derived Electrospun Activated Carbon Nanofibers and Their Potential for Use As An Adsorbent for Toxic Industrial Chemicals (Postprint)

DTIC Science & Technology

2012-09-14

nitro- gen impregnation is a complex process, as retaining the ni- trogen, which can exist in numerous forms—many of which are not basic (e.g., pyrrole ...identity 398.1 35.4 Pyridinic 400.7 57.3 Pyrrolic 403.1 7.3 Pyridine-N-oxide ACFC. The coal-derived BPL™ has been measured to con- tain a significant amount...functionalities as pyrrolic functionalities (Boudou 2003). Others have shown simi- lar results for ammonia-treated carbons (Stohr et al. 1991; Mangun

Energetic Ionic Liquids Based on Lanthanide Nitrate Complex Anions (Postprint)

DTIC Science & Technology

2008-01-01

calculated nitrogen content for CO-balanced aluminum -con- taining ionic liquids is 28%,[3] while the nitrogen content of CO-balanced salts 11 and 12 is...1 mg of 11 was heated to 200 8C in a micro melting point apparatus, gases rapidly evolved to leave white lanthanum oxide powder . The decomposition...Iyen- gar , J. Tomasi, V. Barone, B. Mennucci, M. Cossi, G. Scalmani, N. Rega, G. A. Petersson, H. Nakatsuji, M. Hada, M. Ehara, K. Toyota, R. Fukuda, J

The Stillborn Army: Political Contention and the Fate of De Gaulle’s Armee de Metier

DTIC Science & Technology

1988-05-25

the Germans in antitank weapons S 1Anthony Adamthwaite, France and the Coming of the Second World War 1936-1939 (London: Frank Cass & Co., 1977), xii...Liddell-Hart, . -. History of the Second World War (New York: G. P. Putnam’s Sons, 1971), 21. 3 James F. McMillan, Dreyfus to de Gaulle: Politics and...Comino of the Second World War , xi. ... 55j. R. Tournoux, P~tain and de Gaulle. 1964, trans. Oliver Coburn .4,-.,., (London: William Heinemann, 1966

Determination of the Width of the Carrier Recombination Zone in Organic Light-Emitting Diodes

DTIC Science & Technology

2003-09-18

biphenyl-4,48-diamine ~TPD!/tris-~8-hydroxyquinolinato! aluminum III ( Alq3 )/ Mg:Ag. In addition, an independent evaluation of the light output coupling...5 min. TPD, obtained from H. W. Sands, was used as the hole transport layer and Alq3 , ob- tained from TCI America, was used as the emitting/electron...transport layer. TPD was used as received while Alq3 was purified by train sublimation. A 100 nm thick Mg:Ag film,4 © 2003 American Institute of

Exhaust-Stack Nozzle Area and Shape for Individual Cylinder Exhaust-Gas Jet-Propulsion System

DTIC Science & Technology

1943-01-01

ty and con- siderable loss in the availabfity of the energy occurs because of acoustic shock and because the kinetic energy is trans- formed into heat ...plate in the air-intake duct. A tank was installed between the engine and the oriiice plata to damp out pulsations . The fuel flow was measured by a...with a length of flexible tubing. A tap for measuring static pres- sure was locxded in the tank. Tank pressures were main- tained by operation of an

Experimental Verification and Revision of the Venting Rate Model of the Hazard Assessment Computer System and the Vulnerability Model.

DTIC Science & Technology

1980-11-01

discharge of a nonvolatile liquid can be ob- tained by standard Bernoulli -type relations; it is: WLo = CDA LoPL (2[PT - P-/PL + - ZLh) 1/ (1110) In all...cargo outflow momentum is low (i.e., when the net positive pressure differ- ence across the puncture is near zero). The tests showed that the water...34Benedict-Webb- Rubin Ecuation of State for Methane at Cryogenic Condi- tions," Advances -in Crvccenic ’Encineerinc., 14, po. 49-54, Plen=m Press, 1969

East Europe Report, Economic and Industrial Affairs

DTIC Science & Technology

1984-09-14

there are still places in the fields not adequately treated. Neither can one ignore the effect of contaminating the environment. In order to rectify... underwear , and a small quantity of women’s lingerie. About 30 percent of our production is subject to contract prices. We verify these once a year...34Polish Klondike": A Test of Ore and ... Character"] pText] In the fired interior of the furnace stands a ceramic crucible con- taining 100 kg of melted

Advancing the state-of-the-art of the optical atomic clock

NASA Astrophysics Data System (ADS)

Ye, Jun

2014-05-01

The continued advance in laser phase coherence has permitted an improvement of the stability of optical lattice clocks by a factor of 10. This measurement precision has facilitated characterization of systematic effects, allowing us to improve the lattice clock accuracy by a factor of 20. The accuracy and stability of the JILA Sr clock now reach the 10-18 level. Owing to these advances, the lattice clock has also emerged as an effective laboratory to study many-body spin correlations. NIST, NSF, DARPA-QuASAR.

Density functional Theory Based Generalized Effective Fragment Potential Method (Postprint)

DTIC Science & Technology

2014-07-01

is acceptable for other applications) leads to induced dipole moments within 10−6 to 10−7 au of the precise values . Thus, the applied field of 10−4...noncovalent interactions. The water-benzene clusters17 and WATER2711 reference values were also ob- tained at the CCSD(T)/CBS level, except for the clusters...with n = 20,42 where MP2/CBS was used. The n-alkane dimers18 benchmark values were CCSD(T)/CBS for ethane to butane and a linear extrapolation method

JPRS Report, Near East & South Asia

DTIC Science & Technology

1991-05-01

sensitive positions in scientific Elections fields, which has enabled them to examine secrets per- 91AE0336A Amman JORDAN TIMES in English taining to...undertaking major Arab development projects, which establish the pillars of an Arab economic 91AE0338C Tel Aviv MA ’ARIV in Hebrew 8 Mar 91...stability of the Middle East. Toward this goal, it is 91AEO329D TelAviv ’ALHAMISHMAR in Hebrew reasonable that it have an interest in a pact with demo- 8

A study on venom proteins of Iurus dufoureius asiaticus Birula, 1903 (Scorpiones: Iuridae).

PubMed

Keskin, Nurşen Alpagut; Koç, Halil

2006-01-01

The scorpion Iurus dufoureius asiaticus (Birula 1903) which is the largest scorpion in Europe and Turkey belongs to the family Iuridae and is endemic in Turkey. No data has been found about the venom components of I. d. asiaticus. In this study, the venom extract ob-tained from I. d. asiaticus specimens collected from Aydin were analyzed using the Tris tricine SDS-PAGE method. A total of 28 protein fractions or fraction groups were detected in the range of 6.5-205 kDa.

The Fatigue Characteristics of Bolted Lap Joints of 24S-T Alclad Sheet Materials

DTIC Science & Technology

1946-10-01

extremely close bolt fits are needed to o%tain maximum life of bolt ~oint~ under repeated etreseeci. -. Szvzral ty~+?+s of bolt patterns hava been tegted...Memorial Institute on spec~meris of 0.102-i.nch sheet. In particular, figure 4 shows, on a load- life diagram, . results of tests Qn single-bolt...results of tests at the Univer- sity of’ il~~nols on single—bolt specimens, Tables 10 and 11 give reeults of tests, made at the U“ uiversity of Illino~8 , on

Applied Sciences Department (R&D) Patents; a Compilation

DTIC Science & Technology

1978-12-28

References Cited the first ampoule so that the two ampoules can he bro- UNITED STATES PATENTS ken simultaneously, and, upon mixing of the chemilu...Che-V222/541 miluminescent material and the other ampoule con-.tains an activator material. The almpoules can be bro-(561 References Cited ken by...Eaminer.-Robe" F. Stshl Aimmweys- Edgar J. broere. Ii. H Loach . and Paul S. isat `PYROTECHNCIGNALING ID E 1cER IT4 COMtPiOm WA!Eft EACTII’tIGN11M 4

Serum Zinc, Iron, and Copper Concentrations during Typhoid Fever in Man: Effect of Chloramphenicol Therapy

DTIC Science & Technology

1974-11-12

automated colori- exposure. In those volunteers who became clinically metric technique (13, 14). ill and were hospitalized, blood samples were ob- Monkey ...study. Two adult female rhesus monkeys tained for an additional seven days. were inoculated intravenously with 1 x 1010 viable S. Serum zinc, iron, and...on Serum Transferrin and am0 at-Macroglebullfl Concentrations zoo D a ft T r peora laa r mr U ea n b Uoac t o o Control 283 * 7 ml339 :L 13 10 di 120

Intelligent Multi-Media Integrated Interface Project

DTIC Science & Technology

1990-06-01

RADC (COES) Griffiss AFB NY 13441-5700. This will assist us in main- taining a current mailing list. Do not return copies of this report unless...contractual obligations or notices on a specific document require that it be returned. INTELLIGENT MULTI-MEDIA INTEGRATED INTERFACE PROJECT J. G. Neal J. M...lure ag. A = W qMN 1. AGENCY USE ONLY AM BW 2. REPORT DATE R,,PE AND DATES COYERED June 1990 Final Oct 87 to Oct 89 4. TTLE AND SUIlllLE S. FUNDING

Prediction of Backscatter and Emissivity of Snow at Millimeter Wavelengths.

DTIC Science & Technology

1980-01-01

LIST OF FIGURES Figure Title Page C-I General Area Map 204 C-2 Location of Alpena National Weather 205 Service Station C-3 Photographs of Site E 206 C-4...February 5, 6, 7, 1979 were ob- tained from National Weather Service, Alpena Station and included in Tables C-9 through C-12. Figure C-2 shows the...relative position * 1 of the sites and the Alpena National Weather Service Station. 203 I 0 1 s LAKE HURON ROGERS CITY 20 0 5 10 MILES 0 C HEBOYGAN NORTH

In the Era of Limits: A Galveston District History Update, 1976-1986

DTIC Science & Technology

1990-08-01

Sierra Club vs. Marsh. 34Maass, Muddy Waters, p. 23; Thomas M. Clement, Jr., Glenn Lopez, and Pamela T. Mountain , "Engineering a Victory for Our...great land, I’m sure. It’s got ever-thin’ a man might want-free land, free cattle, beautiful rivers, and mountains too, I hear, in the west. But...meteorologist compared it to "a gorilla with a machine gun. It goes where it wants to.൨ As sus- tained winds increased to 7 4 miles per hour, the

AFRRI Reports, First Quarter 1993

DTIC Science & Technology

1993-05-01

Oncology, Southern Califbrnia Sonw oifI these dlifferenles a rt: t hat, !or these Ia te Cancer Research Labo~ratory, U1Tniversity of’Southern Calilor- (fetp...acid WXR- 1065, lot BK 71 365 vas ob~taine’d fro nt I ndependently, the protective efh(’cts tof ’AR-151326 the )i~vision of’ Cancer Treatmniit...ion nttr one drn ativ kithbi . Cancer Rewarrauh. 45, 5-3 79-538 1. References ti’.~PRATNOr C~., 198.51h. ’’llre radii rotiriie~t’ r XVRI 065 Reeecsred

VACUUM TRAP

DOEpatents

Gordon, H.S.

1959-09-15

An improved adsorption vacuum trap for use in vacuum systems was designed. The distinguishing feature is the placement of a plurality of torsionally deformed metallic fins within a vacuum jacket extending from the walls to the central axis so that substantially all gas molecules pass through the jacket will impinge upon the fin surfaces. T fins are heated by direct metallic conduction, thereby ol taining a uniform temperature at the adeorbing surfaces so that essentially all of the condensible impurities from the evacuating gas are removed from the vacuum system.

Comparative Analysis of Active and Passive Mapping Techniques in an Internet-Based Local Area Network

DTIC Science & Technology

2004-03-01

PIII/500 (K) 512 A11 3C905 Honeynet PIII/1000 (C) 512 A11 3C905 Generator PIII/800 (C) 256 A11 3C905 Each system is running Debian GNU / Linux “unstable...Network,” September 2000. http://www.issues.af.mil/notams/notam00-5.html; accessed January 16, 2004. 5. “Debian GNU / Linux 3.0 Released,” Debian News...interact with those servers. 1.5 Summary The remainder of this document is organized into four chapters. Chapter 2 con - tains the literature review where

Dielectric Performance of High Permitivity Nanocomposites: Impact of Polystyrene Grafting on BaTiO3 and TiO2

DTIC Science & Technology

2016-09-22

group of polymer grafted, hairy nanopar- ticles (HNPs) that feature high εr and refractive index core plus a polymer corona with tunable structure.15–17...Supporting Information, Fig. S6. Discharge efficiency was comparable for 3% v/v PS@BaTiO3 + PS and 4% v/v PS + BaTiO3 and main- tain a value of >85% for...BaTiO3 traditional blend films displayed a marked reduction in break- down strength, decreasing from 139 V/μm at 3% v/v down to Figure 6 Energy discharge

An Expert System Framework for Adaptive Evidential Reasoning: Application to In-Flight Route Re-Planning

DTIC Science & Technology

1986-03-21

i t a t i v e frameworks (e.g., Doyle, Toulmin , P . Cohen), and e f f o r t s t o syn thes i ze l o g i c and p r o b a b i l i t y (Nilsson...logic allows for provisional acceptance of uncer- tain premises, which may later be retracted when they lead to contradictory conclusions. Toulmin (1958...A1 researchers] have accepted without hesitation as impeccable." * The basic framework of an argument, according to Toulmin , is as follows ( Toulmin

Bis(μ2-iso-propyl-imido-κ(2) N:N)bis-[(η(5)-cyclo-penta-dien-yl)(ethenolato-κO)titanium(IV)].

PubMed

Haehnel, Martin; Spannenberg, Anke; Rosenthal, Uwe

2014-01-01

The title dinuclear half-sandwich complex, [CpTi(OCH=CH2)(μ2-N-iPr)]2 (Cp = cyclo-penta-dien-yl; iPr = isopropyl), was ob-tained from the reaction of Cp2TiCl2, n-butyl-lithium and iso-propyl-amine in tetra-hydro-furan. Each Ti(IV) atom is coordinated by one Cp ligand, one vin-yloxy unit and two bridging imido groups in a strongly distorted tetra-hedral geometry. There are two half mol-ecules in the asymmetric unit, such that whole mol-ecules being generated by inversion symmetry.

Analysis of Wind and Sea State in SAR data of Hurricanes

NASA Astrophysics Data System (ADS)

Hoja, D.; Schulz-Stellenfleth, J.; Lehner, S.; Horstmann, J.

2003-04-01

Spaceborne synthetic aperture radar (SAR) is still the only instrument providing directional ocean wave and in addition surface wind information on a global and continuous basis. Operating in ASAR wave mode ENVISAT, launched in 2002, provides 10 km x 5 km SAR images every 100 km along the orbit. These SAR data continue and expand the SAR era of the European Remote Sensing satellites ERS-1 and ERS-2, which have acquired similar SAR data since 1991 on a global basis. To not only use the official ERS SAR wave mode product, which consists only of the SAR image power spectrum, but also the full SAR image information a subset of 27 days globally distributed ERS-2 SAR raw data were processed to single look complex SAR imagettes using the BSAR processor developed at the German Aerospace Center. These data have the same format as the official ESA product for ENVISAT ASAR wave mode data. This subset of 34,000 ERS-2 SAR imagettes was used to develop and validate algorithms for wind and wave retrieval, which are also applicable to ENVISAT ASAR wave mode data. The time frame of the dataset covers several tropical cyclones in the Atlantic Ocean of which hurricane Fran has been investigated in detail together with additional data available from scatterometers, buoys and weather centers. Hurricane Fran was active from August 23 to September 8, 1996. During this time, hurricane Fran developed near the African coast and progressed over the North Atlantic Ocean. Landfall occurred on September 5, 1996 at the coast of North Carolina, USA. Fran was part of a whole series of tropical cyclones travelling about the same course in a short time. The wind is extracted from SAR imagery and compared to results of the numerical model output provided by the European Center for Medium-Range Weather Forecast (ECMWF) and co-located ERS-2 scatterometer measurements. The Swell and wind sea systems generated by the tropical cyclones are measured using SAR cross spectra and a newly developed

Fighting the Russians in Winter: Three Case Studies (Leavenworth Papers, Number 5)

DTIC Science & Technology

1981-12-01

e z s aya elve les rther e e nth ey led ro eir ilroad itions l l- e i lery, inly 75- s ned ite ssians. ey centrated l e ops ey ld e rom...ines een aya e ad itions, ter e rning ree ttalions e oscow iment lanked e lies e rth e pted ture o - s ro e . ieutenant kovsky, e ite...cal e ents s practical, tain itional ts e paign rthern ssia a rant tention r eir nical s. t aya llied t oops lived i erted ilroad cars. he i pro

High Frequency Aircraft Antennas

DTIC Science & Technology

1968-05-03

is ob- tained if the current on the loop is assunned to be a superposition of two oppositely directed uniform traveling -wave currents of equal...effect will be to slow down the traveling wave currents on the loop and thus make the loop appear larger in size. Equations (6), (7), and (IÜ...18C/NDT + 1 NTRAN3=ü L»0 CALL LINSEG<NWIRE.L»X.Y.Z.5I . SALP ,CAB.SAB) N = L NN=N+1 WR|TE(6«11) IF(N-100) 4 1,41.500 41 CONTINUE Jl = l J2

A joint method to retrieve directional ocean wave spectra from SAR and wave spectrometer data

NASA Astrophysics Data System (ADS)

Ren, Lin; Yang, Jingsong; Zheng, Gang; Wang, Juan

2016-07-01

This paper proposes a joint method to simultaneously retrieve wave spectra at different scales from spaceborne Synthetic Aperture Radar (SAR) and wave spectrometer data. The method combines the output from the two different sensors to overcome retrieval limitations that occur in some sea states. The wave spectrometer sensitivity coefficient is estimated using an effective significant wave height (SWH), which is an average of SAR-derived and wave spectrometer-derived SWH. This averaging extends the area of the sea surface sampled by the nadir beam of the wave spectrometer to improve the accuracy of the estimated sensitivity coefficient in inhomogeneous sea states. Wave spectra are then retrieved from SAR data using wave spectrometer-derived spectra as first guess spectra to complement the short waves lost in SAR data retrieval. In addition, the problem of 180° ambiguity in retrieved spectra is overcome using SAR imaginary cross spectra. Simulated data were used to validate the joint method. The simulations demonstrated that retrieved wave parameters, including SWH, peak wave length (PWL), and peak wave direction (PWD), agree well with reference parameters. Collocated data from ENVISAT advanced SAR (ASAR), the airborne wave spectrometer STORM, the PHAROS buoy, and the European Centre for Medium-Range Weather Forecasting (ECMWF) were then used to verify the proposed method. Wave parameters retrieved from STORM and two ASAR images were compared to buoy and ECMWF wave data. Most of the retrieved parameters were comparable to reference parameters. The results of this study show that the proposed joint retrieval method could be a valuable complement to traditional methods used to retrieve directional ocean wave spectra, particularly in inhomogeneous sea states.

The Organization of the Suprachiasmatic Circadian Pacemaker of the Rat and Its Regulation by Neurotransmitters and Modulators

DTIC Science & Technology

1994-02-02

This clock, located in the brain’s suprachiasmatic nucleus (SCN), can be removed in a slice of hypothalamus, main- tained in a. lite support system...slice of hypothalamus, main- 10> tamned in a lite support system for up to 3 days and studied directly. Using this approach, W.. progress in the 3 112...Wmtz .I’’’f’: A.. wklfIfif cm N.. ffttf:T _ ’I.. ’Af.f-:\\f’:f/. IL & Vrf -:fKE It (IMS31 tff’fa/ifft ’if1\\ lhi/ll ff10 1’’ ) imfii/f’/ftfif/f f/f/ill/i!i

Bis(μ2-iso­propyl­imido-κ2 N:N)bis­[(η5-cyclo­penta­dien­yl)(ethenolato-κO)titanium(IV)

PubMed Central

Haehnel, Martin; Spannenberg, Anke; Rosenthal, Uwe

2014-01-01

The title dinuclear half-sandwich complex, [CpTi(OCH=CH2)(μ2-N-iPr)]2 (Cp = cyclo­penta­dien­yl; iPr = isopropyl), was ob­tained from the reaction of Cp2TiCl2, n-butyl­lithium and iso­propyl­amine in tetra­hydro­furan. Each TiIV atom is coordinated by one Cp ligand, one vin­yloxy unit and two bridging imido groups in a strongly distorted tetra­hedral geometry. There are two half mol­ecules in the asymmetric unit, such that whole mol­ecules being generated by inversion symmetry. PMID:24526944

Energy breakdown in capacitive deionization.

PubMed

Hemmatifar, Ali; Palko, James W; Stadermann, Michael; Santiago, Juan G

2016-11-01

We explored the energy loss mechanisms in capacitive deionization (CDI). We hypothesize that resistive and parasitic losses are two main sources of energy losses. We measured contribution from each loss mechanism in water desalination with constant current (CC) charge/discharge cycling. Resistive energy loss is expected to dominate in high current charging cases, as it increases approximately linearly with current for fixed charge transfer (resistive power loss scales as square of current and charging time scales as inverse of current). On the other hand, parasitic loss is dominant in low current cases, as the electrodes spend more time at higher voltages. We built a CDI cell with five electrode pairs and standard flow between architecture. We performed a series of experiments with various cycling currents and cut-off voltages (voltage at which current is reversed) and studied these energy losses. To this end, we measured series resistance of the cell (contact resistances, resistance of wires, and resistance of solution in spacers) during charging and discharging from voltage response of a small amplitude AC current signal added to the underlying cycling current. We performed a separate set of experiments to quantify parasitic (or leakage) current of the cell versus cell voltage. We then used these data to estimate parasitic losses under the assumption that leakage current is primarily voltage (and not current) dependent. Our results confirmed that resistive and parasitic losses respectively dominate in the limit of high and low currents. We also measured salt adsorption and report energy-normalized adsorbed salt (ENAS, energy loss per ion removed) and average salt adsorption rate (ASAR). We show a clear tradeoff between ASAR and ENAS and show that balancing these losses leads to optimal energy efficiency. Copyright © 2016 Elsevier Ltd. All rights reserved.

Sequential combination of multi-source satellite observations for separation of surface deformation associated with serial seismic events

NASA Astrophysics Data System (ADS)

Chen, Qiang; Xu, Qian; Zhang, Yijun; Yang, Yinghui; Yong, Qi; Liu, Guoxiang; Liu, Xianwen

2018-03-01

Single satellite geodetic technique has weakness for mapping sequence of ground deformation associated with serial seismic events, like InSAR with long revisiting period readily leading to mixed complex deformation signals from multiple events. It challenges the observation capability of single satellite geodetic technique for accurate recognition of individual surface deformation and earthquake model. The rapidly increasing availability of various satellite observations provides good solution for overcoming the issue. In this study, we explore a sequential combination of multiple overlapping datasets from ALOS/PALSAR, ENVISAT/ASAR and GPS observations to separate surface deformation associated with the 2011 Mw 9.0 Tohoku-Oki major quake and two strong aftershocks including the Mw 6.6 Iwaki and Mw 5.8 Ibaraki events. We first estimate the fault slip model of major shock with ASAR interferometry and GPS displacements as constraints. Due to the used PALSAR interferogram spanning the period of all the events, we then remove the surface deformation of major shock through forward calculated prediction thus obtaining PALSAR InSAR deformation associated with the two strong aftershocks. The inversion for source parameters of Iwaki aftershock is conducted using the refined PALSAR deformation considering that the higher magnitude Iwaki quake has dominant deformation contribution than the Ibaraki event. After removal of deformation component of Iwaki event, we determine the fault slip distribution of Ibaraki shock using the remained PALSAR InSAR deformation. Finally, the complete source models for the serial seismic events are clearly identified from the sequential combination of multi-source satellite observations, which suggest that the major quake is a predominant mega-thrust rupture, whereas the two aftershocks are normal faulting motion. The estimated seismic moment magnitude for the Tohoku-Oki, Iwaki and Ibaraki evens are Mw 9.0, Mw 6.85 and Mw 6.11, respectively.

Energy breakdown in capacitive deionization

DOE PAGES

Hemmatifar, Ali; Palko, James W.; Stadermann, Michael; ...

2016-08-12

We explored the energy loss mechanisms in capacitive deionization (CDI). We hypothesize that resistive and parasitic losses are two main sources of energy losses. We measured contribution from each loss mechanism in water desalination with constant current (CC) charge/discharge cycling. Resistive energy loss is expected to dominate in high current charging cases, as it increases approximately linearly with current for fixed charge transfer (resistive power loss scales as square of current and charging time scales as inverse of current). On the other hand, parasitic loss is dominant in low current cases, as the electrodes spend more time at higher voltages.more » We built a CDI cell with five electrode pairs and standard flow between architecture. We performed a series of experiments with various cycling currents and cut-off voltages (voltage at which current is reversed) and studied these energy losses. To this end, we measured series resistance of the cell (contact resistances, resistance of wires, and resistance of solution in spacers) during charging and discharging from voltage response of a small amplitude AC current signal added to the underlying cycling current. We performed a separate set of experiments to quantify parasitic (or leakage) current of the cell versus cell voltage. We then used these data to estimate parasitic losses under the assumption that leakage current is primarily voltage (and not current) dependent. Our results confirmed that resistive and parasitic losses respectively dominate in the limit of high and low currents. We also measured salt adsorption and report energy-normalized adsorbed salt (ENAS, energy loss per ion removed) and average salt adsorption rate (ASAR). As a result, we show a clear tradeoff between ASAR and ENAS and show that balancing these losses leads to optimal energy efficiency.« less

Landslide Phenomena in Sevan National Park-Armenia

NASA Astrophysics Data System (ADS)

Lazarov, Dimitrov; Minchev, Dimitar; Aleksanyan, Gurgen; Ilieva, Maya

2010-12-01

Based on data from master and slave complex images obtained on 30 August 2008 and 4 October 2008 by satellite ENVISAT with ASAR sensor,all processing chain is performed to evaluate landslides phenomena in Sevan National park - Republic of Armenia. For this purpose Identification Deformation Inspection and Observation Tool developed by Berlin University of Technology is applied. This software package uses a freely available DEM of the Shuttle Radar Topography Mission (SRTM) and performs a fully automatic generation of differential SAR interferograms from ENVISAT single look complex SAR data. All interferometric processing steps are implemented with maximum quality and precision. The results illustrate almost calm Earth surface in the area of Sevan Lake.

Fungus Resistance of Plastics

DTIC Science & Technology

1951-05-18

Penicillium luteum Triehoderma T’-^l American Type Culture f’elleet-lon.Wo-«- ._ .. 9642 9643 9644 9545 20.0 gm 10 6-0 gm o n W O V 0 = 5 g«5 0V3...the spores« The resulting Repä¥äter"’süspensinn-s were mix-ed: - to oh tain a composite sp ^ suspension for use in inoculating the test specimens...EH O Ö . v o HO Ö © CO £=i - fc> PH P-* -- ©• ra « a ^ Ö 03 CO t CH E* CO 8 o ÜJ OS bU SP * ti i«r HH - -r-i fe CM i

The betainic form of (imidazol-2-yl)phenylphosphinic acid hydrate

PubMed Central

Kunz, Peter C.; Frank, Walter

2010-01-01

Single crystals of the title compound, (imidazolium-2-yl)phenyl­phosphinate monohydrate, C9H9N2O2·H2O, were ob­tained from methanol/water after deprotection and oxidation of bis­(1-diethoxy­methyl­imidazol-2-yl)phenyl­phosphane. In the structure, several N–H⋯O and P—O⋯H–O hydrogen bonds are found. π–π inter­actions between the protonated imidazolyl rings [centroid–centroid distance = 3.977 (2) Å] help to establish the crystal packing. The hydrate water mol­ecule builds hydrogen bridges to three mol­ecules of the phosphinic acid by the O and both H atoms. PMID:21579513

RATIONAL DETERMINATION METHOD OF PROBABLE FREEZING INDEX FOR n-YEARS CONSIDERING THE REGIONAL CHARACTERISTICS

NASA Astrophysics Data System (ADS)

Kawabata, Shinichiro; Hayashi, Keiji; Kameyama, Shuichi

This paper investigates a method for ob taining the probable freezing index for n -years from past frostaction damage and meteorological data. From investigati on of Japanese cold winter data from the areas of Hokkaido, Tohoku and south of Tohoku, it was found that the extent of cold winter had regularity by location south or north. Also, after obtaining return periods of cold winters by area, obvious regional characteristics were found. Mild winters are rare in Hokkaido. However, it was clarified that when Hokkaido had cold winters, its size increased. It wa s effective to determine the probable freezing indices as 20-, 15- and 10-year return periods for Hokkaido, Tohoku and south of Tohoku, respectively.

Quantum Synchronization of three-level atoms

NASA Astrophysics Data System (ADS)

He, Peiru; Rey, Ana Maria; Holland, Murray

2015-05-01

Recent studies show that quantum synchronization, the spontaneous alignment of the quantum phase between different oscillators, can be used to build superradiant lasers with ultranarrow linewidth. We theoretically investigate the effect of quantum synchronization on many coupled three-level atoms where there are richer phase diagrams than the standard two-level system. This three-level model allows two-color ultranarrow coherent light to be produced where more than one phase must be simultaneously synchronized. Of particular interest, we study the V-type geometry that is relevant to current 87 Sr experiments in JILA. As well as the synchronization phenomenon, we explore other quantum effects such as photon correlations and squeezing. This work is supported by the DARPA QuASAR program, the NSF, and NIST.

Recent Progresses of Microwave Marine Remote Sensing

NASA Astrophysics Data System (ADS)

Yang, Jingsong; Ren, Lin; Zheng, Gang; Wang, He; He, Shuangyan; Wang, Juan; Li, Xiaohui

2016-08-01

It is presented in this paper the recent progresses of Dragon 3 Program (ID. 10412) in the field of microwave marine remote sensing including (1) ocean surface wind fields from full polarization synthetic aperture radars (SAR), (2) joint retrieval of directional ocean wave spectra from SAR and wave spectrometer, (3) error analysis on ENVISAT ASAR wave mode significant wave height (SWH) retrievals using triple collocation model, (4) typhoon observation from SAR and optical sensors, (5) ocean internal wave observation from SAR and optical sensors, (6) ocean eddy observation from SAR and optical sensors, (7) retrieval models of water vapor and wet tropospheric path delay for the HY-2A calibration microwave radiometer, (8) calibration of SWH from HY-2A satellite altimeter.

High-spatial-resolution mapping of precipitable water vapour using SAR interferograms, GPS observations and ERA-Interim reanalysis

NASA Astrophysics Data System (ADS)

Tang, Wei; Liao, Mingsheng; Zhang, Lu; Li, Wei; Yu, Weimin

2016-09-01

A high spatial and temporal resolution of the precipitable water vapour (PWV) in the atmosphere is a key requirement for the short-scale weather forecasting and climate research. The aim of this work is to derive temporally differenced maps of the spatial distribution of PWV by analysing the tropospheric delay "noise" in interferometric synthetic aperture radar (InSAR). Time series maps of differential PWV were obtained by processing a set of ENVISAT ASAR (Advanced Synthetic Aperture Radar) images covering the area of southern California, USA from 6 October 2007 to 29 November 2008. To get a more accurate PWV, the component of hydrostatic delay was calculated and subtracted by using ERA-Interim reanalysis products. In addition, the ERA-Interim was used to compute the conversion factors required to convert the zenith wet delay to water vapour. The InSAR-derived differential PWV maps were calibrated by means of the GPS PWV measurements over the study area. We validated our results against the measurements of PWV derived from the Medium Resolution Imaging Spectrometer (MERIS) which was located together with the ASAR sensor on board the ENVISAT satellite. Our comparative results show strong spatial correlations between the two data sets. The difference maps have Gaussian distributions with mean values close to zero and standard deviations below 2 mm. The advantage of the InSAR technique is that it provides water vapour distribution with a spatial resolution as fine as 20 m and an accuracy of ˜ 2 mm. Such high-spatial-resolution maps of PWV could lead to much greater accuracy in meteorological understanding and quantitative precipitation forecasts. With the launch of Sentinel-1A and Sentinel-1B satellites, every few days (6 days) new SAR images can be acquired with a wide swath up to 250 km, enabling a unique operational service for InSAR-based water vapour maps with unprecedented spatial and temporal resolution.

Monitoring Structure and Regional-Level Displacements for Lisbon Using Mltitemporal InSAR Techniques

NASA Astrophysics Data System (ADS)

Roque, Dora; Perissin, Daniele Falcao, Ana Paula; Fonseca, Ana Maria; Henriques, Maria Joao

2015-05-01

The city of Lisbon is the capital of Portugal and has been devastated by catastrophic events in the past, such as earthquakes and tsunamis. This study provides a regional analysis of displacements for the city and its neighbourhoods, between 2008 and 2010, through the application of mutitemporal InSAR techniques on Envisat ASAR images. Smaller areas with identified problems were subjected to a more refined processing. Besides, the behaviour of some key infrastructures, such as important buildings or railways, was carefully analysed in order to evaluate their safety. Subsidence was detected at the regional and small areas, in which the highest subsidence rates were verified on industrial parks or on landfills close to the river. Seasonal trends were found for the small areas, mainly related with structure thermal expansion or variations in underground water.

Sampling Of SAR Imagery For Wind Resource Assesment

NASA Astrophysics Data System (ADS)

Badger, Merete; Badger, Jake; Hasager, Charlotte; Nielsen, Morten

2010-04-01

Wind resources over the sea can be assessed from a series of wind fields retrieved from Envisat ASAR imagery, or other SAR data. Previous wind resource maps have been produced through random sampling of 70 or more satellite scenes over a given area of interest followed by fitting of a Weibull function to the data. Here we introduce a more advanced sampling strategy based on wind class methodology that is normally applied in Risø DTU’s numerical modeling of wind resources. The aim is to obtain a more representative data set using fewer satellite SAR scenes. The new sampling strategy has been applied within a wind and solar resource assessment study for the United Arab Emirates (UAE) and also for wind resource mapping over a domain in the North Sea, as part of the EU- NORSEWInD project (2008-2012).

Non-destructive imaging of spinor Bose-Einstein condensates

NASA Astrophysics Data System (ADS)

Samson, E.; Vinit, Anshuman; Raman, Chandra

2013-05-01

We present a non-destructive differential imaging technique that enables the observation of the spatial distribution of the magnetization in a spinor Bose-Einstein condensate (BEC) through a Faraday rotation protocol. In our procedure, we utilize a linearly polarized, far-detuned laser beam as our imaging probe, and upon interaction with the condensate, the beam's polarization direction undergoes Faraday rotation. A differential measurement of the orthogonal polarization components of the rotated beam provides a spatial map of the net magnetization density within the BEC. The non-destructive aspect of this method allows for continuous imaging of the condensate. This imaging technique will prove useful in experimental BEC studies, such as spatially resolved magnetometry using ultracold atoms, and non-destructive imaging of non-equilibrium behavior of antiferromagnetic spinor condensates. This work was supported by the DARPA QuASAR program through a grant from ARO.

SBAS-InSAR analysis of surface deformation at Mauna Loa and Kilauea volcanoes in Hawaii

USGS Publications Warehouse

Casu, F.; Lanari, Riccardo; Sansosti, E.; Solaro, G.; Tizzani, Pietro; Poland, M.; Miklius, Asta

2009-01-01

We investigate the deformation of Mauna Loa and K??lauea volcanoes, Hawai'i, by exploiting the advanced differential Synthetic Aperture Radar Interferometry (InSAR) technique referred to as the Small BAseline Subset (SBAS) algorithm. In particular, we present time series of line-of-sight (LOS) displacements derived from SAR data acquired by the ASAR instrument, on board the ENVISAT satellite, from the ascending (track 93) and descending (track 429) orbits between 2003 and 2008. For each coherent pixel of the radar images we compute time-dependent surface displacements as well as the average LOS deformation rate. Our results quantify, in space and time, the complex deformation of Mauna Loa and K??lauea volcanoes. The derived InSAR measurements are compared to continuous GPS data to asses the quality of the SBAS-InSAR products. ??2009 IEEE.

Unravelling the structural control of mississippi valley-type deposits and prospects in carbonate sequences of the Western Canada Sedimentary Basin

USGS Publications Warehouse

Pana, D.

2006-01-01

Re-examination of selected MVT outcrops and cores in the Interior Plains and Rocky Moun-tains of Alberta, corroborated with previous paragenetic, isotopic and structural data, suggests Laramide structural channelling of dolomitizing and mineralizing fluids into strained carbonate rocks. At Pine Point, extensional faults underlying the trends of MVT ore bodies and brittle faults overprinting the Great Slave Lake Shear Zone define apinnate fault geometry and appear to be kinematically linked. Chemical and isotopic characteristics of MVT parental fluids are consistent with seawater and brine convection within fault-confined verticalaquifers, strong water-basement rock interaction, metalleaching from the basement, and focused release of hydrothermal fluids within linear zones of strained carbonate caprocks. Zones of recurrent strain in the basement and a cap of carbonate strata constitute the critical criteria for MVTexploration target selection in the WCSB.

On the use of Multisensor and multitemporal data for monitoring risk degradation and looting in archaeological site

NASA Astrophysics Data System (ADS)

Masini, Nicola; Lasaponara, Rosa

2015-04-01

Illegal excavations represent one of the main risks which affect the archaeological heritage all over the world. They cause a massive loss of artefacts but also, and above all, a loss of the cultural context, which makes the subsequent interpretation of archaeological remains very difficult. Remote sensing offers a suitable chance to quantify and analyse this phenomenon, especially in those countries, from Southern America to Middle East, where the surveillance on site is not much effective and time consuming or non practicable due to military or political restrictions. In this paper we focus on the use of GeoEye and Google Earth imagery to quantitatively assess looting in Ventarron (Lambayeque, Peru) that is one of most important archaeological sites in Southern America. Multitemporal satellite images acquired for the study area have been processed by using both autocorrelation statistics and unsupervised classification to highlight and extract looting patterns. The mapping of areas affected by looting offered the opportunity to investigate such areas not previously systematically documented. Reference Lasaponara R.; Giovanni Leucci; Nicola Masini; Raffaele Persico 2014 ": Investigating archaeological looting using very high resolution satellite images and georadar: the experience in Lambayeque in North Peru JASC13-61R1 Cigna Francesca, Deodato Tapete, Rosa Lasaponara and Nicola Masini, 2013 Amplitude Change Detection with ENVISAT ASAR to Image the Cultural Landscape of the Nasca Region, Peru (pages 117-131). Archeological Prospection Article first published online: 21 MAY 2013 | DOI: 10.1002/arp.1451 Tapete Deodato, Francesca Cigna, Nicola Masini and Rosa Lasaponara 2013. Prospection and Monitoring of the Archaeological Heritage of Nasca, Peru, with ENVISAT ASAR Archeological Prospection (pages 133-147) Article first published online: 21 MAY 2013 | DOI: 10.1002/arp.1449 Lasaponara Rosa 2013: Geospatial analysis from space: Advanced approaches for data processing

An empirical understanding of triple collocation evaluation measure

NASA Astrophysics Data System (ADS)

Scipal, Klaus; Doubkova, Marcela; Hegyova, Alena; Dorigo, Wouter; Wagner, Wolfgang

2013-04-01

Triple collocation method is an advanced evaluation method that has been used in the soil moisture field for only about half a decade. The method requires three datasets with an independent error structure that represent an identical phenomenon. The main advantages of the method are that it a) doesn't require a reference dataset that has to be considered to represent the truth, b) limits the effect of random and systematic errors of other two datasets, and c) simultaneously assesses the error of three datasets. The objective of this presentation is to assess the triple collocation error (Tc) of the ASAR Global Mode Surface Soil Moisture (GM SSM 1) km dataset and highlight problems of the method related to its ability to cancel the effect of error of ancillary datasets. In particular, the goal is to a) investigate trends in Tc related to the change in spatial resolution from 5 to 25 km, b) to investigate trends in Tc related to the choice of a hydrological model, and c) to study the relationship between Tc and other absolute evaluation methods (namely RMSE and Error Propagation EP). The triple collocation method is implemented using ASAR GM, AMSR-E, and a model (either AWRA-L, GLDAS-NOAH, or ERA-Interim). First, the significance of the relationship between the three soil moisture datasets was tested that is a prerequisite for the triple collocation method. Second, the trends in Tc related to the choice of the third reference dataset and scale were assessed. For this purpose the triple collocation is repeated replacing AWRA-L with two different globally available model reanalysis dataset operating at different spatial resolution (ERA-Interim and GLDAS-NOAH). Finally, the retrieved results were compared to the results of the RMSE and EP evaluation measures. Our results demonstrate that the Tc method does not eliminate the random and time-variant systematic errors of the second and the third dataset used in the Tc. The possible reasons include the fact a) that the TC

Spaceborne SAR Imaging Algorithm for Coherence Optimized.

PubMed

Qiu, Zhiwei; Yue, Jianping; Wang, Xueqin; Yue, Shun

2016-01-01

This paper proposes SAR imaging algorithm with largest coherence based on the existing SAR imaging algorithm. The basic idea of SAR imaging algorithm in imaging processing is that output signal can have maximum signal-to-noise ratio (SNR) by using the optimal imaging parameters. Traditional imaging algorithm can acquire the best focusing effect, but would bring the decoherence phenomenon in subsequent interference process. Algorithm proposed in this paper is that SAR echo adopts consistent imaging parameters in focusing processing. Although the SNR of the output signal is reduced slightly, their coherence is ensured greatly, and finally the interferogram with high quality is obtained. In this paper, two scenes of Envisat ASAR data in Zhangbei are employed to conduct experiment for this algorithm. Compared with the interferogram from the traditional algorithm, the results show that this algorithm is more suitable for SAR interferometry (InSAR) research and application.

Spaceborne SAR Imaging Algorithm for Coherence Optimized

PubMed Central

Qiu, Zhiwei; Yue, Jianping; Wang, Xueqin; Yue, Shun

2016-01-01

This paper proposes SAR imaging algorithm with largest coherence based on the existing SAR imaging algorithm. The basic idea of SAR imaging algorithm in imaging processing is that output signal can have maximum signal-to-noise ratio (SNR) by using the optimal imaging parameters. Traditional imaging algorithm can acquire the best focusing effect, but would bring the decoherence phenomenon in subsequent interference process. Algorithm proposed in this paper is that SAR echo adopts consistent imaging parameters in focusing processing. Although the SNR of the output signal is reduced slightly, their coherence is ensured greatly, and finally the interferogram with high quality is obtained. In this paper, two scenes of Envisat ASAR data in Zhangbei are employed to conduct experiment for this algorithm. Compared with the interferogram from the traditional algorithm, the results show that this algorithm is more suitable for SAR interferometry (InSAR) research and application. PMID:26871446

A new way to make diamond tip hosting an atomic sized defect

NASA Astrophysics Data System (ADS)

Zhou, Tony; Stohr, Rainer; Dovzhenko, Yuliya; Casola, Francesco; Yacoby, Amir

The nitrogen-vacancy (NV) center in diamond has been fascinating people with its unique role in quantum information and magnetometry. NV magnetometry was used to investigate many fundamental physics studies and develop a number of industrial applications. One of the powerful aspects of NV magnetometry is the ability to scan in space to perform spatial magnetic field sensing with nano-meter resolution. As a new emerging scanning probe technique, it faces a huge challenge to be widely adopted due to its complexity in fabrication. Here, we report a new simple way of creating diamond tips with tools found in basic clean room facilities and mount the tips onto an experimental apparatus with common lab bench tools. Finally, scanning NV magnetometry was performed to demonstrate its application. This work is supported by the QuASAR project and the Gordon and Betty Moore Foundations EPiQS Initiative through Grant GBMF4531.

Using the MicroASAR on the NASA SIERRA UAS in the Characterization of Arctic Sea Ice Experiment

DTIC Science & Technology

2010-05-01

such that the dechirped signal is at an intermediate frequency. Feedthrough rejection is done by a surface acoustic wave (SAW) filter with its first...Fig. 3. NASA SIERRA UAS 3-View and Specifications • Up-looking and down-looking shortwave spectrometers. • Down-looking temperature sensors ( pyrometers

[Disease, experiment and psychology in mid-19th century France].

PubMed

Babini, Valeria P

2002-01-01

This article offers a contribution to the thesis that considers H. Taine and Th. Ribot the theorists of the "pathological method" in psychology, and thus the forefathers of French experimental psychology. At the same time it points out that the idea of equivalence between observation of the pathological and experimentation could already be found in th psychological medicine of the 1840s. The author examines the early years of the Annals médico-psychologiques (1843-1844), the constitution of the Société médico-psychologique (1852), and the work of J. Moreau de Tours (1843) on hashish and mental alienation, with the intention of demonstrating that in the 1850s French psychiatry was actively engaged in the debate on the Science des rapports du physique et du moral, and that consequently the organicistic paradigm, proclaimed in those years in Germany, had not yet spread to France.

Biological science in the Great Basin

USGS Publications Warehouse

,

2005-01-01

The Great Basin is an expanse of desert and high moun-tains situated between the Rocky Mountains and the Sierra Nevada of the western United States. The most explicit description of the Great Basin is that area in the West where surface waters drain inland. In other words, the Great Basin is comprised of many separate drainage areas - each with no outlet. What at first glance may appear as only a barren landscape, the Great Basin upon closer inspection reveals island mountains, sagebrush seas, and intermittent aquatic habitats, all teeming with an incredible number and variety of plants and animals. Biologists at the USGS are studying many different species and ecosystems in the Great Basin in order to provide information about this landscape for policy and land-management decision-making. The following stories represent a few of the many projects the USGS is conducting in the Great Basin.

Near Real Time Ship Detection Experiments

NASA Astrophysics Data System (ADS)

Brusch, S.; Lehner, S.; Schwarz, E.; Fritz, T.

2010-04-01

A new Near Real Time (NRT) ship detection processor SAINT (SAR AIS Integrated Toolbox) was developed in the framework of the ESA project MARISS. Data are received at DLRs ground segment DLR-BN (Neustrelitz, Germany). Results of the ship detection are available on ftp server within 30 min after the acquisition started. The detectability of ships on Synthetic Aperture Radar (SAR) ERS-2, ENVISAT ASAR and TerraSAR-X (TS-X) images is validated by coastal (live) AIS and space AIS. The monitoring areas chosen for surveillance are the North-, Baltic Sea, and Cape Town. The detectability in respect to environmental parameters like wind field, sea state, currents and changing coastlines due to tidal effects is investigated. In the South Atlantic a tracking experiment of the German research vessel Polarstern has been performed. Issues of piracy in particular in respect to ships hijacked at the Somali coast are discussed. Some examples using high resolution images from TerraSAR-X are given.

[Spatial-temporal evolution characterization of land subsidence by multi-temporal InSAR method and GIS technology].

PubMed

Chen, Bei-Bei; Gong, Hui-Li; Li, Xiao-Juan; Lei, Kun-Chao; Duan, Guang-Yao; Xie, Jin-Rong

2014-04-01

Long-term over-exploitation of underground resources, and static and dynamic load increase year by year influence the occurrence and development of regional land subsidence to a certain extent. Choosing 29 scenes Envisat ASAR images covering plain area of Beijing, China, the present paper used the multi-temporal InSAR method incorporating both persistent scatterer and small baseline approaches, and obtained monitoring information of regional land subsidence. Under different situation of space development and utilization, the authors chose five typical settlement areas; With classified information of land-use, multi-spectral remote sensing image, and geological data, and adopting GIS spatial analysis methods, the authors analyzed the time series evolution characteristics of uneven settlement. The comprehensive analysis results suggests that the complex situations of space development and utilization affect the trend of uneven settlement; the easier the situation of space development and utilization, the smaller the settlement gradient, and the less the uneven settlement trend.

Quantum Synchronization of Two Ensembles of Atoms

NASA Astrophysics Data System (ADS)

Xu, Minghui; Tieri, David; Fine, Effie; Thompson, James; Holland, Murray

2014-05-01

We present a system that exhibits quantum synchronization as a modern analogue of the Huygens experiment which is implemented using state-of-the-art neutral atom lattice clocks of the highest precision. In particular, we study the correlated phase dynamics of two mesoscopic ensembles of atoms through their collective coupling to an optical cavity. We find a dynamical quantum phase transition induced by pump noise and cavity output-coupling. The spectral properties of the superradiant light emitted from the cavity show that at a critical pump rate the system undergoes a transition from the independent behavior of two disparate oscillators to the phase-locking that is the signature of quantum synchronization. Besides being of fundamental importance in nonequilibrium quantum many-body physics, this work could have broad implications for many practical applications of ultrastable lasers and precision measurements. This work was supported by the DARPA QuASAR program, the NSF, and NIST.

Understanding the Future Market for NovaSAR-S Flood Mapping Products Using Data Mining and Simulation

NASA Astrophysics Data System (ADS)

Lavender, Samantha; Haria, Kajal; Cooksley, Geraint; Farman, Alex; Beaton, Thomas

2016-08-01

The aim was to understand a future market for NovaSAR-S, with a particular focus on flood mapping, through developing a simple Synthetic Aperture Radar (SAR) simulator that can be used in advance of NovaSAR-S data becoming available.The return signal was determined from a combination of a terrain or elevation model, Envisat S-Band Radar Altimeter (RA)-2, Landsat and CORINE land cover information; allowing for a simulation of a SAR image that's influenced by both the geometry and surface type. The test sites correspond to data from the 2014 AirSAR campaign, and validation is performed by using AirSAR together with Envisat Advanced (ASAR) and Advanced Land Observing Satellite "Daichi" (ALOS) Phased Array type L-Band Synthetic Aperture Radar (PALSAR) data.It's envisaged that the resulting simulated data, and the simulator, will not only aid early understanding of NovaSAR-S, but will also aid the development of flood mapping applications.

INSAR Study Of Landslides In The Region Of Lake Sevan-Armenia

NASA Astrophysics Data System (ADS)

Lazarov, A.; Minchev, D.

2012-01-01

The region of Lake Sevan in Armenia is of theoretical and practical interest due to its very high landslide phenomena caused by metrological and hydrological reasons. Based on the ESA Principal Investigator Number C1P-6051 and requested data from ASAR instrument of ESA ENVISAT satellite four single look complex images including two images from 2008 and two images from 2009 of the region of the Sevan Lake in Armenia are obtained and thoroughly investigated. The one of the images is pointed out as a master and the rest of them, three images as slaves. Hence, three interferometric pairs are produced. Then data of NASA SRTM mission is applied to the interferometric pairs in order to remove topography from the interferograms. Three interferograms generated illustrate decreasing of coherence caused by high temporary decorelation, which means decreasing the level of coincidence of SLC’s in each interferometric pair, according to the time of acquisition each of them.

Monitoring Ground Deformation Using Persistent Scatters Interferometry (PSI) and Small Baselines (SBAS) Techniques Integrated in the ESA RSS Service: The Case Study of Valencia, Rome and South Sardinia

NASA Astrophysics Data System (ADS)

Delgado, Manuel J.; Cuccu, Roberto; Rivolta, Giancarlo

2015-05-01

This work is focused on the infrastructure monitoring of areas which had experienced significant urbanization and therefore, also an increase of the exploitation of natural resources. Persistent Scatters Interferometry (PS-InSAR) and Small Baselines (SBAS) approaches are applied to three study areas for which large datasets of SAR images are available in ascending and descending modes to finally deploy deformation maps of different buildings and infrastructures. Valencia, Rome and South Sardinia areas have been selected for this study, having experienced an increase of the exploitation of natural resources in parallel with their urban expansion. Moreover, Rome is a very special case, where Cultural Heritage permeating the city and its surroundings would suggest the necessity of a tool for monitoring the stability of the different sites. This work wants to analyse the potential deformation that had occurred in these areas during the period 1992 to 2010, by applying Persistent Scatters Interferometry to ESA ERS SAR and Envisat ASAR data.

[Psychophysical parallelism. On a discursive figure in the field of scientific changes in the late 19th century].

PubMed

Wegener, Mai

2009-01-01

The article traces the rise and fall of "psychophysical parallelism" - which was the most advanced scientific formulation of the mind / body relationship in the second half of the 19th century - through an interdisciplinary and broad geographical spectrum. It sheds light on the extremely different positions that rallied round this discursive figure, ranging from Fechner, Hering, Mach, Wundt, Bain, Hughlings Jackson, and Taine to Freud and Saussure. The article develops the thesis that the psychophysical parallelism functioned as a 'hot zone' within and a symptom of the changes in the order of sciences at that time. Against that background, the criticism of the psychophysical parallelism which became prominent around 1900 (Stumpf, Busse, Bergson, Mauthner et. al.) indicates the cooling of this 'hot zone' and the establishment of a new order within the scientific disciplines. The article pays particular attention to the position of this figure in contemporaneous language theories. Its basic assumption is that the relationship between the body and the psyche is itself constituted by language.

Numerical Simulation of A Right-moving Storm Over France

NASA Astrophysics Data System (ADS)

Chancibault, K.; Ducrocq, V.; Lafore, J.-Ph.

A three-dimensional non-hydrostatic mesoscale model is used to simulate the right- moving storm produced through storm splitting, on 30 may 1999, over northern France. The initial state is provided by the French 3D-var ARPEGE analysis and the simuation is performed with two interactive nested domains. The aim of this study is to improve our understanding of such storm dynamics. A vor- ticity analysis has been carried out, with emphasis on stretching and tilting terms of the vertical vorticity equation, thanks to the backward trajectories. The baroclinic produc- tion and stretching terms of the horizontal vorticity equation have also been studied to understand the interaction between the horizontal vorticity and a mesoscale thermal line. Finally, the spatial and temporal variation of the Storm Relative Environmental Helicity has been examined. Most of the results compare well with previous results on right-moving storms ob- tained from theoritical or numerical studies from idealized homogeneous base state.

DIODE STEERED MANGETIC-CORE MEMORY

DOEpatents

Melmed, A.S.; Shevlin, R.T.; Laupheimer, R.

1962-09-18

A word-arranged magnetic-core memory is designed for use in a digital computer utilizing the reverse or back current property of the semi-conductor diodes to restore the information in the memory after read-out. In order to ob tain a read-out signal from a magnetic core storage unit, it is necessary to change the states of some of the magnetic cores. In order to retain the information in the memory after read-out it is then necessary to provide a means to return the switched cores to their states before read-out. A rewrite driver passes a pulse back through each row of cores in which some switching has taken place. This pulse combines with the reverse current pulses of diodes for each column in which a core is switched during read-out to cause the particular cores to be switched back into their states prior to read-out. (AEC)

The Development of the CMS Zero Degree Calorimeters to Derive the Centrality of AA Collisions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wood, Jeffrey Scott

The centrality of РЬРЬ collisions is derived using correlations from the zero degree calorimeter (ZDC) signal and pixel multiplicity at the Compact Muon Solenoid (CMS) Experiment using data from the heavy ion run in 2010. The method to derive the centrality takes the two-dimensional correlation between the ZDC and pixels and linearizes it for sorting events. The initial method for deriving the centrality at CMS uses the energy deposit in the HF detector, and it is compared to the centrality derived Ьу the correlations in ZDC and pixel multiplicity. This comparison highlights the similarities between the results of both methodsmore » in central collisions, as expected, and deviations in the results in peripheral collisions. The ZDC signals in peripheral collisions are selected Ьу low pixel multiplicity to oЬtain а ZDC neutron spectrum, which is used to effectively gain match both sides of the ZDC« less

Colorectal neuroendocrine neoplasms - management guidelines (recommended by the Polish Network of Neuroendocrine Tumours).

PubMed

Starzyńska, Teresa; Londzin-Olesik, Magdalena; Bałdys-Waligórska, Agata; Bednarczuk, Tomasz; Blicharz-Dorniak, Jolanta; Bolanowski, Marek; Boratyn-Nowicka, Agnieszka; Borowska, Małgorzata; Cichocki, Andrzej; Ćwikła, Jarosław B; Deptała, Andrzej; Falconi, Massimo; Foltyn, Wanda; Handkiewicz-Junak, Daria; Hubalewska-Dydejczyk, Alicja; Jarząb, Barbara; Junik, Roman; Kajdaniuk, Dariusz; Kamiński, Grzegorz; Kolasińska-Ćwikła, Agnieszka; Kowalska, Aldona; Król, Robert; Królicki, Leszek; Kunikowska, Jolanta; Kuśnierz, Katarzyna; Lampe, Paweł; Lange, Dariusz; Lewczuk-Myślicka, Anna; Lewiński, Andrzej; Lipiński, Michał; Marek, Bogdan; Nasierowska-Guttmejer, Anna; Nowakowska-Duława, Ewa; Pilch-Kowalczyk, Joanna; Remiszewski, Piotr; Rosiek, Violetta; Ruchała, Marek; Siemińska, Lucyna; Sowa-Staszczak, Anna; Steinhof-Radwańska, Katarzyna; Strzelczyk, Janusz; Sworczak, Krzysztof; Syrenicz, Anhelli; Szawłowski, Andrzej; Szczepkowski, Marek; Wachuła, Ewa; Zajęcki, Wojciech; Zemczak, Anna; Zgliczyński, Wojciech; Kos-Kudła, Beata

2017-01-01

Neuroendocrine neoplasms/tumours (NENs/NETs) of the large intestine are detected increasingly often, especially rectal tumours, which is probably associated with the widespread use of screening colonoscopy. There is a growing body of evidence supporting the thesis that the NENs of the rectum and the NENs of the colon are two different diseases. Rectal NENs are usually small lesions, of low to moderate histological malignancy, associated with good prognosis, and most may be treated endoscopically. NENs of the colon, however, are often aggressive, poorly differentiated, associated with a poor or uncer-tain prognosis, and require surgical treatment. The management guidelines regarding these groups of patients are constantly changing. On the basis of the recent literature data and conclusions reached by the working meeting of the Polish Network of Neuroendocrine Tumours (December 2016), this study completes and updates the data and management guidelines regarding colorectal NENs published in Endokrynologia Polska 2013; 64: 358-368.

Building a time series of water vapour maps: A first step towards assimilation of Interferometric SAR data in forecasting models

NASA Astrophysics Data System (ADS)

Nico, Giovanni; Mateus, Pedro; Catalão, João.

2010-05-01

-PALSAR), C (ENVISAT-ASAR, RADARSAT) and X (TerraSAR, Cosmo-Sky-Med) and with a repetition cycle ranging from 11 (TerraSAR-X) to 35 days (ENVISAT-ASAR). From each SAR sensor, it can be obtained a map of the temporal changes of the IPW occurred between the two subsequent acquisitions by interferometrically processing the SAR data. The accuracy of these maps depends on the radar wavelength and on spatial filtering. A procedure to properly merge all these maps could give information about the temporal evolution of the IPW spatial distribution with a sampling period shorter than the revisiting times of each of the SAR sensors. The main difficulty of this operation is related to the fact that the integration of temporal changes of IPW is not direct when maps are obtained by different SAR sensors. The aim of this work is to describe a methodologiy to merge IPW maps obtained by the different SAR sensor based on the availbality of GPS time series measuring the IPW over the same area. The Lisbon region, Portugal, was chosen as a study area. This region is monitored by a network of 12 GPS permanent stations covering an area of about squared kilometers. A set of SAR interferograms were processed using data acquired by ENVISAT-ASAR and TerraSAR-X mission over the Lisbon region during the period from 2009 to 2010. A time series with GPS measurement of IPW was processed to cover the time interval between the first and last SAR acquisition. This time series is then used to integrate all maps of temporal changes of IPW obtained by the different interferometric SAR couples. This results in a time series giving with the information about the spatial distribution of the IPW.

Tie Points Extraction for SAR Images Based on Differential Constraints

NASA Astrophysics Data System (ADS)

Xiong, X.; Jin, G.; Xu, Q.; Zhang, H.

2018-04-01

Automatically extracting tie points (TPs) on large-size synthetic aperture radar (SAR) images is still challenging because the efficiency and correct ratio of the image matching need to be improved. This paper proposes an automatic TPs extraction method based on differential constraints for large-size SAR images obtained from approximately parallel tracks, between which the relative geometric distortions are small in azimuth direction and large in range direction. Image pyramids are built firstly, and then corresponding layers of pyramids are matched from the top to the bottom. In the process, the similarity is measured by the normalized cross correlation (NCC) algorithm, which is calculated from a rectangular window with the long side parallel to the azimuth direction. False matches are removed by the differential constrained random sample consensus (DC-RANSAC) algorithm, which appends strong constraints in azimuth direction and weak constraints in range direction. Matching points in the lower pyramid images are predicted with the local bilinear transformation model in range direction. Experiments performed on ENVISAT ASAR and Chinese airborne SAR images validated the efficiency, correct ratio and accuracy of the proposed method.

A study of SO2 emissions and ground surface displacements at Lastarria volcano, Antofagasta Region, Northern Chile

NASA Astrophysics Data System (ADS)

Krewcun, Lucie G.

Lastarria volcano (Chile) is located at the North-West margin of the 'Lazufre' ground inflation signal (37x45 km2), constantly uplifting at a rate of ˜2.5 cm/year since 1996 (Pritchard and Simons 2002; Froger et al. 2007). The Lastarria volcano has the double interest to be superimposed on a second, smaller-scale inflation signal and to be the only degassing area of the Lazufre signal. In this project, we compared daily SO2 burdens recorded by AURA's OMI mission for 2005-2010 with Ground Surface Displacements (GSD) calculated from the Advanced Synthetic Aperture Radar (ASAR) images for 2003-2010. We found a constant maximum displacement rate of 2.44 cm/year for the period 2003-2007 and 0.80- 0.95 cm/year for the period 2007-2010. Total SO 2 emitted is 67.0 kT for the period 2005-2010, but detection of weak SO2 degassing signals in the Andes remains challenging owing to increased noise in the South Atlantic radiation Anomaly region.

Quantum synchronization of many coupled atoms for an ultranarrow linewidth laser

NASA Astrophysics Data System (ADS)

He, Peiru; Xu, Minghui; Tieri, David; Zhu, Bihui; Rey, Ana Maria; Hazzard, Kaden; Holland, Murray

2014-05-01

We theoretically investigate the effect of quantum synchronization on many coupled two-level atoms acting as high quality oscillators. We show that quantum synchronization - the spontaneous alignment of the phase (of the two-level superposition) between different atoms - provides a potential approach to produce robust atomic coherences and coherent light with ultranarrow linewidth and extreme phase stability. The atoms may be coupled either through their direct dipole-dipole interactions or, as in a superradiant laser, through an optical cavity. We develop a variety of analytic and computational approaches for this problem, including exact open quantum system methods for small systems, semiclassical theories, and approaches that make use of the permutation symmetry of identically coupled ensembles. We investigate the first and second order coherence properties of both the optical and atomic degrees of freedom. We study synchronization in both the steady-state, as well as during the dynamically applied pulse sequences of Rabi and Ramsey interferometry. This work was supported by the DARPA QuASAR program, the NSF, and NIST.

Mapping Changes and Damages in Areas of Conflict: From Archive C-Band SAR Data to New HR X-Band Imagery, Towards the Sentinels

NASA Astrophysics Data System (ADS)

Tapete, Deodato; Cigna, Francesca; Donoghue, Daniel N. M.; Philip, Graham

2015-05-01

On the turn of radar space science with the recent launch of Sentinel-1A, we investigate how to better exploit the opportunities offered by large C-band SAR archives and increasing datasets of HR to VHR X-band data, to map changes and damages in urban and rural areas affected by conflicts. We implement a dual approach coupling multi-interferogram processing and amplitude change detection, to assess the impact of the recent civil war on the city of Homs, Western Syria, and the surrounding semi-arid landscape. More than 280,000 coherent pixels are retrieved from Small BAseline Subset (SBAS) processing of the 8year-long ENVISAT ASAR IS2 archive, to quantify land subsidence due to pre-war water abstraction in rural areas. Damages in Homs are detected by analysing the changes of SAR backscattering (σ0), comparing 3m-resolution StripMap TerraSAR-X pairs from 2009 to 2014. Pre-war alteration is differentiated from war-related damages via operator-driven interpretation of the σ0 patterns.

A New Perspective on Fault Geometry and Slip Distribution of the 2009 Dachaidan Mw 6.3 Earthquake from InSAR Observations.

PubMed

Liu, Yang; Xu, Caijun; Wen, Yangmao; Fok, Hok Sum

2015-07-10

On 28 August 2009, the northern margin of the Qaidam basin in the Tibet Plateau was ruptured by an Mw 6.3 earthquake. This study utilizes the Envisat ASAR images from descending Track 319 and ascending Track 455 for capturing the coseismic deformation resulting from this event, indicating that the earthquake fault rupture does not reach to the earth's surface. We then propose a four-segmented fault model to investigate the coseismic deformation by determining the fault parameters, followed by inverting slip distribution. The preferred fault model shows that the rupture depths for all four fault planes mainly range from 2.0 km to 7.5 km, comparatively shallower than previous results up to ~13 km, and that the slip distribution on the fault plane is complex, exhibiting three slip peaks with a maximum of 2.44 m at a depth between 4.1 km and 4.9 km. The inverted geodetic moment is 3.85 × 10(18) Nm (Mw 6.36). The 2009 event may rupture from the northwest to the southeast unilaterally, reaching the maximum at the central segment.

InSAR observations of deformation associated with new episodes of volcanism at Kilauea Volcano, Hawai'i, 2007

USGS Publications Warehouse

Poland, Michael P.

2008-01-01

In June 2007, the Pu'u 'Ō'ō-Kūpaianaha eruption of Kīlauea Volcano was interrupted when magma intruded the east rift zone (ERZ), resulting in a small extrusion of lava near Makaopuhi Crater. Deformation associated with the activity was exceptionally well-documented by ASAR interferometry, which indicates deflation of the summit and uplift and extension of the ERZ. Models of co-intrusion interferograms suggest that the dike was emplaced in two distinct segments. The modeled volume of the dike greatly exceeds that of the deflation source, raising the possibility that magma from the downrift Pu'u 'Ō'ō vent (dominant extrusion site at Kīlauea since 1983) contributed to the eruption near Makaopuhi, or that the magma that fed the eruption from the summit was compressible. A month following the Makaopuhi eruption, an eruptive fissure opened on the east flank of Pu'u 'Ō'ō. Interferograms, processed within 48 hours of the event, were critical in demonstrating that the magma source feeding the eruption was shallow. The eruption probably resulted from overpressure in Pu'u 'Ō'ō's magmatic system.

Strategies for Validating and Directions for Employing SMOS Data, in the Cal-Val Project SWEX (3275)

NASA Astrophysics Data System (ADS)

Marczewski, Wojciech; Usowicz, Boguslaw; Usowicz, Jerzy; Romanov, Sergey; Maryskevych, Oksana; Nastula, Jolanta; Slominski, Jan; Zawadzki, Jaroslaw

2009-11-01

Earth land surface target of observations is naturally diversified in its physical and bio-physical properties. SMOS observation of SM (Soil Moisture) is highly dependent on proper physical and environmental data necessary, because SM is retrieved from the directly observable BT (Brightness Temperature) on the basis of these external data. That way, SMOS realizes a real data fusion performed NRT (Nearly Real Time) and thus needs validating. Global range of SMOS observations makes it generalizing the diversity on complex way engaging technical, modelling and organizational means. That is a new quality of EO (Earth Observations) in the matter of managing diversity of the target. The paper presents several proofs on employing external data by means of the SMOS software tools, for L1c and L2 data levels. Authors take validation in few selected sites in Poland, and describe their strategy for employing external data from ASAR, MERIS, and other auxiliary sources. Finally the conclusions come to understanding of a use of SMOS data, and seek ways of referencing SM in large scales to known results of the gravitational Mission GRACE.

Parallel Adjective High-Order CFD Simulations Characterizing SOFIA Cavity Acoustics

NASA Technical Reports Server (NTRS)

Barad, Michael F.; Brehm, Christoph; Kiris, Cetin C.; Biswas, Rupak

2016-01-01

This paper presents large-scale MPI-parallel computational uid dynamics simulations for the Stratospheric Observatory for Infrared Astronomy (SOFIA). SOFIA is an airborne, 2.5-meter infrared telescope mounted in an open cavity in the aft fuselage of a Boeing 747SP. These simulations focus on how the unsteady ow eld inside and over the cavity interferes with the optical path and mounting structure of the telescope. A temporally fourth-order accurate Runge-Kutta, and spatially fth-order accurate WENO- 5Z scheme was used to perform implicit large eddy simulations. An immersed boundary method provides automated gridding for complex geometries and natural coupling to a block-structured Cartesian adaptive mesh re nement framework. Strong scaling studies using NASA's Pleiades supercomputer with up to 32k CPU cores and 4 billion compu- tational cells shows excellent scaling. Dynamic load balancing based on execution time on individual AMR blocks addresses irregular numerical cost associated with blocks con- taining boundaries. Limits to scaling beyond 32k cores are identi ed, and targeted code optimizations are discussed.

Parallel Adaptive High-Order CFD Simulations Characterizing SOFIA Cavitiy Acoustics

NASA Technical Reports Server (NTRS)

Barad, Michael F.; Brehm, Christoph; Kiris, Cetin C.; Biswas, Rupak

2015-01-01

This paper presents large-scale MPI-parallel computational uid dynamics simulations for the Stratospheric Observatory for Infrared Astronomy (SOFIA). SOFIA is an airborne, 2.5-meter infrared telescope mounted in an open cavity in the aft fuselage of a Boeing 747SP. These simulations focus on how the unsteady ow eld inside and over the cavity interferes with the optical path and mounting structure of the telescope. A tempo- rally fourth-order accurate Runge-Kutta, and a spatially fth-order accurate WENO-5Z scheme were used to perform implicit large eddy simulations. An immersed boundary method provides automated gridding for complex geometries and natural coupling to a block-structured Cartesian adaptive mesh re nement framework. Strong scaling studies using NASA's Pleiades supercomputer with up to 32k CPU cores and 4 billion compu- tational cells shows excellent scaling. Dynamic load balancing based on execution time on individual AMR blocks addresses irregular numerical cost associated with blocks con- taining boundaries. Limits to scaling beyond 32k cores are identi ed, and targeted code optimizations are discussed.

DETERMINING THE EFFECT OF ANIMAL MATURITY AND FAT DISTRIBUTION ON THE QUALITY OF IRRADIATED BEEF. Report No. 5 (Progress) for Period: December 6, 1958 to June 5, 1959

DOE Office of Scientific and Technical Information (OSTI.GOV)

Henrickson, R.L.

1960-10-31

Ground beef and longissimus dorsi steaks from 24-month old animals are being evaluated for irradiation flavor. The fat content of the two lots of ground beef are 6.8 and 31.8%. Samples from animals 6 months old are also being evaluated. The fat content being studied is 6.9 and 27.3%. Taste panel data do not indicate major difference in flavor among steak from different animals of similar breeding. However, there did appear to be some difference in irradiation intensity. Aging the steak before irradiation did not greatly improve the flavor of the irradiated product. Irradiation does however make beef more tender.more » When cystine was irradiated in pure solution, carbonyls were found to be present in greater quantities than in non-irradiated cystine. Ammonia was also found to increase as the concentration was increased. Various cultures of bacteria were isolated from longissimus dorsi steak broiled at 150 tained F and irradiated with 5 x 10/sup 6/ rads of gamma rays. (auth)« less

Preliminary Geological Map of the Fortuna Tessera (V-2) Quadrangle, Venus

NASA Technical Reports Server (NTRS)

Ivanov, M. A.; Head, J. W.

2009-01-01

The Fortuna Tessera quadrangle (50-75 N, 0-60 E) is a large region of tessera [1] that includes the major portion of Fortuna and Laima Tesserae [2]. Near the western edge of the map area, Fortuna Tessera is in contact with the highest moun-tain belt on Venus, Maxwell Montes. Deformational belts of Sigrun-Manto Fossae (extensional structures) and Au ra Dorsa (contractional structures) separate the tessera regions. Highly deformed terrains correspond to elevated regions and mildly deformed units are with low-lying areas. The sets of features within the V-2 quadrangle permit us to address the following important questions: (1) the timing and processes of crustal thickening/thinning, (2) the nature and origin of tesserae and deformation belts and their relation to crustal thickening processes, (3) the existence or absence of major evolutionary trends of volcanism and tectonics. The key feature in all of these problems is the regional sequence of events. Here we present description of units that occur in the V-2 quadrangle, their regional correlation chart (Fig. 1), and preliminary geological map of the region (Fig. 2).

Building Exposure Maps Of Urban Infrastructure And Crop Fields In The Mekong River Basin

NASA Astrophysics Data System (ADS)

Haas, E.; Weichselbaum, J.; Gangkofner, U.; Miltzer, J.; Wali, A.

2013-12-01

In the frame of the Integrated Water Resources Management (IWRM) initiative for the Mekong river basin World Bank is collaborating with the Mekong River Commission and governmental organizations in Cambodia, Lao PDR, Thailand and Vietnam to build national and regional capacities for managing the risks associated with natural disasters, such as floods, flash floods and droughts. Within ‘eoworld', a joint initiative set up by ESA and World Bank to foster the use of Earth Observation (EO) for sustainable development work, a comprehensive database of elements at risk in the Lower Mekong river basin has been established by GeoVille, including urban infrastructure and crops (primarily rice paddies). In the long term, this exposure information shall be fed into an open-source multi- hazard modeling tool for risk assessment along the Mekong River, which then shall be used by national stakeholders as well as insurance and financial institutions for planning, disaster preparedness and emergency management. Earth Observation techniques can provide objective, synoptic and repetitive observations of elements at risk including buildings, infrastructure and crops. Through the fusion of satellite-based with in-situ data from field surveys and local knowledge (e.g. on building materials) features at risk can be characterised and mapped with high accuracy. Earth Observation data utilised comprise bi-weekly Envisat ASAR imagery programmed for a period of 9 months in 2011 to map the development of the rice cultivation area, identify predominant cropping systems (wet-season vs. dry season cultivation), crop cycles (single /double / triple crop per year), date of emergence/harvest and the distinction between rice planted under intensive (SRI) vs. regular rice cultivation techniques. Very High Resolution (VHR) optical data from SPOT, KOMPSAT and QuickBird were used for mapping of buildings and infrastructure, such as building footprints, residential / commercial areas, industrial

Climate change effects on Glacier recession in Himalayas using Multitemporal SAR data and Automatic Weather Station observations

NASA Astrophysics Data System (ADS)

Kumar, V.; Singh, S. K.; Venkataraman, G.

2009-04-01

The Himalaya is the highest but the youngest mountain belt (20 to 60 million years B.P.) of the earth running in arc shape for about 2500 km. It has more than 90 peaks above 6000 m and contains about 50% of all glaciers outside of the polar environments (Bahadur, 1993). All glaciers in this region are in general recession since last 150 years (Paul et al.,1979). Gangotri, Siachen, Bara Shigri and Patsio are major glaciers in this region which are showing retreat with different rates and their respective tributary glaciers are completely disconnected from main body of glaciers. Spaceborne synthetic aperture radar data provide an important tool for monitoring the fluctuation of the glaciers. In this paper attempt has been made for quantifying the glacier retreat using multitemporal synthetic aperture radar (SAR) data. SAR intensity and phase information will be exploited separately under SAR intensity tracking and interferometric SAR (InSAR) coherence tracking (Strozzi et al., 2002) respectively. Glacier retreat study have been done using time series coregistered multi temporal SAR images. Simultaneously InSAR coherence thresholding is applied for tracking the snout of Gangotri glacier. It is observed that glacier is retreating at the rate of 21 m/a. Availability of high resolution spotlight mode TerraSAR-X SAR data will supplement the ENVISAT ASAR and ERS-1/2 based observations. The observatory in the proximity of Gangotri glacier has been made functional at Bhojbasa and all weather parameters viz. Snow fall, temperature, pressure, air vector, column water vapor and humidity are recorded twice a day as per WMO standards manually and automatically. Three Automatic Weather Stations (AWS) have been established in the glacier area at Bhojbasa , Kalindipass and Nandaban. Since Himalayan environment is presently under great stress of decay and degeneration, AWS data will be analyzed in the context of climate change effects on fluctuation of glaciers. References 1.Jagdish

Breaking Quantum and Thermal Limits on Precision Measurements

NASA Astrophysics Data System (ADS)

Thompson, James K.

2016-05-01

I will give an overview of our efforts to use correlations and entanglement between many atoms to overcome quantum and thermal limits on precision measurements. In the first portion of my talk, I will present a path toward a 10000 times reduced sensitivity to the thermal mirror motion that limits the linewidth of today's best lasers. By utilizing narrow atomic transitions, the laser's phase information is primarily stored in the atomic gain medium rather than in the vibration-sensitive cavity field. To this end, I will present the first observation of lasing based on the mHz linewidth optical-clock transition in a laser-cooled ensemble of strontium atoms. In the second portion of my talk, I will describe how we use collective measurements to surpass the standard quantum limit on phase estimation 1 /√{ N} for N unentangled atoms. We achieve a directly observed reduction in phase variance relative to the standard quantum limit of as much as 17.7(6) dB. Supported by DARPA QuASAR, NIST, ARO, and NSF PFC. This material is based upon work supported by the National Science Foundation under Grant Number 1125844 Physics Frontier Center.

Quantum synchronization and the no-photon laser

NASA Astrophysics Data System (ADS)

Holland, Murray

2014-03-01

This talk will present a new approach to lasers that is based on the quantum synchronization of many atoms. Such lasers are predicted to produce light of unprecedented spectral purity and coherence, some two orders of magnitude better than any system available today. The idea is based on superradiant emission, where an ensemble of atoms with an extremely narrow atomic transition can phase-lock and form a macroscopic dipole that radiates light collectively. This is quite unlike a typical laser where atoms essentially act independently. The resulting light source is expected to have a spectral linewidth of just a few millihertz and could lead to more accurate and stable atomic clocks. Atomic clocks based on optical transitions have improved tremendously in recent years, giving clocks that tick 1015 times per second, and can have a fractional stability exceeding one part in 1016. This new sharper light source aims to push the frontier even further, so that fundamental tests of physics, such as the time variation of constants and tests of gravity, might even be possible. We acknowledge support from NSF and the DARPA QuASAR program.

Optimal land use/cover classification using remote sensing imagery for hydrological modelling in a Himalayan watershed

NASA Astrophysics Data System (ADS)

Saran, Sameer; Sterk, Geert; Kumar, Suresh

2007-10-01

Land use/cover is an important watershed surface characteristic that affects surface runoff and erosion. Many of the available hydrological models divide the watershed into Hydrological Response Units (HRU), which are spatial units with expected similar hydrological behaviours. The division into HRU's requires good-quality spatial data on land use/cover. This paper presents different approaches to attain an optimal land use/cover map based on remote sensing imagery for a Himalayan watershed in northern India. First digital classifications using maximum likelihood classifier (MLC) and a decision tree classifier were applied. The results obtained from the decision tree were better and even improved after post classification sorting. But the obtained land use/cover map was not sufficient for the delineation of HRUs, since the agricultural land use/cover class did not discriminate between the two major crops in the area i.e. paddy and maize. Therefore we adopted a visual classification approach using optical data alone and also fused with ENVISAT ASAR data. This second step with detailed classification system resulted into better classification accuracy within the 'agricultural land' class which will be further combined with topography and soil type to derive HRU's for physically-based hydrological modelling.

A New Perspective on Fault Geometry and Slip Distribution of the 2009 Dachaidan Mw 6.3 Earthquake from InSAR Observations

PubMed Central

Liu, Yang; Xu, Caijun; Wen, Yangmao; Fok, Hok Sum

2015-01-01

On 28 August 2009, the northern margin of the Qaidam basin in the Tibet Plateau was ruptured by an Mw 6.3 earthquake. This study utilizes the Envisat ASAR images from descending Track 319 and ascending Track 455 for capturing the coseismic deformation resulting from this event, indicating that the earthquake fault rupture does not reach to the earth’s surface. We then propose a four-segmented fault model to investigate the coseismic deformation by determining the fault parameters, followed by inverting slip distribution. The preferred fault model shows that the rupture depths for all four fault planes mainly range from 2.0 km to 7.5 km, comparatively shallower than previous results up to ~13 km, and that the slip distribution on the fault plane is complex, exhibiting three slip peaks with a maximum of 2.44 m at a depth between 4.1 km and 4.9 km. The inverted geodetic moment is 3.85 × 1018 Nm (Mw 6.36). The 2009 event may rupture from the northwest to the southeast unilaterally, reaching the maximum at the central segment. PMID:26184210

Wind impact on the Black Sea ecosystem

NASA Astrophysics Data System (ADS)

Stanichny, Sergey; Ratner, Yuriy; Shokurov, Mike; Stanychna, Rimma; Soloviev, Dmytro; Burdyugov, Vyacheslav

2010-05-01

Combination of the recent satellite and meteorological data for the regional investigation allowed to describe new features of the processes in marine ecosystem and detect some relations with wind variability for different time scales. Next topics are highlighted in presentation: 1. Inter-annual variability of the wind stress curl over the Black Sea. Shift in the atmospheric processes after 2003 year and related variations in chlorophyll concentration and intensity of the mesoscale currents. 2. Like-tropical cyclone in September 2005 and its impact o the Black Sea upper layer. 3. Strong storm November 11, 2007 and oil pollutions of the Kerch Strait. 4. Relation of the Danube waters transport with wind fields for summer 2007 and 2008. 5. "Valley" wind in the Eastern part of the Black Sea and its impact on the Rim current formation. 6. Low wind conditions and blue -green algae bloom. NCEP, SKIRON and MHI MM5 wind data together with AVHRR, MODIS, MERIS, ETM+, QuikSCAT, ASAR (ESA) satellite data were used for investigation. Work was done with support of the SESAME FP7, "Stable Ecosystem" and Operational Oceanography NASU projects.

Extended fusion yield integral using pathway idea in case of Shock-compressed heated plasma

NASA Astrophysics Data System (ADS)

Kumar, Dilip; Haubold, Hans

The extended non-resonant thermonuclear reaction rate probability integral obtained in Haubold and Kumar [Haubold, H.J. and Kumar, D.: 2008, Extension of thermonuclear functions through the pathway model including Maxwell-Boltzmann and Tsallis distributions, Astroparticle Physics, 29, 70-76] is used to evaluate the fusion energy by itegrating it over temperature. The closed form representation of the extended reaction rate integral via Meijer's G-function is expressed as a solution of a homogeneous differential equation. A physical model of Guderley[Guderley G. :1942, Starke kugelige und zylindrische Verdichtungsstsse in der Nhe des Kugelmittelpunktes bzw. der Zylinderachse, Luftfahrtforschung, 19, 302] has been considered for the laser driven hydrodynamical process in a compressed fusion plasma and heated strong spherical shock wave. The fusion yield integral obtained in the paper is compared with the standard fusion yield ob-tained by Haubold and John [Haubold, H.J. and John, R.W.:1981, Analytical representation of the thermonuclear reaction rate and fusion energy production in a spherical plasma shock wave, Plasma Physics, 5, 399-411]. The pathway parameter used in this paper is given an interpretation in terms of moments.

Magnetic monitoring in Saguaro National Park

USGS Publications Warehouse

Love, Jeffrey J.; Finn, Carol; Gamez Valdez, Yesenia C.; Swann, Don

2017-06-02

On a sandy, arid plain, near the Rincon Moun­tain Visitor Center of Saguaro National Park, tucked in among brittlebush, creosote, and other hardy desert plants, is an unusual type of observatory—a small unmanned station that is used for monitor­ing the Earth’s variable magnetic field. Named for the nearby city of Tucson, Arizona, the observatory is 1 of 14 that the Geomagnetism Program of the U.S. Geological Survey operates at various locations across the United States and Ter­ritories.Data from USGS magnetic observatories, including the Tucson observatory, as well as observatories operated by institutions in other countries, record a variety of signals related to a wide diversity of physical phenomena in the Earth’s interior and its surrounding outer-space environment. The data are used for geomagnetic mapping and surveying, for fundamental scientific research, and for assessment of magnetic storms, which can be hazardous for the activities and infra­structure of our modern, technologically based society. The U.S. Geological Survey observatory service is an integral part of a U.S. national project for monitoring and assessing space weather hazards.

Multirisk analysis along the Road 7, Mendoza Province, Argentina

NASA Astrophysics Data System (ADS)

Wick, Emmanuel; Baumann, Valérie; Michoud, Clément; Derron, Marc-Henri; Jaboyedoff, Michel; Rune Lauknes, Tom; Marengo, Hugo; Rosas, Mario

2010-05-01

The National Road 7 crosses Argentina from East to West, linking Buenos Aires to the Chile border. This road is an extremely important corridor crossing the Andes Cordillera, but it is exposed to numerous natural hazards, such as rockfalls, debris flows and snow avalanches. The study area is located in the Mendoza Province, between Potrerillos and Las Cuevas in the Chilean border. This study has for main goals to achieve a regional mapping of geohazards susceptibility along the Road 7 corridor using modern remote sensing and numerical modelling techniques completed by field investigations. The main topics are: - Detection and monitoring of deep-seated gravitational slope deformations by time-series satellite radar interferometry (InSAR) methods. The area of interest is mountainous with almost no vegetation permitting an optimized InSAR processing. Our results are based on applying the small-baseline subset (SBAS) method to a time-series of Envisat ASAR images. - Rockfalls susceptibility mapping is realized using statistical analysis of the slope angle distribution, including external knowledge on the geology and land cover, to detect the potential source areas (quantitative DEM analysis). The run-outs are assessed with numerical methods based on the shallow angle method with Conefall. A second propagation is performed using the alpha-beta methodology (3D numerical modelling) with RAS and is compared to the first one. - Debris flow susceptibility mapping is realized using DF-IGAR to detect starting and spreading areas. Slope, flow accumulations, contributive surfaces, plan curvature, geological and land use dataset are used. The spreading is simulated by a multiple flow algorithm (rules the path that the debris flow will follow) coupled to a run-out distance calculation (energy-based). - Snow avalanches susceptibility mapping is realized using DF-IGAR to map sources areas and propagations. To detect the sources areas, slope, altitude, land-use and minimum surfaces

Retrieving current and wind vectors from ATI SAR data: airborne evidence and inversion strategy

NASA Astrophysics Data System (ADS)

Martin, Adrien; Gommenginger, Christine; Chapron, Bertrand; Marquez, José; Doody, Sam

2017-04-01

Conventional and along-track interferometric (ATI) Synthetic Aperture Radar (SAR) sense the motion of the ocean surface by measuring the Doppler shift of reflected signals. Together with the water displacement associated with ocean currents, the SAR measurements are also affected by a Wind-wave induced Artefact Surface Velocity (WASV) caused by the velocity of Bragg scatterers and the orbital velocity of ocean surface gravity waves. The WASV has been modelled theoretically in past studies but has been estimated empirically only once using Envisat ASAR. Here we propose, firstly, to evaluate this WASV from airborne ATI SAR data, secondly, to validate the airborne retrieved surface current after correction of the WASV against HF radar measurements and thirdly to examine the best inversion strategy for a an Ocean Surface Current (OSC) satellite mission to retrieve accurately both the ocean surface current vector (OSCV) and the wind vector in the frame of an OSC satellite mission. The airborne ATI SAR data were acquired in the tidally dominated Irish Sea using a Wavemill-type dual-beam SAR interferometer. A comprehensive collection of airborne Wavemill data acquired in a star pattern over a well-instrumented site made it possible to estimate the magnitude and dependence on azimuth and incidence angle of the WASV. The airborne results compare favourably with those reported for Envisat ASAR, empirical model, which has been used to correct for it. Validation of the current retrieval capabilities of the proof-of-concept has been conducted against HF radar giving a precisions typically better than 0.1 m/s for surface current speed and 7° for direction. Comparisons with POLCOMS (1.8 km) indicate that the model reproduces well the overall temporal evolution but does not capture the high spatial variability of ocean surface currents at the maximum ebb flow. Airborne retrieved currents highlight a short-scale spatial variability up to 100m related to bathymetry channels, which

An advance forecasting system for ship originated oil spills in the Mediterranean

NASA Astrophysics Data System (ADS)

Zodiatis, G.; Lardner, R.; De Dominicis, M.; Coppini, G.; Pinardi, N.

2012-04-01

One of the permanent risks from an oil spill incident in the Mediterranean is associated with the heavy traffic in maritime transport, as well nowadays with the coastal and offshore installations related to the oil and gas industry. Such dense activity imposes on the coastal countries the need for preparing an operational response to major oil spill incidents. In the recent past, several policies related to oil spill response have been adopted internationally. At the regional level the Barcelona convention, recognizing pollution from oil spills as one of the major threats to the marine environment of the Mediterranean, initiated the preparedness for responding to major oil spill incidents, through various national and sub-regional contingency plans. At the European level the Member States was obliged to implement the EU Directive 2005/35, aimed at identifying the polluter and bringing them to prosecution. The response to an oil spill incident employs various measures and equipment. However, the success of such response depends greatly on the prediction of the movement and weathering of the oil spills. Such predictions may obtained through the operational application of advanced numerical oil spill models integrated with met-ocean forecasting data. A well established operational system for oil spill predictions in the Mediterranean is the MEDSLIK three dimensional model that predicts the transport, diffusion and spreading of oil spill and incorporates the fate processes of evaporation, emulsification, viscosity changes, dispersion into the water column and coastal impact and adhesion. MEDSLIK is integrated with the MyOCEAN regional and several downscaled ocean forecasting systems in the Mediterranean, contributing to the development of the GMES marine services. Moreover, MEDSLIK has been coupled with EMSA-CSN and ESA ASAR imageries, for short forward and backward predictions, to assist the response agencies in the implementation of the EU Directive 2005/35. From

Remote sensing-based Information for crop monitoring: contribution of SAR and Moderate resolution optical data on Asian rice production

NASA Astrophysics Data System (ADS)

Boschetti, Mirco; Holectz, Francesco; Manfron, Giacinto; Collivignarelli, Francesco; Nelson, Andrew

2013-04-01

Updated information on crop typology and status are strongly required to support suitable action to better manage agriculture production and reduce food insecurity. In this field, remote sensing has been demonstrated to be a suitable tool to monitor crop condition however rarely the tested system became really operative. The ones today available, such as the European Commission MARS, are mainly based on the analysis of NDVI time series and required ancillary external information like crop mask to interpret the seasonal signal. This condition is not always guarantied worldwide reducing the potentiality of the remote sensing monitoring. Moreover in tropical countries cloud contamination strongly reduce the possibility of using optical remote sensing data for crop monitoring. In this framework we focused our analysis on the rice production monitoring in Asian tropical area. Rice is in fact the staple food for half of the world population (FAO 2004), in Asia almost 90% of the world's rice is produced and consumed and Rice and poverty often coincide. In this contest the production of reliable rice production information is of extreme interest. We tried to address two important issue in terms of required geospatial information for crop monitoring: rice crop detection (rice map) and seasonal dynamics analysis (phenology). We use both SAR and Optical data in order to exploit the potential complementarity of this system. Multi-temporal ASAR Wide Swath data are in fact the best option to deal with cloud contamination. SAR can easily penetrate the clouds providing information on the surface target. Temporal analysis of archive ASAR data allowed to derived accurate map, at 100m spatial resolution, of permanent rice cultivated areas. On the other and high frequency revisiting optical data, in this case MODIS, have been used to extract seasonal information for the year under analysis. MOD09A1 Surface Reflectance 8-Day L3 Global 500m have been exploited to derive time series of

Programme for Monitoring of the Greenland Ice Sheet - Ice Surface Velocities

NASA Astrophysics Data System (ADS)

Andersen, S. B.; Ahlstrom, A. P.; Boncori, J. M.; Dall, J.

2011-12-01

In 2007, the Danish Ministry of Climate and Energy launched the Programme for Monitoring of the Greenland Ice Sheet (PROMICE) as an ongoing effort to assess changes in the mass budget of the Greenland Ice Sheet. Iceberg calving from the outlet glaciers of the Greenland Ice Sheet, often termed the ice-dynamic mass loss, is responsible for an important part of the mass loss during the last decade. To quantify this part of the mass loss, we combine airborne surveys yielding ice-sheet thickness along the entire margin, with surface velocities derived from satellite synthetic-aperture radar (SAR). In order to derive ice sheet surface velocities from SAR a processing chain has been developed for GEUS by DTU Space based on a commercial software package distributed by GAMMA Remote Sensing. The processor, named SUSIE (Scripts and Utilities for SAR Ice-motion Estimation), can use both differential SAR interferometry and offset-tracking techniques to measure the horizontal velocity components, providing also an estimate of the corresponding measurement error. So far surface velocities have been derived for a number of sites including Nioghalvfjerdsfjord Glacier, the Kangerlussuaq region, the Nuuk region, Helheim Glacier and Daugaard-Jensen Glacier using data from ERS-1/ERS-2, ENVISAT ASAR and ALOS Palsar. Here we will present these first results.

Integration of MODIS data and Short Baseline Subset (SBAS) technique for land subsidence monitoring in Datong, China

NASA Astrophysics Data System (ADS)

Zhao, Chao-ying; Zhang, Qin; Yang, Chengsheng; Zou, Weibao

2011-07-01

Datong is located in the north of Shanxi Province, which is famous for its old-fashioned coal-mining preservation in China. Some serious issues such as land subsidence, ground fissures, mining collapse, and earthquake hazards have occurred over this area for a long time resulting in significant damages to buildings and roads. In order to monitor and mitigate these natural man-made hazards, Short Baseline Subsets (SBAS) InSAR technique with ten Envisat ASAR data is applied to detect the surface deformation over an area of thousands of square kilometers. Then, five MODIS data are used to check the atmospheric effects on InSAR interferograms. Finally, nine nonlinear land subsidence cumulative results during September 2004 and February 2008 are obtained. Based on the deformation data, three kinds of land subsidence are clearly detected, caused by mine extraction, underground water withdrawal and construction of new economic zones, respectively. The annual mean velocity of subsidence can reach 1 to 4 cm/year in different subsidence areas. A newly designed high-speed railway (HSR) with speeds of 350 km/h will cross through the Datong hi-tech zone. Special measures should be taken for the long run of this project. In addition, another two subsidence regions need further investigation to mitigate such hazards.

Xurography as a Rapid Fabrication Alternative for Point-of-Care Devices: Assessment of Passive Micromixers

PubMed Central

Martínez-López, J. Israel; Mojica, Mauricio; Rodríguez, Ciro A.; Siller, Héctor R.

2016-01-01

Despite the copious amount of research on the design and operation of micromixers, there are few works regarding manufacture technology aimed at implementation beyond academic environments. This work evaluates the viability of xurography as a rapid fabrication tool for the development of ultra-low cost microfluidic technology for extreme Point-of-Care (POC) micromixing devices. By eschewing photolithographic processes and the bulkiness of pumping and enclosure systems for rapid fabrication and passively driven operation, xurography is introduced as a manufacturing alternative for asymmetric split and recombine (ASAR) micromixers. A T-micromixer design was used as a reference to assess the effects of different cutting conditions and materials on the geometric features of the resulting microdevices. Inspection by stereographic and confocal microscopy showed that it is possible to manufacture devices with less than 8% absolute dimensional error. Implementation of the manufacturing methodology in modified circular shape- based SAR microdevices (balanced and unbalanced configurations) showed that, despite the precision limitations of the xurographic process, it is possible to implement this methodology to produce functional micromixing devices. Mixing efficiency was evaluated numerically and experimentally at the outlet of the microdevices with performances up to 40%. Overall, the assessment encourages further research of xurography for the development of POC micromixers. PMID:27196904

Xurography as a Rapid Fabrication Alternative for Point-of-Care Devices: Assessment of Passive Micromixers.

PubMed

Martínez-López, J Israel; Mojica, Mauricio; Rodríguez, Ciro A; Siller, Héctor R

2016-05-16

Despite the copious amount of research on the design and operation of micromixers, there are few works regarding manufacture technology aimed at implementation beyond academic environments. This work evaluates the viability of xurography as a rapid fabrication tool for the development of ultra-low cost microfluidic technology for extreme Point-of-Care (POC) micromixing devices. By eschewing photolithographic processes and the bulkiness of pumping and enclosure systems for rapid fabrication and passively driven operation, xurography is introduced as a manufacturing alternative for asymmetric split and recombine (ASAR) micromixers. A T-micromixer design was used as a reference to assess the effects of different cutting conditions and materials on the geometric features of the resulting microdevices. Inspection by stereographic and confocal microscopy showed that it is possible to manufacture devices with less than 8% absolute dimensional error. Implementation of the manufacturing methodology in modified circular shape- based SAR microdevices (balanced and unbalanced configurations) showed that, despite the precision limitations of the xurographic process, it is possible to implement this methodology to produce functional micromixing devices. Mixing efficiency was evaluated numerically and experimentally at the outlet of the microdevices with performances up to 40%. Overall, the assessment encourages further research of xurography for the development of POC micromixers.

Quantum optics, cavity QED, and quantum optomechanics

NASA Astrophysics Data System (ADS)

Meystre, Pierre

2013-05-01

Quantum optomechanics provides a universal tool to achieve the quantum control of mechanical motion. It does that in devices spanning a vast range of parameters, with mechanical frequencies from a few Hertz to GHz, and with masses from 10-20 g to several kilos. Its underlying ideas can be traced back to the study of gravitational wave antennas, quantum optics, cavity QED and laser cooling which, when combined with the recent availability of advanced micromechanical and nanomechanical devices, opens a path to the realization of macroscopic mechanical systems that operate deep in the quantum regime. At the fundamental level this development paves the way to experiments that will lead to a more profound understanding of quantum mechanics; and from the point of view of applications, quantum optomechanical techniques will provide motion and force sensing near the fundamental limit imposed by quantum mechanics (quantum metrology) and significantly expand the toolbox of quantum information science. After a brief summary of key historical developments, the talk will give a broad overview of the current state of the art of quantum optomechanics, and comment on future prospects both in applied and in fundamental science. Work supported by NSF, ARO and the DARPA QuASAR and ORCHID programs.

Broadscale postseismic deformation and lower crustal relaxation in the central Bayankala Block (central Tibetan Plateau) observed using InSAR data

NASA Astrophysics Data System (ADS)

Zhao, Dezheng; Qu, Chunyan; Shan, Xinjian; Zuo, Ronghu; Liu, Yunhua; Gong, Wenyu; Zhang, Guohong

2018-04-01

We have generated a more than 500 km long postseismic deformation rate map and cumulative displacement time series in the central Bayankala Block of the Tibetan Plateau using ENVISAT/ASAR data from 2003 to 2010 by the π-RATE stacking algorithm. This rate map spans a period of ∼7.2 years and reveals that postseismic motion of 2001 Kokoxili earthquake exhibits a striking signal, dominating crustal deformation of the central Bayankala Block with a cross-fault magnitude ∼9-11 mm/yr in line of sight (LOS) (∼93.1°E). The southern and northern parts of the postseismic deformation field exhibit different patterns and variable magnitudes, reflecting asymmetry of the displacement distribution. Postseismic motion affects eastward extrusion of the central Bayankala Block, which reaches ∼15 km north of the Ganzi-Yushu fault. To further investigate viscoelastic relaxation of the lower crust in this area after approximately two years, E-M, E-M-M and E-S models are constructed. The result shows that the best fit viscosity for the lower crust is about 1 × 1019 Pa·s. Comparison between cumulative displacements resolved by these three models shows that viscoelastic relaxation of the lower crust makes the most significant contribution to postseismic stress relaxation after 2001 event.

An all-optronic synthetic aperture lidar

NASA Astrophysics Data System (ADS)

Turbide, Simon; Marchese, Linda; Terroux, Marc; Babin, François; Bergeron, Alain

2012-09-01

Synthetic Aperture Radar (SAR) is a mature technology that overcomes the diffraction limit of an imaging system's real aperture by taking advantage of the platform motion to coherently sample multiple sections of an aperture much larger than the physical one. Synthetic Aperture Lidar (SAL) is the extension of SAR to much shorter wavelengths (1.5 μm vs 5 cm). This new technology can offer higher resolution images in day or night time as well as in certain adverse conditions. It could be a powerful tool for Earth monitoring (ship detection, frontier surveillance, ocean monitoring) from aircraft, unattended aerial vehicle (UAV) or spatial platforms. A continuous flow of high-resolution images covering large areas would however produce a large amount of data involving a high cost in term of post-processing computational time. This paper presents a laboratory demonstration of a SAL system complete with image reconstruction based on optronic processing. This differs from the more traditional digital approach by its real-time processing capability. The SAL system is discussed and images obtained from a non-metallic diffuse target at ranges up to 3m are shown, these images being processed by a real-time optronic SAR processor origiinally designed to reconstruct SAR images from ENVISAT/ASAR data.

SAR observation and model tracking of an oil spill event in coastal waters.

PubMed

Cheng, Yongcun; Li, Xiaofeng; Xu, Qing; Garcia-Pineda, Oscar; Andersen, Ole Baltazar; Pichel, William G

2011-02-01

Oil spills are a major contributor to marine pollution. The objective of this work is to simulate the oil spill trajectory of oil released from a pipeline leaking in the Gulf of Mexico with the GNOME (General NOAA Operational Modeling Environment) model. The model was developed by NOAA (National Oceanic and Atmospheric Administration) to investigate the effects of different pollutants and environmental conditions on trajectory results. Also, a Texture-Classifying Neural Network Algorithm (TCNNA) was used to delineate ocean oil slicks from synthetic aperture radar (SAR) observations. During the simulation, ocean currents from NCOM (Navy Coastal Ocean Model) outputs and surface wind data measured by an NDBC (National Data Buoy Center) buoy are used to drive the GNOME model. The results show good agreement between the simulated trajectory of the oil spill and synchronous observations from the European ENVISAT ASAR (Advanced Synthetic Aperture Radar) and the Japanese ALOS (Advanced Land Observing Satellite) PALSAR (Phased Array L-band Synthetic Aperture Radar) images. Based on experience with past marine oil spills, about 63.0% of the oil will float and 18.5% of the oil will evaporate and disperse. In addition, the effects from uncertainty of ocean currents and the diffusion coefficient on the trajectory results are also studied. Copyright © 2010 Elsevier Ltd. All rights reserved.

Fusion of space-borne multi-baseline and multi-frequency interferometric results based on extended Kalman filter to generate high quality DEMs

NASA Astrophysics Data System (ADS)

Zhang, Xiaojie; Zeng, Qiming; Jiao, Jian; Zhang, Jingfa

2016-01-01

Repeat-pass Interferometric Synthetic Aperture Radar (InSAR) is a technique that can be used to generate DEMs. But the accuracy of InSAR is greatly limited by geometrical distortions, atmospheric effect, and decorrelations, particularly in mountainous areas, such as western China where no high quality DEM has so far been accomplished. Since each of InSAR DEMs generated using data of different frequencies and baselines has their own advantages and disadvantages, it is therefore very potential to overcome some of the limitations of InSAR by fusing Multi-baseline and Multi-frequency Interferometric Results (MMIRs). This paper proposed a fusion method based on Extended Kalman Filter (EKF), which takes the InSAR-derived DEMs as states in prediction step and the flattened interferograms as observations in control step to generate the final fused DEM. Before the fusion, detection of layover and shadow regions, low-coherence regions and regions with large height error is carried out because MMIRs in these regions are believed to be unreliable and thereafter are excluded. The whole processing flow is tested with TerraSAR-X and Envisat ASAR datasets. Finally, the fused DEM is validated with ASTER GDEM and national standard DEM of China. The results demonstrate that the proposed method is effective even in low coherence areas.

Monitoring ground subsidence in Shanghai maglev area using two kinds of SAR data

NASA Astrophysics Data System (ADS)

Wu, Jicang; Zhang, Lina; Chen, Jie; Li, Tao

2012-11-01

Shanghai maglev is a very fast traffic tool, so it is very strict with the stability of the roadbed. However, the ground subsidence is a problem in Shanghai because of the poor geological condition and human-induced factors. So it is necessary to monitor ground subsidence in the area along the Shanghai maglev precisely and frequently. Traditionally, a precise levelling method is used to survey along the track. It is expensive and time consuming, and can only get the ground subsidence information on sparse benchmarks. Recently, the small baseline differential SAR technique plays a valuable part in monitoring ground subsidence, which can extract ground subsidence information with high spatial resolution in a wide area. In this paper, L-band ALOS PALSAR data and C-band Envisat ASAR data are used to extract ground subsidence information using the SBAS method in the Shanghai maglev area. The results show that the general pattern of ground subsidence from InSAR processing of two differential bands of SAR images is similar. Both results show that there is no significant ground subsidence on the maglev line. Near the railway line, there are a few places with subsidence rates at about -20 mm/y or even more, such as Chuansha town, the junction of the maglev and Waihuan road.

Detection of ground deformation in the broader area of Sharm El- Shiekh (Sinai Peninsula, Egypt) by SAR interferometry

NASA Astrophysics Data System (ADS)

Seleem, Tarek A.; Foumelis, Michael; Parcharidis, Issaak

2009-09-01

Sharm El-Shiekh area is located in the most southern part of Sinai Peninsula boarded by the Gulf of Suez to the west and by the Gulf of Aqaba to the east. The present study concerns the application of Multibaseline/Stacking Differential SAR Interferometry (DInSAR) in order to monitor ground deformation rates in the southern part of Sharm El-Shiekh area. The specific technique was applied in order to reduce the influence of atmospheric effects on ground deformation estimates. For this purpose a total number of 24 ENVISAT ASAR scenes covering the period between 2002 and 2008 were processed and analysed. Interferometric results show both patterns of uplift and downlift in the study area. Specifically an area along the coastline with a N-S direction, corresponding to the build up zone of Sharm El-Shiekh, shows average annual subsidence rates between -5 and -7 mm/yr along the line of sight (LOS). On the contrary, Sharm El Maya, an inner zone parallel to the above subsided area, shows slant range uplift of around 5 mm/yr. The obtained results of SAR inteferometry probably indicate the presence of an active fault that affects the coastal zones of Sharm El-Shiekh area.

Flood monitoring in a semi-arid environment using spatially high resolution radar and optical data.

PubMed

Seiler, Ralf; Schmidt, Jana; Diallo, Ousmane; Csaplovics, Elmar

2009-05-01

The geographic term "Niger Inland Delta" stands for a vast plain of approximately 40,000 km(2), which is situated in the western Sahel (Republic of Mali). The Inland Delta is affected by yearly inundation through the variable water levels of the Niger-Bani river system. Due to a good availability of (surface) water, the ecosystem at the Niger Inland Delta serves as resting place stop-over for many migrating birds and other wildlife species as well as economic base for farmers and pastoral people. To foster the sustainable usage of its natural resources and to protect this natural heritage, the entire Niger Inland Delta became RAMSAR site in 2004. This paper aims to test to which extent texture analysis can improve the quality of flood monitoring in a semi-arid environment using spatially high resolution ASAR imaging mode data. We found the Gray Level Dependence Method (GLDM) was most suitable proceeding for our data. Several statistical parameters were calculated via co-occurrence matrices and were used to classify the images in different gradation of soil moisture classes. In a second step we used additional information from spatially high resolution optical data (ASTER) to improve the separability of open water areas from moisture/vegetated areas.

Change detection of polarimetric SAR images based on the KummerU Distribution

NASA Astrophysics Data System (ADS)

Chen, Quan; Zou, Pengfei; Li, Zhen; Zhang, Ping

2014-11-01

In the society of PolSAR image segmentation, change detection and classification, the classical Wishart distribution has been used for a long time, but it especially suit to low-resolution SAR image, because in traditional sensors, only a small number of scatterers are present in each resolution cell. With the improving of SAR systems these years, the classical statistical models can therefore be reconsidered for high resolution and polarimetric information contained in the images acquired by these advanced systems. In this study, SAR image segmentation algorithm based on level-set method, added with distance regularized level-set evolution (DRLSE) is performed using Envisat/ASAR single-polarization data and Radarsat-2 polarimetric images, respectively. KummerU heterogeneous clutter model is used in the later to overcome the homogeneous hypothesis at high resolution cell. An enhanced distance regularized level-set evolution (DRLSE-E) is also applied in the later, to ensure accurate computation and stable level-set evolution. Finally, change detection based on four polarimetric Radarsat-2 time series images is carried out at Genhe area of Inner Mongolia Autonomous Region, NorthEastern of China, where a heavy flood disaster occurred during the summer of 2013, result shows the recommend segmentation method can detect the change of watershed effectively.

Ground deformation monitoring using small baseline DInSAR technique: A case study in Taiyuan City from 2003 to 2009

USGS Publications Warehouse

Wu, H.-A.; Zhang, Y.-H.; Chen, X.-Y.; Lu, T.; Du, J.; Sun, Z.-H.; Sun, G.-T.

2011-01-01

DInSAR technique based on time series of SAR images has been very popular to monitor ground stow deformation in recent years such as permanent scatterers (PS) method small baseline subsets (SBAS) method and coherent targets (CT) method. By taking advantage of PS method and CT method in this paper small baseline DTnSAR technique is used to investigate the ground deformation of Taiyuan City Shanxi Province from 2003 to 2009 by using 23 ENVISAT ASAR images. The experiment results demonstrate that: (1) during this period four significant subsidence centers have been developed in Taiyuan namely Xiayuan Wujiabu Xiaodian Sunjiazhai. The largest subsidence center is Sunjiazhai with an average subsidence rate of -77. 28 mm/a; (2) The subsidence of the old center Wanbolin has sHowed down. And the subsidence in the northern region has stopped and some areas even rebounded. (3) The change of subsidence centers indicates that the control measures of "closing wells and reducing exploitation" taken by the Taiyuan government has achieved initial effects. (4) The experiment results have been validated with leveling data and the acouracy is 2. 90 mm which shows that the small baseline DInSAR technique can be used to monitor urban ground deformation.

Crustal and Upper Mantle S-velocity Structure From Receiver Functions Analisys Around Terra Nova Bay Base, Antartica

NASA Astrophysics Data System (ADS)

Piana Agostinetti, N.; Amato, A.; Cattaneo, M.; de Gori, P.; di Bona, M.

In the framework of the italian PNRA (Progetto Nazionale di Ricerche in Antartide), we have started to re-analize teleseismic waveforms recorded, using three-components seismometers (equipped with 5 seconds sensors, Lennartz 3D-5s), during five summer campaings, from 1993 to 2000. Seismic stations were deployed around Terra Nova Bay (TNB) italian base, from the sea to reach the interior of the Transantartic Moun- tains (TAM), the most striking example of nocontractional mountain belt. During the last campaingn (1999-2000) seismic stations were deployed deep into Northern Vic- toria Land to reach Rennik and Lillie Glaciers Area and George V coast region, the northest part of TAM. Our main goals were: to compute, using frequency-domanin deconvolution method by Di Bona [1998], Receiver Functions covering all the area around TNB italian antartic base; to map of Moho-depth and intercrustal S-waves ve- locity discontinuity from 1-D velocity model computed using Sambridge's inversion scheme [Sambridge,1999]; to analize new teleseimic waveforms recorded near TNB base: continuos recording, from 1999 to present, permits more accurate modelling S-velocity crustal structure in this critical area situated at the edge of the ipothetic rift [Stern and ten Brik, 1989; Stump and Fitzgerald, 1992; ten Brik et al., 1997]; to present final results from BACKTAM expedition.

Polyethylene Films Containing Silver Nanoparticles for Applications in Food Packaging: Characterization of Physico-Chemical and Anti-Microbial Properties.

PubMed

Becaro, Aline A; Puti, Fernanda C; Correa, Daniel S; Paris, Elaine C; Marconcini, José M; Ferreira, Marcos D

2015-03-01

This paper reports the antibacterial effect and physico-chemical characterization of films containing silver nanoparticles for use as food packaging. Two masterbatches (named PEN and PEC) con- taining silver nanoparticles embedded in distinct carriers (silica and titanium dioxide) were mixed with low-density polyethylene (LDPE) in different compositions and extruded to produce plain films. These films were characterized by Scanning Electron Microscopy (SEM), X-ray diffraction (XRD), Differential Scanning Calorimetry (DSC), Thermogravimetric analysis (TGA) and Fourier Transform Infrared Spectroscopy (FTIR). The morphology of the films showed the formation of agglomerates of nanoparticles in both PEN and PEC composites. X-ray analyses confirmed the presence of SiO2 in PEN samples and TiO2 in PEC samples. Thermal analyses indicated an increase in thermal stability of the PEC compositions. The antimicrobial efficacy was determined by applying the test strain for Escherichia coli and Staphylococcus aureus, according to the Japanese Industrial Standard Method (JIS Z 2801:2000). The films analyzed showed antimicrobial properties against the tested microorganisms, presenting better activity against the S. aureus than E. Coli. These findings suggest that LDPE films with silver nanoparticles are promising to provide a significant contribution to the quality and safety of packaged food.

Manifestation of a neuro-fuzzy model to produce landslide susceptibility map using remote sensing data derived parameters

NASA Astrophysics Data System (ADS)

Pradhan, Biswajeet; Lee, Saro; Buchroithner, Manfred

Landslides are the most common natural hazards in Malaysia. Preparation of landslide suscep-tibility maps is important for engineering geologists and geomorphologists. However, due to complex nature of landslides, producing a reliable susceptibility map is not easy. In this study, a new attempt is tried to produce landslide susceptibility map of a part of Cameron Valley of Malaysia. This paper develops an adaptive neuro-fuzzy inference system (ANFIS) based on a geographic information system (GIS) environment for landslide susceptibility mapping. To ob-tain the neuro-fuzzy relations for producing the landslide susceptibility map, landslide locations were identified from interpretation of aerial photographs and high resolution satellite images, field surveys and historical inventory reports. Landslide conditioning factors such as slope, plan curvature, distance to drainage lines, soil texture, lithology, and distance to lineament were extracted from topographic, soil, and lineament maps. Landslide susceptible areas were analyzed by the ANFIS model and mapped using the conditioning factors. Furthermore, we applied various membership functions (MFs) and fuzzy relations to produce landslide suscep-tibility maps. The prediction performance of the susceptibility map is checked by considering actual landslides in the study area. Results show that, triangular, trapezoidal, and polynomial MFs were the best individual MFs for modelling landslide susceptibility maps (86

How Pierre Janet used pathological psychology to save the philosophical self.

PubMed

Carroy, J; Plas, R

2000-01-01

According to traditional French historiography, French scientific psychology was born when it differentiated itself from philosophy. This split between the two disciplines is attributed to Taine and Ribot, who, consequently, are considered to be the "founding fathers" of French psychology. In this paper we shall examine the case of Pierre Janet, who, at the turn of the century, was recognized worldwide as the most important French psychologist. It is generally said that he was the follower of Ribot and of Charcot. However, he was also Paul Janet's nephew. Paul Janet was a very well known and influential philosopher of the so-called French "spiritualistic" school, for which psychology was central to philosophy. In 1889, Pierre Janet published his doctoral dissertation, L'Automatisme psychologique, which was immediately considered to be a classic in psychology. We shall argue that this book is as much indebted to the old spiritualistic psychology, which claimed the substantial unity of the self, as to the new psychology at the time, which questioned it. With Pierre Janet, the split between psychology and philosophy in France was reconsidered. It would be more accurate to speak in terms of a compromise between philosophy and the "new" physiological and pathological psychology. Copyright 2000 John Wiley & Sons, Inc.

Measurements of Size Resolved Organic Particulate Mass Using An On-line Aerosol Mass Spectrometer (ams) Laboratory Validation; Analysis Tool Development; and Interpretation of Field Data

NASA Astrophysics Data System (ADS)

Alfarra, M. R.; Coe, H.; Allan, J. D.; Bower, K. N.; Garforth, A. A.; Canagaratna, M.; Worsnop, D.

The aerosol mass spectrometer (AMS) is a quantitative instrument designed to deliver real-time size resolved chemical composition of the volatile and semi volatile aerosol fractions. The AMS response to a wide range of organic compounds has been exper- imentally characterized, and has been shown to compare well with standard libraries of 70 eV electron impact ionization mass spectra. These results will be presented. Due to the scanning nature of the quadrupole mass spectrometer, the AMS provides averaged composition of ensemble of particles rather than single particle composi- tion. However, the mass spectra measured by AMS are reproducible and similar to those of standard libraries so analysis tools can be developed on large mass spectral libraries that can provide chemical composition information about the type of organic compounds in the aerosol. One such tool is presented and compared with laboratory measurements of single species and mixed component organic particles by the AMS. We will then discuss the applicability of these tools to interpreting field AMS data ob- tained in a range of experiments at different sites in the UK and Canada. The data will be combined with other measurements to show the behaviour of the organic aerosol fraction in urban and sub-urban environments.

The impact of climate and composition on playa surface roughness: Investigation of atmospheric mineral dust emission mechanisms

NASA Astrophysics Data System (ADS)

Tollerud, H. J.; Fantle, M. S.

2011-12-01

Atmospheric mineral dust has a wide range of impacts, including the transport of elements in geochemical cycles, health hazards from small particles, and climate forcing via the reflection of sunlight from dust particles. In particular, the mineral dust component of climate forcing is one of the most uncertain elements in the IPCC climate forcing summary. Mineral dust is also an important component of geochemical cycles. For instance, dust inputs to the ocean potentially affect the iron cycle by stimulating natural iron fertilization, which could then modify climate via the biological pump. Also dust can transport nutrients over long distances and fertilize nutrient-poor regions, such as island ecosystems or the Amazon rain forest. However, there are still many uncertainties in quantifying dust emissions from source regions. One factor that influences dust emission is surface roughness and texture, since a weak, unconsolidated surface texture is more easily ablated by wind than a strong, hard crust. We are investigating the impact of processes such as precipitation, groundwater evaporation, and wind on surface roughness in a playa dust source region. We find that water has a significant influence on surface roughness. We utilize ESA's Advanced Synthetic Aperture Radar (ASAR) instrument to measure roughness in the playa. A map of roughness indicates where the playa surface is smooth (on the scale of centimeters) and potentially very strong, and where it is rough and might be more sensitive to disturbance. We have analyzed approximately 40 ASAR observations of the Black Rock Desert from 2007-2011. In general, the playa is smoother and more variable over time relative to nearby areas. There is also considerable variation within the playa. While the playa roughness maps changed significantly between summers and between observations during the winters, over the course of each summer, the playa surface maintained essentially the same roughness pattern. This suggests that

[Land cover classification of Four Lakes Region in Hubei Province based on MODIS and ENVISAT data].

PubMed

Xue, Lian; Jin, Wei-Bin; Xiong, Qin-Xue; Liu, Zhang-Yong

2010-03-01

Based on the differences of back scattering coefficient in ENVISAT ASAR data, a classification was made on the towns, waters, and vegetation-covered areas in the Four Lakes Region of Hubei Province. According to the local cropping systems and phenological characteristics in the region, and by using the discrepancies of the MODIS-NDVI index from late April to early May, the vegetation-covered areas were classified into croplands and non-croplands. The classification results based on the above-mentioned procedure was verified by the classification results based on the ETM data with high spatial resolution. Based on the DEM data, the non-croplands were categorized into forest land and bottomland; and based on the discrepancies of mean NDVI index per month, the crops were identified as mid rice, late rice, and cotton, and the croplands were identified as paddy field and upland field. The land cover classification based on the MODIS data with low spatial resolution was basically consistent with that based on the ETM data with high spatial resolution, and the total error rate was about 13.15% when the classification results based on ETM data were taken as the standard. The utilization of the above-mentioned procedures for large scale land cover classification and mapping could make the fast tracking of regional land cover classification.

Deconvolution enhanced direction of arrival estimation using one- and three-component seismic arrays applied to ocean induced microseisms

NASA Astrophysics Data System (ADS)

Gal, M.; Reading, A. M.; Ellingsen, S. P.; Koper, K. D.; Burlacu, R.; Gibbons, S. J.

2016-07-01

Microseisms in the period of 2-10 s are generated in deep oceans and near coastal regions. It is common for microseisms from multiple sources to arrive at the same time at a given seismometer. It is therefore desirable to be able to measure multiple slowness vectors accurately. Popular ways to estimate the direction of arrival of ocean induced microseisms are the conventional (fk) or adaptive (Capon) beamformer. These techniques give robust estimates, but are limited in their resolution capabilities and hence do not always detect all arrivals. One of the limiting factors in determining direction of arrival with seismic arrays is the array response, which can strongly influence the estimation of weaker sources. In this work, we aim to improve the resolution for weaker sources and evaluate the performance of two deconvolution algorithms, Richardson-Lucy deconvolution and a new implementation of CLEAN-PSF. The algorithms are tested with three arrays of different aperture (ASAR, WRA and NORSAR) using 1 month of real data each and compared with the conventional approaches. We find an improvement over conventional methods from both algorithms and the best performance with CLEAN-PSF. We then extend the CLEAN-PSF framework to three components (3C) and evaluate 1 yr of data from the Pilbara Seismic Array in northwest Australia. The 3C CLEAN-PSF analysis is capable in resolving a previously undetected Sn phase.

Merging of an EET CInSAR DEM with the SRTM DEM

NASA Astrophysics Data System (ADS)

Wegmuller, Urs; Wiesmann, Andreas; Santoro, Maurizio

2010-03-01

Cross-interferometry (CInSAR) using ERS-2 and ENVISAT ASAR SAR data acquired in the ERS like mode IS2 at VV-polarization with perpendicular baselines of approximately 2 kilometers permits generation of digital elevation models (DEMs). Thanks to the long perpendicular baselines CInSAR has a good potential to generate accurate DEMs over relatively flat terrain. Over sloped terrain the topographic phase gradients get very high and the signals decorrelate if the carrier frequency difference and the baseline effects do not compensate any more. As a result phase unwrapping gets very difficult so that often no reliable solution is obtained for hilly terrain, resulting in DEMs with significant spatial gaps.Spatial gaps in ERS-2 ENVISAT Tandem (EET) CInSAR DEMs over hilly terrain are clearly an important limitation to the utility of these DEMs. On the other hand the high quality achieved over relatively flat terrain is of high interest. As an attempt to significantly improve the utility of the "good information" contained in the CInSAR DEM we developed a methodology to merge a CInSAR DEM with another available DEM, e.g. the SRTM DEM.The methodology was applied to an area in California, USA, including relatively flat terrain belonging to the Mohave desert as well as hilly to mountainous terrain of the San Gabriel and Tehachapi Mountains.

A-Differential Synthetic Aperture Radar Interferometry analysis of a Deep Seated Gravitational Slope Deformation occurring at Bisaccia (Italy).

PubMed

Di Martire, Diego; Novellino, Alessandro; Ramondini, Massimo; Calcaterra, Domenico

2016-04-15

This paper presents the results of an investigation on a Deep Seated Gravitational Slope Deformation (DSGSD), previously only hypothesized by some authors, affecting Bisaccia, a small town located in Campania region, Italy. The study was conducted through the integration of conventional methods (geological-geomorphological field survey, air-photo interpretation) and an Advanced-Differential Interferometry Synthetic Aperture Radar (A-DInSAR) technique. The DSGSD involves a brittle lithotype (conglomerates of the Ariano Irpino Supersynthem) resting over a Structurally Complex Formation (Varycoloured Clays of Calaggio Formation). At Bisaccia, probably as a consequence of post-cyclic recompression phenomena triggered by reiterated seismic actions, the rigid plate made up of conglomeratic sediments resulted to be split in five portions, showing different rates of displacements, whose deformations are in the order of some centimeter/year, thus inducing severe damage to the urban settlement. A-DInSAR techniques confirmed to be a reliable tool in monitoring slow-moving landslides. In this case 96 ENVIronmental SATellite-Advanced Synthetic Aperture Radar (ENVISAT-ASAR) images, in ascending and descending orbits, have been processed using SUBSOFT software, developed by the Remote Sensing Laboratory (RSLab) group from the Universitat Politècnica de Catalunya (UPC). The DInSAR results, coupled with field survey, supported the analysis of the instability mechanism and confirmed the historical record of the movements already available for the town. Copyright © 2016 Elsevier B.V. All rights reserved.

Delineation of small reservoirs using radar imagery in a semi-arid environment: A case study in the upper east region of Ghana

NASA Astrophysics Data System (ADS)

Annor, F. O.; van de Giesen, N.; Liebe, J.; van de Zaag, P.; Tilmant, A.; Odai, S. N.

Small reservoirs serve many people living in semi-arid environments. Water stored in these reservoirs is used to supplement rainfed agriculture, allow for dry season irrigated agriculture and ensure the availability of water for domestic purposes. In order to manage the water effectively for competing uses, the actual storage of these reservoirs needs to be known. Recent attempts to delineate these reservoirs using remote sensing with Landsat imagery have been successful, especially in the upper east region of Ghana, West Africa. This paper shows that radar images (ENVISAT ASAR) can be used to provide similar information all year-round. Radar images have as an important advantage that they are not impaired by cloud cover and thus can be used during the rainy season. Another advantage of radar images is that images taken during night time are usable. The paper compares satellite derived data with field measurements of 21 small reservoirs. Whereas ENVISAT images on the average tend to overestimate the surface areas of small reservoirs, in certain reservoirs these areas are systematically under-estimated due to the shallow tail-ends of reservoirs that tend to have reed vegetation. These cannot be readily distinguished from the surrounding vegetation outside the reservoirs. This paper therefore provides a proof of concept of the monitoring of small reservoir volumes by radar imagery.

Multi-temporal InSAR monitoring of landslides in a tropical urban environment: focus on Bukavu (DR Congo)

NASA Astrophysics Data System (ADS)

Nobile, Adriano; Monsieurs, Elise; Dewitte, Olivier; d'Oreyes, Nicolas; Kervyn, Francois

2016-04-01

The western branch of the East African Rift System, in Central Africa, is characterized by the presence of several geohazards: earthquakes, volcanoes, and landslides. Every year, landslides cause fatalities, structural and functional damage to infrastructure and private properties with serious disruptions of the organization of societies and severe impact on the populations. These impacts are particularly important in the city of Bukavu (DR Congo) located within the Rift, on the southern shore of Lake Kivu. Large slow-moving landslides continuously affect highly populated slopes in the city. However little is known about their actual kinematics and the processes at play. Here we use multi-temporal InSAR technique to monitor these ground deformations. Using 50 Cosmo-SkyMed SAR images, acquired between March - October 2015 with a revisiting time of 8 days (ascending and descending orbits), we produce displacement-rate maps and ground deformation time series using the PS technique. Movements with a velocity >5cm/yr are detected, which is consistent with field observations. DGPS measurements, taken at 21 benchmarks in the area during the same period, allow validating the results. Similar ground deformation rates are found for the period 2002-2008 using Envisat ASAR images. Furthermore, comparison with rainfall monitoring data acquire on site should help us to understand the influence of water and the tropical seasonality in the slide mechanisms.

Detection of ground deformation over Sharm El-Sheikh-Ras Nasrani coastal zone, South Sinai (Egypt), by using time series SAR interferometry

NASA Astrophysics Data System (ADS)

Seleem, Tarek A.; Parcharidis, Issaak; Foumelis, Michael; Kourkouli, Penelope

2011-03-01

The investigation area is located in the most southern part of Sinai Peninsula boarded from the west by the Gulf of Suez and from the east by the Gulf of Aqaba. The present study concerns the application of stacking and persistent scattering of SAR interferometry in order to monitor ground deformation in the southern part of Sharm El-Shiekh area. The specific techniques were applied in order to reduce the influence of atmospheric effects on the ground deformation estimates. For this purpose a total number of 26 ENVISAT ASAR scenes covering the period between 2003 and 2009 were processed and analyzed. Interferometric processing results show both patterns of uplift and downlift in the study area. Specifically an area along the coastline with a N-S direction, corresponding to the build up zone of Sharm El-Sheikh, shows annual average subsidence rates between 5 and 7 mm/yr along the line of sight (LOS). On the contrary, Sharm El-Maya, an inner zone, parallel to the above subsided area; shows maximum slant range uplift of 5 mm/yr. The obtained results of both stacking and persistent scattering indicate that the ground deformation in Sharm El-Sheikh-Ras Nasrani coastal zone is attributed to several effecting factors compromising water pumping, lithology, seismicity, and possible active fracture. The contribution of all these factors is discussed in the context.

Coarse Resolution SAR Imagery to Support Flood Inundation Models in Near Real Time

NASA Astrophysics Data System (ADS)

Di Baldassarre, Giuliano; Schumann, Guy; Brandimarte, Luigia; Bates, Paul

2009-11-01

In recent years, the availability of new emerging data (e.g. remote sensing, intelligent wireless sensors, etc) has led to a sudden shift from a data-sparse to a data-rich environment for hydrological and hydraulic modelling. Furthermore, the increased socioeconomic relevance of river flood studies has motivated the development of complex methodologies for the simulation of the hydraulic behaviour of river systems. In this context, this study aims at assessing the capability of coarse resolution SAR (Synthetic Aperture Radar) imagery to support and quickly validate flood inundation models in near real time. A hydraulic model of a 98km reach of the River Po (Italy), previously calibrated on a high-magnitude flood event with extensive and high quality field data, is tested using a SAR flood image, acquired and processed in near real time, during the June 2008 low-magnitude event. Specifically, the image is an acquisition by the ENVISAT-ASAR sensor in wide swath mode and has been provided through ESA (European Space Agency) Fast Registration system at no cost 24 hours after the acquisition. The study shows that the SAR image enables validation and improvement of the model in a time shorter than the flood travel time. This increases the reliability of model predictions (e.g. water elevation and inundation width along the river reach) and, consequently, assists flood management authorities in undertaking the necessary prevention activities.

Study of the anticorrelations between ozone and UV-B radiation using linear and exponential fits in Southern Brazil

NASA Astrophysics Data System (ADS)

Guarnieri, R.; Padilha, L.; Guarnieri, F.; Echer, E.; Makita, K.; Pinheiro, D.; Schuch, A.; Boeira, L.; Schuch, N.

Ultraviolet radiation type B (UV-B 280-315nm) is well known by its damage to life on Earth, including the possibility of causing skin cancer in humans. However, the atmo- spheric ozone has absorption bands in this spectral radiation, reducing its incidence on Earth's surface. Therefore, the ozone amount is one of the parameters, besides clouds, aerosols, solar zenith angles, altitude, albedo, that determine the UV-B radia- tion intensity reaching the Earth's surface. The total ozone column, in Dobson Units, determined by TOMS spectrometer on board of a NASA satellite, and UV-B radiation measurements obtained by a UV-B radiometer model MS-210W (Eko Instruments) were correlated. The measurements were obtained at the Observatório Espacial do Sul - Instituto Nacional de Pesquisas Espaciais (OES/CRSPE/INPE-MCT) coordinates: Lat. 29.44oS, Long. 53.82oW. The correlations were made using UV-B measurements in fixed solar zenith angles and only days with clear sky were selected in a period from July 1999 to December 2001. Moreover, the mathematic behavior of correlation in dif- ferent angles was observed, and correlation coefficients were determined by linear and first order exponential fits. In both fits, high correlation coefficients values were ob- tained, and the difference between linear and exponential fit can be considered small.

Is chronic groin pain a Bermuda triangle of sports medicine?

PubMed

Šebečić, Božidar; Japjec, Mladen; Janković, Saša; Vencel Čuljak; Dojčinović, Bojan; Starešinić, Mario

2014-12-01

Chronic groin pain is one the most complex conditions encountered in the field of sports medicine. Conservative treatment is long lasting and the result of treatment is often uncer- tain and symptom recurrences are common, which can be very frustrating for both the patient and the physician. The complex etiology and uncertainties during treatment of chronic groin pain is the reason why some authors call it the Bermuda Triangle of sports medicine. In our prospective, 7-year study, 114 athletes with chronic groin pain resistant to conservative therapy were treated surgically. In 109 athletes with sports hernia, we performed nerve neurolysis along with resection of the genital branch of the genitofemoral nerve and we also reinforced the posterior wall of inguinal canal using a modified Shouldice technique. In 26 athletes that had concomitant adductor tendinosis and in 5 athletes with isolated tendinosis we performed tenotomy. Eighty-one of 83 patients with isolated sports hernia returned to sports within a mean of 4.4 (range, 3-16) weeks. Thirty-one athletes with adductor tenotomy returned to sports activity within a mean of 11.8 (range, 10-15) weeks. If carefully diagnosed using detailed history taking, physical examination and correct imaging techniques, chronic groin pain can be treated very successfully and quickly, so it need not be a Bermuda Triangle of sports medicine.

Rainfall, streamflow, and water-quality data for five small watersheds, Nashville, Tennessee, 1990-92

USGS Publications Warehouse

Outlaw, George S.; Hoos, Anne B.; Pankey, John T.

1994-01-01

Rainfall, streamflow, and water-quality data were collected furing storm conditions at five urban watersheds in Nashville, Tennessee. These data can be used to build a database for developing predictive models of the relations between storm- water quality and land use, storm characteristics, and seasonal variations. The primary land and mix of land uses was different for each watershed. Stormwater samples were collected during three storms at each watershed and analyzed for selected volatile, acidic and base/neutral organic compounds; organic pesticides; trace metals; conventional pollutants; and several physical properties. Storm loads were computed for all constituents and properties with event mean concentration above the minimum reporting level. None of the samples con- tained acidic organic compounds at concentrations above the minimum reporting levels. Several constituents in each of the other categories, however, were present at concentrations above the minimum reporting level. For 21 of these constituents, water-quality criteria have been pro- mulgated by the State of Tennessee. For only 8 of the 21 did the value exceed the most restrictive of the criteria: pyrene, dieldrin, and mercury concen- trations and counts of fecal coliform exceeded the criteria for recreational use, copper and zinc concentrations and pH value exceeded the criteria for fish and aquatic life, and lead concentrations exceeded the criteria for domestic supply.

Mutation detection for inventories of traffic signs from street-level panoramic images

NASA Astrophysics Data System (ADS)

Hazelhoff, Lykele; Creusen, Ivo; De With, Peter H. N.

2014-03-01

Road safety is positively influenced by both adequate placement and optimal visibility of traffic signs. As their visibility degrades over time due to e.g. aging, vandalism, accidents and vegetation coverage, up-to-date inven­tories of traffic signs are highly attractive for preserving a high road safety. These inventories are performed in a semi-automatic fashion from street-level panoramic images, exploiting object detection and classification tech­niques. Next to performing inventories from scratch, these systems are also exploited for the efficient retrieval of situation changes by comparing the outcome of the automated system to a baseline inventory (e.g. performed in a previous year). This allows for specific manual interactions to the found changes, while skipping all unchanged situations, thereby resulting in a large efficiency gain. This work describes such a mutation detection approach, with special attention to re-identifying previously found signs. Preliminary results on a geographical area con­taining about 425 km of road show that 91.3% of the unchanged signs are re-identified, while the amount of found differences equals about 35% of the number of baseline signs. From these differences, about 50% correspond to physically changed traffic signs, next to false detections, misclassifications and missed signs. As a bonus, our approach directly results in the changed situations, which is beneficial for road sign maintenance.

Prior-knowledge Fitting of Accelerated Five-dimensional Echo Planar J-resolved Spectroscopic Imaging: Effect of Nonlinear Reconstruction on Quantitation.

PubMed

Iqbal, Zohaib; Wilson, Neil E; Thomas, M Albert

2017-07-24

1 H Magnetic Resonance Spectroscopic imaging (SI) is a powerful tool capable of investigating metabolism in vivo from mul- tiple regions. However, SI techniques are time consuming, and are therefore difficult to implement clinically. By applying non-uniform sampling (NUS) and compressed sensing (CS) reconstruction, it is possible to accelerate these scans while re- taining key spectral information. One recently developed method that utilizes this type of acceleration is the five-dimensional echo planar J-resolved spectroscopic imaging (5D EP-JRESI) sequence, which is capable of obtaining two-dimensional (2D) spectra from three spatial dimensions. The prior-knowledge fitting (ProFit) algorithm is typically used to quantify 2D spectra in vivo, however the effects of NUS and CS reconstruction on the quantitation results are unknown. This study utilized a simulated brain phantom to investigate the errors introduced through the acceleration methods. Errors (normalized root mean square error >15%) were found between metabolite concentrations after twelve-fold acceleration for several low concentra- tion (<2 mM) metabolites. The Cramér Rao lower bound% (CRLB%) values, which are typically used for quality control, were not reflective of the increased quantitation error arising from acceleration. Finally, occipital white (OWM) and gray (OGM) human brain matter were quantified in vivo using the 5D EP-JRESI sequence with eight-fold acceleration.

Using remote sensing data for exploitation of integrated renewable energy at coastal site in South Italy

NASA Astrophysics Data System (ADS)

Calaudi, Rosamaria; Lo Feudo, Teresa; Calidonna, Claudia Roberta; Sempreviva, Anna Maria

2016-04-01

estimation we used Synthetic-Aperture-Radar (SAR) images from March 2002 to April 2012 for a total of 3269 ENVISAT-ASAR scenes acquired in Wide-Swath-Mode (WSM). Wind speed in the Mediterranean is retrieved using the Johns Hopkins University, Applied Physics Laboratory (JHU-APL) software APL-NOAA-SAR Wind Retrieval System. The ASAR is a C-band VV and HH instrument with a 405 km swath with 150 m and 1 km resolution in wide-swath mode. With a 35-day repeat orbit the revisit frequency will give daily coverage near the poles and weekly at the equator. We performed statistical analyses for wind parameters. The SAR-based wind results at the location test near Vibo Valentia show that the average of wind speed is U= 5.63 ms-1, the Weibull parameters are A=6.3 ms-1 and k=1.70. The power density of the wind is E=245 Wm-2.The high spatial resolution of the gridded SAR data is particularly relevant to study coastal sites, where most part of human activities is located. In order to create a zero emissions' harbor area, remote sensing satellite data, can be used for smart grid which employed renewable energies.

SAR Observation and Numerical Simulation of Internal Solitary Wave Refraction and Reconnection Behind the Dongsha Atoll

NASA Astrophysics Data System (ADS)

Jia, T.; Liang, J. J.; Li, X.-M.; Sha, J.

2018-01-01

The refraction and reconnection of internal solitary waves (ISWs) around the Dongsha Atoll (DSA) in the northern South China Sea (SCS) are investigated based on spaceborne synthetic aperture radar (SAR) observations and numerical simulations. In general, a long ISW front propagating from the deep basin of the northern SCS splits into northern and southern branches when it passes the DSA. In this study, the statistics of Envisat Advanced SAR (ASAR) images show that the northern and southern wave branches can reconnect behind the DSA, but the reconnection location varies. A previously developed nonlinear refraction model is set up to simulate the refraction and reconnection of the ISWs behind the DSA, and the model is used to evaluate the effects of ocean stratification, background currents, and incoming ISW characteristics at the DSA on the variation in reconnection locations. The results of the first realistic simulation agree with consecutive TerraSAR-X (TSX) images captured within 12 h of each other. Further sensitivity simulations show that ocean stratification, background currents, and initial wave amplitudes all affect the phase speeds of wave branches and therefore shift their reconnection locations while shapes and locations of incoming wave branches upstream of the DSA profoundly influence the subsequent propagation paths. This study clarifies the variation in reconnection locations of ISWs downstream of the DSA and reveals the important mechanisms governing the reconnection process, which can improve our understanding of the propagation of ISWs near the DSA.

MINERVA: An INSAR Monitoring Service for Volcanic Hazard

NASA Astrophysics Data System (ADS)

Tampellini, M. L.; Sansosti, E.; Usai, S.; Lanari, R.; Borgstrom, S.; van Persie, M.; Ricciardi, G. P.; Maddalena, V.; Cicero, L.; Pepe, A.

2004-06-01

MINERVA (Monitoring by Interferometric SAR of Environmental Risk in Volcanic Areas) is a small scale service demonstration project financed by ESA in the Data User Programme framework. The objective of the project is the design, development and assessment of a demonstrative information service based on the interferometric processing of images acquired from either the ASAR instrument on board ENVISAT-I or SAR instruments on board ERS1/2. The system is based on a new approach for the processing of INSAR data, which allows to optimize the quality of interferograms spanning from 35 days up to several years, and to merge them to generate a single solution describing the temporal evolution of the ground deformations in the examined risk area. The system allows to update this solution each time a new SAR image is available, and constitutes therefore an innovative tool for monitoring of the ground displacements in risk areas. The system has been implemented and demonstrated at Osservatorio Vesuviano (Naples, Italy), which is the institution responsible for monitoring the volcanic phenomena in the Neapolitan volcanic district, and for alerting the Italian civil authorities (''Protezione Civile'') in case such monitoring activity reveals signals of imminent eruptions. In particular, the MINERVA system has been used to monitor the ground deformations at the Phlegrean Fields, a densely populated, high-hazard zone which is subject to alternate phases of uplift and subsidence, accompanied often by seismic activity.

Monitoring of Large Scale Volcanic Deformations in the Andes Using Geodetic Time Series (DInSAR, GPS and Microgravity)

NASA Astrophysics Data System (ADS)

Remy, D.; Froger, J. L.; Bonvalot, S.; Gabalda, G.; Albino, F.; Byrdina, S.

2010-03-01

Lastarria (25°10'S, 68°31'W, 5706 m) and Cordon del Azufre (25°18'S, 68°33'W, 5480 m) are part of a broad polygenic quaternary volcanic complex lying on the Altiplano, on the border of Chile and Argentina. This large scale volcanic area attracted particular attention in recent years because of its relatively intense unrest characterised by a peculiar style of on-going ground deformation, apparently begun in 1998. Interferometric Synthetic Aperture Radar (InSAR) data collected between 1998 and 2009 revealed two scales of inflation: a large elliptical area (50 km NNE- SSW major axis and a 40 minor axis), which has been inflating at a rate of around 3 cm.yr-1; and a short wavelength inflation (6 km wide), which is located at Lastarria volcano on the northern margin of the large elliptical area. The temporal evolution of these two distinct inflating signals suggests that they could be linked. The origin of this inflation period is still debated and various source mechanisms have been proposed to explain the observed deformation. Here, we present new observations of surface deformation in the Lastarria-Cordon del Azufre complex based on InSAR, levelling global positioning system (GPS), and microgravity data. Ascending and descending ASAR interferograms are combined to determine vertical and the EW horizontal component of displacement. Geodetic data are discussed from the standpoint of providing better constraints to understand the mechanics of the observed process at the volcanic complex.

Characterize the hydrogeological properties and probe the stress field in Salt Lake Valley, Utah using SAR imagery

NASA Astrophysics Data System (ADS)

Hu, X.; Lu, Z.; Barbot, S.; Wang, T.

2017-12-01

Aquifer skeletons deform actively in response to the groundwater redistribution and hydraulic head changes with varied time scales of delay and sensitivity, that can also, in some instances, trigger earthquakes. However, determining the key hydrogeological properties and understanding the interactions between aquifer and seismicity generally requires the analysis of dense water level data combined with expensive drilling data (borehole breakouts). Here we investigate the spatiotemporal correlation among ground motions, hydrological changes, earthquakes, and faults in Salt Lake Valley, Utah, based on InSAR observations from ENVISAT ASAR (2004-2010) and Sentinel-1A (2015-2016). InSAR results show a clear seasonal and long-term correlation between surface uplift/subsidence and groundwater recharge/discharge, with evidence for an average net uplift of 15 mm/yr for a period of 7 years. The long-term uplift, remarkably bounded by faults, reflects a net increase in pore pressure associated with prolonged water recharge probably decades ago. InSAR-derived ground deformation and its correlation with head variations allow us to quantify hydrogeological properties - decay coefficient, storage coefficient, and bulk compressibility. We also model the long-term deformation using a shallow vertical shearing reservoir to constrain its thickness and strain rate. InSAR-derived deformation help reveal the coupled hydrological and tectonic processes in Salt Lake Valley: the embedded faults disrupt the groundwater flow and partition the hydrological units, and the pore pressure changes rearrange the aquifer skeleton and modulate the stress field, which may affect the basin-wide seismicity.

Application of Persistent Scatterer Interferometry (PSI) in monitoring slope movements in Nainital, Uttarakhand Lesser Himalaya, India

NASA Astrophysics Data System (ADS)

Yhokha, Akano; Goswami, Pradeep K.; Chang, Chung-Pai; Yen, Jiun-Yee; Ching, Kuo-En; Aruche, K. Manini

2018-02-01

Orogenic movements and sub-tropical climate have rendered the slopes of the Himalayan region intensely deformed and weathered. As a result, the incidences of slope failure are quite common all along the Himalayan region. The Lesser Himalayan terrane is particularly vulnerable to mass-movements owing to geological fragility, and many parts of it are bearing a high-risk of associated disaster owing to the high population density. An important step towards mitigation of such disasters is the monitoring of slope movement. Towards this, the Persistent Scatterer Interferometry (PSI) technique can be applied. In the present study, the PSI technique is employed in Lesser Himalayan town of Nainital in Uttarakhand state of India to decipher and monitor slope movements. A total of 15 multi-date ENVISAT ASAR satellite images, acquired during August 2008 to August 2010 period, were subjected to PSI, which revealed a continuous creep movement along the hillslopes located towards the eastern side of the Nainital lake. The higher reaches of the hill seem to be experiencing accelerated creep of {˜ }21 mm/year, which decreases downslope to {˜ }5 mm/year. Based on spatial pattern of varying PSI Mean LOS Velocity (MLV) values, high (H), moderate (M), low (L) and very low (S) creeping zones have been delineated in the hillslopes. Given the long history of mass movements and continuously increasing anthropogenic activities in Nainital, these results call for immediate measures to avert any future disaster in the town.

Optimal land use/land cover classification using remote sensing imagery for hydrological modeling in a Himalayan watershed

NASA Astrophysics Data System (ADS)

Saran, Sameer; Sterk, Geert; Kumar, Suresh

2009-10-01

Land use/land cover is an important watershed surface characteristic that affects surface runoff and erosion. Many of the available hydrological models divide the watershed into Hydrological Response Units (HRU), which are spatial units with expected similar hydrological behaviours. The division into HRU's requires good-quality spatial data on land use/land cover. This paper presents different approaches to attain an optimal land use/land cover map based on remote sensing imagery for a Himalayan watershed in northern India. First digital classifications using maximum likelihood classifier (MLC) and a decision tree classifier were applied. The results obtained from the decision tree were better and even improved after post classification sorting. But the obtained land use/land cover map was not sufficient for the delineation of HRUs, since the agricultural land use/land cover class did not discriminate between the two major crops in the area i.e. paddy and maize. Subsequently the digital classification on fused data (ASAR and ASTER) were attempted to map land use/land cover classes with emphasis to delineate the paddy and maize crops but the supervised classification over fused datasets did not provide the desired accuracy and proper delineation of paddy and maize crops. Eventually, we adopted a visual classification approach on fused data. This second step with detailed classification system resulted into better classification accuracy within the 'agricultural land' class which will be further combined with topography and soil type to derive HRU's for physically-based hydrological modeling.

A Robust and Multi-Weighted Approach to Estimating Topographically Correlated Tropospheric Delays in Radar Interferograms

PubMed Central

Zhu, Bangyan; Li, Jiancheng; Chu, Zhengwei; Tang, Wei; Wang, Bin; Li, Dawei

2016-01-01

Spatial and temporal variations in the vertical stratification of the troposphere introduce significant propagation delays in interferometric synthetic aperture radar (InSAR) observations. Observations of small amplitude surface deformations and regional subsidence rates are plagued by tropospheric delays, and strongly correlated with topographic height variations. Phase-based tropospheric correction techniques assuming a linear relationship between interferometric phase and topography have been exploited and developed, with mixed success. Producing robust estimates of tropospheric phase delay however plays a critical role in increasing the accuracy of InSAR measurements. Meanwhile, few phase-based correction methods account for the spatially variable tropospheric delay over lager study regions. Here, we present a robust and multi-weighted approach to estimate the correlation between phase and topography that is relatively insensitive to confounding processes such as regional subsidence over larger regions as well as under varying tropospheric conditions. An expanded form of robust least squares is introduced to estimate the spatially variable correlation between phase and topography by splitting the interferograms into multiple blocks. Within each block, correlation is robustly estimated from the band-filtered phase and topography. Phase-elevation ratios are multiply- weighted and extrapolated to each persistent scatter (PS) pixel. We applied the proposed method to Envisat ASAR images over the Southern California area, USA, and found that our method mitigated the atmospheric noise better than the conventional phase-based method. The corrected ground surface deformation agreed better with those measured from GPS. PMID:27420066

A Robust and Multi-Weighted Approach to Estimating Topographically Correlated Tropospheric Delays in Radar Interferograms.

PubMed

Zhu, Bangyan; Li, Jiancheng; Chu, Zhengwei; Tang, Wei; Wang, Bin; Li, Dawei

2016-07-12

Spatial and temporal variations in the vertical stratification of the troposphere introduce significant propagation delays in interferometric synthetic aperture radar (InSAR) observations. Observations of small amplitude surface deformations and regional subsidence rates are plagued by tropospheric delays, and strongly correlated with topographic height variations. Phase-based tropospheric correction techniques assuming a linear relationship between interferometric phase and topography have been exploited and developed, with mixed success. Producing robust estimates of tropospheric phase delay however plays a critical role in increasing the accuracy of InSAR measurements. Meanwhile, few phase-based correction methods account for the spatially variable tropospheric delay over lager study regions. Here, we present a robust and multi-weighted approach to estimate the correlation between phase and topography that is relatively insensitive to confounding processes such as regional subsidence over larger regions as well as under varying tropospheric conditions. An expanded form of robust least squares is introduced to estimate the spatially variable correlation between phase and topography by splitting the interferograms into multiple blocks. Within each block, correlation is robustly estimated from the band-filtered phase and topography. Phase-elevation ratios are multiply- weighted and extrapolated to each persistent scatter (PS) pixel. We applied the proposed method to Envisat ASAR images over the Southern California area, USA, and found that our method mitigated the atmospheric noise better than the conventional phase-based method. The corrected ground surface deformation agreed better with those measured from GPS.

Radar remote sensing of wind-driven land degradation processes in northeastern Patagonia.

PubMed

del Valle, H F; Blanco, P D; Metternicht, G I; Zinck, J A

2010-01-01

Wind-driven land degradation negatively impacts on rangeland production and infrastructure in the Valdes Peninsula, northeastern Patagonia. The Valdes Peninsula has the most noticeable dunefields of the Patagonian drylands. Wind erosion has been assessed at different scales in this region, but often with limited data. In general, terrain features caused by wind activity are better discriminated by active microwaves than by sensors operating in the visible and infrared regions of the electromagnetic spectrum. This paper aims to analyze wind-driven land degradation processes that control the radar backscatter observed in different sources of radar imagery. We used subsets derived from SIR-C, ERS-1 and 2, ENVISAT ASAR, RADARSAT-1, and ALOS PALSAR data. The visibility of aeolian features on radar images is mostly a function of wavelength, polarization, and incidence angle. Stabilized sand deposits are clearly observed in radar images, with defined edges but also signals of ongoing wind erosion. One of the most conspicuous features corresponds to old track sand dunes, a mixture of active and inactive barchanoid ridges and parabolic dunes. This is a clear example of deactivation of migrating dunes under the influence of vegetation. The L-band data reveal details of these sand ridges, whereas the C-band data only allow detecting a few of the larger tracks. The results of this study enable us to make recommendations about the utility of some radar sensor configurations for wind-driven land degradation reconnaissance in mid-latitude regions.

Deformation of the western Indian Plate boundary: insights from differential and multi-aperture InSAR data inversion for the 2008 Baluchistan (Western Pakistan) seismic sequence

NASA Astrophysics Data System (ADS)

Pezzo, Giuseppe; Merryman Boncori, John Peter; Atzori, Simone; Antonioli, Andrea; Salvi, Stefano

2014-07-01

In this study, we use Differential Synthetic Aperture Radar Interferometry (DInSAR) and multi-aperture interferometry (MAI) to constrain the sources of the three largest events of the 2008 Baluchistan (western Pakistan) seismic sequence, namely two Mw 6.4 events only 12 hr apart and an Mw 5.7 event that occurred 40 d later. The sequence took place in the Quetta Syntaxis, the most seismically active region of Baluchistan, tectonically located between the colliding Indian Plate and the Afghan Block of the Eurasian Plate. Surface displacements estimated from ascending and descending ENVISAT ASAR acquisitions were used to derive elastic dislocation models for the sources of the two main events. The estimated slip distributions have peak values of 120 and 130 cm on a pair of almost parallel and near-vertical faults striking NW-SE, and of 50 cm and 60 cm on two high-angle faults striking NE-SW. Values up to 50 cm were found for the largest aftershock on an NE-SW fault located between the sources of the main shocks. The MAI measurements, with their high sensitivity to the north-south motion component, are crucial in this area to accurately describe the coseismic displacement field. Our results provide insight into the deformation style of the Quetta Syntaxis, suggesting that right-lateral slip released at shallow depths on large NW fault planes is compatible with left-lateral activation on smaller NE-SW faults.

Phylogenetic comparisons of a coastal bacterioplankton community with its counterparts in open ocean and freshwater systems.

PubMed

Rappé; Vergin; Giovannoni

2000-09-01

In order to extend previous comparisons between coastal marine bacterioplankton communities and their open ocean and freshwater counterparts, here we summarize and provide new data on a clone library of 105 SSU rRNA genes recovered from seawater collected over the western continental shelf of the USA in the Pacific Ocean. Comparisons to previously published data revealed that this coastal bacterioplankton clone library was dominated by SSU rRNA gene phylotypes originally described from surface waters of the open ocean, but also revealed unique SSU rRNA gene lineages of beta Proteobacteria related to those found in clone libraries from freshwater habitats. beta Proteobacteria lineages common to coastal and freshwater samples included members of a clade of obligately methylotrophic bacteria, SSU rRNA genes affiliated with Xylophilus ampelinus, and a clade related to the genus Duganella. In addition, SSU rRNA genes were recovered from such previously recognized marine bacterioplankton SSU rRNA gene clone clusters as the SAR86, SAR11, and SAR116 clusters within the class Proteobacteria, the Roseobacter clade of the alpha subclass of the Proteobacteria, the marine group A/SAR406 cluster, and the marine Actinobacteria clade. Overall, these results support and extend previous observations concerning the global distribution of several marine planktonic prokaryote SSU rRNA gene phylotypes, but also show that coastal bacterioplankton communities contain SSU rRNA gene lineages (and presumably bacterioplankton) shown previously to be prevalent in freshwater habitats.

Refined Modeling of Flexural Deformation of Layered Plates with a Regular Structure Made from Nonlinear Hereditary Materials

NASA Astrophysics Data System (ADS)

Yankovskii, A. P.

2018-01-01

On the basis of constitutive equations of the Rabotnov nonlinear hereditary theory of creep, the problem on the rheonomic flexural behavior of layered plates with a regular structure is formu-lated. Equations allowing one to describe, with different degrees of accuracy, the stress-strain state of such plates with account of their weakened resistance to transverse shear were ob-tained. From them, the relations of the nonclassical Reissner- and Reddytype theories can be found. For axially loaded annular plates clamped at one edge and loaded quasistatically on the other edge, a simplified version of the refined theory, whose complexity is comparable to that of the Reissner and Reddy theories, is developed. The flexural strains of such metal-composite annular plates in shortterm and long-term loadings at different levels of heat action are calcu-lated. It is shown that, for plates with a relative thickness of order of 1/10, neither the classical theory, nor the traditional nonclassical Reissner and Reddy theories guarantee reliable results for deflections even with the rough 10% accuracy. The accuracy of these theories decreases at elevated temperatures and with time under long-term loadings of structures. On the basic of relations of the refined theory, it is revealed that, in bending of layered metal-composite heat-sensitive plates under elevated temperatures, marked edge effects arise in the neighborhood of the supported edge, which characterize the shear of these structures in the transverse direction

[The Belgian and French medicine and the "Ordres" facing the "jewish question" during the Second World War].

PubMed

Noterman, J

2014-01-01

The attitude of the medical community and the "Ordres" to the "jewish question" differs in Belgium and France. This difference originates before the Second World War. Xenophobia and antisemitism were stronger in France. In addition, the Belgian capitulation of May 1940 and the armistice of June 22 in France do not represent the same situation. In France, a legal government, under the direction of Marshal Pétain, took a series of xenophobic measures of which the Jews were the first victims. In Belgium, in the absence of any government, the General Secretaries in Ministries were the ones who had to apply the antijewish measures dictated by the German occupant. By law, they could not legislate on the political level. The "Ordre", of French physicians was created in late 1940 by the Vichy government. In Belgium, the "Ordre " had existed since 1938 but had been unable to meet in the absence of implement decrees. An "Ordre bis" was created in late 1941, the legality of which was questioned by many lawyers and physicians. The French "Ordre" was to apply the antijewish measures by taking responsibility for the selection of Jewish physicians entitled to practice. In Belgium, the "Ordre" frowned upon by the physicians, played no official role in this regard. It simply applied the antijewish measures dictated by the Germans without protesting. After the conflict, the leaders of the "Ordres" had a different fate in both countries. In France, they escaped sentences. In Belgium, they were heavily condemned.

Functional characterisation and permeation studies of lyophilised thiolated chitosan xerogels for buccal delivery of insulin.

PubMed

Boateng, Joshua S; Mitchell, John C; Pawar, Harshavardhan; Ayensu, Isaac

2014-01-01

Stable and mucoadhesive, lyophilised, thiolated chitosan xerogels, loaded with insulin for buccal mucosa deliv- ery, in place of the currently used parenteral route have been developed. The xerogels were backed with impervious ethyl- cellulose laminate to ensure unidirectional release and also loaded with enzyme inhibitor to enhance insulin permeability across the buccal mucosa. Characterisation of xerogels using(1) HNMR confirmed the degree of deacetylation of the syn- thesised thiolated chitosan. The amount of thiol groups immobilised on the modified chitosan was quantified by Ellman's reaction and molecular weight monitored by gel permeation chromatography. The stability of the secondary structure of insulin was examined by attenuated total reflectance Fourier transform infra-red spectroscopy and circular dichroism. In vitro and ex vivo permeation studies were undertaken by using EpiOral ™ and sheep buccal membrane respectively. Insu- lin released from thiolated chitosan xerogels, loaded with aprotinin (enzyme inhibitor and permeation enhancer) showed a 1.7-fold increase in permeation through EpiOral ™ buccal tissue construct compared to the pure drug. However, permea- tion was decreased for xerogels containing the enzyme inhibitor glutathione. Further, aprotinin containing xerogels en- hanced insulin permeation through sheep buccal membrane and demonstrated good linear correlation with the permeation data from the EpiOral ™ study. The results show the potential application of lyoph ilised thiolated chitosan xerogels con- taining aprotinin with improved mucoadhesion, penetration enhancing and enzyme inhibition characteristics for buccal mucosa delivery of macromolecules such as insulin.

Wave Tank Studies of Phase Velocities of Short Wind Waves

NASA Astrophysics Data System (ADS)

Ermakov, S.; Sergievskaya, I.; Shchegolkov, Yu.

Wave tank studies of phase velocities of short wind waves have been carried out using Ka-band radar and an Optical Spectrum Analyser. The phase velocities were retrieved from measured radar and optical Doppler shifts, taking into account measurements of surface drift velocities. The dispersion relationship was studied in centimetre (cm)- and millimetre(mm)-scale wavelength ranges at different fetches and wind speeds, both for a clean water surface and for water covered with surfactant films. It is ob- tained that the phase velocities do not follow the dispersion relation of linear capillary- gravity waves, increasing with fetch and, therefore, depending on phase velocities of dominant decimetre (dm)-centimetre-scale wind waves. One thus can conclude that nonlinear cm-mm-scale harmonics bound to the dominant wind waves and propagat- ing with the phase velocities of the decimetric waves are present in the wind wave spectrum. The resulting phase velocities of short wind waves are determined by re- lation between free and bound waves. The relative intensity of the bound waves in the spectrum of short wind waves is estimated. It is shown that this relation depends strongly on the surfactant concentration, because the damping effect due to films is different for free and bound waves; this results to changes of phase velocities of wind waves in the presence of surfactant films. This work was supported by MOD, UK via DERA Winfrith (Project ISTC 1774P) and by RFBR (Project 02-05-65102).

Identification of Foreign Particles in Human Tissues using Raman Microscopy.

PubMed

Campion, Alan; Smith, Kenneth J; Fedulov, Alexey V; Gregory, David; Fan, Yuwei; Godleski, John J

2018-06-12

The precise identification of foreign particles in tissue for patient care and research has been studied using polarized light microscopy, electron microscopy with X-ray analysis, and electron diffraction. The goal of this study was to unambiguously identify particles in tissues using a combina-tion of polarized light microscopy and Raman microscopy, which provides chemical composition and microstructural characterization of complex materials with submicron spatial resolution. We designed a model system of stained and unstained cells that contained birefringent talc particles, and systematically investigated the influence of slide and coverslip materials, laser wavelengths, and mounting media on the Raman spectra ob-tained. Hematoxylin and eosin stained slides did not produce useful results because of fluorescence interference from the stains. Unstained cell samples prepared with standard slides and coverslips produce high quality Raman spectra when excited at 532 nm; the spectra are uniquely as-signed to talc. We also obtain high quality Raman spectra specific for talc in unstained tissue samples (pleural tissue following talc pleurodesis and ovarian tissue following long-term perineal talc exposure). Raman microscopy is sufficiently sensitive and compositionally selective to identify particles as small as one micron in diameter. Among commonly used coverslip mounting media, Cytoseal 60 is recommended; Permount was unacceptable due to intense background interference. Raman spectra have been catalogued for thousands of substances, which suggests that this approach is likely to be successful in identifying other particles of interest in tissues, potentially making Raman microscopy a powerful new tool in pathology.

Probabilistic mapping of flood-induced backscatter changes in SAR time series

NASA Astrophysics Data System (ADS)

Schlaffer, Stefan; Chini, Marco; Giustarini, Laura; Matgen, Patrick

2017-04-01

The information content of flood extent maps can be increased considerably by including information on the uncertainty of the flood area delineation. This additional information can be of benefit in flood forecasting and monitoring. Furthermore, flood probability maps can be converted to binary maps showing flooded and non-flooded areas by applying a threshold probability value pF = 0.5. In this study, a probabilistic change detection approach for flood mapping based on synthetic aperture radar (SAR) time series is proposed. For this purpose, conditional probability density functions (PDFs) for land and open water surfaces were estimated from ENVISAT ASAR Wide Swath (WS) time series containing >600 images using a reference mask of permanent water bodies. A pixel-wise harmonic model was used to account for seasonality in backscatter from land areas caused by soil moisture and vegetation dynamics. The approach was evaluated for a large-scale flood event along the River Severn, United Kingdom. The retrieved flood probability maps were compared to a reference flood mask derived from high-resolution aerial imagery by means of reliability diagrams. The obtained performance measures indicate both high reliability and confidence although there was a slight under-estimation of the flood extent, which may in part be attributed to topographically induced radar shadows along the edges of the floodplain. Furthermore, the results highlight the importance of local incidence angle for the separability between flooded and non-flooded areas as specular reflection properties of open water surfaces increase with a more oblique viewing geometry.

The cardiac sonography workforce in New Zealand.

PubMed

Buckley, Belinda; White, Steve; Poppe, Katrina; Whalley, Gillian

2013-05-01

Introduction : The aim of this paper is to investigate the cardiac sonography workforce characteristics and registration requirements in New Zealand (NZ), with a comparison to similar workforces internationally. Methods : The Survey of Clinical Echocardiography in New Zealand 2 (SCANZ2) audit was performed in December 2010. All of NZ's public-funded District Health Board (DHB) centers providing echocardiography services responded to questions relating to staff, equipment, procedure types and patient statistics. The Medical Radiation Technologists Board (MRTB), Clinical Physiologists Registration Board (CPRB) and Australian Sonographers Association Registry (ASAR) websites were reviewed in March 2012 for registered sonographers with a cardiac scope of practice. The cardiac sonography workforces in Australia, the UK, the USA and Canada were investigated for comparison. Results : There are 84 cardiac sonographers (60.3 full-time equivalent) working in DHBs: 71% from a cardiac technical background; 40% have post-graduate qualifications; a further 17% are undertaking post-graduate qualifications; and 59 cardiac sonographers have registration with professional bodies in NZ and/or Australia. Cardiac sonographers in NZ do not undergo compulsory registration, but other sonographers in NZ have compulsory registration with the MRTB. Sonographers are predominantly not licensed internationally. Discussion : Disparity exists between registration of cardiac and non-cardiac sonographers in NZ. Many cardiac sonographers have voluntary registration but few are registered with the MRTB. Reasons for this include professional alignment, educational qualifications and representation. International trends show increased pressure from governments and professional bodies to regulate sonographers. Conclusion : This study provides a snapshot of the cardiac sonography workforce in NZ for the first time.

Potential inundated coastal area estimation in Shanghai with multi-platform SAR and altimetry data

NASA Astrophysics Data System (ADS)

Ma, Guanyu; Yang, Tianliang; Zhao, Qing; Kubanek, Julia; Pepe, Antonio; Dong, Hongbin; Sun, Zhibin

2017-09-01

As global warming problem is becoming serious in recent decades, the global sea level is continuously rising. This will cause damages to the coastal deltas with the characteristics of low-lying land, dense population, and developed economy. Continuously reclamation costal intertidal and wetland areas are making Shanghai, the mega city of Yangtze River Delta, more vulnerable to sea level rise. In this paper, we investigate the land subsidence temporal evolution of patterns and processes on a stretch of muddy coast located between the Yangtze River Estuary and Hangzou Bay with differential synthetic aperture radar interferometry (DInSAR) analyses. By exploiting a set of 31 SAR images acquired by the ENVISAT/ASAR from February 2007 to May 2010 and a set of 48 SAR images acquired by the COSMO-SkyMed (CSK) sensors from December 2013 to March 2016, coherent point targets as long as land subsidence velocity maps and time series are identified by using the Small Baseline Subset (SBAS) algorithm. With the DInSAR constrained land subsidence model, we predict the land subsidence trend and the expected cumulative subsidence in 2020, 2025 and 2030. Meanwhile, we used altimetrydata and densely distributed in the coastal region are identified (EEMD) algorithm to obtain the average sea level rise rate in the East China Sea. With the land subsidence predictions, sea level rise predictions, and high-precision digital elevation model (DEM), we analyze the combined risk of land subsidence and sea level rise on the coastal areas of Shanghai. The potential inundated areas are mapped under different scenarios.

Monitoring of land subsidence and ground fissures in Xian, China 2005-2006: Mapped by sar Interferometry

USGS Publications Warehouse

Zhao, C.Y.; Zhang, Q.; Ding, X.-L.; Lu, Z.; Yang, C.S.; Qi, X.M.

2009-01-01

The City of Xian, China, has been experiencing significant land subsidence and ground fissure activities since 1960s, which have brought various severe geohazards including damages to buildings, bridges and other facilities. Monitoring of land subsidence and ground fissure activities can provide useful information for assessing the extent of, and mitigating such geohazards. In order to achieve robust Synthetic Aperture Radar Interferometry (InSAR) results, six interferometric pairs of Envisat ASAR data covering 2005–2006 are collected to analyze the InSAR processing errors firstly, such as temporal and spatial decorrelation error, external DEM error, atmospheric error and unwrapping error. Then the annual subsidence rate during 2005–2006 is calculated by weighted averaging two pairs of D-InSAR results with similar time spanning. Lastly, GPS measurements are applied to calibrate the InSAR results and centimeter precision is achieved. As for the ground fissure monitoring, five InSAR cross-sections are designed to demonstrate the relative subsidence difference across ground fissures. In conclusion, the final InSAR subsidence map during 2005–2006 shows four large subsidence zones in Xian hi-tech zones in western, eastern and southern suburbs of Xian City, among which two subsidence cones are newly detected and two ground fissures are deduced to be extended westward in Yuhuazhai subsidence cone. This study shows that the land subsidence and ground fissures are highly correlated spatially and temporally and both are correlated with hi-tech zone construction in Xian during the year of 2005–2006.

The cardiac sonography workforce in New Zealand

PubMed Central

White, Steve; Poppe, Katrina; Whalley, Gillian

2015-01-01

Abstract Introduction: The aim of this paper is to investigate the cardiac sonography workforce characteristics and registration requirements in New Zealand (NZ), with a comparison to similar workforces internationally. Methods: The Survey of Clinical Echocardiography in New Zealand 2 (SCANZ2) audit was performed in December 2010. All of NZ's public‐funded District Health Board (DHB) centers providing echocardiography services responded to questions relating to staff, equipment, procedure types and patient statistics. The Medical Radiation Technologists Board (MRTB), Clinical Physiologists Registration Board (CPRB) and Australian Sonographers Association Registry (ASAR) websites were reviewed in March 2012 for registered sonographers with a cardiac scope of practice. The cardiac sonography workforces in Australia, the UK, the USA and Canada were investigated for comparison. Results: There are 84 cardiac sonographers (60.3 full‐time equivalent) working in DHBs: 71% from a cardiac technical background; 40% have post‐graduate qualifications; a further 17% are undertaking post‐graduate qualifications; and 59 cardiac sonographers have registration with professional bodies in NZ and/or Australia. Cardiac sonographers in NZ do not undergo compulsory registration, but other sonographers in NZ have compulsory registration with the MRTB. Sonographers are predominantly not licensed internationally. Discussion: Disparity exists between registration of cardiac and non‐cardiac sonographers in NZ. Many cardiac sonographers have voluntary registration but few are registered with the MRTB. Reasons for this include professional alignment, educational qualifications and representation. International trends show increased pressure from governments and professional bodies to regulate sonographers. Conclusion: This study provides a snapshot of the cardiac sonography workforce in NZ for the first time. PMID:28191178

Empirical validation of the CRAFFT Abuse Screening Test in a Spanish sample.

PubMed

Rial, Antonio; Kim-Harris, Sion; Knight, John R; Araujo, Manuel; Gómez, Patricia; Braña, Teresa; Varela, Jesús; Golpe, Sandra

2018-01-15

The CRAFFT Substance Abuse Screening Instrument, developed by the Center for Adolescents Substance Abuse Research (CeASAR) (Knight et al., 1999), is a screening tool for high-risk alcohol and drug risk consumption designed for use with adolescents. Since its publication it has been the subject of translations and validations in different countries, populations and contexts that have demonstrated its enormous potential. However, there is still no empirical validation study that would ensure its good psychometric performance in Spain. The aim of this paper is to develop an adapted version of the CRAFFT in Spanish and to analyze its psychometric properties in a sample of Spanish adolescents. For this purpose an individual interview was conducted on 312 adolescents aged between 12 and 18 years of age (M = 15.01; SD = 1.83) from the Galician community. The interview included a part of the Adolescent Diagnostic Interview (ADI) and the Problem Oriented Screening Instrument for Teenagers (POSIT). The results obtained, similar to those found in other countries, allow us to report that the Spanish version of the CRAFFT has a good psychometric behaviorproperties. It was found to have a satisfactory internal consistency with a Cronbach’s alpha value of .74. In terms of sensitivity and specificity, values of 74.4% and 96.4% respectively, were obtained and the area under the ROC curve was .946. The Spanish version of the CRAFFT is made available to researchers and professionals in the field of addictive behaviors, so that it can be used with the necessary psychometric guarantees.

Flood Extent Mapping for Namibia Using Change Detection and Thresholding with SAR

NASA Technical Reports Server (NTRS)

Long, Stephanie; Fatoyinbo, Temilola E.; Policelli, Frederick

2014-01-01

A new method for flood detection change detection and thresholding (CDAT) was used with synthetic aperture radar (SAR) imagery to delineate the extent of flooding for the Chobe floodplain in the Caprivi region of Namibia. This region experiences annual seasonal flooding and has seen a recent renewal of severe flooding after a long dry period in the 1990s. Flooding in this area has caused loss of life and livelihoods for the surrounding communities and has caught the attention of disaster relief agencies. There is a need for flood extent mapping techniques that can be used to process images quickly, providing near real-time flooding information to relief agencies. ENVISAT/ASAR and Radarsat-2 images were acquired for several flooding seasons from February 2008 to March 2013. The CDAT method was used to determine flooding from these images and includes the use of image subtraction, decision based classification with threshold values, and segmentation of SAR images. The total extent of flooding determined for 2009, 2011 and 2012 was about 542 km2, 720 km2, and 673 km2 respectively. Pixels determined to be flooded in vegetation were typically <0.5 % of the entire scene, with the exception of 2009 where the detection of flooding in vegetation was much greater (almost one third of the total flooded area). The time to maximum flooding for the 2013 flood season was determined to be about 27 days. Landsat water classification was used to compare the results from the new CDAT with SAR method; the results show good spatial agreement with Landsat scenes.

Successes and Challenges in Linking Observations and Modeling of Marine and Terrestrial Cryospheric Processes

NASA Astrophysics Data System (ADS)

Herzfeld, U. C.; Hunke, E. C.; Trantow, T.; Greve, R.; McDonald, B.; Wallin, B.

2014-12-01

Understanding of the state of the cryosphere and its relationship to other components of the Earth system requires both models of geophysical processes and observations of geophysical properties and processes, however linking observations and models is far from trivial. This paper looks at examples from sea ice and land ice model-observation linkages to examine some approaches, challenges and solutions. In a sea-ice example, ice deformation is analyzed as a key process that indicates fundamental changes in the Arctic sea ice cover. Simulation results from the Los Alamos Sea-Ice Model CICE, which is also the sea-ice component of the Community Earth System Model (CESM), are compared to parameters indicative of deformation as derived from mathematical analysis of remote sensing data. Data include altimeter, micro-ASAR and image data from manned and unmanned aircraft campaigns (NASA OIB and Characterization of Arctic Sea Ice Experiment, CASIE). The key problem to linking data and model results is the derivation of matching parameters on both the model and observation side.For terrestrial glaciology, we include an example of a surge process in a glacier system and and example of a dynamic ice sheet model for Greenland. To investigate the surge of the Bering Bagley Glacier System, we use numerical forward modeling experiments and, on the data analysis side, a connectionist approach to analyze crevasse provinces. In the Greenland ice sheet example, we look at the influence of ice surface and bed topography, as derived from remote sensing data, on on results from a dynamic ice sheet model.

Surface Subsidence Analysis by Multi-Temporal InSAR and GRACE: A Case Study in Beijing.

PubMed

Guo, Jiming; Zhou, Lv; Yao, Chaolong; Hu, Jiyuan

2016-09-14

The aim of this study was to investigate the relationship between surface subsidence and groundwater changes. To investigate this relationship, we first analyzed surface subsidence. This paper presents the results of a case study of surface subsidence in Beijing from 1 August 2007 to 29 September 2010. The Multi-temporal Interferometric Synthetic Aperture Radar (multi-temporal InSAR) technique, which can simultaneously detect point-like stable reflectors (PSs) and distributed scatterers (DSs), was used to retrieve the subsidence magnitude and distribution in Beijing using 18 ENVISAT ASAR images. The multi-temporal InSAR-derived subsidence was verified by leveling at an accuracy better than 5 mm/year. Based on the verified multi-temporal InSAR results, a prominent uneven subsidence was identified in Beijing. Specifically, most of the subsidence velocities in the downtown area were within 10 mm/year, and the largest subsidence was detected in Tongzhou, with velocities exceeding 140 mm/year. Furthermore, Gravity Recovery and Climate Experiment (GRACE) data were used to derive the groundwater change series and trend. By comparison with the multi-temporal InSAR-derived subsidence results, the long-term decreasing trend between groundwater changes and surface subsidence showed a relatively high consistency, and a significant impact of groundwater changes on the surface subsidence was identified. Additionally, the spatial distribution of the subsidence funnel was partially consistent with that of groundwater depression, i.e., the former possessed a wider range than the latter. Finally, the relationship between surface subsidence and groundwater changes was determined.

Surface Subsidence Analysis by Multi-Temporal InSAR and GRACE: A Case Study in Beijing

PubMed Central

Guo, Jiming; Zhou, Lv; Yao, Chaolong; Hu, Jiyuan

2016-01-01

The aim of this study was to investigate the relationship between surface subsidence and groundwater changes. To investigate this relationship, we first analyzed surface subsidence. This paper presents the results of a case study of surface subsidence in Beijing from 1 August 2007 to 29 September 2010. The Multi-temporal Interferometric Synthetic Aperture Radar (multi-temporal InSAR) technique, which can simultaneously detect point-like stable reflectors (PSs) and distributed scatterers (DSs), was used to retrieve the subsidence magnitude and distribution in Beijing using 18 ENVISAT ASAR images. The multi-temporal InSAR-derived subsidence was verified by leveling at an accuracy better than 5 mm/year. Based on the verified multi-temporal InSAR results, a prominent uneven subsidence was identified in Beijing. Specifically, most of the subsidence velocities in the downtown area were within 10 mm/year, and the largest subsidence was detected in Tongzhou, with velocities exceeding 140 mm/year. Furthermore, Gravity Recovery and Climate Experiment (GRACE) data were used to derive the groundwater change series and trend. By comparison with the multi-temporal InSAR-derived subsidence results, the long-term decreasing trend between groundwater changes and surface subsidence showed a relatively high consistency, and a significant impact of groundwater changes on the surface subsidence was identified. Additionally, the spatial distribution of the subsidence funnel was partially consistent with that of groundwater depression, i.e., the former possessed a wider range than the latter. Finally, the relationship between surface subsidence and groundwater changes was determined. PMID:27649183

i4OilSpill, an operational marine oil spill forecasting model for Bohai Sea

NASA Astrophysics Data System (ADS)

Yu, Fangjie; Yao, Fuxin; Zhao, Yang; Wang, Guansuo; Chen, Ge

2016-10-01

Oil spill models can effectively simulate the trajectories and fate of oil slicks, which is an essential element in contingency planning and effective response strategies prepared for oil spill accidents. However, when applied to offshore areas such as the Bohai Sea, the trajectories and fate of oil slicks would be affected by time-varying factors in a regional scale, which are assumed to be constant in most of the present models. In fact, these factors in offshore regions show much more variation over time than in the deep sea, due to offshore bathymetric and climatic characteristics. In this paper, the challenge of parameterizing these offshore factors is tackled. The remote sensing data of the region are used to analyze the modification of wind-induced drift factors, and a well-suited solution is established in parameter correction mechanism for oil spill models. The novelty of the algorithm is the self-adaptive modification mechanism of the drift factors derived from the remote sensing data for the targeted sea region, in respect to empirical constants in the present models. Considering this situation, a new regional oil spill model (i4OilSpill) for the Bohai Sea is developed, which can simulate oil transformation and fate processes by Eulerian-Lagrangian methodology. The forecasting accuracy of the proposed model is proven by the validation results in the comparison between model simulation and subsequent satellite observations on the Penglai 19-3 oil spill accident. The performance of the model parameter correction mechanism is evaluated by comparing with the real spilled oil position extracted from ASAR images.

Effect of surficial disturbance on exchange between groundwater and surface water in nearshore margins

USGS Publications Warehouse

Rosenberry, Donald O.; Toran, Laura; Nyquist, Jonathan E.

2010-01-01

Low‐permeability sediments situated at or near the sediment‐water interface can influence seepage in nearshore margins, particularly where wave energy or currents are minimal. Seepage meters were used to quantify flow across the sediment‐water interface at two lakes where flow was from surface water to groundwater. Disturbance of the sediment bed substantially increased seepage through the sandy sediments of both lakes. Seepage increased by factors of 2.6 to 7.7 following bed disturbance at seven of eight measurement locations at Mirror Lake, New Hampshire, where the sediment representing the greatest restriction to flow was situated at the sediment‐water interface. Although the veneer of low‐permeability sediment was very thin and easily disturbed, accumulation on the bed surface was aided by a physical setting that minimized wind‐generated waves and current. At Lake Belle Taine, Minnesota, where pre‐disturbance downward seepage was smaller than at Mirror Lake, but hydraulic gradients were very large, disturbance of a 20 to 30 cm thick medium sand layer resulted in increases in seepage of 2 to 3 orders of magnitude. Exceptionally large seepage rates, some exceeding 25,000 cm/d, were recorded following bed disturbance. Since it is common practice to walk on the bed while installing or making seepage measurements, disruption of natural seepage rates may be a common occurrence in nearshore seepage studies. Disturbance of the bed should be avoided or minimized when utilizing seepage meters in shallow, nearshore settings, particularly where waves or currents are infrequent or minimal.

Geochemistry and migration of contaminants at the Weldon Spring chemical plant site, St. Charles County, Missouri, 1989-91

USGS Publications Warehouse

Schumacher, John G.

1993-01-01

The geochemistry of the shallow aquifer and geochemical controls on the migration of uranium and other constituents from raffinate pits were determined at the Weldon Spring chemical plant site. Surface-water samples from the raffinate pits con- tained large concentrations of calcium, magnesium, sodium, potassium, sulfate, nitrite, lithium, moly- bdenum, strontium, vanadium, and uranium. Analyses of interstitial-water samples from raffinate pit 3 indicated that concentrations of most constituents increased with increasing depth below the water- sediment interface. Nitrate and uranium were not chemically reduced and attenuated within the raffinate pits and can be expected to migrate into the overburden. Laboratory sorption experiments were performed to evaluate the effect of pH value on the sorption of several raffinate constituents by the overburden. No sorption of calcium, sodium, sulfate, nitrate, or lithium was observed. Sorption of molybdenum was dependent on solution pH and sorption of uranium was dependent on solution pH and carbonate concentration. The sorption of uranium and molybdenum was consistent with sorption controlled by oxyhydroxides. The quality of water collected in overburden lysimeters near raffinate pit 4 can be modeled as a mixture of water from raffinate pits 3 and 4, and an uncontaminated com- ponent in a system at equilibrium with ferrihydrite and calcite. Increased constituent concentrations in a perennial spring north of the site were the result of a subsurface connection between the spring and several losing stream segments receiving runoff from the site, in addition to seepage from the raffinate pits.

Optimal Decision-making Model of Integrated Water Resources Management - A Case of Hsinchu Water Resources Management

NASA Astrophysics Data System (ADS)

Wang, S. Y.; Ho, C. C.; Chang, L. C.

2017-12-01

The public use water in Hsinchu are mainly supplied from Baoshan Reservoir, Second Baoshan Reservoir, Yongheshan Reservoir and Longen Weir. However, the increasing water demand, caused by development of the Hsinchu Science and Industrial Park, results in supply stable water getting more difficult. For stabilize water supply in Hsinchu, the study applies long-term and short-term plans to fulfill the water shortage. Developing an efficient methodology to define a cost-effective action portfolio is an important task. Hence, the study develops a novel decision model, the Stochastic Programming with Recourse Decision Model (SPRDM), to estimate a cost-effective action portfolio. The first-stage of SPRDM determine the long-term action portfolio and the portfolio accompany recourse information (the probability for water shortage event). The second-stage of SPRDM optimize the cost-effective action portfolio in response to the recourse information. In order to consider the uncertainty of reservoir sediment and demand growth, the study set 9 scenarios comprise optimistic, most likely, and pessimistic reservoir sediment and demand growth. The results show the optimal action portfolio consist of FengTain Lake and Panlon Weir, Hsinchu Desalination Plant, Domestic and Industrial Water long-term plans, and Emergency Backup Well, Irrigation Water Transference, Preliminary Water Rationing, Advanced Water Rationing and Water Transport from Other Districts short-term plans. The minimum expected cost of optimal action portfolio is NT$1.1002 billion. The results can be used as a reference for decision making because the results have considered the uncertainty of varied hydrology, reservoir sediment, and water demand growth.

The Effects of Thermal Metamorphism on the Amino Acid Content of the CI-Like Chondrite Y-86029

NASA Technical Reports Server (NTRS)

Burton, A. S.; Grunsfeld, S.; Glavin, D. P.; Dworkin, J. P.

2014-01-01

Carbonaceous chondrites con-tain a diverse suite of amino acids that varies in abundance and structural diversity depending on the degree of aqueous alteration and thermal histo-ry that the parent body experienced [1 - 3]. We recently determined the amino acid contents of several fragments of the Sutter's Mill CM2 chon-drite [4]. In contrast with most other CM2 chon-drites, the Sutter's Mill meteorites showed minimal evidence for the presence of indigenous amino acids. A notable difference between the Sutter's Mill meteorites and other CM2 chondrites are that the Sutter's Mill stones were heated to tempera-tures of 150 - 400 C [4], whereas most other CM2 chondrites do not show evidence for thermal met-amorphism [5]. Because empirical studies have shown that amino acids rapidly degrade in aqueous solutions above 150 C and the presence of miner-als accelerates this degradation [6], a plausible explanation for the lack of amino acids observed in the Sutter's Mill meteorites is that they were destroyed during metamorphic alteration. Fewer CI chondrites have been analyzed for amino acids because only a small number of these meteorites have been recovered. Nevertheless, indigenous amino acids have been reported in the CI chondrites Ivuna and Orgueil [7]. Here we report on the amino acid analysis of the CI-like chondrite, Yamato 86029 (Y-86029; sample size of 110 mg). Just as the Sutter's Mill meteorites were thermally metamporphosed CM2 chondrites, Y-86029 has experienced thermal metamorphism at higher temperatures than Orgueil and Ivuna (normal CI chondrites) experienced, possibly up to 600 C [8].

Datasets related to in-land water for limnology and remote sensing applications: distance-to-land, distance-to-water, water-body identifier and lake-centre co-ordinates.

PubMed

Carrea, Laura; Embury, Owen; Merchant, Christopher J

2015-11-01

Datasets containing information to locate and identify water bodies have been generated from data locating static-water-bodies with resolution of about 300 m (1/360 ∘ ) recently released by the Land Cover Climate Change Initiative (LC CCI) of the European Space Agency. The LC CCI water-bodies dataset has been obtained from multi-temporal metrics based on time series of the backscattered intensity recorded by ASAR on Envisat between 2005 and 2010. The new derived datasets provide coherently: distance to land, distance to water, water-body identifiers and lake-centre locations. The water-body identifier dataset locates the water bodies assigning the identifiers of the Global Lakes and Wetlands Database (GLWD), and lake centres are defined for in-land waters for which GLWD IDs were determined. The new datasets therefore link recent lake/reservoir/wetlands extent to the GLWD, together with a set of coordinates which locates unambiguously the water bodies in the database. Information on distance-to-land for each water cell and the distance-to-water for each land cell has many potential applications in remote sensing, where the applicability of geophysical retrieval algorithms may be affected by the presence of water or land within a satellite field of view (image pixel). During the generation and validation of the datasets some limitations of the GLWD database and of the LC CCI water-bodies mask have been found. Some examples of the inaccuracies/limitations are presented and discussed. Temporal change in water-body extent is common. Future versions of the LC CCI dataset are planned to represent temporal variation, and this will permit these derived datasets to be updated.

Monitoring the effect of restoration measures in Indonesian peatlands by radar satellite imagery.

PubMed

Jaenicke, J; Englhart, S; Siegert, F

2011-03-01

In the context of the ongoing climate change discussions the importance of peatlands as carbon stores is increasingly recognised in the public. Drainage, deforestation and peat fires are the main reasons for the release of huge amounts of carbon from peatlands. Successful restoration of degraded tropical peatlands is of high interest due to their huge carbon store and sequestration potential. The blocking of drainage canals by dam building has become one of the most important measures to restore the hydrology and the ecological function of the peat domes. This study investigates the capability of using multitemporal radar remote sensing imagery for monitoring the hydrological effects of these measures. The study area is the former Mega Rice Project area in Central Kalimantan, Indonesia, where peat drainage and forest degradation is especially intense. Restoration measures started in July 2004 by building 30 large dams until June 2008. We applied change detection analysis with more than 80 ENVISAT ASAR and ALOS PALSAR images, acquired between 2004 and 2009. Radar signal increases of up to 1.36 dB show that high frequency multitemporal radar satellite imagery can be used to detect an increase in peat soil moisture after dam construction, especially in deforested areas with a high density of dams. Furthermore, a strong correlation between cross-polarised radar backscatter coefficients and groundwater levels above -50 cm was found. Monitoring peatland rewetting and quantifying groundwater level variations is important information for vegetation re-establishment, fire hazard warning and making carbon emission mitigation tradable under the voluntary carbon market or REDD (Reducing Emissions from Deforestation and Degradation) mechanism. Copyright © 2010 Elsevier Ltd. All rights reserved.

A novel multi-band SAR data technique for fully automatic oil spill detection in the ocean

NASA Astrophysics Data System (ADS)

Del Frate, Fabio; Latini, Daniele; Taravat, Alireza; Jones, Cathleen E.

2013-10-01

With the launch of the Italian constellation of small satellites for the Mediterranean basin observation COSMO-SkyMed and the German TerraSAR-X missions, the delivery of very high-resolution SAR data to observe the Earth day or night has remarkably increased. In particular, also taking into account other ongoing missions such as Radarsat or those no longer working such as ALOS PALSAR, ERS-SAR and ENVISAT the amount of information, at different bands, available for users interested in oil spill analysis has become highly massive. Moreover, future SAR missions such as Sentinel-1 are scheduled for launch in the very next years while additional support can be provided by Uninhabited Aerial Vehicle (UAV) SAR systems. Considering the opportunity represented by all these missions, the challenge is to find suitable and adequate image processing multi-band procedures able to fully exploit the huge amount of data available. In this paper we present a new fast, robust and effective automated approach for oil-spill monitoring starting from data collected at different bands, polarizations and spatial resolutions. A combination of Weibull Multiplicative Model (WMM), Pulse Coupled Neural Network (PCNN) and Multi-Layer Perceptron (MLP) techniques is proposed for achieving the aforementioned goals. One of the most innovative ideas is to separate the dark spot detection process into two main steps, WMM enhancement and PCNN segmentation. The complete processing chain has been applied to a data set containing C-band (ERS-SAR, ENVISAT ASAR), X-band images (Cosmo-SkyMed and TerraSAR-X) and L-band images (UAVSAR) for an overall number of more than 200 images considered.

Spatial and temporal patterns of sea ice variations in Vilkitsky strait, Russian High Arctic

NASA Astrophysics Data System (ADS)

Ci, T.; Cheng, X.; Hui, F.

2013-12-01

The Arctic Ocean has been greatly affected by climate change. Future predications show an even more drastic reduction of the ice cap which will open new areas for the exploration of natural resources and maritime transportation.Shipping through the Arctic Ocean via the Northern Sea Route (NSR) could save about 40% of the sailing distance from Asia (Yokohama) to Europe (Rotterdam) compared to the traditional route via the Suez Canal. Vilkitsky strait is the narrowest and northest portion of the Northern Sea Route with heaviest traffic between the Taimyr Peninsular and the Severnaya Zemlya archipelago. The preliminary results of sea ice variations are presented by using moderate-resolution imaging spectro radiometer(MODIS) data with 250-m resolution in the Vilkitsky strait during 2009-2012. Temporally, the first rupture on sea ice in Vilkitsky strait usually comes up in April and sea ice completely break into pieces in early June. The strait would be ice-free between August and late September. The frequency of ice floes grows while temperature falls down in October. There are always one or two months suitable for transport. Spatially, Sea ice on Laptev sea side breaks earlier than that of Kara sea side while sea ice in central of strait breaks earlier than in shoreside. The phenomena are directly related with the direction of sea wind and ocean current. In summmary, study on Spatial and temporal patterns in this area is significant for the NSR. An additional research issue to be tackled is to seeking the trends of ice-free duration in the context of global warming. Envisat ASAR data will also be used in this study.

Exploring the optimal integration levels between SAR and optical data for better urban land cover mapping in the Pearl River Delta

NASA Astrophysics Data System (ADS)

Zhang, Hongsheng; Xu, Ru

2018-02-01

Integrating synthetic aperture radar (SAR) and optical data to improve urban land cover classification has been identified as a promising approach. However, which integration level is the most suitable remains unclear but important to many researchers and engineers. This study aimed to compare different integration levels for providing a scientific reference for a wide range of studies using optical and SAR data. SAR data from TerraSAR-X and ENVISAT ASAR in both WSM and IMP modes were used to be combined with optical data at pixel level, feature level and decision levels using four typical machine learning methods. The experimental results indicated that: 1) feature level that used both the original images and extracted features achieved a significant improvement of up to 10% compared to that using optical data alone; 2) different levels of fusion required different suitable methods depending on the data distribution and data resolution. For instance, support vector machine was the most stable at both the feature and decision levels, while random forest was suitable at the pixel level but not suitable at the decision level. 3) By examining the distribution of SAR features, some features (e.g., homogeneity) exhibited a close-to-normal distribution, explaining the improvement from the maximum likelihood method at the feature and decision levels. This indicated the benefits of using texture features from SAR data when being combined with optical data for land cover classification. Additionally, the research also shown that combining optical and SAR data does not guarantee improvement compared with using single data source for urban land cover classification, depending on the selection of appropriate fusion levels and fusion methods.

Retrieval of interseismic displacement from multi-temporal InSAR measurements: challenges and solutions

NASA Astrophysics Data System (ADS)

Zhang, L.; Ding, X.; Lu, Z.; Wen, Y.; Hu, J.

2016-12-01

High-resolution measurements of interseismic displacement are critical for understanding the earthquake cycle and for assessing earthquake hazard. Compared with sparsely located GNSS sites, it is well-known that by jointly analyzing a set of data over the same area acquired on different dates, multi-temporal InSAR (MTInSAR) is capable of remotely imaging interseismic deformation at an unprecedented level of spatial resolution. However conventional MTInSAR cannot hold a considerate promise for the precise retrieval of interseismic deformation in tectonically active zones where complicated atmospheric delay, orbital errors, and localized seasonal ground fluctuations commonly exist. Of interest in this study is to develop reliable solutions to correct or suppress these unwanted signals thereby to improve the accuracy of mapped interseismic displacement. Our technical innovations lie in the following aspects. According to different spatial-temporal characteristics, a joint model that takes both orbit errors and interseismic displacement as parameters is designed to isolate long wavelength motion from orbit error even in the case these two types of signals exhibit similar spatial patterns. To suppress the localized impacts (e.g., a portion of atmospheric artifacts and small-scale anthropogenic deformation), spatial correlation is employed as a constraint during the parameter estimation. The proposed solutions are evaluated by synthetic tests and applied to map the interseismic displacement over Eastern Turkey that spans the Arabia-Eurasia plate boundary zone from a large set of radar images acquired by Envisat/ASAR and Sentinel-1. The derived interseismic displacement validated by GPS data is further used to invert the slip rate and locking depth for the North and East Anatolian Faults. A cross-comparison with published results is also conducted.

Deformation along the western Indian plate boundary: new constraints from differential and multi-aperture InSAR data inversion for the 2008, Baluchistan (Western Pakistan) seismic sequence.

NASA Astrophysics Data System (ADS)

Pezzo, Giuseppe; Merryman Boncori, John Peter; Atzori, Simone; Antonioli, Andrea; Salvi, Stefano

2014-05-01

We use Synthetic Aperture Radar Differential Interferometry (DInSAR) and Multi-Aperture Interferometry (MAI) to constrain the sources of the three largest events of the 2008 Baluchistan (western Pakistan) seismic sequence, namely two Mw 6.4 events only 12 hours apart and an Mw 5.7event occurred 40 days later. The sequence took place in the Quetta Syntaxis, the most seismically active region of Baluchistan, tectonically located between the colliding Indian Plate and the Afghan block of the Eurasian Plate. Elastic dislocation modelling of the surface displacements, derived from ascending and descending ENVISAT ASAR acquisitions, yields slip distributions with peak values of 80 cm and 70 cm for the two main events on a pair of strike-slip near-vertical faults, and values up to 50 cm for the largest aftershock on a NE-SW strike-slip fault. The MAI measurements, with their high sensitivity to the north-south motion component, are crucial in this area to resolve the fault plane ambiguity of moment tensors. We also studied the relationships between the largest earthquakes of the sequence by means of the Coulomb Failure Function to verify the agreement of our source modelling with the stress variations induced by the October 28 earthquake on the October 29 fault plane, and the stress variations induced by the two mainshocks on the December 09 fault plane. Our results provide insight into the deformation style of the Quetta Syntaxis, suggesting that right-lateral slip released at intermediate depths on large NW fault planes is compatible with contemporaneous left-lateral activation on NE-SW minor faults at shallower depths, in agreement with a bookshelf deformation mechanism.

Microseisms Generated by Super Typhoon Megi in the Western Pacific Ocean

NASA Astrophysics Data System (ADS)

Lin, Jianmin; Lin, Jian; Xu, Min

2017-12-01

Microseisms generated by the super typhoon Megi (13-24 October 2010) were detected on both land-based and island-based seismic stations. We applied temporal frequency spectrum analysis to investigate the temporal evolution of the microseisms. When Megi was over the deep basins of the Philippine Sea, only weak microseisms with short-period double frequency (SPDF, ˜0.20-0.40 Hz) were observed. However, after Megi traveled into the shallower waters of the South China Sea, microseisms with both long-period double frequency (LPDF, ˜0.12-0.20 Hz) and SPDF were recorded. The excitation source regions of the microseisms were analyzed using seismic waveform records and synthetic modeling in frequency domain. Results reveal that part of the LPDF microseisms were excited in coastal source regions, while the intensity of both LPDF and SPDF microseisms correlated well with the distance from seismic stations to the typhoon center. Synthetic computations of equivalent surface pressure and corresponding microseisms show that the wave-to-wave interaction induced by coastal reflection has primary effects on microseismic frequency band of ˜0.10-0.20 Hz. The coastal generation of the dispersive LPDF microseisms is also supported by the observation of ocean swells induced by Megi through the images of C-band ENVISAT-ASAR satellite during its migration process. Two source regions of the microseisms during the life span of Megi are finally distinguished: One was mainly located in the left-rear quadrant of the typhoon center that generated both LPDF and SPDF microseisms at shallow seas, while the other one was near the coasts that generated mostly LPDF microseisms.

Site Effects Study In Athens (greece) Using The 7th September 1999 Earthquake Aftershock Sequence

NASA Astrophysics Data System (ADS)

Serpetsidaki, A.; Sokos, E.

On 7 September 1999 at 11:56:50 GMT, an earthquake of Mw=5.9 occurred at Athens capital of Greece. The epicenter was located in the Northwest area of Parnitha Moun- tain at 18km distance from the city centre. This earthquake was one of the most de- structive in Greece during the modern times. The intensity of the earthquake reached IX in the Northwest territories of the city and caused the death of 143 people and seri- ous structural damage in many buildings. On the 13th of September the Seismological Laboratory of Patras University, installed a seismic network of 30 stations in order to observe the evolution of the aftershock sequence. This temporary seismic network remained in the area of Attika for 50 days and recorded a significant part of the af- tershock sequence. In this paper we use the high quality recordings of this network to investigate the influence of the surface geology to the seismic motion, on sites within the epicentral area, which suffered the most during this earthquake. We applied the horizontal-to-vertical (H/V) spectral ratio method on noise and on earthquake records and the obtained results exhibit very good agreement. Finally we compare the results with the geological conditions of the study area and the damage distribution. Most of the obtained amplification levels were low with an exemption in the site of Ano Liosia were a significant amount of damage was observed and the results indicate that the earthquake motion was amplified four times. Based on the above we conclude that the damages in the city of Athens were due to source effects rather than site effects.

The essential work of fracture of thermoplastic orthodontic retainer materials.

PubMed

Pascual, Albert L; Beeman, Cynthia S; Hicks, E Preston; Bush, Heather M; Mitchell, Richard J

2010-05-01

To investigate whether oral cleansing agents affect the essential work of fracture (EWF) and plastic work of fracture (PWF) for two types of orthodontic thermoplastic retainer materials. Polyethylene-terephthalate-glycol (PETG; Tru-Tain Splint) and polypropylene/ethylene-propylene rubber (PP-EPR) blend (Essix-C+) sheets were compared. For each material, six sets of 25 sheets were thermoformed into double-edge-notched-tension specimens; subsets of five specimens were formed with internotch distances (L) equal to 6, 8, 10, 12, or 14 mm, respectively. Sets were stored (160 hours, 25 degrees C) in air (DRY), distilled water (DW), Original Listerine (LIS), mint Crest ProHealth (CPH), 3% hydrogen peroxide (HP), or Polident solution (POL). Specimens were fractured in tension at 2.54 mm/min. Areas under load-elongation curves were measured to determine total work of fracture (W(f)). Linear regressions (W(f) vs L [n = 25]) yielded intercepts (EWF) and slopes (PWF). Ninety-five percent confidence intervals were used to evaluate differences in EWF and PWF estimates. PP-EPR blends showed higher EWFs after storage in HP vs storage in DW. PP-EPR blend showed higher EWFs after storage in CPH vs PETG. After HP storage, PP-EPR exhibited lower PWFs than with any other storage conditions. PP-EPR exhibited higher PWFs than PETG after storage in DRY, DW, and LIS. Compared with DW, none of the cleansers decreased the energy to initiate fracture. With one exception, no cleanser decreased the energy to continue plastic fracture extension. In PP-EPR blend, increased resistance to fracture initiation was observed with CPH and HP, yet, surprisingly, HP decreased resistance to plastic fracture growth.

The ground subsidence anomaly investigation around Ambala, India by InSAR and spatial analyses: Why and how the Ambala city behaves as the most significant subsidence region in the Northwest India?

NASA Astrophysics Data System (ADS)

Kim, J.; Lin, S. Y.; Tsai, Y.; Singh, S.; Singh, T.

2017-12-01

A large ground deformation which may be caused by a significant groundwater depletion of the Northwest India Aquifer has been successfully observed throughout space geodesy techniques (Tsai et al, 2016). Employing advanced time-series ScanSAR InSAR analysis and Gravity Recovery and Climate Experiment (GRACE) satellites data, it revealed 400-km wide huge ground deformation in and around Haryana. It was further notified that the Ambala city located in northern Haryana district shown the most significant ground subsidence with maximum cumulative deformation up to 0.2 meters within 3 years in contrast to the nearby cities such as Patiala and Chandigarh that did not present similar subsidence. In this study, we investigated the details of "Ambala Anomaly" employing advanced time-series InSAR and spatial analyses together with local geology and anthropogenic contexts and tried to identify the factors causing such a highly unique ground deformation pattern. To explore the pattern and trend of Ambala' subsidence, we integrated the time-series deformation results of both ascending L-band PALSAR-1 (Phased Array type L-band Synthetic Aperture Radar) from 2007/1 to 2011/1 and descending C-band ASAR (Advanced Synthetic Aperture Radar) from 2008/9 to 2010/8 to process the 3D decomposition, expecting to reveal the asymmetric movement of the surface. In addition. The spatial analyses incorporating detected ground deformations and local economical/social factors were then applied for the interpretation of "Ambala Anomaly". The detailed interrelationship of driving factors of the "Ambala Anomaly" and the spatial pattern of corresponding ground subsidence will be further demonstrated. After all, we determined the uniqueness of Ambala subsidence possibly be driven by both anthropogenic behaviors including the rapid growth rate of population and constructing of industrial centers as well as the natural geological characteristics and sediment deposition.

Integrating geologic and satellite radar data for mapping dome-and-basin patterns in the In Ouzzal Terrane, Western Hoggar, Algeria

NASA Astrophysics Data System (ADS)

Deroin, Jean-Paul; Djemai, Safouane; Bendaoud, Abderrahmane; Brahmi, Boualem; Ouzegane, Khadidja; Kienast, Jean-Robert

2014-11-01

The In Ouzzal Terrane (IOT) located in the north-western part of the Tuareg Shield forms an elongated N-S trending block, more than 400 km long and 80 km wide. It involves an Archaean crust remobilized during a very high-temperature metamorphic event related to the Palaeoproterozoic orogeny. The IOT largely crops out in the rocky and sandy desert of Western Hoggar. It corresponds mainly to a flat area with some reliefs composed of Late Panafrican granites, dyke networks or Cambrian volcanic rocks. These flat areas are generally covered by thin sand veneers. They are favorable for discriminating bedrock geological units using imaging radar, backscattering measurements, and field checking, because the stony desert is particularly sensitive to the radar parameters such as wavelength or polarization. The main radar data used are those obtained with the ALOS-PALSAR sensor (L-band), in ScanSAR mode (large swath) and Fine Beam modes. The PALSAR sensor has been also compared to ENVISAT-ASAR and to optical imagery. Detailed mapping of some key areas indicates extensive Archaean dome-and-basin patterns. In certain parts, the supracrustal synforms and orthogneiss domes exhibit linear or circular features corresponding to shear zones or rolling structures, respectively. The geological mapping of these dome-and-basin structures, and more generally of the Archaean and Proterozoic lithological units, is more accurate with the SAR imagery, particularly when using the L-band, than with the optical imagery. A quantitative approach is carried out in order to estimate the backscatter properties of the main rock types. Due to the large variety of configurations, radar satellite imagery such as ALOS PALSAR represents a key tool for geological mapping in arid region at different scales from the largest (e.g., 1:500,000) to the smallest (e.g., 1:50,000).

Satellite on-board real-time SAR processor prototype

NASA Astrophysics Data System (ADS)

Bergeron, Alain; Doucet, Michel; Harnisch, Bernd; Suess, Martin; Marchese, Linda; Bourqui, Pascal; Desnoyers, Nicholas; Legros, Mathieu; Guillot, Ludovic; Mercier, Luc; Châteauneuf, François

2017-11-01

A Compact Real-Time Optronic SAR Processor has been successfully developed and tested up to a Technology Readiness Level of 4 (TRL4), the breadboard validation in a laboratory environment. SAR, or Synthetic Aperture Radar, is an active system allowing day and night imaging independent of the cloud coverage of the planet. The SAR raw data is a set of complex data for range and azimuth, which cannot be compressed. Specifically, for planetary missions and unmanned aerial vehicle (UAV) systems with limited communication data rates this is a clear disadvantage. SAR images are typically processed electronically applying dedicated Fourier transformations. This, however, can also be performed optically in real-time. Originally the first SAR images were optically processed. The optical Fourier processor architecture provides inherent parallel computing capabilities allowing real-time SAR data processing and thus the ability for compression and strongly reduced communication bandwidth requirements for the satellite. SAR signal return data are in general complex data. Both amplitude and phase must be combined optically in the SAR processor for each range and azimuth pixel. Amplitude and phase are generated by dedicated spatial light modulators and superimposed by an optical relay set-up. The spatial light modulators display the full complex raw data information over a two-dimensional format, one for the azimuth and one for the range. Since the entire signal history is displayed at once, the processor operates in parallel yielding real-time performances, i.e. without resulting bottleneck. Processing of both azimuth and range information is performed in a single pass. This paper focuses on the onboard capabilities of the compact optical SAR processor prototype that allows in-orbit processing of SAR images. Examples of processed ENVISAT ASAR images are presented. Various SAR processor parameters such as processing capabilities, image quality (point target analysis), weight and

Assimilation of flood extent data with 2D flood inundation models for localised intense rainfall events

NASA Astrophysics Data System (ADS)

Neal, J. C.; Wood, M.; Bermúdez, M.; Hostache, R.; Freer, J. E.; Bates, P. D.; Coxon, G.

2017-12-01

Remote sensing of flood inundation extent has long been a potential source of data for constraining and correcting simulations of floodplain inundation. Hydrodynamic models and the computing resources to run them have developed to the extent that simulation of flood inundation in two-dimensional space is now feasible over large river basins in near real-time. However, despite substantial evidence that there is useful information content within inundation extent data, even from low resolution SAR such as that gathered by Envisat ASAR in wide swath mode, making use of the information in a data assimilation system has proved difficult. He we review recent applications of the Ensemble Kalman Filter (EnKF) and Particle Filter for assimilating SAR data, with a focus on the River Severn UK and compare these with complementary research that has looked at the internal error sources and boundary condition errors using detailed terrestrial data that is not available in most locations. Previous applications of the EnKF to this reach have focused on upstream boundary conditions as the source of flow error, however this description of errors was too simplistic for the simulation of summer flood events where localised intense rainfall can be substantial. Therefore, we evaluate the introduction of uncertain lateral inflows to the ensemble. A further limitation of the existing EnKF based methods is the need to convert flood extent to water surface elevations by intersecting the shoreline location with a high quality digital elevation model (e.g. LiDAR). To simplify this data processing step, we evaluate a method to directly assimilate inundation extent as a EnKF model state rather than assimilating water heights, potentially allowing the scheme to be used where high-quality terrain data are sparse.

Improved measurements of mean sea surface velocity in the Nordic Seas from synthetic aperture radar

NASA Astrophysics Data System (ADS)

Wergeland Hansen, Morten; Johnsen, Harald; Engen, Geir; Øie Nilsen, Jan Even

2017-04-01

The warm and saline surface Atlantic Water (AW) flowing into the Nordic Seas across the Greenland-Scotland ridge transports heat into the Arctic, maintaining the ice-free oceans and regulating sea-ice extent. The AW influences the region's relatively mild climate and is the northern branch of the global thermohaline overturning circulation. Heat loss in the Norwegian Sea is key for both heat transport and deep water formation. In general, the ocean currents in the Nordic Seas and the North Atlantic Ocean is a complex system of topographically steered barotropic and baroclinic currents of which the wind stress and its variability is a driver of major importance. The synthetic aperture radar (SAR) Doppler centroid shift has been demonstrated to contain geophysical information about sea surface wind, waves and current at an accuracy of 5 Hz and pixel spacing of 3.5 - 9 × 8 km2. This corresponds to a horizontal surface velocity of about 20 cm/s at 35° incidence angle. The ESA Prodex ISAR project aims to implement new and improved SAR Doppler shift processing routines to enable reprocessing of the wide swath acquisitions available from the Envisat ASAR archive (2002-2012) at higher resolution and better accuracy than previously obtained, allowing combined use with Sentinel-1 and Radarsat-2 retrievals to build timeseries of the sea surface velocity in the Nordic Seas. Estimation of the geophysical Doppler shift from new SAR Doppler centroid shift retrievals will be demonstrated, addressing key issues relating to geometric (satellite orbit and attitude) and electronic (antenna mis-pointing) contributions and corrections. Geophysical Doppler shift retrievals from one month of data in January 2010 and the inverted surface velocity in the Nordic Seas are then addressed and compared to other direct and indirect estimates of the upper ocean current, in particular those obtained in the ESA GlobCurrent project.

Selection of reference genes for quantitative real-time PCR normalization in Panax ginseng at different stages of growth and in different organs.

PubMed

Liu, Jing; Wang, Qun; Sun, Minying; Zhu, Linlin; Yang, Michael; Zhao, Yu

2014-01-01

Quantitative real-time reverse transcription PCR (qRT-PCR) has become a widely used method for gene expression analysis; however, its data interpretation largely depends on the stability of reference genes. The transcriptomics of Panax ginseng, one of the most popular and traditional ingredients used in Chinese medicines, is increasingly being studied. Furthermore, it is vital to establish a series of reliable reference genes when qRT-PCR is used to assess the gene expression profile of ginseng. In this study, we screened out candidate reference genes for ginseng using gene expression data generated by a high-throughput sequencing platform. Based on the statistical tests, 20 reference genes (10 traditional housekeeping genes and 10 novel genes) were selected. These genes were tested for the normalization of expression levels in five growth stages and three distinct plant organs of ginseng by qPCR. These genes were subsequently ranked and compared according to the stability of their expressions using geNorm, NormFinder, and BestKeeper computational programs. Although the best reference genes were found to vary across different samples, CYP and EF-1α were the most stable genes amongst all samples. GAPDH/30S RPS20, CYP/60S RPL13 and CYP/QCR were the optimum pair of reference genes in the roots, stems, and leaves. CYP/60S RPL13, CYP/eIF-5A, aTUB/V-ATP, eIF-5A/SAR1, and aTUB/pol IIa were the most stably expressed combinations in each of the five developmental stages. Our study serves as a foundation for developing an accurate method of qRT-PCR and will benefit future studies on gene expression profiles of Panax Ginseng.

Plate kinematics of the Afro-Arabian Rift System with emphasis on the Afar Depression, Ethiopia

NASA Astrophysics Data System (ADS)

Bottenberg, Helen Carrie

This work utilizes the Four-Dimensional Plates (4DPlates) software, and Differential Interferometric Synthetic Aperture Radar (DInSAR) to examine plate-scale, regional-scale and local-scale kinematics of the Afro-Arabian Rift System with emphasis on the Afar Depression in Ethiopia. First, the 4DPlates is used to restore the Red Sea, the Gulf of Aden, the Afar Depression and the Main Ethiopian Rift to development of a new model that adopts two poles of rotation for Arabia. Second, the 4DPlates is used to model regional-scale and local-scale kinematics within the Afar Depression. Most plate reconstruction models of the Afro-Arabian Rift System relies on considering the Afar Depression as a typical rift-rift-rift triple junction where the Arabian, Somali and Nubian (African) plates are separating by the Red Sea, the Gulf of Aden and the Main Ethiopian Rift suggesting the presence of "sharp and rigid" plate boundaries. However, at the regional-scale the Afar kinematics are more complex due to stepping of the Red Sea propagator and the Gulf of Aden propagator onto Afar as well as the presence of the Danakil, Ali Sabieh and East Central Block "micro-plates". This study incorporates the motion of these micro-plates into the regional-scale model and defined the plate boundary between the Arabian and the African plates within Afar as likely a diffused zone of extensional strain within the East Central Block. Third, DInSAR technology is used to create ascending and descending differential interferograms from the Envisat Advanced Synthetic Aperture Radar (ASAR) C-Band data for the East Central Block to image active crustal deformation related to extensional tectonics and volcanism. Results of the DInSAR study indicate no strong strain localization but rather a diffused pattern of deformation across the entire East Central Block.

RECENT DEVELOPMENTS IN HYDROWEB DATABASE Water level time series on lakes and reservoirs (Invited)

NASA Astrophysics Data System (ADS)

Cretaux, J.; Arsen, A.; Calmant, S.

2013-12-01

We present the current state of the Hydroweb database as well as developments in progress. It provides offline water level time series on rivers, reservoirs and lakes based on altimetry data from several satellites (Topex/Poseidon, ERS, Jason-1&2, GFO and ENVISAT). The major developments in Hydroweb concerns the development of an operational data centre with automatic acquisition and processing of IGDR data for updating time series in near real time (both for lakes & rivers) and also use of additional remote sensing data, like satellite imagery allowing the calculation of lake's surfaces. A lake data centre is under development at the Legos in coordination with Hydrolare Project leaded by SHI (State Hydrological Institute of the Russian Academy of Science). It will provide the level-surface-volume variations of about 230 lakes and reservoirs, calculated through combination of various satellite images (Modis, Asar, Landsat, Cbers) and radar altimetry (Topex / Poseidon, Jason-1 & 2, GFO, Envisat, ERS2, AltiKa). The final objective is to propose a data centre fully based on remote sensing technique and controlled by in situ infrastructure for the Global Terrestrial Network for Lakes (GTN-L) under the supervision of WMO and GCOS. In a longer perspective, the Hydroweb database will integrate data from future missions (Jason-3, Jason-CS, Sentinel-3A/B) and finally will serve for the design of the SWOT mission. The products of hydroweb will be used as input data for simulation of the SWOT products (water height and surface variations of lakes and rivers). In the future, the SWOT mission will allow to monitor on a sub-monthly basis the worldwide lakes and reservoirs bigger than 250 * 250 m and Hydroweb will host water level and extent products from this

Sea Ice Concentration Estimation Using Active and Passive Remote Sensing Data Fusion

NASA Astrophysics Data System (ADS)

Zhang, Y.; Li, F.; Zhang, S.; Zhu, T.

2017-12-01

In this abstract, a decision-level fusion method by utilizing SAR and passive microwave remote sensing data for sea ice concentration estimation is investigated. Sea ice concentration product from passive microwave concentration retrieval methods has large uncertainty within thin ice zone. Passive microwave data including SSM/I, AMSR-E, and AMSR-2 provide daily and long time series observations covering whole polar sea ice scene, and SAR images provide rich sea ice details with high spatial resolution including deformation and polarimetric features. In the proposed method, the merits from passive microwave data and SAR data are considered. Sea ice concentration products from ASI and sea ice category label derived from CRF framework in SAR imagery are calibrated under least distance protocol. For SAR imagery, incident angle and azimuth angle were used to correct backscattering values from slant range to ground range in order to improve geocoding accuracy. The posterior probability distribution between category label from SAR imagery and passive microwave sea ice concentration product is modeled and integrated under Bayesian network, where Gaussian statistical distribution from ASI sea ice concentration products serves as the prior term, which represented as an uncertainty of sea ice concentration. Empirical model based likelihood term is constructed under Bernoulli theory, which meets the non-negative and monotonically increasing conditions. In the posterior probability estimation procedure, final sea ice concentration is obtained using MAP criterion, which equals to minimize the cost function and it can be calculated with nonlinear iteration method. The proposed algorithm is tested on multiple satellite SAR data sets including GF-3, Sentinel-1A, RADARSAT-2 and Envisat ASAR. Results show that the proposed algorithm can improve the accuracy of ASI sea ice concentration products and reduce the uncertainty along the ice edge.

Comparison and Analysis of Geometric Correction Models of Spaceborne SAR

PubMed Central

Jiang, Weihao; Yu, Anxi; Dong, Zhen; Wang, Qingsong

2016-01-01

Following the development of synthetic aperture radar (SAR), SAR images have become increasingly common. Many researchers have conducted large studies on geolocation models, but little work has been conducted on the available models for the geometric correction of SAR images of different terrain. To address the terrain issue, four different models were compared and are described in this paper: a rigorous range-doppler (RD) model, a rational polynomial coefficients (RPC) model, a revised polynomial (PM) model and an elevation derivation (EDM) model. The results of comparisons of the geolocation capabilities of the models show that a proper model for a SAR image of a specific terrain can be determined. A solution table was obtained to recommend a suitable model for users. Three TerraSAR-X images, two ALOS-PALSAR images and one Envisat-ASAR image were used for the experiment, including flat terrain and mountain terrain SAR images as well as two large area images. Geolocation accuracies of the models for different terrain SAR images were computed and analyzed. The comparisons of the models show that the RD model was accurate but was the least efficient; therefore, it is not the ideal model for real-time implementations. The RPC model is sufficiently accurate and efficient for the geometric correction of SAR images of flat terrain, whose precision is below 0.001 pixels. The EDM model is suitable for the geolocation of SAR images of mountainous terrain, and its precision can reach 0.007 pixels. Although the PM model does not produce results as precise as the other models, its efficiency is excellent and its potential should not be underestimated. With respect to the geometric correction of SAR images over large areas, the EDM model has higher accuracy under one pixel, whereas the RPC model consumes one third of the time of the EDM model. PMID:27347973

Rupture parameters of the 2003 Zemmouri (Mw 6.8), Algeria, earthquake from joint inversion of interferometric synthetic aperture radar, coastal uplift, and GPS

USGS Publications Warehouse

Belabbes, S.; Wicks, Charles; Cakir, Z.; Meghraoui, M.

2009-01-01

We study the surface deformation associated with the 21 May 2003 (M w = 6.8) Zemmouri (Algeria) earthquake, the strongest seismic event felt in the Algiers region since 1716. The thrust earthquake mechanism and related surface deformation revealed an average 0.50 m coastal uplift along ??55-km-long coastline. We obtain coseismic interferograms using Envisat advanced synthetic aperture radar (ASAR) (IS2) and RADARSAT standard beam (ST4) data from both the ascending and descending orbits of Envisat satellite, whereas the RADARSAT data proved useful only in the descending mode. While the two RADARSAT interferograms cover the earthquake area, Envisat data cover only the western half of the rupture zone. Although the interferometric synthetic aperture radar (InSAR) coherence in the epicenter area is poor, deformation fringes are observed along the coast in different patches. In the Boumerdes area, the maximum coseismic deformation is indicated by the high gradient of fringes visible in all interferograms in agreement with field measurements (tape, differential GPS, leveling, and GPS). To constrain the earthquake rupture parameters, we model the interferograms and uplift measurements using elastic dislocations on triangular fault patches in an elastic and homogeneous half-space. We invert the coseismic slip using first, a planar surface and second, a curved fault, both constructed from triangular elements using Poly3Dinv program that uses a damped least square minimization. The best fit of InSAR, coastal uplift, and GPS data corresponds to a 65-km-long fault rupture dipping 40?? to 50?? SE, located at 8 to 13 km offshore with a change in strike west of Boumerdes from N60??-65?? to N95??-105??. The inferred rupture geometry at depth correlates well with the seismological results and may have critical implications for the seismic hazard assessment of the Algiers region. Copyright 2009 by the American Geophysical Union.

Geospatial Analysis Using Remote Sensing Images: Case Studies of Zonguldak Test Field

NASA Astrophysics Data System (ADS)

Bayık, Çağlar; Topan, Hüseyin; Özendi, Mustafa; Oruç, Murat; Cam, Ali; Abdikan, Saygın

2016-06-01

Inclined topographies are one of the most challenging problems for geospatial analysis of air-borne and space-borne imageries. However, flat areas are mostly misleading to exhibit the real performance. For this reason, researchers generally require a study area which includes mountainous topography and various land cover and land use types. Zonguldak and its vicinity is a very suitable test site for performance investigation of remote sensing systems due to the fact that it contains different land use types such as dense forest, river, sea, urban area; different structures such as open pit mining operations, thermal power plant; and its mountainous structure. In this paper, we reviewed more than 120 proceeding papers and journal articles about geospatial analysis that are performed on the test field of Zonguldak and its surroundings. Geospatial analysis performed with imageries include elimination of systematic geometric errors, 2/3D georeferencing accuracy assessment, DEM and DSM generation and validation, ortho-image production, evaluation of information content, image classification, automatic feature extraction and object recognition, pan-sharpening, land use and land cover change analysis and deformation monitoring. In these applications many optical satellite images are used i.e. ASTER, Bilsat-1, IKONOS, IRS-1C, KOMPSAT-1, KVR-1000, Landsat-3-5-7, Orbview-3, QuickBird, Pleiades, SPOT-5, TK-350, RADARSAT-1, WorldView-1-2; as well as radar data i.e. JERS-1, Envisat ASAR, TerraSAR-X, ALOS PALSAR and SRTM. These studies are performed by Departments of Geomatics Engineering at Bülent Ecevit University, at İstanbul Technical University, at Yıldız Technical University, and Institute of Photogrammetry and GeoInformation at Leibniz University Hannover. These studies are financially supported by TÜBİTAK (Turkey), the Universities, ESA, Airbus DS, ERSDAC (Japan) and Jülich Research Centre (Germany).

Comparison Of Semi-Automatic And Automatic Slick Detection Algorithms For Jiyeh Power Station Oil Spill, Lebanon

NASA Astrophysics Data System (ADS)

Osmanoglu, B.; Ozkan, C.; Sunar, F.

2013-10-01

After air strikes on July 14 and 15, 2006 the Jiyeh Power Station started leaking oil into the eastern Mediterranean Sea. The power station is located about 30 km south of Beirut and the slick covered about 170 km of coastline threatening the neighboring countries Turkey and Cyprus. Due to the ongoing conflict between Israel and Lebanon, cleaning efforts could not start immediately resulting in 12 000 to 15 000 tons of fuel oil leaking into the sea. In this paper we compare results from automatic and semi-automatic slick detection algorithms. The automatic detection method combines the probabilities calculated for each pixel from each image to obtain a joint probability, minimizing the adverse effects of atmosphere on oil spill detection. The method can readily utilize X-, C- and L-band data where available. Furthermore wind and wave speed observations can be used for a more accurate analysis. For this study, we utilize Envisat ASAR ScanSAR data. A probability map is generated based on the radar backscatter, effect of wind and dampening value. The semi-automatic algorithm is based on supervised classification. As a classifier, Artificial Neural Network Multilayer Perceptron (ANN MLP) classifier is used since it is more flexible and efficient than conventional maximum likelihood classifier for multisource and multi-temporal data. The learning algorithm for ANN MLP is chosen as the Levenberg-Marquardt (LM). Training and test data for supervised classification are composed from the textural information created from SAR images. This approach is semiautomatic because tuning the parameters of classifier and composing training data need a human interaction. We point out the similarities and differences between the two methods and their results as well as underlining their advantages and disadvantages. Due to the lack of ground truth data, we compare obtained results to each other, as well as other published oil slick area assessments.

Surface deformation analysis of the Mauna Loa and Kilauea volcanoes, Hawaii , revealed by InSAR measurements

NASA Astrophysics Data System (ADS)

Casu, F.; Poland, M.; Solaro, G.; Tizzani, P.; Miklius, A.; Sansosti, E.; Lanari, R.

2009-04-01

The Big Island of Hawaii is home to three volcanoes that have historically erupted. Hualālai, on the east side of the island, Mauna Loa, the largest volcano on the planet which has erupted 39 times since 1832 (most recently in 1984) and Kilauea, which has been in a state of continuous eruption since 1983 from vents on the volcano's east rift zone. Deformation at Kilauea is characterized by summit and rift zone displacements related to magmatic activity and seaward motion of the south flank caused by slip along a basal decollement. In this work we investigate the deformation affecting the Mauna Loa and Kilauea volcanoes, Hawaii , by exploiting the advanced Interferometric Synthetic Aperture Radar (InSAR) technique referred to as Small BAseline Subset (SBAS) algorithm. In particular, we present time series of line-of-sight (LOS) displacements derived from the SAR data acquired by the ASAR instrument, on board the ENVISAT satellite, from the ascending (track 93, frame 387) and descending (track 429, frame 3213) orbits over a time period between 2003 and 2008. For each coherent pixel of the radar images we compute time-dependent surface displacements as well as the average LOS deformation velocity. We also benefit from the use of the multi-orbit (ascending and descending) data which permit us to discriminate the vertical and east-west components of the revealed displacements. The retrieved InSAR measurements are also favourably compared to the continuous GPS data available in the area in order to asses the quality of the SBAS-InSAR products. The presented results show the complex and articulated deformation behavior of the investigated volcanoes; moreover, the possibility to invert the retrieved DInSAR products, in order to model both deep geological structures and magmatic sources, represents a relevant issue for the comprehension of the volcanoes dynamics.

Complex faulting in the Quetta Syntaxis: fault source modeling of the October 28, 2008 earthquake sequence in Baluchistan, Pakistan, based on ALOS/PALSAR InSAR data

NASA Astrophysics Data System (ADS)

Usman, Muhammad; Furuya, Masato

2015-09-01

The Quetta Syntaxis in western Baluchistan, Pakistan, is the result of an oroclinal bend of the western mountain belt and serves as a junction for different faults. As this area also lies close to the left-lateral strike-slip Chaman fault, which marks the boundary between the Indian and Eurasian plates, the resulting seismological behavior of this regime is very complex. In the region of the Quetta Syntaxis, close to the fold and thrust belt of the Sulaiman and Kirthar Ranges, an earthquake with a magnitude of 6.4 (Mw) occurred on October 28, 2008, which was followed by a doublet on the very next day. Six more shocks associated with these major events then occurred (one foreshock and five aftershocks), with moment magnitudes greater than 4. Numerous researchers have tried to explain the source of this sequence based on seismological, GPS, and Environmental Satellite (ENVISAT)/Advanced Synthetic Aperture Radar (ASAR) data. Here, we used Advanced Land Observing Satellite (ALOS)/Phased Array-type L-band Synthetic Aperture Radar (PALSAR) InSAR data sets from both ascending and descending orbits that allow us to more completely detect the deformation signals around the epicentral region. The results indicated that the shock sequence can be explained by two right-lateral and two left-lateral strike-slip faults that also included reverse slip. The right-lateral faults have a curved geometry. Moreover, whereas previous studies have explained the aftershock crustal deformation with a different fault source, we found that the same left-lateral segment of the conjugate fault was responsible for the aftershocks. We thus confirmed the complex surface deformation signals from the moderate-sized earthquake. Intra-plate crustal bending and shortening often seem to be accommodated as conjugate faulting, without any single preferred fault orientation. We also detected two possible landslide areas along with the crustal deformation pattern.

[Coral reefs in the face of ecological threats of XXI century].

PubMed

Tkachenko, K S

2015-01-01

To date, more than a quarter of tropical coral reefs of the World Ocean are believed to be totally de- stroyed. Given the present rates of reefs degradation, this value may be doubled in the nearest 30 years. For the essential part of coastal community, the destruction of coral ecosystems implies the loss of the major food sources, natural protection from storms, and significant (if not the only) revenue from exploi- tation of reefs especially in tourism industry. Finally, the disappearance of low-laying coral islands may threat the local communities by deprivation of living space. Global negative effects include temperature anomalies of sea surface waters and an increase of atmospheric CO2 concentration leading to ocean acidification. Local negative effects are related to in- crease of sedimentation and eutrophication, cyclone and storm passes, coral diseases, chemical pollution, mechanical destruction of corals by humans, anthropogenic depletion of functional groups of fish and invertebrates. An entire set of responses of coral ecosystems to stressful factors on the levels of both separate taxa and ecosystem is discussed. An analysis of published data suggests that with high probability the tropical coral communities will come to collapse stage by the middle of the current century at more than 50% of the area of their biogeographic range, especially in the regions of dense human population. At the most optimistic scenario, complex effect of reviewed negative factors will result in coral ecosystems main- taining in some areas. However, after global transformations, these ecosystems will be dominated by the most resistant taxa, mainly massive and encrusting forms of long-lived species with low growth rates and high competitive ability. Among such taxa, Poritidae demonstrates the highest adaptive capability. At the most pessimistic scenario, scleractinian communities will be replaced by alternative communities of macroalgae and non-calcareous anthozoans.

The western limits of the Seattle fault zone and its interaction with the Olympic Peninsula, Washington

USGS Publications Warehouse

A.P. Lamb,; L.M. Liberty,; Blakely, Richard J.; Pratt, Thomas L.; Sherrod, B.L.; Van Wijk, K.

2012-01-01

We present evidence that the Seattle fault zone of Washington State extends to the west edge of the Puget Lowland and is kinemati-cally linked to active faults that border the Olympic Massif, including the Saddle Moun-tain deformation zone. Newly acquired high-resolution seismic reflection and marine magnetic data suggest that the Seattle fault zone extends west beyond the Seattle Basin to form a >100-km-long active fault zone. We provide evidence for a strain transfer zone, expressed as a broad set of faults and folds connecting the Seattle and Saddle Mountain deformation zones near Hood Canal. This connection provides an explanation for the apparent synchroneity of M7 earthquakes on the two fault systems ~1100 yr ago. We redefi ne the boundary of the Tacoma Basin to include the previously termed Dewatto basin and show that the Tacoma fault, the southern part of which is a backthrust of the Seattle fault zone, links with a previously unidentifi ed fault along the western margin of the Seattle uplift. We model this north-south fault, termed the Dewatto fault, along the western margin of the Seattle uplift as a low-angle thrust that initiated with exhu-mation of the Olympic Massif and today accommodates north-directed motion. The Tacoma and Dewatto faults likely control both the southern and western boundaries of the Seattle uplift. The inferred strain trans-fer zone linking the Seattle fault zone and Saddle Mountain deformation zone defi nes the northern margin of the Tacoma Basin, and the Saddle Mountain deformation zone forms the northwestern boundary of the Tacoma Basin. Our observations and model suggest that the western portions of the Seattle fault zone and Tacoma fault are com-plex, require temporal variations in principal strain directions, and cannot be modeled as a simple thrust and/or backthrust system.

Synergistic method for boreal soil moisture and soil freeze retrievals using active and passive microwave instruments

NASA Astrophysics Data System (ADS)

Smolander, Tuomo; Lemmetyinen, Juha; Rautiainen, Kimmo; Schwank, Mike; Pulliainen, Jouni

2017-04-01

Soil moisture and soil freezing are important for diverse hydrological, biogeochemical, and climatological applications. They affect surface energy balance, surface and subsurface water flow, and exchange rates of carbon with the atmosphere. Soil freezing controls important biogeochemical processes, like photosynthetic activity of plants and microbial activity within soils. Permafrost covers approximately 24% of the land surface in the Northern Hemisphere and seasonal freezing occurs on approximately 51% of the area. The retrieval method presented is based on an inversion technique and applies a semiempirical backscattering model that describes the dependence of radar backscattering of forest as a function of stem volume, soil permittivity, the extinction coefficient of forest canopy, surface roughness, incidence angle, and radar frequency. It gives an estimate of soil permittivity using active microwave measurements. Applying a Bayesian assimilation scheme, it is also possible to use other soil permittivity retrievals to regulate this estimate to combine for example low resolution passive observations with high resolution active observations for a synergistic retrieval. This way the higher variance in the active retrieval can be constricted with the passive retrieval when at the same time the spatial resolution of the product is improved compared to the passive-only retrieval. The retrieved soil permittivity estimate can be used to detect soil freeze/thaw state by considering the soil to be frozen when the estimate is below a threshold value. The permittivity retrieval can also be used to estimate the relative moisture of the soil. The method was tested using SAR (Synthetic Aperture Radar) measurements from ENVISAT ASAR instrument for the years 2010-2012 and from Sentinel-1 satellite for the years 2015-2016 in Sodankylä area in Northern Finland. The synergistic method was tested combining the SAR measurements with a SMOS (Soil Moisture Ocean Salinity) radiometer

Utilization of Envisat/ers SAR Data Over the Jharia Coalfield, India for Subsidence Monitoring

NASA Astrophysics Data System (ADS)

Srivastava, Vinay Kumar

2012-07-01

Extended abstract Jharia coalfield the prime coking coal-producing belt in India, started commercial production in 1894. Mining in Jharia coalfield (JCF) is in form of both opencast and underground mining. The area is affected by various environmental hazards such as, coal fire, subsidence, land degradation and toxic gas emissions. Currently, coal fire and subsidence are the major problems in the coalfield and causes continuous changes in topography. Monitoring of such dynamic topographic changes in a hazard-prone mining belt is a critical input for land environmental management. Such temporal topographic changes over span of the time and even short term mining activity within a year could be done from Digital Elevation Model (DEM) generated using various space-borne techniques.. Among all techniques available for generating DEM, SAR Interferometry technique has been successful and effective which offers high resolution spatial detail to a level of few cm. DEM obtained from processing of SAR Interferometry (InSAR) technique using ERS SAR data of April 12 and 13, 1995 provides high spatial resolution images which is useful for monitoring and measuring dynamic changes in land topography. Several workers have successfully InSAR this technique for mapping and monitoring of changes in land surface due to various causes. Using ERS tandem data sets of 16 and 17 May 1996 passes, DInSAR map over the Jharia coal field has been obtained from the interferogram generated by integrating information from ground control points and precise high coherence orbital parameters. Further, using ENVISAT/ ASAR data of June 5 and 6, 2007 and integrating GPS measurements at 4 ground points where corner reflectors were preinstalled for getting bright spots on images and using orbital parameters, a slant range corrected image over the study area has been obtained. shows the plot of differential phases along a particular profile l over a subsidence region in Jharia coal field and the

Detection of Slope Instabilities Along the National Road 7, Mendoza Province, Argentina, Using Multi-Temporal InSAR

NASA Astrophysics Data System (ADS)

Michoud, Clément; Derron, Marc-Henri; Baumann, Valérie; Jaboyedoff, Michel; Rune Lauknes, Tom

2013-04-01

About 2'230 vehicles per day pass through the National Road 7 that link Buenos Aires to Santiago de Chile, crossing Andes Cordillera. This extremely important corridor, being the most important land pass between Argentina and Chile, is exposed to numerous natural hazards, such as snow avalanches, rockfalls and debris flows and remains closed by natural hazards several days per year. This goal of this study is to perform a regional mapping of geohazard susceptibilities along the Road 7 corridor, as started by Baumann et al. (2005), using modern remote sensing and numerical approaches with field checking. The area of interest is located in the Mendoza Province, between the villages Potrerillos and Las Cuevas near the Chilean border. The diversity of soil and rock conditions, the active geomorphological processes associated to post-glacial decompression, seasonal freeze and thaw and severe storms along the road corridor, increase the risk to natural hazard. With the support of the European Space Agency (ESA Category-1 Project 7154), we have in this study processed a large number of ERS and Envisat ASAR scenes, covering the period from 1995 to 2000. We applied both the small-baseline (SB) and the persistent scatterer (PSI) multi-temporal interferometric SAR (InSAR) techniques. The study area contains sparse vegetation, and the SB InSAR method is therefore well suited to map the area containing mainly distributed scatterers. Furthermore, PSI algorithms are also used for comparison for selected landslides in the inventory. Both approaches show a relatively good coherence within mountain areas, which is a good point for the landslide detections along the road. Indeed, the authors identified several large slope instabilities even active scree deposits. This inventory is finally compared with field observations and with existing susceptibility maps regarding snow avalanches, debris-flows and rockfalls. The final objective of this project is to develop a risk strategy that

A User-Oriented Methodology for DInSAR Time Series Analysis and Interpretation: Landslides and Subsidence Case Studies

NASA Astrophysics Data System (ADS)

Notti, Davide; Calò, Fabiana; Cigna, Francesca; Manunta, Michele; Herrera, Gerardo; Berti, Matteo; Meisina, Claudia; Tapete, Deodato; Zucca, Francesco

2015-11-01

Recent advances in multi-temporal Differential Synthetic Aperture Radar (SAR) Interferometry (DInSAR) have greatly improved our capability to monitor geological processes. Ground motion studies using DInSAR require both the availability of good quality input data and rigorous approaches to exploit the retrieved Time Series (TS) at their full potential. In this work we present a methodology for DInSAR TS analysis, with particular focus on landslides and subsidence phenomena. The proposed methodology consists of three main steps: (1) pre-processing, i.e., assessment of a SAR Dataset Quality Index (SDQI) (2) post-processing, i.e., application of empirical/stochastic methods to improve the TS quality, and (3) trend analysis, i.e., comparative implementation of methodologies for automatic TS analysis. Tests were carried out on TS datasets retrieved from processing of SAR imagery acquired by different radar sensors (i.e., ERS-1/2 SAR, RADARSAT-1, ENVISAT ASAR, ALOS PALSAR, TerraSAR-X, COSMO-SkyMed) using advanced DInSAR techniques (i.e., SqueeSAR™, PSInSAR™, SPN and SBAS). The obtained values of SDQI are discussed against the technical parameters of each data stack (e.g., radar band, number of SAR scenes, temporal coverage, revisiting time), the retrieved coverage of the DInSAR results, and the constraints related to the characterization of the investigated geological processes. Empirical and stochastic approaches were used to demonstrate how the quality of the TS can be improved after the SAR processing, and examples are discussed to mitigate phase unwrapping errors, and remove regional trends, noise and anomalies. Performance assessment of recently developed methods of trend analysis (i.e., PS-Time, Deviation Index and velocity TS) was conducted on two selected study areas in Northern Italy affected by land subsidence and landslides. Results show that the automatic detection of motion trends enhances the interpretation of DInSAR data, since it provides an objective

Flood mapping with multitemporal MODIS data

NASA Astrophysics Data System (ADS)

Son, Nguyen-Thanh; Chen, Chi-Farn; Chen, Cheng-Ru

2014-05-01

Flood is one of the most devastating and frequent disasters resulting in loss of human life and serve damage to infrastructure and agricultural production. Flood is phenomenal in the Mekong River Delta (MRD), Vietnam. It annually lasts from July to November. Information on spatiotemporal flood dynamics is thus important for planners to devise successful strategies for flood monitoring and mitigation of its negative effects. The main objective of this study is to develop an approach for weekly mapping flood dynamics with the Moderate Resolution Imaging Spectroradiometer data in MRD using the water fraction model (WFM). The data processed for 2009 comprises three main steps: (1) data pre-processing to construct smooth time series of the difference in the values (DVLE) between land surface water index (LSWI) and enhanced vegetation index (EVI) using the empirical mode decomposition (EMD), (2) flood derivation using WFM, and (3) accuracy assessment. The mapping results were compared with the ground reference data, which were constructed from Envisat Advanced Synthetic Aperture Radar (ASAR) data. As several error sources, including mixed-pixel problems and low-resolution bias between the mapping results and ground reference data, could lower the level of classification accuracy, the comparisons indicated satisfactory results with the overall accuracy of 80.5% and Kappa coefficient of 0.61, respectively. These results were reaffirmed by a close correlation between the MODIS-derived flood area and that of the ground reference map at the provincial level, with the correlation coefficients (R2) of 0.93. Considering the importance of remote sensing for monitoring floods and mitigating the damage caused by floods to crops and infrastructure, this study eventually leads to the realization of the value of using time-series MODIS DVLE data for weekly flood monitoring in MRD with the aid of EMD and WFM. Such an approach that could provide quantitative information on

Satellite/Submarine Arctic Sea Ice Remote Sensing in 2004 and 2007

NASA Astrophysics Data System (ADS)

Hughes, N. E.; Wadhams, P.; Rodrigues, J.

2007-12-01

After an interlude of 8 years the U.K. Royal Navy returned to the Arctic Ocean with an under-ice mission by the submarine shape HMS Tireless in April 2004. A full environmental monitoring programme in which U.K. civilian scientists were allowed to participate was integrated into the mission. This was subsequently followed by a second expedition, in March 2007, which allowed further measurements to be acquired. These have so far been the only opportunities for civilian scientists to utilise navy submarines in the Arctic since the demise of the U.S. SCICEX programme in 2000. This paper presents some of the data collected on these new missions and uses it for validation of sea ice information derived from coincident acquisitions by modern satellite sensors such as the ESA Envisat ASAR and NASA MODIS. In both the 2004 and 2007 expeditions shape Tireless took a track north of Greenland along the latitude 85° N. This was similar to the route used for an earlier submarine-aircraft combined survey in April 1987 with which our results shall be compared. In all three missions the submarine was equipped with a standard upward-looking echosounder and sidescan for ice observations and a full range of satellite-borne, or airborne in the case of the earlier mission, microwave and optical sensors were available for validation. In this study we concentrate on the submarine track north of Greenland from the Marginal Ice Zone (MIZ) in Fram Strait through to the Lincoln Sea around 65° W. This transect encompasses a wide range of differing sea ice conditions, from the highly mobile mixture of first year and multi year ice being transported on the trans-polar drift through to the highly deformed ice north of Greenland and Ellesmere Island. The combination of submarine measurements of ice thickness and satellite/aircraft top-side measurements gives an accurate indication of how changes in the ice regime are taking place and allows the potential development of multi-sensor data fusion

Monitoring of infrastructural sites by means of advanced multi-temporal DInSAR methods

NASA Astrophysics Data System (ADS)

Vollrath, Andreas; Zucca, Francesco; Stramondo, Salvatore

2013-10-01

With the launch of Sentinel-1, advanced interferometric measurements will become more applicable then ever. The foreseen standard Wide Area Product (WAP), with its higher spatial and temporal resolution than comparable SAR missions, will provide the basement for the use of new wide scale and multitemporal analysis. By now the use of SAR interferometry methods with respect to risk assessment are mainly conducted for active tectonic zones, plate boundaries, volcanoes as well as urban areas, where local surface movement rates exceed the expected error and enough pixels per area contain a relatively stable phase. This study, in contrast, aims to focus on infrastructural sites that are located outside cities and are therefore surrounded by rural landscapes. The stumbling bock was given by the communication letter by the European Commission with regard to the stress tests of nuclear power plants in Europe in 2012. It is mentioned that continuously re-evaluated risk and safety assessments are necessary to guarantee highest possible security to the European citizens and environment. This is also true for other infrastructural sites, that are prone to diverse geophysical hazards. In combination with GPS and broadband seismology, multitemporal Differential Interferometric SAR approaches demonstrated great potential in contributing valuable information to surface movement phenomenas. At this stage of the project, first results of the Stamps-MTI approach (combined PSInSAR and SBAS) will be presented for the industrial area around Priolo Gargallo in South East Sicily by using ENVISAT ASAR IM mode data from 2003-2010. This area is located between the Malta Escarpment fault system and the Hyblean plateau and is prone to earthquake and tsunami risk. It features a high density of oil refineries that are directly located at the coast. The general potential of these techniques with respect to the SENTINEL-1 mission will be shown for this area and a road-map for further improvements

Circumpolar patterns of ground-fast lake ice and landscape development

NASA Astrophysics Data System (ADS)

Bartsch, Annett; Pointner, Georg; Leibmann, Marina; Dvornikov, Yuri; Khomutov, Artem

2017-04-01

Shallow lakes in the Arctic are often associated with thermokarst processes which are characteristic for permafrost environments. They partially or completely freeze-up during winter time what can be observed from space using Synthetic Aperture Radar (SAR) data. Spatial patterns of ground-fast and floating ice relate to geomorphological and hydrological processes, but no circumpolar account of this phenomenon is currently available due to challenges when dealing with the varying observation geometry typical for SAR. An approach using ENVISAT ASAR Wide Swath data (approximately 120 m resolution) has been developed supported by bathymetric measurements in Siberia and eventually applied across the entire Arctic for late winter 2008. In total about 2 Million lake objects have been analyzed considering the boundaries of the Last Glacial Maximum, permafrost zones and soil organic carbon content. Distinct patterns of ground-fast lake ice fraction can be found across the Arctic. Clusters of variable fractions of ground-fast ice occur especially in Yedoma regions of Eastern Siberia and Alaska. This reflects the nature of thaw lake dynamics. Analyses of lake depth measurements from several sites (Alaskan North Slope, Richards Island in Canada, Yamal Peninsula and Lena Delta) suggest that the used method yields the potential to utilize ground-fast lake ice information over larger areas with respect to landscape development, but results need to be treated with care, specifically for larger lakes and along river courses. A combination of general lake features and ground-fast ice fraction may lead to an advanced understanding of landscape patterns and development. Ground-fast ice fraction information may support to some extent the identification of landscape units, for example areas of adjacent lakes with similar patterns (terraces) or areas with mixed ground-fast fractions which indicate different lake development stages. This work was supported by the Austrian Science Fund

Remote Sensing and Wetland Ecology: a South African Case Study.

PubMed

De Roeck, Els R; Verhoest, Niko E C; Miya, Mtemi H; Lievens, Hans; Batelaan, Okke; Thomas, Abraham; Brendonck, Luc

2008-05-26

Remote sensing offers a cost efficient means for identifying and monitoring wetlands over a large area and at different moments in time. In this study, we aim at providing ecologically relevant information on characteristics of temporary and permanent isolated open water wetlands, obtained by standard techniques and relatively cheap imagery. The number, surface area, nearest distance, and dynamics of isolated temporary and permanent wetlands were determined for the Western Cape, South Africa. Open water bodies (wetlands) were mapped from seven Landsat images (acquired during 1987 - 2002) using supervised maximum likelihood classification. The number of wetlands fluctuated over time. Most wetlands were detected in the winter of 2000 and 2002, probably related to road constructions. Imagery acquired in summer contained fewer wetlands than in winter. Most wetlands identified from Landsat images were smaller than one hectare. The average distance to the nearest wetland was larger in summer. In comparison to temporary wetlands, fewer, but larger permanent wetlands were detected. In addition, classification of non-vegetated wetlands on an Envisat ASAR radar image (acquired in June 2005) was evaluated. The number of detected small wetlands was lower for radar imagery than optical imagery (acquired in June 2002), probably because of deterioration of the spatial information content due the extensive pre-processing requirements of the radar image. Both optical and radar classifications allow to assess wetland characteristics that potentially influence plant and animal metacommunity structure. Envisat imagery, however, was less suitable than Landsat imagery for the extraction of detailed ecological information, as only large wetlands can be detected. This study has indicated that ecologically relevant data can be generated for the larger wetlands through relatively cheap imagery and standard techniques, despite the relatively low resolution of Landsat and Envisat imagery. For

Influence of the external DEM on PS-InSAR processing and results on Northern Appennine slopes

NASA Astrophysics Data System (ADS)

Bayer, B.; Schmidt, D. A.; Simoni, A.

2014-12-01

We present an InSAR analysis of slow moving landslide in the Northern Appennines, Italy, and assess the dependencies on the choice of DEM. In recent years, advanced processing techniques for synthetic aperture radar interferometry (InSAR) have been applied to measure slope movements. The persistent scatterers (PS-InSAR) approach is probably the most widely used and some codes are now available in the public domain. The Stanford method of Persistent Scatterers (StamPS) has been successfully used to analyze landslide areas. One problematic step in the processing chain is the choice of an external DEM that is used to model and remove the topographic phase in a series of interferograms in order to obtain the phase contribution caused by surface deformation. The choice is not trivial, because the PS InSAR results differ significantly in terms of PS identification, positioning, and the resulting deformation signal. We use four different DEMs to process a set of 18 ASAR (Envisat) scenes over a mountain area (~350 km2) of the Northern Appennines of Italy, using StamPS. Slow-moving landslides control the evolution of the landscape and cover approximately 30% of the territory. Our focus in this presentation is to evaluate the influence of DEM resolution and accuracy by comparing PS-InSAR results. On an areal basis, we perform a statistical analysis of displacement time-series to make the comparison. We also consider two case studies to illustrate the differences in terms of PS identification, number and estimated displacements. It is clearly shown that DEM accuracy positively influences the number of PS, while line-of-sight rates differ from case to case and can result in deformation signals that are difficult to interpret. We also take advantage of statistical tools to analyze the obtained time-series datasets for the whole study area. Results indicate differences in the style and amount of displacement that can be related to the accuracy of the employed DEM.

Water Resources Management In The Eastern Himalayan Urban Ecosystem

NASA Astrophysics Data System (ADS)

Bomjan, S.

The Himalayan ecosystem is one of the most important and threatened ecosystems on the earth. In this region, the scarcity of water in general, and drinking water in par- ticular is affecting common people and drawing the attention of researchers. Given the present situation and governance, in the near future it is most likely to deteriorate further. With expanding population and urbanization, accelerating human activities, and increasing per capita water consumption, problem of water supply in the moun- tain households will be certainly acute in the coming years. This crisis of decreasing availability of water is not only going to hamper the economic development of the region, but is also likely to threaten the very survival of the already marginalised and deprived people who are also on the brink of poverty and are incapable of coping with such crisis. Sustainable water harvesting and management of water resources offers the best hope for meeting the challenges of the growing water crisis. For this appropriate policy intervention, use of latest technology, application of tools like GIS and information from the satellite imageries, community participation and use of tra- ditional knowledge and traditional water management practices will be essential to overcome the challenge of looming water crisis. Darjiling Himalaya, located in the eastern Himalayas has a fragile environment and it is witnessing serious problems both in quality and quantity of water supply. Weak institutional arrangements, lack of awareness among citizens and a gap in the effective arrangements are huge stumbling blocks. This region is endowed with abundance of water resources and rich ecosystem. Therefore, this calls for an effective and participatory water management system with due attention given to the upgradation and expansion of the existing infrastructure. This paper takes a stock of the existing water resources in the Darjiling Himalaya, especially around the town of Darjiling, discusses

Satellite SAR data assessment for Silk Road archaeological prospection

NASA Astrophysics Data System (ADS)

Chen, Fulong; Lasaponara, Rosa; Masini, Nicola; Yang, Ruixia

2015-04-01

direction of observed targets is beneficial for improved detection of potential linear remains (e.g. Great Wall in Han-dynasty surrounding the Yumen Frontier Pass) owing to the formation of dihedral and helix scatterings based on the theory of radar physics. Morevorer, spatial resolution of multi-mode SAR images for archaeology was compared in the sites of Niya, Yumen Frontier Pass and suspected protectorate of the western regions. Results indicated that high resolution tended to easier detection of ancient targets through the identification of backscattering anomalies. Finally, interferometric analysis was also evaluated to provide complementary information rather than the backscattering. The variation of coherence is closely related to the physical parameters of observed surface, e.g. soil moisture, mild-relief as well as materials; and consequently it is useful for the relic feature enhancement and identification, validated by the PALSAR coherence images in Niya site. Acknowledgement This research was performed within the framework of the project "Smart management of cultural heritage sites in Italy and China: Earth Observation and pilot projects", funded by the Italian Ministry of Foreign Affairs and the Hundred Talents Program of the Institute of Remote Sensing and Digital Earth, Chinese Academy of Sciences (Y2ZZ27101B). The PALSAR data were provided by the European Space Agency to the authors through the Category-1 Project Id. 28640. Reference [1] Lasaponara R., Masini N. 2013, Satellite Synthetic Aperture Radar in Archaeology and Cultural Landscape: An Overview. Archaeological Prospection, 20, 71-78, doi: 10.1002/arp.1452 [2] Chen F., Masini N., Yang R., Milillo P., Feng D., Lasaponara R., 2015 A Space View of Radar Archaeological Marks: First Applications of COSMO-SkyMed X-Band Data. Remote Sens. 2015, 7, 24-50; doi:10.3390/rs70100024. [3] Cigna, F.; Tapete, D.; Lasaponara, R.; Masini, N. Amplitude change detection with Envisat ASAR to image the cultural landscape

Water Resource Monitoring Based n EO Data: Gained Experience After 10 Years of Dragon Programme over the Yangtze River Reaches: From ERS 1 to Sentinel 1 and from MERIS to HJ1 and Pleiades

NASA Astrophysics Data System (ADS)

Yesou, Herve; Huber, Claire; Huang, Shifeng; Studer, Mathias; Lai, Xijun; Chen, Xiaoling; Daillet, Sylviane

2014-11-01

Water resources monitoring from space is an application of remote sensing under full development, with arriving satellite such as the Sentinels, and of course the development of inland applications of altimetry and the future mission as SWOT. Since 10 years within the framework of the DRAGON ESA MOST programme, a monitoring of Chines major fresh water lakes, Poyang and Dongting lakes on Yangtze reaches, is realized exploiting large source of EO data. Thanks to EO data archive exploitation, the covered period starts in 2000 up to 2014, over these two core lakes, whereas, since a 2012, a similar approach is carried over the small lakes of Anhui Province. A key question is how to access to convenient satellite data with sufficient resource to insure a high temporal frequency, ie ideally with about 10 days of revisit. An opportunistic approach was followed in order to insure this data access thanks to a large ESA support, accessing Envisat and ESA TPM, as well Chinese data. From 2004 to April 2012, ENVISAT Medium resolution products, MERIS and ASAR WSM data, were the core of the monitoring system. Since the lost of Envisat, the data exploited moved from MR to HR (20-30 m), thanks to the access to large volume of HJ1 images in 2012 and 2014, as well as coverage CSK data (30m) thanks agreement with ASI. The assimilation of these data is a fine preparation for the future exploitation of Sentinel1 and 2 dataset. Furthermore a first Sentinel data have been exploited, less than 45 after satellite launch. In addition on most sensitive areas, such as the Poyang Lake natural Reserve (Jiangxi Pr) and Shenjing Lake (Anhui Prov.) a unique set of VHR data, Pleiades, Kompsat, have been exploited. The expect strategy for the coming months and years will be in a first period, the jointly exploitation of Sentinel 1 data if the Chinese areas are rapidly integrated within the Sentinel 1 acquisition scheme, jointly with the Chinese HJ1AB data. In a second time HJ1AB data would be

Water Resource Monitoring Based on EO Data: Gained Experience After 10 Years of Dragon Programme over the Yangtze Middle Reaches: From ERS 1 to Sentinel 1 and from MERIS to HJ1 and Pleiades

NASA Astrophysics Data System (ADS)

Yesou, Herve; Huber, Claire; Huang, Shifeng; Studer, Mathais; Lai, Xijun; Chen, Xiaoling; Daillet, Sylviane

2014-11-01

Water resources monitoring from space is an application of remote sensing under full development, with arriving satellite such as the Sentinels, and of course the development of inland applications of altimetry and the future mission as SWOT. Since 10 years within the framework of the DRAGON ESA MOST programme, a monitoring of Chines major fresh water lakes, Poyang and Dongting lakes on Yangtze reaches, is realized exploiting large source of EO data. Thanks to EO data archive exploitation, the covered period starts in 2000 up to 2014, over these two core lakes, whereas, since a 2012, a similar approach is carried over the small lakes of Anhui Province. A key question is how to access to convenient satellite data with sufficient resource to insure a high temporal frequency, ie ideally with about 10 days of revisit. An opportunistic approach was followed in order to insure this data access thanks to a large ESA support, accessing Envisat and ESA TPM, as well Chinese data. From 2004 to April 2012, ENVISAT Medium resolution products, MERIS and ASAR WSM data, were the core of the monitoring system. Since the lost of Envisat, the data exploited moved from MR to HR (20-30 m), thanks to the access to large volume of HJ1 images in 2012 and 2014, as well as coverage CSK data (30m) thanks agreement with ASI. The assimilation of these data is a fine preparation for the future exploitation of Sentinel1 and 2 dataset. Furthermore a first Sentinel data have been exploited, less than 45 after satellite launch. In addition on most sensitive areas, such as the Poyang Lake natural Reserve (Jiangxi Pr) and Shenjing Lake (Anhui Prov.) a unique set of VHR data, Pleiades, Kompsat, have been exploited. The expect strategy for the coming months and years will be in a first period, the jointly exploitation of Sentinel 1 data if the Chinese areas are rapidly integrated within the Sentinel 1 acquisition scheme, jointly with the Chinese HJ1AB data. In a second time HJ1AB data would be

Viterbi sparse spike detection and a compositional origin to ultralow-velocity zones

NASA Astrophysics Data System (ADS)

Brown, Samuel Paul

Accurate interpretation of seismic travel times and amplitudes in both the exploration and global scales is complicated by the band-limited nature of seismic data. We present a stochastic method, Viterbi sparse spike detection (VSSD), to reduce a seismic waveform into a most probable constituent spike train. Model waveforms are constructed from a set of candidate spike trains convolved with a source wavelet estimate. For each model waveform, a profile hidden Markov model (HMM) is constructed to represent the waveform as a stochastic generative model with a linear topology corresponding to a sequence of samples. The Viterbi algorithm is employed to simultaneously find the optimal nonlinear alignment between a model waveform and the seismic data, and to assign a score to each candidate spike train. The most probable travel times and amplitudes are inferred from the alignments of the highest scoring models. Our analyses show that the method can resolve closely spaced arrivals below traditional resolution limits and that travel time estimates are robust in the presence of random noise and source wavelet errors. We applied the VSSD method to constrain the elastic properties of a ultralow- velocity zone (ULVZ) at the core-mantle boundary beneath the Coral Sea. We analyzed vertical component short period ScP waveforms for 16 earthquakes occurring in the Tonga-Fiji trench recorded at the Alice Springs Array (ASAR) in central Australia. These waveforms show strong pre and postcursory seismic arrivals consistent with ULVZ layering. We used the VSSD method to measure differential travel-times and amplitudes of the post-cursor arrival ScSP and the precursor arrival SPcP relative to ScP. We compare our measurements to a database of approximately 340,000 synthetic seismograms finding that these data are best fit by a ULVZ model with an S-wave velocity reduction of 24%, a P-wave velocity reduction of 23%, a thickness of 8.5 km, and a density increase of 6%. We simultaneously

Identification of sensitive parameters of a tropical forest in Southern Mexico to improve the understanding of C-band radar images

NASA Astrophysics Data System (ADS)

Monsivais-Huertero, A.; Jimenez-Escalona, J. C.; Ramos, J.; Zempoaltecatl-Ramirez, E.

2013-05-01

Forest areas cover the 32% of the Mexican territory. Due to their geographical location, Mexico presents heterogeneous climatic and topographic conditions. The country is divided into two different regions: an arid /semiarid zone (North) and a tropical/temperate zone (South). Due to the effects of climate change, Mexico has been affected in two ways. In the North, there has been a desertification of regions as result of the absence of rainfall and a low rate of soil moisture. On the other hand, in the South, there has been an increase in the intensity of rainfall causing serious flooding. Another effect is the excessive deforestation in Southern Mexico. The FAO has determined that Mexico could present one of the highest losses of forest areas mainly in temperate and subtropical ecosystems. The Biosphere Reserve of Calakmul is the protected area with the largest surface of tropical forest in Mexico. The Biosphere Reserve of Calakmul is located in the state of Campeche that the flora and fauna are being affected. The type of vegetation located in the reserve of Calakmul Biosphere is rainforest with high spatial density and highly heterogeneous due to multiple plant species and the impact of human activities in the area. The satellite remote sensing techniques becomes a very useful tool to monitor the area because a large area can be covered. To understand the radar images, the identification of sensitive parameters governing the radar signal is necessary. With the launch of the satellites Radarsat-2, ASAR-Envisat and ALOSPalSAR, significant progress has been done in the interpretation of satellite radar images. Directly applying physical models becomes a problem due to the large number of input parameters in the models, together with the difficulty in measuring these parameters in the field. The models developed so far have been applied and validated for homogeneous forests with low or average spatial density of trees. This is why it is recommended in a comprehensive

Ground observations and remote sensing data for integrated modelisation of water budget in the Merguellil catchment, Tunisia

NASA Astrophysics Data System (ADS)

Mougenot, Bernard

2016-04-01

The Mediterranean region is affected by water scarcity. Some countries as Tunisia reached the limit of 550 m3/year/capita due overexploitation of low water resources for irrigation, domestic uses and industry. A lot of programs aim to evaluate strategies to improve water consumption at regional level. In central Tunisia, on the Merguellil catchment, we develop integrated water resources modelisations based on social investigations, ground observations and remote sensing data. The main objective is to close the water budget at regional level and to estimate irrigation and water pumping to test scenarios with endusers. Our works benefit from French, bilateral and European projects (ANR, MISTRALS/SICMed, FP6, FP7…), GMES/GEOLAND-ESA) and also network projects as JECAM and AERONET, where the Merguellil site is a reference. This site has specific characteristics associating irrigated and rainfed crops mixing cereals, market gardening and orchards and will be proposed as a new environmental observing system connected to the OMERE, TENSIFT and OSR systems respectively in Tunisia, Morocco and France. We show here an original and large set of ground and remote sensing data mainly acquired from 2008 to present to be used for calibration/validation of water budget processes and integrated models for present and scenarios: - Ground data: meteorological stations, water budget at local scale: fluxes tower, soil fluxes, soil and surface temperature, soil moisture, drainage, flow, water level in lakes, aquifer, vegetation parameters on selected fieds/month (LAI, height, biomass, yield), land cover: 3 times/year, bare soil roughness, irrigation and pumping estimations, soil texture. - Remote sensing data: remote sensing products from multi-platform (MODIS, SPOT, LANDSAT, ASTER, PLEIADES, ASAR, COSMO-SkyMed, TerraSAR X…), multi-wavelength (solar, micro-wave and thermal) and multi-resolution (0.5 meters to 1 km). Ground observations are used (1) to calibrate soil

Holocene Flexural Deformation over the Nile Delta: Evidence from Radar Interferometry

NASA Astrophysics Data System (ADS)

Gebremichael, E.; Sultan, M.; Becker, R.

2017-12-01

Isostatic adjustment and subsequent subsidence and uplift due to sediment and water loading and unloading mechanisms is one of the major factors that produce regional deformational patterns across river deltas. Using 84 Envisat ASAR scenes that were acquired (2004 - 2010) along three tracks and applying Persistent scatterer (PS) radar interferometric techniques, we documented flexural deformational patterns over the entire Nile Delta (length: 186 km; width: 240 km) of Egypt. The passive continental margin of Africa subsided from Jurassic time onwards due to isostatic loading creating an accommodation space and consequently, the deposition of relatively younger sediments on the oceanic crust. In river deltas, the flexural isostasy model dictates that a subsidence in the oceanic crust side should be balanced by a bulge (uplift) in the flanking regions. Using radar interferometry, we were able to identify the flexural deformation pattern and map its spatial extent over the northern and central Nile Delta region. Findings include: (1) the northern Nile Delta region (block) is separated from the southern delta region by an east-west trending, extensively faulted, hinge line that signifies the boundary between two deformational patterns (subsidence and uplift). It separates the highly subsiding (up to 9.8 mm/yr) northern delta block (up to 85 km long) from the nearly stable (0.4 mm/yr; averaged) southern delta block (up to 91 km long). The hinge line marks the end of the passive continental margin of Africa and the beginning of the oceanic crust of the Mediterranean. (2) We mapped the extent of a 20-40 km wide flexural uplift zone to the south of the hinge line. Within the flexural uplift zone (2.5 mm/yr; averaged), there is a gradual increase in uplift rate reaching peak value (up to 7 mm/yr) near the midpoint of the zone. (3) The uplift rate gradually decreases south of the flexure boundary reaching 0.3 mm/yr at the southern periphery of the delta. (4) The flexural

Tracking sea ice floes from the Lincoln Sea to Nares Strait and deriving large scale melt from coincident spring and summer (2009) aerial EM thickness surveys

NASA Astrophysics Data System (ADS)

Lange, B. A.; Haas, C.; Beckers, J.; Hendricks, S.

2011-12-01

Satellite observations demonstrate a decreasing summer Arctic sea ice extent over the past ~40 years, as well as a smaller perennial sea ice zone, with a significantly accelerated decline in the last decade. Recent ice extent observations are significantly lower than predicted by any model employed by the Intergovernmental Panel on Climate Change. The disagreement of the modeled and observed results, along with the large variability of model results, can be in part attributed to a lack of consistent and long term sea ice mass balance observations for the High Arctic. This study presents the derivation of large scale (individual floe) seasonal sea ice mass balance in the Lincoln Sea and Nares Strait. Large scale melt estimates are derived by comparing aerial borne electromagnetic induction thickness surveys conducted in spring with surveys conducted in summer 2009. The comparison of coincident floes is ensured by tracking sea ice using ENIVSAT ASAR and MODIS satellite imagery. Only EM thickness survey sections of floes that were surveyed in both spring and summer are analyzed and the resulting modal thicknesses of the distributions, which represent the most abundant ice type, are compared to determine the difference in thickness and therefore total melt (snow+basal ice+surface ice melt). Preliminary analyses demonstrate a bulk (regional ice tracking) seasonal total thickness variability of 1.1m, Lincoln Sea modal thickness 3.7m (April, 2009) and Nares Strait modal thickness 2.6m (August 2009)(Fig1). More detailed floe tracking, in depth analysis of EM surveys and removal of deformed ridged/rafted sea ice (due to inaccuracies over deformed ice) will result in more accurate melt estimates for this region and will be presented. The physical structure of deformed sea ice and the footprint of the EM instrument typically underestimate the total thicknesses observed. Seasonal variations of sea ice properties can add additional uncertainty to the response of the EM

Study of Retreat and Movement of Himalayan Glaciers Using Spaceborne Repeat Pass SAR Data

NASA Astrophysics Data System (ADS)

Kumar, V.; Venkataraman, G.; Rao, Y. S.

2008-12-01

In this study retreat and movement of Himalayan glaciers using Spaceborne SAR data have been attempted. Gangotri, Siachen, Bara Shigri and Patsio are major glaciers in the Himalayan region which are showing retreat and their respective tributary glaciers are completely disconnected from main body of glaciers. Glacier retreat study will be done using time series coregistered multi temporal SAR data. Simultaneously InSAR coherence thresholding will be applied for tracking snout of Gangotri glacier. Information about dynamism of glaciated terrain can be retrieved by differential interferograms. In this study, movement of Himalayan glaciers will be deciphered using Spaceborne InSAR technique. ERS-1/2 tandem observations showed high correlation on glacier area and hence movement of Siachen and Gangotri glacier are measured for year 1996. Displacement of Gangotri glacier in the radar look direction has been observed as 8.4 cm per day whereas Siachen glacier exhibits a displacement of 22 cm per day (Venkataraman et al. 2005). ERS-1/2 tandem data over all these glaciers show highest correlation over glacier areas but ENVISAT ASAR data shows coherence loss over glacier area due to decorrelation (Vijay et al. 2008). Coherence loss is usual phenomena in glaciated terrain as repeativity of sensor is high (35 days for ENVISAT). A tandem pair of ERS- 1&2 acquired on April 1 and 2, 1996 in descending pass over Siachen shows high coherence than the ascending pair acquired on May 2 and 3, 1996. It is due to change in climate between two acquisitions at glacier locations. Due to the X-band frequency TerraSAR-X interferometry will be more sensitive to orbit errors than current SAR sensors that operate in C-band or L-band (Eineder et al. 2003). A single frequency GPS receiver plus an additional dual-frequency GPS flown as an experimental payload will deliver an orbit accuracy in the order of centimeters. TerraSAR-X will supplement and enhance the InSAR based observations using other

Strain Partitioning and Localization within Dobe Graben Using Differential Interferometric Synthetic Aperture Radar (D-INSAR) and Shuttle Radar Terrain Model

NASA Astrophysics Data System (ADS)

Demissie, Z. S.; Abdelsalam, M. G.; Byrnes, J. M.; Bridges, D.

2014-12-01

The Dobe graben is a northwestern trending, Quaternary continental rift found within the east-central block of the Afar Depression (AD), Ethiopia. The AD is one of only few places where three active tectonic rift arms meet on land. Extensional rifting is ongoing in the Dobe graben as evident by the 1989 swarm of intermediate magnitude (5.7 < Ms < 6.3) earthquakes. Dobe graben extension occurs on steeply dipping faults, where the maximum displacement, fault length, heave and spacing spans in three orders of magnitude. Crustal deformation within the graben was measured through ascending and descending interferograms using the Advanced Synthetic Aperture Radar (ASAR), C- Band (l = 5.6 cm) of the ENVISAT satellite. Results from the Differential Interferometric Synthetic Aperture Radar (D-INSAR) over a period of four years (05/20/2005 to 03/05/2010) suggests that the vertical component of deformation is distributed along a 50 km long NW trending zone in the Dobe graben. The vertical component of deformation is -0.5 to -0.3 cm along the graben axial rift floor likely representing subsidence due to riftingand +0.6 cm to 0.9 cm at the middle of the Dobe relay zone due to uplifting along the border escarpment faults. An estimate for the extension rate has been calculated from twelve traverses across the Dobe graben using Shuttle Rader Terrain Model (SRTM). Results show a deformation elongation (e) value ranging from 0.225 to 0.348. A fractal dimension of 0.03 from the graben floor was obtained for the measured population of fault throws (n= 162) in 12 traverses totaling 172 km. This value is interpreted to represent the dominant contribution to extension from faults with large throw. Moreover, frequency distribution of a natural fault population along the graben floor revealed a negative exponential law distribution indicating a strong strain partitioning within the active axial graben floor. A fractal dimension of 0.01 from the graben shoulder escarpment was obtained for

Multi-sensor detection of glacial lake outburst floods in Greenland from space

NASA Astrophysics Data System (ADS)

Citterio, M.

2015-12-01

GLOFs cause substantial erosion, transport and delivery of sediment along the river system from the glaciated parts of the hydrologic catchment to the sea, and have been found to control the riverine export dynamics of some pollutants like mercury in NE Greenland. GLOFs also pose a risk to human presence and infrastracture. Ice-dammed lakes at the margin of the ice sheet and of local glaciers and ice caps are common features of Greenland's landscape. The occasional or periodic emptying of some of these lakes have been described as early as the 18thcentury. Thinning glaciers in a warming climate are already changing the behaviour of some of these lakes. However, little is known of the frequency and seasonality of glacier lake outburst floods (GLOF) outside of the relatively more densely populated parts of West and South Greenland. This contribution demonstrates automatic multi-sensor detection of ice-dammed lake emptying events from space for three test regions in West, South and Northeast Greenland, using visible imagery from Landsat, ASTER, PROBA-V and MODIS. The current detection algorithm relies on prior knowledge of lakes location and approximate shape from a topographic map at the scale of 1:250.000, and it is meant as a prototype for a future operational product. For the well documented case of the glacier-dammed lake of A.P. Olsen Ice Cap (NE Greenland), where GLOF's observations at Zackenberg Research Station started in 1996, the remote sensing and in situ records are compared, showing good agreement. ICESat altimetry, MODIS and AVHRR thermal imagery, and the ENVISAR ASAR signature of two detected GLOFs that took place late autumn and winter are also discussed to demonstrate the potential for successful retrievals during the polar night. The upcoming Sentinel-3 missions will alleviate what is currently the major drawback of implementing this prototype into an operational service, namely the limited availability of high resolution imagery. This is of special

Use of Persistent Scatterer Interferometry to Assess Land Deformation in the Nile Delta and its Controlling Factors

NASA Astrophysics Data System (ADS)

Gebremichael, E.; Sultan, M.; Becker, R.; Emil, M.; Ahmed, M.; Chouinard, K.

2015-12-01

We applied Persistent scatterer interferometry (PSInSAR) to assess land deformation (subsidence and uplift) across the entire Nile delta and its surroundings and to identify possible causes of the observed deformation. For the purpose of the present study, 100 Envisat Advanced Synthetic Aperture Radar (ASAR; level 0) scenes that were acquired along four tracks and covering a time span of seven years (2004 to 2010) were used. The scenes extend from the Mediterranean coast in the north to Cairo city in the south. These scenes were focused using Repeat Orbit Interferometry PACkage (ROI_PAC) software and the subsequent PSI processing was done using the Stanford Method for Persistent Scatterers (StaMPS) method. A low coherence threshold (0.2) was used to decrease the impact of vegetation-related poor coherence and decorrelation of the scenes over the investigated time span. Subsidence was observed over: (1) the Demietta Nile River branch (3 to 14 mm/yr) where it intersects the Mediterranean coastline, (2) thick (~ 40 m) Holocene sediments in lake Manzala (up to 9 mm/yr), (3) reclaimed desert areas (west of Nile Delta; up to 12 mm/yr) of high groundwater extraction, (4) along parts of a previously proposed flexure line (up to 10 mm/yr), and (5) along the eastern sections of the Mediterranean coastline (up to 15.7 mm/yr). The city of Alexandria (underlain by carbonate platform) and the terminus of the Rosetta branch of the Nile River seem to experience almost no ground movement (mean subsidence of 0.28 mm/yr and 0.74 mm/yr respectively) while the cities of Ras Elbar and Port Said (underlain by thick Holocene sediment) exhibit the highest subsidence values (up to 14 mm/yr and 8.5 mm/yr respectively). The city of Cairo has also experienced subsidence in limited areas of up to 7.8 mm/yr. High spatial correlation was also observed between the subsiding areas and the Abu Madi incised valley; the largest gas field in the Nile Delta. Most of the area undergoing subsidence in the

Methodologies For A Physically Based Rockfall Hazard Assessment

NASA Astrophysics Data System (ADS)

Agliardi, F.; Crosta, G. B.; Guzzetti, F.; Marian, M.

"hazard index". Different hazard maps have been ob- tained combining and classifying variables in different ways. The performance of the different hazard maps has been evaluated on the basis of past rockfall events and com- pared to the results of existing methodologies. The sensitivity of the hazard index with respect to the included variables and their combinations is discussed in order to constrain as objective as possible assessment criteria.

Results from the PharmaSat Nanosatellite Mission: Dose Dependence of Growth and Metabolic Parameters for S. cerevisiae Grown in Microgravity and Challenged by Voriconazole

NASA Astrophysics Data System (ADS)

Ricco, Antonio; Parra, Macarena; Niesel, David; Ly, Diana; Kudlicki, Andrzej; McGinnis, Michael; Hines, John

We report cellular growth and metabolic activity results for Saccharomyces cerevisiae grown aboard PharmaSat, a 5.0-kg autonomous, self-contained biological nanosatellite launched as a secondary payload in May of 2009 and presently in Earth orbit at 450 km. The response of S. cerevisiae to three dose levels bracketing the minimum inhibitory concentration (MIC) of the antifungal voriconazole was monitored in microgravity using 3-color absorbance to measure metabolic activity and turbidity (cell number), which were characterized chiefly by two param-eters: (1) the doubling time and (2) the time delay before the onset of rapid growth. Growth was conducted in forty-eight 100-L microwells containing the yeast—one fluidically separate bank of 12 wells for each voriconazole concentration, plus a control bank. Yeast were main-tained in stasis until the satellite had been deployed, the orbit stabilized, the communications links established, and the growth temperature of 27 ° C stabilized. To re-initiate yeast growth, RPMI growth medium was added. The S. cerevisiae were grown for approximately 12 hr, at which time they were challenged with varying concentrations (0, 0.25xMIC, MIC, 4xMIC) of voriconazole; the optical density and the color change of the redox-based viability indicator alamar blue were recorded as growth proceeded for an additional 84 hr. Results telemetered to the ground reveal a 33 percent longer lag time in microgravity and 60 percent longer dou-bling time than identical ground control experiments. Lag and doubling times are essentially unaffected by voriconazole at 0.125 g/mL in either environment; they lengthen similarly at 0.5 g/mL, voriconazole's MIC. At four times MIC, ground controls show no significant growth nor metabolic activity as tracked by alamar blue; in space, while there was also no measurable cellu-lar growth, remarkably, metabolic activity was clearly present (n = 12 wells). Explanations for the differences in metabolic activity and

Ion-ion Recombination and Chemiion Concentrations In Aircraft Exhaust

NASA Astrophysics Data System (ADS)

Turco, R. P.; Yu, F.

Jet aircraft emit large quantities of ultrafine volatile aerosols, as well as soot parti- cles, into the environment. To determine the long-term effects of these emissions, a better understanding of the mechanisms that control particle formation and evolution is needed, including the number and size dispersion. A recent explanation for aerosol nucleation in a jet wake involves the condensation of sulfuric acid vapor, and cer- tain organic compounds, onto charged molecular clusters (chemiions) generated in the engine combustors (Yu and Turco, 1997). Massive charged aggregates, along with sulfuric acid and organic precursor vapors, have been detected in jet plumes under cruise conditions. In developing the chemiion nucleation theory, Yu and Turco noted that ion-ion recombination in the engine train and jet core should limit the chemiion emission index to 1017/kg-fuel. This value is consistent with ion-ion recombination coefficients of 1×10-7 cm3/s over time scales of 10-2 s. However, the evolution of the ions through the engine has not been adequately studied. The conditions at the combustor exit are extreme-temperatures approach 1500 K, and pressures can reach 30 atmospheres. In this presentation, we show that as the combustion gases expand and cool, two- and three-body ion-ion recombination processes control the chemiion concentration. The concepts of mutual neutralization and Thomson recombination are first summarized, and appropriate temperature and pressure dependent recombination rate coefficients are derived for the aircraft problem. A model for ion losses in jet exhaust is then formulated using an "invariance" principle discussed by Turco and Yu (1997) in the context of a coagulating aerosol in an expanding plume. This recombina- tion model is applied to estimate chemiion emission indices for a range of operational engine conditions. The predicted ion emission rates are found to be consistent with observations. We discuss the sources of variance in chemiion

Operational Satellite-based Surface Oil Analyses (Invited)

NASA Astrophysics Data System (ADS)

Streett, D.; Warren, C.

2010-12-01

During the Deepwater Horizon spill, NOAA imagery analysts in the Satellite Analysis Branch (SAB) issued more than 300 near-real-time satellite-based oil spill analyses. These analyses were used by the oil spill response community for planning, issuing surface oil trajectories and tasking assets (e.g., oil containment booms, skimmers, overflights). SAB analysts used both Synthetic Aperture Radar (SAR) and high resolution visible/near IR multispectral satellite imagery as well as a variety of ancillary datasets. Satellite imagery used included ENVISAT ASAR (ESA), TerraSAR-X (DLR), Cosmo-Skymed (ASI), ALOS (JAXA), Radarsat (MDA), ENVISAT MERIS (ESA), SPOT (SPOT Image Corp.), Aster (NASA), MODIS (NASA), and AVHRR (NOAA). Ancillary datasets included ocean current information, wind information, location of natural oil seeps and a variety of in situ oil observations. The analyses were available as jpegs, pdfs, shapefiles and through Google, KML files and also available on a variety of websites including Geoplatform and ERMA. From the very first analysis issued just 5 hours after the rig sank through the final analysis issued in August, the complete archive is still publicly available on the NOAA/NESDIS website http://www.ssd.noaa.gov/PS/MPS/deepwater.html SAB personnel also served as the Deepwater Horizon International Disaster Charter Project Manager (at the official request of the USGS). The Project Manager’s primary responsibility was to acquire and oversee the processing and dissemination of satellite data generously donated by numerous private companies and nations in support of the oil spill response including some of the imagery described above. SAB has begun to address a number of goals that will improve our routine oil spill response as well as help assure that we are ready for the next spill of national significance. We hope to (1) secure a steady, abundant and timely stream of suitable satellite imagery even in the absence of large-scale emergencies such as

1km Soil Moisture from Downsampled Sentinel-1 SAR Data: Harnessing Assets and Overcoming Obstacles.

NASA Astrophysics Data System (ADS)

Bauer-Marschallinger, Bernhard; Cao, Senmao; Schaufler, Stefan; Paulik, Christoph; Naeimi, Vahid; Wagner, Wolfgang

2017-04-01

Radars onboard Earth observing satellites allow estimating Surface Soil Moisture (SSM) regularly and globally. The use of coarse-scale measurements from active or passive radars for SSM retrieval is well established and in operational use. Thanks to the Sentinel-1 mission, launched in 2014 and deploying Synthetic Aperture Radars (SAR), high-resolution radar imagery is routinely available at the scale of 20 meters, with a high revisit frequency of 3-6 days and with unprecedented radiometric accuracy. However, the direct exploitation of high-resolution SAR data for SSM retrieval is complicated by several problems: Small-scaled contributions to the radar backscatter from individual ground features often obscure the soil moisture signal, rendering common algorithms insensitive to SSM. Furthermore, the influence of vegetation dynamics on the radar signal is less understood than in the coarse-scale case, leading to biases during the vegetation period. Finally, the large data volumes of high-resolution remote sensing data present a great load on hardware systems. Consequently, a spatial resampling of the high-resolution SAR data to a 500 meters sampling is done, allowing the exploitation of information at 10 meter sampling, but reducing effectively the inherent uncertainties. The thereof retrieved 1km SSM product aims to describe the soil moisture dynamics at medium scale with high quality. We adopted the TU-Wien Change Detection algorithm to the Sentinel-1 data, which was already successfully used for retrieving SSM from ERS-1/2 and Envisat-ASAR observations. The adoption entails a new method for SAR image resampling, including a masking for pixels that do not carry soil moisture signals, preventing them to spread during downsampling. Furthermore, the observation angle between the radar sensors and the ground is treated in a different way, as Sentinel-1 sensors observe from fixed orbit paths (in contrast to other radar sensors). Here, a regression model is developed that

Multiscale, multispectral and multitemporal satellite data to identify archaeological remains in the archaeological area of Tiwanaku (Bolivia)

NASA Astrophysics Data System (ADS)

Masini, Nicola; Lasaponara, Rosa

2015-04-01

The aim of this paper is to investigate the cultural landscape of the archaeological area of Tiwanaku (Bolivia) using multiscale, multispectral and multitemporal satellite data. Geospatial analysis techniques were applied to the satellite data sets in order to enhance and map traces of past human activities and perform a spatial characterization of environmental and cultural patterns. In particular, in the Tiwanaku area, the approach based on local indicators of spatial autocorrelation (LISA) applied to ASTER data allowed us to identify traces of a possible ancient hydrographic network with a clear spatial relation with the well-known moat surrounding the core of the monumental area. The same approach applied to QuickBird data, allowed us to identify numerous traces of archaeological interest, in Mollo Kontu mound, less investigated than the monumental area. Some of these traces were in perfect accordance with the results of independent studies, other were completely unknown. As a whole, the detected features, composing a geometric pattern with roughly North-South orientation, closely match those of the other residential contexts at Tiwanaku. These new insights, captured from multitemporal ASTER and QuickBird data processing, suggested new questions on the ancient landscape and provided important information for planning future field surveys and archaeogeophyical investigations. Reference [1] Lasaponara R., Masini N. 2014. Beyond modern landscape features: New insights in thearchaeological area of Tiwanaku in Bolivia from satellite data. International Journal of Applied Earth Observation and Geoinformation, 26, 464-471, http://dx.doi.org/10.1016/j.jag.2013.09.00. [2] Tapete D., Cigna F., Masini N., Lasaponara R. 2013. Prospection and monitoring of the archaeological heritage of Nasca, Peru, with ENVISAT ASAR, Archaeological Prospection, 20, 133-147, doi: 10.1002/arp.1449. [3] Lasaponara R, N Masini, 2012 Satellite Remote Sensing, A New Tool for Archaeology (Series

High-Resolution Regional Biomass Map of Siberia from Glas, Palsar L-Band Radar and Landsat Vcf Data

NASA Astrophysics Data System (ADS)

Sun, G.; Ranson, K.; Montesano, P.; Zhang, Z.; Kharuk, V.

2015-12-01

The Arctic-Boreal zone is known be warming at an accelerated rate relative to other biomes. The taiga or boreal forest covers over 16 x106 km2 of Arctic North America, Scandinavia, and Eurasia. A large part of the northern Boreal forests are in Russia's Siberia, as area with recent accelerated climate warming. During the last two decades we have been working on characterization of boreal forests in north-central Siberia using field and satellite measurements. We have published results of circumpolar biomass using field plots, airborne (PALS, ACTM) and spaceborne (GLAS) lidar data with ASTER DEM, LANDSAT and MODIS land cover classification, MODIS burned area and WWF's ecoregion map. Researchers from ESA and Russia have also been working on biomass (or growing stock) mapping in Siberia. For example, they developed a pan-boreal growing stock volume map at 1-kilometer scale using hyper-temporal ENVISAT ASAR ScanSAR backscatter data. Using the annual PALSAR mosaics from 2007 to 2010 growing stock volume maps were retrieved based on a supervised random forest regression approach. This method is being used in the ESA/Russia ZAPAS project for Central Siberia Biomass mapping. Spatially specific biomass maps of this region at higher resolution are desired for carbon cycle and climate change studies. In this study, our work focused on improving resolution ( 50 m) of a biomass map based on PALSAR L-band data and Landsat Vegetation Canopy Fraction products. GLAS data were carefully processed and screened using land cover classification, local slope, and acquisition dates. The biomass at remaining footprints was estimated using a model developed from field measurements at GLAS footprints. The GLAS biomass samples were then aggregated into 1 Mg/ha bins of biomass and mean VCF and PALSAR backscatter and textures were calculated for each of these biomass bins. The resulted biomass/signature data was used to train a random forest model for biomass mapping of entire region from 50o

A multi-sensor approach to assess erosion risk in low mountain range landscapes - a comparative case study in western Germany

NASA Astrophysics Data System (ADS)

Seeling, S.; Buddenbaum, H.; Seeger, M.; Löhnertz, M.

2009-04-01

In this presentation we summarize our experience in the derivation of variables for identification of erosion and areas endagered of erosion from different remote sensing sensors. The field study is situated at the "Zemmer-Plateau" (north-east from Trier) and was undertaken to compare the ability of different, passive and active, remote sensing sensors to derive several process parameters of soil erosion in agricultural landscapes. Additionally the added value of sensor combinations was investigated. Backscatter of C-Band microwave instruments is known to be sensitive to soil roughness and surface soil moisture. If landuse and roughness is approximately constant, backscatter is mostly affected by temporal changes in soil moisture. For the test site multitemporal imagery from the ASAR and ERS2 sensors was available. For the identification of areas prone to waterlogging an approach based on principal component analysis was used. Multitemporal imagery from optical sensors like Landsat and SPOT HRV allow the assessment of slow changes within the landscape and annual changes of vegetation cover. We used Landsat imagery from 1975, 1984 and 2000 to map the changes in landuse and associated soil development, multi temporal imagery from SPOT 4 and 5 satellites was used to identify different crop types. Additionally we investigated which areas that are prone to erosion by their topography position, have, due to maladjusted land management, not been protected by vegetation cover during the main annual rainfall season in 2003. Airborne Laser Scanning (ALS) data is well suited for discovering areas susceptible of erosion. Even under forest canopies ALS can provide high-resolution terrain models that can be used for identifying trenches, linear features, steep hills and other terrain features, which trigger erosion or are even results of erosion. ALS-derived DTMs usually have a spatial resolution of about 1 m, while DTMs from other data sources are much coarser. A key problem

Surface deformation of Ayaz-Akhtarma Mud volcano in Azerbaijan detected by ALOS/ALOS-2 InSAR and its source modeling

NASA Astrophysics Data System (ADS)

Iio, K.; Furuya, M.

2017-12-01

Interferometric synthetic aperture radar (InSAR) allows us to image a wide area with dense spatial resolution without a need for ground-based measurement tools with a precision on the order of a few centimeters. This technique has been mainly used to investigate such ground deformation associated with earthquakes, volcanic eruptions and ground subsidence due to water pumping. However there have been few cases that applied the technique to the activity of mud volcanos. Azerbaijan, located on the western edge of the Caspian Sea in Central Asia, is one of the most abundant countries in term of the population of mud volcanoes over the land. We focused on an especially large and unique mud volcano known as the Ayaz-Akhtarma because the deformation signals are the most evident and peculiar. Antonielli et al., (2014) detected the ground deformation of this mud volcano, using ENVISAT/ASAR C-band SAR data spanning from 2003 to 2005 only along descending path. While the ground displacement at the volcano was 20 cm in line of sight (LOS) for the two years, Antonielli et al., (2014) attributed the observed LOS changes to the uplift and subsidence in the eastern half and western half, respectively, whereas no source model was presented in the study. In the previous study, however, the 3D displacements were totally uncertain because of the restricted looking geometry. We could observe the displacements, based not only on the ALOS data along the ascending path that is the opposite look direction from the previous study but also on the ALOS-2 data for ascending and descending paths. Our observed LOS change data indicated more active and larger horizontal displacements. The cumulative LOS displacement is up to nearly 300 cm for four years by ALOS and 100 cm for two years by ALOS-2. In addition to InSAR, we performed MAI analysis. MAI is a technique for measuring ground displacement along flight direction, which is not sensitive to the InSAR measurement. The result of MAI showed a

Measurement of long-term land subsidence by combination of InSAR and time series analysis - Application study to Kanto Plains of Japan -

NASA Astrophysics Data System (ADS)

Deguchi, T.; Rokugawa, S.; Matsushima, J.

2009-04-01

InSAR is an application technique of synthetic aperture radars and is now drawing attention as a methodology capable of measuring subtle surface deformation over a wide area with a high spatial resolution. In this study, the authors applied the method of measuring long-term land subsidence by combining InSAR and time series analysis to Kanto Plains of Japan using 28 images of ENVISAT/ASAR data. In this measuring method, the value of land deformation is set as an unknown parameter and the optimal solution to the land deformation amount is derived by applying a smoothness-constrained inversion algorithm. The vicinity of the Kanto Plain started to subside in the 1910s, and became exposed to extreme land subsidence supposedly in accordance with the reconstruction efforts after the Second World War and the economic development activities. The main causes of the land subsidence include the intake of underground water for the use in industries, agriculture, waterworks, and other fields. In the Kujukuri area, the exploitation of soluble natural gas also counts. The Ministry of Environment reported in its documents created in fiscal 2006 that a total of 214 km2 in Tokyo and the six prefectures around the Plain had undergone a subsidence of 1 cm or more per a year. As a result of long-term land subsidence over approximately five and a half years from 13th January, 2003, to 30th June, 2008, unambiguous land deformation was detected in six areas: (i) Haneda Airport, (ii) Urayasu City, (iii) Kasukabe-Koshigaya, (iv) Southern Kanagawa, (v) Toride-Ryugasaki, and (vi) Kujukuri in Chiba Prefecture. In particular, the results for the Kujukuri area were compared with the leveling data taken around the same area to verify the measuring accuracy. The comparative study revealed that the regression formula between the results obtained by time series analysis and those by the leveling can be expressed as a straight line with a gradient of approximately 1, though including a bias of about

Preliminary assessment of active rock slope instabilities in the high Himalaya of Bhutan

NASA Astrophysics Data System (ADS)

Dini, Benedetta; Manconi, Andrea; Leith, Kerry; Loew, Simon

2016-04-01

detectable movement along the satellite line of sight by assuming that the dominant motion is along the line of maximum slope. Finally, we present the preliminary surface velocities and displacement time series obtained by applying the P-SBAS technique (implemented within the ESA Geohazard Exploitation Platform) on available SAR data (24 images, period 2007-2010, Envisat ASAR, track 176), where several anomalies identified have been interpreted as active rock slope instabilities previously unknown.

Monitoring LongBao Wetland Ecosystem in Tibetan Plateau using time-series SAR and Optical dataset

NASA Astrophysics Data System (ADS)

Brisco, B.; Wei, Q.; Xie, C.; Shao, Y.; Tian, B.; Li, K.

2017-12-01

As a highly productive and sensitive ecosystem, plateau wetlands provide indispensable habitats for the black-necked crane, an endangered species of crane. In this research, we focus on Longbao plateau wetland, the only habitat of black-necked crane in Tibetan Plateau, located in Yushu, Qinghai province, with an area of about 100 km2 and elevation about 4100 4200m. Monitoring Longbao wetland during the past 30 years using time series SAR and optical dataset and analysis its effect on black-necked crane have great significance for endangered species protection. Water and vegetation resources are two important indicators of wetland productivity. In this study, we aim at providing the open water area dynamics and the variation of vegetation during the past 30 years using SAR and optical imageries and analyzing their effect on black-necked cranes. The changes of the open water area and NDVI reflect the environment variety of Longbao wetland. And the relationship between these biological parameters and climates were analyzed, especially their influence on the black-necked cranes, which is the only kind of crane in the world that grows and breeds in the plateau. The method of level set segmentation with KummerU distribution was applied to open water bodies (wetlands) delimitation using time series SAR dataset, including Envisat-ASAR acquired from 2003 to 2010 and Radasat-2 from 2013 to 2014. Also the NDVI is calculated from Landsat images (acquired during 2003-2015) using google earth engine which is a cloud-based platform for planetary-scale environmental data analysis.The results indicate that the open water area fluctuates with seasons and reaches the maximum in summer. While in the spring and winter the wetland is usually covered by ice and snow. The highest values of NDVI occurred in years with a sufficient amount of precipitation. The abundant vegetation, water and suitable temperature of Longbao wetland in summer effectively promote the boost and growth of the

Meteorological conditions influencing the formation of level ice within the Baltic Sea

NASA Astrophysics Data System (ADS)

Mazur, A. K.; Krezel, A.

2012-12-01

The Baltic Sea is covered by ice every winter and on average, the ice-covered area is 45% of the total area of the Baltic Sea. The beginning of ice season usually starts in the end of November, ice extent is the largest between mid-February and mid-March and sea ice disappears completely in May. The ice covered areas during a typical winter are the Gulf of Bothnia, the Gulf of Finland and the Gulf of Riga. The studies of sea ice in the Baltic Sea are related to two aspects: climate and marine transport. Depending on the local weather conditions during the winter different types of sea ice can be formed. From the point of winter shipping it is important to locate level and deformed ice areas (rafted ice, ridged ice, and hummocked ice). Because of cloud and daylight independency as well as good spatial resolution, SAR data seems to be the most suitable source of data for sea ice observation in the comparatively small area of the Baltic Sea. We used ASAR Wide Swath Mode data with spatial resolution 150 m. We analyzed data from the three winter seasons which were examples of severe, typical and mild winters. To remove the speckle effect the data were resampled to 250 m pixel size and filtred using Frost filter 5x5. To detect edges we used Sobel filter. The data were also converted into grayscale. Sea ice classification was based on Object-Based Image Analysis (OBIA). Object-based methods are not a common tool in sea ice studies but they seem to accurately separate level ice within the ice pack. The data were segmented and classified using eCognition Developer software. Level ice were classified based on texture features defined by Haralick (Grey Level Co-Occurrence Matrix homogeneity, GLCM contrast, GLCM entropy and GLCM correlation). The long-term changes of the Baltic Sea ice conditions have been already studied. They include date of freezing, date of break-up, sea ice extent and some of work also ice thickness. There is a little knowledge about the relationship of

Toward an integrated storm surge application: ESA Storm Surge project

NASA Astrophysics Data System (ADS)

Lee, Boram; Donlon, Craig; Arino, Olivier

2010-05-01

Storm surges and their associated coastal inundation are major coastal marine hazards, both in tropical and extra-tropical areas. As sea level rises due to climate change, the impact of storm surges and associated extreme flooding may increase in low-lying countries and harbour cities. Of the 33 world cities predicted to have at least 8 million people by 2015, at least 21 of them are coastal including 8 of the 10 largest. They are highly vulnerable to coastal hazards including storm surges. Coastal inundation forecasting and warning systems depend on the crosscutting cooperation of different scientific disciplines and user communities. An integrated approach to storm surge, wave, sea-level and flood forecasting offers an optimal strategy for building improved operational forecasts and warnings capability for coastal inundation. The Earth Observation (EO) information from satellites has demonstrated high potential to enhanced coastal hazard monitoring, analysis, and forecasting; the GOCE geoid data can help calculating accurate positions of tide gauge stations within the GLOSS network. ASAR images has demonstrated usefulness in analysing hydrological situation in coastal zones with timely manner, when hazardous events occur. Wind speed and direction, which is the key parameters for storm surge forecasting and hindcasting, can be derived by using scatterometer data. The current issue is, although great deal of useful EO information and application tools exist, that sufficient user information on EO data availability is missing and that easy access supported by user applications and documentation is highly required. Clear documentation on the user requirements in support of improved storm surge forecasting and risk assessment is also needed at the present. The paper primarily addresses the requirements for data, models/technologies, and operational skills, based on the results from the recent Scientific and Technical Symposium on Storm Surges (www

Assessing seasonal backscatter variations with respect to uncertainties in soil moisture retrieval in Siberian tundra regions

NASA Astrophysics Data System (ADS)

Högström, Elin; Trofaier, Anna Maria; Gouttevin, Isabella; Bartsch, Annett

2015-04-01

Data from the Advanced Scatterometer (ASCAT) instrument provide the basis of a near real-time, coarse scale, global soil moisture product. Numerous studies have shown the applicability of this product, including recent operational use for numerical weather forecasts. Soil moisture is a key element in the global cycles of water, energy and carbon. Among many application areas, it is essential for the understanding of permafrost development in a future climate change scenario. Dramatic climate changes are expected in the Arctic, where ca 25% of the land is underlain by permafrost, and it is to a large extent remote and inaccessible. The availability and applicability of satellite derived land-surface data relevant for permafrost studies, such as surface soil moisture, is thus crucial to landscape-scale analyses of climate-induced change. However, there are challenges in the soil moisture retrieval that are specific to the Arctic. This study investigates backscatter variability unrelated to soil moisture variations in order to understand the possible impact on the soil moisture retrieval. The focus is on tundra lakes, which are a common feature in the Arctic and are expected to affect the retrieval. ENVISAT Advanced Synthetic Aperture Radar (ASAR) Wide Swath (120 m) data are used to resolve lakes and later understand and quantify their impacts on Metop ASCAT (25 km) soil moisture retrieval during the snow free period. Sites of interest are chosen according to high or low agreement between output from the land surface model ORCHIDEE and ASCAT derived SSM. The results show that in most cases low model agreement is related to high water fraction. The water fraction correlates with backscatter deviations (relative to a smooth water surface reference image) within the ASCAT footprint areas (R = 0.91-0.97). Backscatter deviations of up to 5 dB can occur in areas with less than 50% water fraction and an assumed soil moisture related range (sensitivity) of 7 dB in the ASCAT

The MELISSA food data base: space food preparation and process optimization

NASA Astrophysics Data System (ADS)

Creuly, Catherine; Poughon, Laurent; Pons, A.; Farges, Berangere; Dussap, Claude-Gilles

Life Support Systems have to deal with air, water and food requirement for a crew, waste management and also to the crew's habitability and safety constraints. Food can be provided from stocks (open loops) or produced during the space flight or on an extraterrestrial base (what implies usually a closed loop system). Finally it is admitted that only biological processes can fulfil the food requirement of life support system. Today, only a strictly vegetarian source range is considered, and this is limited to a very small number of crops compared to the variety available on Earth. Despite these constraints, a successful diet should have enough variety in terms of ingredients and recipes and sufficiently high acceptability in terms of acceptance ratings for individual dishes to remain interesting and palatable over a several months period and an adequate level of nutrients commensurate with the space nutritional requirements. In addition to the nutritional aspects, others parameters have to be considered for the pertinent selection of the dishes as energy consumption (for food production and transformation), quantity of generated waste, preparation time, food processes. This work concerns a global approach called MELISSA Food Database to facilitate the cre-ation and the management of these menus associated to the nutritional, mass, energy and time constraints. The MELISSA Food Database is composed of a database (MySQL based) con-taining multiple information among others crew composition, menu, dishes, recipes, plant and nutritional data and of a web interface (PHP based) to interactively access the database and manage its content. In its current version a crew is defined and a 10 days menu scenario can be created using dishes that could be cooked from a set of limited fresh plant assumed to be produced in the life support system. The nutritional covering, waste produced, mass, time and energy requirements are calculated allowing evaluation of the menu scenario and its

On the use of COSMO-SkyMed time series for the identification of Archaeological traces dating from the Eastern-Han to Northern-Wei Dynasties in Luoyang city.

NASA Astrophysics Data System (ADS)

Chen, Fulong; Masini, Nicola; Yang, Ruixia; Feng, Dexian; Lasaponara, Rosa

2015-04-01

Prospection, 20, 71-78, doi: 10.1002/arp.1452 Tapete D., Cigna F., Masini N., Lasaponara R. 2013. Prospection and monitoring of the archaeological heritage of Nasca, Peru, with ENVISAT ASAR, Archaeological Prospection, 20, 133-147, doi: 10.1002/arp.1449. Ciminale M, D Gallo, R Lasaponara, N Masini, 2009 A multiscale approach for reconstructing archaeological landscapes: applications in Northern Apulia (Italy) Archaeological Prospection 16 (3), 143-153 Lasaponara R, N Masini, 2012 Satellite Remote Sensing, A New Tool for Archaeology (Series Remote Sensing and Digital Image) Springer book Masini N, R Lasaponara, 2006, Satellite-based recognition of landscape archaeological features related to ancient human transformation Journal of Geophysics and Engineering 3 (3), 230.

The changing spatio-temporal dynamics of thaw lake development, Seward Peninsula, Alaska.

NASA Astrophysics Data System (ADS)

Cooper, Michael; Rees, Gareth; Bartsch, Annett

2014-05-01

Contemporary anthropogenic climatic warming is having an accelerated, and more pronounced effect upon Arctic regions than any other environment on Earth. Increased surface temperatures have led to widespread permafrost degradation and a shift in dynamics. One landscape manifestation of localised permafrost decay, seen to be ubiquitous across low-lying tundra regions of Alaska, Canada and Siberia, is the thermokarst lake - or 'thaw' lake. These features are seen to be truly dynamic, with a relatively rapid evolution and decay. The exact impacts of climatic perturbation on thaw lake development are in contention; however, recent studies have suggested an increased vulnerability of these features, owing to the susceptibility of the fundamental processes of initiation, expansion and drainage to climatic variation. It is often hypothesised that with current trends, thaw lakes will see a net increase in expansion rate, and areal extent, with a potential for increased drainage events. Increased permafrost thaw and thermokarst activity has also led to shifts in biogeochemical cycles, leading to an amplified release from large carbon reservoirs currently sequestered within permafrost. An example of carbon release exhibited from thaw lakes is that of methane ebullition (gas bubble formation); this has been theorised to have the potential to initiate a major positive climatic feedback leading to a continued rise in global temperatures. Due to the remote nature and large area over which these landforms occur, remotely sensed data has been widely used in order to both accurately classify features and measure change over spatially large and great temporal extents. As well as studies interpreting data collected in the visible and near-infrared spectra, studies have recently made use of radar or microwave products in order to capture imagery avoiding adverse atmospheric conditions, most notably cloud cover. Data from Envisat ASAR operating in Wide Swath Mode was acquired for this

Satellite SAR imagery for site discovery, change detection and monitoring activities in cultural heritage sites: experiments on the Nasca region, Peru

NASA Astrophysics Data System (ADS)

Tapete, D.; Cigna, F.; Masini, N.; Lasaponara, R.

2012-04-01

data stacks were selected: ERS-2 ascending data acquired in 2001-2011, ENVISAT ASAR ascending and descending data acquired in 2003-2007, and ALOS PALSAR descending and ascending data acquired in 2007 and 2008. The feature extraction was specifically addressed to the recognition of buried structures, archaeological deposits and the study of the buried networks of aqueducts, as well as the morphological study of the Nasca geoglyphs. Change detection analysis also included the multi-temporal reconstruction of the evolution of the Rio Nasca catchment basin, while specific tests were performed to demonstrate the usefulness of SAR imagery for monitoring looting activities. The results of the radar-interpretation compared and integrated with the field investigations will support the archaeological activities and contribute to the monitoring and enhancement of archaeological heritage and cultural landscape of the Nasca region.

Changes in ice dynamics along the northern Antarctic Peninsula

NASA Astrophysics Data System (ADS)

Seehaus, Thorsten; Marinsek, Sebastian; Cook, Alison; Van Wessem, Jan-Melchior; Braun, Matthias

2017-04-01

The climatic conditions along the Antarctic Peninsula have undergone considerable changes during the last 50 years. A period of pronounced air temperature rise, increasing ocean temperatures as well as changes in the precipitation pattern have been reported by various authors. Consequently, the glacial systems showed changes including widespread retreat, surface lowering as well as variations in flow speeds. During the last decades numerous ice shelves along the Antarctic Peninsula retreated, started to break-up or disintegrated completely. The loss of the buttressing effect caused tributary glaciers to accelerate with increasing ice discharge along the Antarctic Peninsula. Quantification of the mass changes is still subject to considerable errors although numbers derived from the different methods are converging. The aim is to study the reaction of glaciers at the northern Antarctic Peninsula to the changing climatic conditions and the readjustments of tributary glaciers to ice shelf disintegration, as well as to better quantify the ice mass loss and its temporal changes. We analysed time series of various satellite sensors (ERS-1/2 SAR, ENVISAT ASAR, RADARSAT-1, ALOS PALSAR, TerraSAR-X/TanDEM-X, ASTER, Landsat) to detect changes in ice dynamics of 74 glacier basins along the northern Antarctic Peninsula (<65°). Intensity feature tracking techniques were applied on data stacks from different SAR satellites over the last 20 years to infer temporal trends in glacier surface velocities. In combination with ice thickness reconstructions and modeled climatic mass balance fields regional imbalances were calculated. Variations in ice front position were mapped based on optical and SAR satellite data sets. Along the west coast of the northern Antarctic Peninsula an increase in flow speeds by 40% between 1992 and 2014 was observed, whereas glaciers on the east side (north of former Prince-Gustav Ice Shelf) showed a strong deceleration. Nearly all former ice shelf

A time series deformation estimation in the NW Himalayas using SBAS InSAR technique

NASA Astrophysics Data System (ADS)

Kumar, V.; Venkataraman, G.

2012-12-01

A time series land deformation studies in north western Himalayan region has been presented in this study. Synthetic aperture radar (SAR) interferometry (InSAR) is an important tool for measuring the land displacement caused by different geological processes [1]. Frequent spatial and temporal decorrelation in the Himalayan region is a strong impediment in precise deformation estimation using conventional interferometric SAR approach. In such cases, advanced DInSAR approaches PSInSAR as well as Small base line subset (SBAS) can be used to estimate earth surface deformation. The SBAS technique [2] is a DInSAR approach which uses a twelve or more number of repeat SAR acquisitions in different combinations of a properly chosen data (subsets) for generation of DInSAR interferograms using two pass interferometric approach. Finally it leads to the generation of mean deformation velocity maps and displacement time series. Herein, SBAS algorithm has been used for time series deformation estimation in the NW Himalayan region. ENVISAT ASAR IS2 swath data from 2003 to 2008 have been used for quantifying slow deformation. Himalayan region is a very active tectonic belt and active orogeny play a significant role in land deformation process [3]. Geomorphology in the region is unique and reacts to the climate change adversely bringing with land slides and subsidence. Settlements on the hill slopes are prone to land slides, landslips, rockslides and soil creep. These hazardous features have hampered the over all progress of the region as they obstruct the roads and flow of traffic, break communication, block flowing water in stream and create temporary reservoirs and also bring down lot of soil cover and thus add enormous silt and gravel to the streams. It has been observed that average deformation varies from -30.0 mm/year to 10 mm/year in the NW Himalayan region . References [1] Massonnet, D., Feigl, K.L.,Rossi, M. and Adragna, F. (1994) Radar interferometry mapping of

Present day vertical deformation of Pico and Faial islands revealed by merged INSAR and GPS data

NASA Astrophysics Data System (ADS)

Catalao, Joao; Nico, Giovanni; Catita, Cristina

2010-05-01

In this paper we investigate the problem of the integration of repeated GPS geodetic measurements and interferometric Synthetic Aperture Radar (SAR) observations for the determination of high resolution vertical deformation maps. The Faial and Pico islands in the Azores archipelago were chosen as study area. These islands are characterized by a intense volcanic and seismic activity. Both islands are covered by huge vegetation and have very unstable atmospheric conditions which negatively influence the interferometric processing. In this work, we apply the advanced interferometric SAR processing based on Persistent Scatterers. However, the small number of man made structures reduces the density of Persistent Scatterers. Furthermore, the different ascending and descending acquisition geometries give different sets of Persistent Scatterers, with complementary spatial coverage, and different line-of-sight velocities. The estimated velocities are relative to the master image (different from ascending and descending) and must be referred to an absolute velocity (in the sense of referred to a geodetic reference frame). The strategy used to overcome the aforementioned problems is based on the combination of sparse GPS 3D-velocities with two sets of Persistent Scatterers determined from ascending and descending passes. The input data are: a set of GPS - 3D velocities relative to ITRF05 (18 Stations) and two sets of Persistent Scatterers corresponding to the descending and ascending orbits. A dataset of 60 interferometric repeat-pass ASAR/ENVISAT images were acquired over the Faial and Pico islands, from 2006 to 2008, along ascending and descending passes. Each interferogram obtained by this dataset was corrected for atmospheric artefacts using a Weather Forecasting model. Initially, the horizontal velocity component (east and north) is assigned to each PS from interpolation of available GPS observations. Then, the vertical component of the velocity is determined from the

Monitoring Snow and Land Ice Using Satellite data in the GMES Project CryoLand

NASA Astrophysics Data System (ADS)

Bippus, Gabriele; Nagler, Thomas

2013-04-01

The main objectives of the project "CryoLand - GMES Service Snow and Land Ice" are to develop, implement and validate services for snow, glaciers and lake and river ice products as a Downstream Service within the Global Monitoring for Environment and Security (GMES) program of the European Commission. CryoLand exploits Earth Observation data from current optical and microwave sensors and of the upcoming GMES Sentinel satellite family. The project prepares also the basis for the cryospheric component of the GMES Land Monitoring services. The CryoLand project team consists of 10 partner organisations from Austria, Finland, Norway, Sweden, Switzerland and Romania and is funded by the 7th Framework Program of the European Commission. The CryoLand baseline products for snow include fractional snow extent from optical satellite data, the extent of melting snow from SAR data, and coarse resolution snow water equivalent maps from passive microwave data. Experimental products include maps of snow surface wetness and temperature. The products range from large scale coverage at medium resolution to regional products with high resolution, in order to address a wide user community. Medium resolution optical data (e.g. MODIS, in the near future Sentinel-3) and SAR (ENVISAT ASAR, in the near future Sentinel-1) are the main sources of EO data for generating large scale products in near real time. For generation of regional products high resolution satellite data are used. Glacier products are based on high resolution optical (e.g. SPOT-5, in the near future Sentinel-2) and SAR (TerraSAR-X, in the near future Sentinel-1) data and include glacier outlines, mapping of glacier facies, glacier lakes and ice velocity. The glacier products are generated on users demand. Current test areas are located in the Alps, Norway, Greenland and the Himalayan Mountains. The lake and river ice products include ice extent and its temporal changes and snow extent on ice. The algorithms for these

Modelling coastal processes by means of innovative integration of remote sensing and modelling analysis

NASA Astrophysics Data System (ADS)

Taramelli, A.; Zanuttigh, B.; Zucca, F.; Dejana, M.; Valentini, E.

2011-12-01

Coastal marine and inland landforms are dynamic systems undergoing adjustments in form at different time and space scales in response to varying conditions external to the system. Coastal emerged and shallow submerged nearshore areas, affected by short-term perturbations, return to their pre-disturbance morphology and generally reach a dynamic equilibrium. Worldwide in the last century we have experienced in increased coastal inundation, erosion and ecosystem losses. However, erosion can result from a number of other factors, such as altered wind and current patterns, high-energy waves, and reduced fluvial sediment inputs. Direct impacts of human activities, including reclamation of coastal wetlands, deforestation, damming, channelization, diversions of coastal waterways, construction of seawalls and other structures, alter circulation patterns. Also indirect human impacts such as land-uses changes through time (eg. from agricultural to industrial use) have affected coastal ecosystems. The objective of this research is to propose innovative remote sensing applications to monitor specific coastal processes in order to use them within a physical modelling to quantify and model their time evolution. The research was applied in two dynamic and densely populated deltas and coastal areas (the Po and the Plymouth delta) by combining multi-sensor spaceborne remote sensing (SAR and OPTICAL) to physical modelling. The main results are: a) deformation and spatiotemporal variations maps in coastal morphology with a special focus to point out the temporal subsidence evolution, b) inter and intra-annual change detection maps that are both used a to feed a coastal physical modelling (MIKE 21). The basic strategy was to highlight the different components of the coastal system environment through: 1) deformation and spatio-temporal variations maps of coastal morphology, by the use of time-stack from 1992 up today of ESA SAR data (ERS-1/2 and ENVISAT-ASAR sensors) were used to

Toward An Unstructured Mesh Database

NASA Astrophysics Data System (ADS)

Rezaei Mahdiraji, Alireza; Baumann, Peter Peter

2014-05-01

Unstructured meshes are used in several application domains such as earth sciences (e.g., seismology), medicine, oceanography, cli- mate modeling, GIS as approximate representations of physical objects. Meshes subdivide a domain into smaller geometric elements (called cells) which are glued together by incidence relationships. The subdivision of a domain allows computational manipulation of complicated physical structures. For instance, seismologists model earthquakes using elastic wave propagation solvers on hexahedral meshes. The hexahedral con- tains several hundred millions of grid points and millions of hexahedral cells. Each vertex node in the hexahedrals stores a multitude of data fields. To run simulation on such meshes, one needs to iterate over all the cells, iterate over incident cells to a given cell, retrieve coordinates of cells, assign data values to cells, etc. Although meshes are used in many application domains, to the best of our knowledge there is no database vendor that support unstructured mesh features. Currently, the main tool for querying and manipulating unstructured meshes are mesh libraries, e.g., CGAL and GRAL. Mesh li- braries are dedicated libraries which includes mesh algorithms and can be run on mesh representations. The libraries do not scale with dataset size, do not have declarative query language, and need deep C++ knowledge for query implementations. Furthermore, due to high coupling between the implementations and input file structure, the implementations are less reusable and costly to maintain. A dedicated mesh database offers the following advantages: 1) declarative querying, 2) ease of maintenance, 3) hiding mesh storage structure from applications, and 4) transparent query optimization. To design a mesh database, the first challenge is to define a suitable generic data model for unstructured meshes. We proposed ImG-Complexes data model as a generic topological mesh data model which extends incidence graph model to multi

Lithium-Ion Electrolytes Containing Phosphorous-Based, Flame-Retardant Additives

NASA Technical Reports Server (NTRS)

Smart, Marshall C.; Smith, Kiah A.; Bugga, Ratnakumar V.; Prakash, G. K. Surya

2010-01-01

Future NASA missions aimed at exploring Mars, the Moon, and the outer planets require rechargeable batteries that can operate over a wide temperature range (-60 to +60 C) to satisfy the requirements of various applications. In addition, many of these applications will require improved safety, due to their use by humans. Currently, the state-of-the-art lithium-ion (Li-ion) system has been demonstrated to operate over a wide range of temperatures (-40 to +40 C); however, abuse conditions can often lead to cell rupture and fire. The nature of the electrolyte can greatly affect the propensity of the cell/battery to catch fire, given the flammability of the organic solvents used within. Li-ion electrolytes have been developed that contain a flame-retardant additive in conjunction with fluorinated co-solvents to provide a safe system with a wide operating temperature range. Previous work incorporated fluorinated esters into multi-component electrolyte formulations, which were demonstrated to cover a temperature range from 60 to +60 C. This work was described in Fluoroester Co-Solvents for Low-Temperature Li+ Cells (NPO-44626), NASA Tech Briefs, Vol. 33, No. 9 (September 2009), p. 37; and Optimized Li-Ion Electrolytes Con tain ing Fluorinated Ester Co-Solvents (NPO-45824), NASA Tech Briefs, Vol. 34, No. 3 (March 2010), p. 48. Other previous work improved the safety characteristics of the electrolytes by adding flame-retardant additives such as triphenyl phosphate (TPhPh), tri-butyl phosphate (TBuPh), triethyl phosphate (TEtPh), and bis(2,2,2-trifluoroethyl) methyl phosphonate (TFMPo). The current work involves further investigation of other types of flame-retardant additives, including tris(2,2,2-trifluoroethyl) phosphate, tris(2,2,2-trifluoroethyl) phosphite, triphenylphosphite, diethyl ethylphosphonate, and diethyl phenylphosphonate added to an electrolyte composition intended for wide operating temperatures. In general, many of the formulations investigated in this

Geologic framework, hydrostratigraphy, and ichnology of the Blanco, Payton, and Rough Hollow 7.5-minute quadrangles, Blanco, Comal, Hays, and Kendall Counties, Texas

USGS Publications Warehouse

Clark, Allan K.; Golab, James A.; Morris, Robert E.

2016-09-13

This report presents the geologic framework, hydro­stratigraphy, and ichnology of the Trinity and Edwards Groups in the Blanco, Payton, and Rough Hollow 7.5-minute quad­rangles in Blanco, Comal, Hays, and Kendall Counties, Texas. Rocks exposed in the study area are of the Lower Cretaceous Trinity Group and lower part of the Fort Terrett Formation of the Lower Cretaceous Edwards Group. The mapped units in the study area are the Hammett Shale, Cow Creek Limestone, Hensell Sand, and Glen Rose Limestone of the Trinity Group and the lower portion of the Fort Terrett Formation of the Edwards Group. The Glen Rose Limestone is composed of the Lower and Upper Members. These Trinity Group rocks con­tain the upper and middle Trinity aquifers. The only remaining outcrops of the Edwards Group are the basal nodular member of the Fort Terrett Formation, which caps several hills in the northern portion of the study area. These rocks were deposited in an open marine to supratidal flats environment. The faulting and fracturing in the study area are part of the Balcones fault zone, an extensional system of faults that generally trends southwest to northeast in south-central Texas.The hydrostratigraphic units of the Edwards and Trinity aquifers were mapped and described using a classification system based on fabric-selective or not-fabric-selective poros­ity types. The only hydrostratigraphic unit of the Edwards aquifer present in the study area is hydrostratigraphic unit VIII. The mapped hydrostratigraphic units of the upper Trinity aquifer are (from top to bottom) the Camp Bullis, upper evaporite, fossiliferous, and lower evaporite which are interval equivalent to the Upper Member of the Glen Rose Limestone. The middle Trinity aquifer encompasses (from top to bottom) the Lower Member of the Glen Rose Limestone, the Hensell Sand Member, and the Cow Creek Limestone Member of the Pearsall Formation. The Lower Member of the Glen Rose Limestone is subdivided into six informal hydro

Hydrological Dynamics In High Mountain Catchment Areas of Central Norway

NASA Astrophysics Data System (ADS)

Löffler, J.; Rössler, O.

Large-scaled landscape structure is regarded as a mosaic of ecotopes where pro- cess dynamics of water and energy fluxes are analysed due to its effects on ecosys- tem functioning. The investigations have been carried out in the continental most Vågå/Oppland high mountains in central Norway since 1994 (LÖFFLER WUN- DRAM 1999, 2000, 2001). Additionally, comparable investigations started in 2000 dealing with the oceanic high mountain landscapes on same latitudes (LÖFFLER et al. 2001). The theoretical and methodological framework of the project is given by the Landscape-Ecological Complex Analysis (MOSIMANN 1984, 1985) and its variations due to technical and principle methodical challenges in this high moun- tain landscape (KÖHLER et al. 1994, LÖFFLER 1998). The aim of the project is to characterize high mountain ecosystem structure, functioning and dynamics within small catchment areas, that are chosen in two different altitudinal belts each in the eastern continental and the western oceanic region of central Norway. In the frame of this research project hydrological and meteorological measurements on ground water, percolation and soil moisture dynamics as well as on evaporation, air humidity and air-, surface- and soil-temperatures have been conducted. On the basis of large-scaled landscape-ecological mappings (LÖFFLER 1997) one basic meteorological station and several major data logger run stations have been installed in representative sites of each two catchment areas in the low and mid alpine belts of the investigation re- gions (JUNG et al. 1997, LÖFFLER WUNDRAM 1997). Moreover, spatial differ- entiations of groundwater level, soil moisture and temperature profiles have been in- vestigated by means of hand held measurements at different times of the day, during different climatic situations and different seasons. Daily and annual air-, surface- and soil-temperature dynamics are demonstrated by means of thermoisopleth-diagrams for different types of

Extreme variation of sulfur isotopic compositions in pyrite from the Qiuling sediment-hosted gold deposit, West Qinling orogen, central China: An in situ SIMS study with implications for the source of sulfur

USGS Publications Warehouse

Chen, Lei; Li, Xian-hua; Li, Jian-wei; Hofstra, Albert H.; Liu, Yu; Koenig, Alan E.

2015-01-01

High spatial resolution textural (scanning electron microscope (SEM)), chemical (electron microprobe (EMP)) and laser ablation-inductively coupled plasma-mass spec- trometry (LA-ICP-MS)), and sulfur isotopic (secondary ion mass spectrometry (SIMS)) analyses of pyrite from the Qiuling sediment-hosted gold deposit (232±4 Ma) in the West Qinling orogen, central China were conducted to distinguish pyrite types and gain insights into the source and evolution of sulfur in hydrothermal fluids. The results reveal an enormous variation (−27.1 to +69.6‰) in sulfur isotopic composition of pyrite deposited during three paragenetic stages. Pre-ore framboidal pyrite, which is characterized by low concentra- tions of As, Au, Cu, Co, and Ni, has negative δ34S values of −27.1 to −7.6‰ that are interpreted in terms of bacterial re- duction of marine sulfate during sedimentation and diagenesis of the Paleozoic carbonate and clastic sequences, the predom- inant lithologies in the deposit area, and the most important hosts of many sediment-hosted gold deposits throughout the West Qinling orogen. The ore-stage hydrothermal pyrite con- tains high concentrations of Au, As, Cu, Sb, Tl, and Bi and hasa relatively narrow range of positive δ34S values ranging from +8.1 to +15.2‰. The sulfur isotope data are comparable to those of ore pyrite from many Triassic orogenic gold deposits and Paleozoic sedimentary exhalative (SEDEX) Pb-Zn de- posits in the West Qinling orogen, both being hosted mainly in the Devonian sequence. This similarity indicates that sulfur, responsible for the auriferous pyrite at Qiuling, was largely derived from the metamorphic devolatization of Paleozoic marine sedimentary rocks. Post-ore-stage pyrite, which is sig- nificantly enriched in Co and Ni but depleted in Au and As, has unusually high δ34S values ranging from +37.4 to +69.6 ‰, that are interpreted to result from thermochemical reduc- tion of evaporite sulfates in underlying Cambrian sedimentary

Aqueducts and geoglyphs : the response of Ancient Nasca to water shortages in the desert of Atacama (Peru)

NASA Astrophysics Data System (ADS)

Masini, Nicola; Lasaponara, Rosa

2016-04-01

origin of Nasca religious belief based on the worship of the mountain gods, in charge of the rain, and, therefore, related to the worship of water and fertility, including rituals which took place inside and outside Cahuachi pyramids (Orefici 2012; Masini et al. 2008; 2009) and over the famous geoglyphs (Orefici 2009; Reinhard 1988) Therefore, the response of Nasca to make liveable the desert was twofold, aimed at addressing the problem in its causes (climate), by religion, ritual and ceremonial activities, and in its effects, through the construction of aqueducts. The paper deals with the results from 3-year scientific and interdisciplinary investigations conducted by ITACA Mission (Masini et al. 2012) in Peru of CNR-IBAM and IMAA, in the Rio Nasca drainage basin. The main purpose of the investigations was the study of lost and functioning aqueducts using active and passive satellite data along with spatial analysis and geophysics (Cigna et al. 2013: Tapete et al. 2013). In particular, multitemporal analyses of satellite data were carried out in order to identify the different moisture content from upper to lower valley and the seasonal changes from one to another year. Geoelectrical prospecting along with geological investigations enabled us to characterize the table water and to study the hydrogeology of the investigated area. Finally, GIS and spatial analyses provided new information on the relationship between the puquios , settlement patterns and geoglyphs. References Cigna F., Tapete D., Lasaponara R., Masini N. 2013. Amplitude change detection with ENVISAT ASAR to image the cultural landscape of the Nasca region, Peru Archaeological Prospection, 20, 117-131, doi: 10.1002/arp.1451 Lasaponara R., Masini N. 2012a. Following the Ancient Nasca Puquios from Space, In: Lasaponara R., Masini N. (Eds) 2012, Satellite Remote Sensing: a new tool for Archaeology, Springer, Verlag Berlin Heidelberg, ISBN 978-90-481-8800-0, pp. 269-290, doi: 10

Mitigation of Atmospheric Errors in Differential InSAR Data Using a High-Resolution Weather Model, Mauna Loa and Kilauea volcanoes, Hawaii

NASA Astrophysics Data System (ADS)

Brooks, B. A.; Foster, J.; Cherubini, T.; Businger, S.; Miklius, A.; Mouginis-Mark, P.

2004-12-01

We investigate the utility of a mesoscale weather model for mitigating atmospheric errors in InSAR-derived displacement fields associated with volcanotectonic phenomena at Mauna Loa and Kilauea volcanoes on the Island of Hawaii. The MM5 (NCAR-Penn State Mesoscale Model Version 5) forecast is run twice daily for the island of Hawaii by the Mauna Kea Weather Center in support of Mauna Kea's astronomical observatories. MM5 has a 60-hour forecast window and the forecast fields are output in 3-hour increments. A high-resolution analysis that incorporates weather observations from National Weather Service and satellite-derived winds from the University of Wisconsin, provides the initial conditions for MM5. In turn, MM5 produces predictions of thermodynamic properties of the atmosphere, including temperature, pressure, and moisture fields at a 3 km horizontal resolution. The vertical resolution is density weighted with the greatest vertical resolution (10s of meters) near the surface. For any radar image acquisition there is a high-resolution 3D simulation of atmospheric water vapor valid within 1.5 hours of the acquisition time and predicted forward no more than 12 hours from the initial observations. Using MM5 forecast water vapor, we create line-of-sight delay maps that can be either directly removed from InSAR differential pairs or used to create synthetic radar interferograms that can be compared with the observed interferogram. We analyze Envisat ASAR radar data collected during 2003-2004 and find, qualitatively, that contours of excess path delay in MM5 model runs often closely mimic both topographic contours and fringes observed in differential interferograms which have had topographic phase removed. Over periods of days, the delays can vary in magnitude and spatial scale by 10s of mms and 10s of kms, respectively. Individual models can predict peak delays associated with moist layer inversions of order ~20 mm around the summits of Mauna Loa and Kilauea, both

The Applicability of Incoherent Array Processing to IMS Seismic Array Stations

NASA Astrophysics Data System (ADS)

Gibbons, S. J.

2012-04-01

The seismic arrays of the International Monitoring System for the CTBT differ greatly in size and geometry, with apertures ranging from below 1 km to over 60 km. Large and medium aperture arrays with large inter-site spacings complicate the detection and estimation of high frequency phases since signals are often incoherent between sensors. Many such phases, typically from events at regional distances, remain undetected since pipeline algorithms often consider only frequencies low enough to allow coherent array processing. High frequency phases that are detected are frequently attributed qualitatively incorrect backazimuth and slowness estimates and are consequently not associated with the correct event hypotheses. This can lead to missed events both due to a lack of contributing phase detections and by corruption of event hypotheses by spurious detections. Continuous spectral estimation can be used for phase detection and parameter estimation on the largest aperture arrays, with phase arrivals identified as local maxima on beams of transformed spectrograms. The estimation procedure in effect measures group velocity rather than phase velocity and the ability to estimate backazimuth and slowness requires that the spatial extent of the array is large enough to resolve time-delays between envelopes with a period of approximately 4 or 5 seconds. The NOA, AKASG, YKA, WRA, and KURK arrays have apertures in excess of 20 km and spectrogram beamforming on these stations provides high quality slowness estimates for regional phases without additional post-processing. Seven arrays with aperture between 10 and 20 km (MJAR, ESDC, ILAR, KSRS, CMAR, ASAR, and EKA) can provide robust parameter estimates subject to a smoothing of the resulting slowness grids, most effectively achieved by convolving the measured slowness grids with the array response function for a 4 or 5 second period signal. The MJAR array in Japan recorded high SNR Pn signals for both the 2006 and 2009 North Korea

Probabilistic Assessment of Soil Moisture using C-band Quad-polarized Remote Sensing Data from RISAT1

NASA Astrophysics Data System (ADS)

Pal, Manali; Suman, Mayank; Das, Sarit Kumar; Maity, Rajib

2017-04-01

estimated SMC. Supervised Principal Component Analysis (SPCA) is used for development of combined index and Frank copula is found to be the best-fit copula. The developed model is validated with the field soil moisture values over 334 monitoring points within the study area and used for development of a soil moisture map. While the performance is promising, the model is applicable only for bare and vegetated land. References: Pal, M., Maity, R., Suman, M., Das, S.K., Patel, P., and Srivastava, H.S., (2016). "Satellite-Based Probabilistic Assessment of Soil Moisture Using C-Band Quad-Polarized RISAT1 Data." IEEE Transactions on Geoscience and Remote Sensing, In Press, doi:10.1109/TGRS.2016.2623378. Zribi, M., Baghdadi, N., Holah, N., and Fafin, O., (2005)."New methodology for soil surface moisture estimation and its application to ENVISAT-ASAR multi-incidence data inversion." Remote Sensing of Environment, vol. 96, nos. 3-4, pp. 485-496.

Derivation of a northern-hemispheric biomass map for use in global carbon cycle models

NASA Astrophysics Data System (ADS)

Thurner, Martin; Beer, Christian; Santoro, Maurizio; Carvalhais, Nuno; Wutzler, Thomas; Schepaschenko, Dmitry; Shvidenko, Anatoly; Kompter, Elisabeth; Levick, Shaun; Schmullius, Christiane

2013-04-01

Quantifying the state and the change of the World's forests is crucial because of their ecological, social and economic value. Concerning their ecological importance, forests provide important feedbacks on the global carbon, energy and water cycles. In addition to their influence on albedo and evapotranspiration, they have the potential to sequester atmospheric carbon dioxide and thus to mitigate global warming. The current state and inter-annual variability of forest carbon stocks remain relatively unexplored, but remote sensing can serve to overcome this shortcoming. While for the tropics wall-to-wall estimates of above-ground biomass have been recently published, up to now there was a lack of similar products covering boreal and temperate forests. Recently, estimates of forest growing stock volume (GSV) were derived from ENVISAT ASAR C-band data for latitudes above 30° N. Utilizing a wood density and a biomass compartment database, a forest carbon density map covering North-America, Europe and Asia with 0.01° resolution could be derived out of this dataset. Allometric functions between stem, branches, root and foliage biomass were fitted and applied for different leaf types (broadleaf, needleleaf deciduous, needleleaf evergreen forest). Additionally, this method enabled uncertainty estimation of the resulting carbon density map. Intercomparisons with inventory-based biomass products in Russia, Europe and the USA proved the high accuracy of this approach at a regional scale (r2 = 0.70 - 0.90). Based on the final biomass map, the forest carbon stocks and densities (excluding understorey vegetation) for three biomes were estimated across three continents. While 40.7 ± 15.7 Gt of carbon were found to be stored in boreal forests, temperate broadleaf/mixed forests and temperate conifer forests contain 24.5 ± 9.4 Gt(C) and 14.5 ± 4.8 Gt(C), respectively. In terms of carbon density, most of the carbon per area is stored in temperate conifer (62.1 ± 20.7 Mg

Ground deformations along Ionian coastline of the northern Calabria (Southern Italy) from Capo Trionto to Capo Colonna detected by InSAR data

NASA Astrophysics Data System (ADS)

Vollrath, Andreas; Cianflone, Giuseppe; Bignami, Christian; Brunori, Carlo Alberto; Dominici, Rocco; Zucca, Francesco; Stramondo, Salvatore; Baldi, Paolo; Fabris, Massimo; Sepe, Vincenzo; Anzidei, Marco

2015-04-01

The study area is located along the Ionian coast of the northern Calabrian Arc, in correspondence of the Crotone and Spartivento fore-arc basins. The investigated coastal area represents the western margin of the Gulf of Taranto. The seafloor of this sector has been investigated by several authors during the last three decades and is characterized by numerous submarine depositional systems strictly related to main drainage basins which feed into the Ionian Sea. Northward, the area is limited by the Corigliano Canyon which connects the continental shelf with the Taranto Valley and separates the Cariati and Cirò Ridges. The latter is bounded, along its southern side, by the NW-SE trending Alice Canyon which reaches the inner continental shelf offshore Punta Alice and is not related to an onshore drainage system. Southward, the wide Neto-Lipuda Canyons system originates close to the coastline and is connected to the Neto and Lipuda Rivers. Toward South, this system is separated from the Esaro Canyon by the Luna-Hera Lacinia High. The southernmost canyon is connected to the Esaro River and runs subparallel to the coastline. Previous authors have been highlighted ground deformations, with sometimes associated km-long surface fractures and damages to buildings, in the Cirò coastal plain and in the area southward from Crotone. The cause of these deformation is attributed to megaslides. The multi-temporal (1958, 1985, 1998, 2008) analysis of the coastline variations shows a general erosive trend characterized by m and dm coastline retreats. We applied the multi-temporal StaMPS SBAS technique for two SAR datasets, one acquired from 2003 up to 2010 by Envisat ASAR instrument, and another from 1995 up to 2000 from the ERS satellite (ESA, European Space Agency) to investigate ground displacements in the studied coastal area. The Up component (recording the vertical ground deformation) allows to identify the main subsidence areas in correspondence of the Capo Colonna

Ocean Classification of Dynamical Structures Detected by SAR and Spectral Methods

NASA Astrophysics Data System (ADS)

Redondo, J. M.; Martinez-Benjamin, J. J.; Tellez, J. D.; Jorge, J.; Diez, M.; Sekula, E.

2016-08-01

We discuss a taxonomy of different dynamical features in the ocean surface and provide some eddy and front statistics, as well as describing some events detected by several satellites and even with additional cruise observations and measurements, in the North-west Mediterranean Sea area between 1996 and 2012. The structure of the flows are presented using self-similar traces that may be used to parametrize mixing at both limits of the Rossby Deformation Radius scale, RL. Results show the ability to identify different SAR signatures and at the same time provide calibrations for the different local configurations of vortices, spirals, Langmuir cells, oil spills and tensioactive slicks that eventually allow the study of the self-similar structure of the turbulence. Depending on the surface wind and wave level, and also on the fetch. the bathimetry, the spiral parameters and the resolution of vortical features change. Previous descriptions did not include the new wind and buoyancy features. SAR images also show the turbulence structure of the coastal area and the Regions of Fresh Water Influence (ROFI). It is noteworthy tt such complex coastal field-dependent behavior is strongly influenced by stratification and rotation of the turbulence spectrum is observed only in the range smaller than the local Rossby deformation radius, RL. The measures of diffusivity from buoy or tracer experiments are used to calibrate the behavior of different tracers and pollutants, both natural and man-made in the NW Mediterranean Sea. Thanks to different polarization and intensity levels in ASAR satellite imagery, these can be used to distinguish between natural and man-made sea surface features due to their distinct self-similar and fractal as a function of spill and slick parameters, environmental conditions and history of both oil releases and weather conditions. Eddy diffusivity map derived from SAR measurements of the ocean surface, performing a feature spatial correlation of the

Long-Term Monitoring of Water Dynamics in the Sahel Region Using the Multi-Sar

NASA Astrophysics Data System (ADS)

Bertram, A.; Wendleder, A.; Schmitt, A.; Huber, M.

2016-06-01

Fresh water is a scarce resource in the West-African Sahel region, seasonally influenced by droughts and floods. Particularly in terms of climate change, the importance of wetlands increases for flora, fauna, human population, agriculture, livestock and fishery. Hence, access to open water is a key factor. Long-term monitoring of water dynamics is of great importance, especially with regard to the spatio-temporal extend of wetlands and drylands. It can predict future trends and facilitate the development of adequate management strategies. Lake Tabalak, a Ramsar wetland of international importance, is one of the most significant ponds in Niger and a refuge for waterbirds. Nevertheless, human population growth increased the pressure on this ecosystem, which is now degrading for all uses. The main objective of the study is a long-term monitoring of the Lake Tabalak's water dynamics to delineate permanent and seasonal water bodies, using weather- and daytime-independent multi-sensor and multi-temporal Synthetic Aperture Radar (SAR) data available for the study area. Data of the following sensors from 1993 until 2016 are used: Sentinel-1A, TerraSARX, ALOS PALSAR-1/2, Envisat ASAR, RADARSAT-1/2, and ERS-1/2. All SAR data are processed with the Multi-SAR-System, unifying the different characteristics of all above mentioned sensors in terms of geometric, radiometric and polarimetric resolution to a consistent format. The polarimetric representation in Kennaugh elements allows fusing single-polarized data acquired by older sensors with multi-polarized data acquired by current sensors. The TANH-normalization guarantees a consistent and therefore comparable description in a closed data range in terms of radiometry. The geometric aspect is solved by projecting all images to an earth-fixed coordinate system correcting the brightness by the help of the incidence angle. The elevation model used in the geocoding step is the novel global model produced by the TanDEM-X satellite

Satellite observations of eddies in the Baltic, Black and Caspian seas

NASA Astrophysics Data System (ADS)

Karimova, S.

2012-04-01

In the present paper mesoscale and sub-mesoscale eddies in the Baltic, Black and Caspian seas are studied by means of satellite radiometer and radar images. Using these data makes it possible to investigate the vortical structures of a wide spatial range, from the basin scale through mesoscale to a small scale with a few kilometers in size. Over 2000 Envisat ASAR and ERS-2 SAR images with two-year time coverage (2009-2010) and spatial resolution of 75 m obtained in different parts of the Baltic, Black and Caspian Seas were applied to study submesoscale (with a diameter less than ca. 20 km) eddies in the basins mentioned. As a result of the analysis performed the role of different mechanisms (ones due to surfactant films, wave/current interactions and thermal fronts) in eddy visualization in SAR imagery was revealed. In every basin studied the main eddy characteristics such as number of eddies, frequency of their occurrence in SAR imagery, sign of vorticity, typical length scale and lifetime as well as spatial distribution patterns were investigated. Spatio-temporal parameters of the vortices were subjected to statistical analysis. Interannual and seasonal variabilities of the eddy parameters were traced. Hypotheses about the most important mechanisms of generation of the eddies observed were proposed. Among them there are barotropic, baroclinic and topographic instabilities, convection in the surface layer and heterogeneous wind forcing. Satellite infrared and visible images were used for retrieving statistical information on the Black Sea mesoscale vortical structures. The dataset used included ~5000 AVHRR NOAA Sea Surface Temperature (SST) images covering the entire Black Sea with time coverage since September, 2004 to December, 2010 and ~1500 MODIS Aqua (SST, normalized water-leaving radiance at 551 nm, chlorophyll-a concentration) images obtained in 2006-2010. Spatial resolution of the images was 1 km. Analysis performed revealed that numerous vortical

Characterising Passive Dosemeters for Dosimetry of Biological Experiments in Space (dobies)

NASA Astrophysics Data System (ADS)

Vanhavere, Filip; Spurny, Frantisek; Yukihara, Eduardo; Genicot, Jean-Louis

Introduction: The DOBIES (Dosimetry of biological experi-ments in space) project focusses on the use of a stan-dard dosimetric method (as a combination of differ-ent passive techniques) to measure accurately the absorbed doses and equivalent doses in biological samples. Dose measurements on biological samples are of high interest in the fields of radiobiology and exobiology. Radiation doses absorbed by biological samples must be quantified to be able to determine the relationship between observed biological effects and the radiation dose. The radiation field in space is very complex, con-sisting of protons, neutrons, electrons and high-energy heavy charged particles. It is not straightfor-ward to measure doses in this radiation field, cer-tainly not with only small and light passive doseme-ters. The properties of the passive detectors must be tested in radiation fields that are representative of the space radiation. We will report on the characterisation of different type of passive detectors at high energy fields. The results from such characterisation measurements will be applied to recent exposures of detectors on the International Space Station. Material and methods: Following passive detectors are used: • thermoluminescent detectors (TLD) • optically stimulated luminescence detectors (OSLD) • track etch detectors (TED) The different groups have participated in the past to the ICCHIBAN series of irradiations. Here protons and other particles of high energy were used to de-termine the LET-dependency of the passive detec-tors. The last few months, new irradiations have been done at the iThemba labs (100-200 MeV protons), Dubna (145 MeV protons) and the JRC-IRMM (quasi mono energetic neutrons up to 19 MeV). All these detectors were also exposed to a simulated space radiation field at CERN (CERF-field). Discussion: The interpretation of the TLD and OSLD results is done using the measured LET spectrum (TED) and the LET-dependency curves of ths TLD and OSLDs

Gas Cromatography In Solar System Exploration:decoding Complex Chromatograms Recovered From Space Missions

NASA Astrophysics Data System (ADS)

Pietrogrande, M. C.; Tellini, I.; Dondi, F.; Felinger, A.; Sternberg, R.; Szopa, C.; Vidal-Madjar, C.

compared. Also an independent procedure was used to estimate peak width, in order to validate the ob- tained results. The number of components present in the mixture and the peak width (related to separation efficiency) can be accurately estimated for the experimental chromatograms. Such information are useful to interpret data recovered from space 1 missions and to select the optimal analysis conditions compatible with flight con- straints. 1. C. Szopa et al., J. Chromatogr. A 2000, 904, 73. 2. M. C. Pietrogrande et al., J. Chromatogr. A, in press. 3. A. Felinger et al, Anal. Chem., 1990, 62, 1854. 4. A. Felinger et al, Anal. Chem., 1991, 63, 2627. 5. M. C. Pietrogrande et al., J. High Resol. Chromatogr. 1996, 19, 327. 6. F. Dondi et al, Chromatographia, 1997, 45, 435. 7. A. Felinger, M.C. Pietrogrande, Anal. Chem., 2001, 73, 618A. 2

Transmission Electron Microscopy of Itokawa Regolith Grains

NASA Technical Reports Server (NTRS)

Keller, Lindsay P.; Berger, E. L.

2013-01-01

Introduction: In a remarkable engineering achievement, the JAXA space agency successfully recovered the Hayabusa space-craft in June 2010, following a non-optimal encounter and sur-face sampling mission to asteroid 25143 Itokawa. These are the first direct samples ever obtained and returned from the surface of an asteroid. The Hayabusa samples thus present a special op-portunity to directly investigate the evolution of asteroidal sur-faces, from the development of the regolith to the study of the effects of space weathering. Here we report on our preliminary TEM measurements on two Itokawa samples. Methods: We were allocated particles RA-QD02-0125 and RA-QD02-0211. Both particles were embedded in low viscosity epoxy and thin sections were prepared using ultramicrotomy. High resolution images and electron diffraction data were ob-tained using a JEOL 2500SE 200 kV field-emission scanning-transmission electron microscope. Quantitative maps and anal-yses were obtained using a Thermo thin-window energy-dispersive x-ray (EDX) spectrometer. Results: Both particles are olivine-rich (Fo70) with µm-sized inclusions of FeS and have microstructurally complex rims. Par-ticle RA-QD02-0125 is rounded and has numerous sub-µm grains attached to its surface including FeS, albite, olivine, and rare melt droplets. Solar flare tracks have not been observed, but the particle is surrounded by a continuous 50 nm thick, stuctur-ally disordered rim that is compositionally similar to the core of the grain. One of the surface adhering grains is pyrrhotite show-ing a S-depleted rim (8-10 nm thick) with nanophase Fe metal grains (<5 nm) decorating the outermost surface. The pyrrhotite displays a complex superstructure in its core that is absent in the S-depleted rim. Particle RA-QD02-0211 contains solar flare particle tracks (2x109 cm-2) and shows a structurally disordered rim 100 nm thick. The track density corresponds to a surface exposure of 103-104 years based on the track production rate

From local to national scale DInSAR analysis for the comprehension of Earth's surface dynamics.

NASA Astrophysics Data System (ADS)

De Luca, Claudio; Casu, Francesco; Manunta, Michele; Zinno, Ivana; lanari, Riccardo

2017-04-01

of thousands of square kilometers wide, from ascending and descending orbits. The exploited SAR data are processed, on a local basis, through the Parallel SBAS (P-SBAS) approach thus generating the displacement time series and the corresponding mean deformation velocity maps. Subsequently, starting from the so generated DInSAR results, the proposed methodology lays on a proper mosaicking procedure to finally retrieve the mean velocity maps of the Vertical and Horizontal (East-West) deformation components relevant to the overall AoI. This technique permits to account for possible regional trends (tectonics trend) not easily detectable by the local scale DInSAR analyses. We tested the proposed methodology with the ENVISAT ASAR archives that have been acquired, from ascending and descending orbits, over California (US), covering an area of about 100.000 km2. The presented methodology can be easily applied also to other SAR satellite data. Above all, it is particularly suitable to deal with the very large data flow provided by the Sentinel-1 constellation, which collects data with a global coverage policy and an acquisition mode specifically designed for interferometric applications.

Multisensor satellite observations of meso- and submesoscale surface circulation in the Liguro-Provençal Basin

NASA Astrophysics Data System (ADS)

Karimova, Svetlana; Alvera-Azcarate, Aida

2017-04-01

Despite great efforts being paid to studying circulation of the Western Mediterranean Basin and the factors triggering bioproductivity of its marine ecosystem, the evidence provided by satellite imagery has not been fully analysed yet. In the present paper, we concentrate our attention on mesoscale and submesoscale circulation features of the Liguro-Provençal Basin captured by satellite radiometer, spectroradiometer, and radar images. Using such a dataset makes it possible to observe the circulation features from a wide spatial range, from the basin scale through mesoscale to the scales of a few kilometers. Mesoscale features in this study are being mostly observed with thermal infrared imagery retrieved by AVHRR and AATSR sensors. Special attention in the work was paid to an analysis of the data coming from a geostationary satellite, namely ones provided by SEVIRI. Due to their uniquely high temporal resolution, such imagery allows observing circulation features in their evolution. During the winter blooming events, surface circulation at meso- to submesoscales in the region of interest was additionally highlighted by images obtained in the visible range. Full spatial resolution images provided by Envisat MERIS, Sentinel-2 MSI, and Landsat TM/ETM+/OLI made the greatest contribution to this part. The smallest scales (namely submesoscale) are being observed with synthetic aperture radar (SAR) imagery provided by Envisat ASAR and Sentinel-1 SAR. During an analysis of SAR images, it was noted that there was strikingly great amount of biogenic surfactants on the water surface in the region of interest. Apparently, low biological productivity typical for the Western Mediterranean ecosystem is not a limiting factor for the formation of surfactant films seen in SAR imagery. This finding though requires further consideration in some other researches, and hereafter we just benefited from the presence of surfactants, because they behave as good tracers of surface currents

The ESA Geohazard Exploitation Platform

NASA Astrophysics Data System (ADS)

Bally, Philippe; Laur, Henri; Mathieu, Pierre-Philippe; Pinto, Salvatore

2015-04-01

expanded to address broader objectives of the geohazards community. In particular it is a contribution to the CEOS WG Disasters and its Seismic Hazards Pilot and terrain deformation applications of its Volcano Pilot. The geohazards platform is sourced with elements - data, tools, and processing- relevant to the geohazards theme and related exploitation scenarios. For example, platform provides access to large SAR data collections and services to support SAR Interferometry (InSAR), in particular the Persistent Scatterer Interferometry (PSI) and Small Baseline Subset (SBAS) techniques, to provide precise terrain deformation. The GEP includes data coming from the ENVISAT ASAR and ERS archives, already hosted in the ESA clusters and in ESA's Virtual Archive and further extended to cover the requirements of the CEOS Pilot on Seismic Hazards. The GEP is gradually accessing Sentinel-1A data alongside with EO data from other space agencies with an interest in the geohazard exploitation platform. Further to this, the platform is intended to be available in the framework of the European Plate Observing System (EPOS) initiative, in order to help its users exploit EO data to support solid Earth monitoring and geophysical and geological analysis.

Integration of Remote Sensing and other public GIS data source to identify suitable zones for groundwater exploitation by manual drilling

NASA Astrophysics Data System (ADS)

Fussi, Fabio; Fava, Francesco; Di Mauro, Biagio; Bonomi, Tullia; Fumagalli, Letizia; DI Leo, Margherita; Hamidou Kane, Cheik; Faye, Gayane; Niang, Magatte; Wade, Souleye; Hamidou, Barry; Colombo, Roberto

2015-04-01

In several countries of the world the situation of water supply is still critical, far from the international target defined by United Nations for 2015 (Millenium Development Goals) and producing a huge impact on health and living condition of the population. Manual drilling (it means techniques to drill boreholes for water using human or animal power) is well known and practiced for centuries in many countries. In recent years, it has been considered a potential strategy to increase water access in poor countries and has raised the attention of national governments and international organizations. Manual drilling is applicable only where hydrogeological context is suitable, according to the following conditions: thick layers of unconsolidated sediments and shallow water table. Mapping of zones with suitable hydrogeological context has been carried out in several countries in Africa, but the results have evident limitations; previous methods are based on existing direct data and qualitative experience, leading to unreliable interpretation when direct data are limited. This research aims to develop a methodology to estimate shallow hydrogeological features and asses the distribution of suitable zones for manual drilling through the integration of indirect information obtained from remote sensing and other existing source of data. The research is carried out in two different study areas, in Senegal and Guinea (Western Africa), with semi-arid climate, moderate vegetation cover, unconsolidated sandy and clay deposits overlaying sedimentary and igneous rocks A set of variables have been obtained through processing of three categories of data, listed below: - geology, geomorphology, soil and land cover, obtained from existing thematic maps; - vegetation phenology, apparent thermal inertia, and soil moisture, obtained from analysis of multitemporal optical (MOD13Q1), thermal (MOD11A1), and radar (ASAR) remotely sensed data: -morphometric parameters, obtained from public

Frontal Generation of Waves: A Geostrophic Adjustment Interpretation of The Observations

NASA Astrophysics Data System (ADS)

Blumen, W.; Lundquist, J. K.

motions and how much is associated with a geostrophically balanced state. It is not possible to separate waves from other types of motion from the observed energy spectrum, but there is evidence of a spectral peak in the range of 7 to 23 minutes in the 16 October energy spectrum. This peak is assumed to be associated with wave excitation by the frontal passage, although other types of motion may also be a contributors. A model calculation reveals that the energy con- tained in this spectral peak represents about 10 to 15 percent of the energy contained in the initial state (time t = 0). This result, although based on crude estimates of the 1 observed wave energy is, nevertheless, in general agreement with the prediction of geostrophic theory:a relatively small amount of energy is expected to be associated with relatively high-frequency, small-scale gravity waves. Additional details regard- ing the geostrophic adjustment interpretation of the observations will be presented in the talk. 2

Oxy-Component in low-Pressure Kaersutite: How Much can be a Primary Magmatic Feature?

NASA Astrophysics Data System (ADS)

McCubbin, F.; Nekvasil, H.; Lindsley, D. H.

2006-05-01

Introduction: The presence of an oxy-component in kaersutite has been well established [1]. Many workers have attributed this oxy-component to dehydration or dehydrogenation [1, 2]. However, it has also been suggested that the oxy-component can be a primary magmatic feature because of a Ti-oxy substitution mechanism [2, 3], although the exact mechanism has yet to be determined experimentally [3]. This work focuses on experimentally determining how much oxy-component can be incorporated into kaersutite (specifically F-kaersutite) as a primary magmatic feature at 0 kbar. Additionally, substitution mechanisms involving Ti-oxy substitutions are con-sidered. Experimental Procedure: Powdered mixes of oxides and CaF2 were used as starting materials. F2/O ratios were different for each starting material in hopes of creating kaersutites with specific oxy- components for each starting composition. The powders were loaded into Fe-capsules and dried at 800°C under vacuum in silica-glass tubes. Next the silica-glass tubes were sealed and placed in a Deltech furnace. The temperature within the furnace was raised above the melting temperature of the starting material and main-tained for 3 hours to allow for liquid equilibration. The tempera-ture was then lowered to a crystallization temperature and left for several days. Pressures of both melting and crystallization were nominally 0 kbar (tensile strength of silica glass tubes used is ~3 atm). The resulting phases were considered to be nomi-nally water-free. [Quenched glass experiments at these conditions yielded 0.0 wt% H2O as determined by micro-FTIR]. Ex-perimental run products were analyzed by electron-microprobe. Results: To date, experiments on a starting mate-rial with 3.55 wt% fluorine yielded kaersutite that had ~75 mol% F-component and ~25 mol% oxy-component (as-suming O(3) site stoichiometry). Experiments on a starting mate-rial with 0.89 wt% F yielded kaersutites ranging from ~55 mol% F- component and ~45 mol% Oxy

Robust GNSS and InSAR tomography of neutrospheric refractivity using a Compressive Sensing approach

NASA Astrophysics Data System (ADS)

Heublein, Marion; Alshawaf, Fadwa; Zhu, Xiao Xiang; Hinz, Stefan

2017-04-01

. The made-up ZWD values can be mapped into different elevation and azimuth angles. Moreover, using the same observation geometry as in the case of the GNSS and InSAR data, a synthetic set of SWD values was generated based on WRF simulations. Results: The CS approach shows particular strength in the case of a small number of SWD estimates. When compared to LSQ, the sparse reconstruction is much more robust. In the case of a low density of GNSS sites, adding InSAR SWD estimates improves the reconstruction accuracy for both LSQ and CS. Based on a synthetic SWD dataset generated using WRF simulations of wet refractivity, the CS based solution of the tomographic system is validated. In the vertical direction, the refractivity distribution deduced from GNSS and InSAR SWD estimates is compared to a tropospheric humidity data set provided by EUMETSAT consisting of daily mean values of specific humidity given on six pressure levels between 1000 hPa and 200 hPa. Study area: The Upper Rhine Graben (URG) characterized by negligible surface deformations is chosen as study area. A network of seven permanent GNSS receivers is used for this study, and a total number of 17 SAR images, acquired by ENVISAT ASAR is available.

Application of remote and in situ information to the management of wetlands in Poland.

PubMed

Dabrowska-Zielinska, Katarzyna; Gruszczynska, Maria; Lewinski, Stanislaw; Hoscilo, Agata; Bojanowski, Jedrzej

2009-05-01

The protection and regeneration of wetlands has been of crucial importance as a goal in ecological research and in nature conservation for some time and is more important than ever now. Knowledge about the biophysical properties of wetlands' vegetation retrieved from satellite images enables us to improve the monitoring of these unique areas, which are otherwise very often impenetrable and therefore difficult to examine, analyze and assess by means of site visits. The Biebrza Wetlands are situated in the North-East part of Poland and are one of the largest areas made up of marshes and swamps in the entire EU. This is still one of the wildest areas and one of the least destroyed, damaged or changed by human impact. However, in the recent decades there have been attempts made to intensify and overexploit the natural resources of the region and implement new agriculture practices in the area. In this period, drainage canals have been built, and a good deal of the area has been drained. The area of this precious ecosystem covers 25 494 ha. This valuable area of peat with unique vegetation species and with very special birds is one of the most valuable areas in Europe and in 1995 was added to the list of Ramsar sites. The investigation of wetlands in the Biebrza River Valley has been carried out at ground level by taking measurements of soil moisture, evapotranspiration, Leaf Area Index, wet and dry biomass and the levels of ground water and meteorological parameters. Also examined were radiative temperature, detailed vegetation mapping, and APAR. For some years the deterioration of peat lands has been noticed due to the drying out of the area and the frequent outbreak of fires. The consequence is the succession of new vegetation and the appearance of new ecosystems. The Remote Sensing Centre in the Institute of Geodesy and Cartography has undertaken the investigation by applying ERS-2.SAR and ENVISAT ASAR of IS2 and IS4 and VV, HH, HV polarization for the purpose of

GENESI-DR: Discovery, Access and on-Demand Processing in Federated Repositories

NASA Astrophysics Data System (ADS)

Cossu, Roberto; Pacini, Fabrizio; Parrini, Andrea; Santi, Eliana Li; Fusco, Luigi

2010-05-01

GENESI-DR (Ground European Network for Earth Science Interoperations - Digital Repositories) is a European Commission (EC)-funded project, kicked-off early 2008 lead by ESA; partners include Space Agencies (DLR, ASI, CNES), both space and no-space data providers such as ENEA (I), Infoterra (UK), K-SAT (N), NILU (N), JRC (EU) and industry as Elsag Datamat (I), CS (F) and TERRADUE (I). GENESI-DR intends to meet the challenge of facilitating "time to science" from different Earth Science disciplines in discovery, access and use (combining, integrating, processing, …) of historical and recent Earth-related data from space, airborne and in-situ sensors, which are archived in large distributed repositories. In fact, a common dedicated infrastructure such as the GENESI-DR one permits the Earth Science communities to derive objective information and to share knowledge in all environmental sensitive domains over a continuum of time and a variety of geographical scales so addressing urgent challenges such as Global Change. GENESI-DR federates data, information and knowledge for the management of our fragile planet in line with one of the major goals of the many international environmental programmes such as GMES, GEO/GEOSS. As of today, 12 different Digital Repositories hosting more than 60 heterogeneous dataset series are federated in GENESI-DR. Series include satellite data, in situ data, images acquired by airborne sensors, digital elevation models and model outputs. ESA has started providing access to: Category-1 data systematically available on Internet; level 3 data (e.g., GlobCover map, MERIS Global Vegetation Index); ASAR products available in ESA Virtual Archive and related to the Supersites initiatives. In all cases, existing data policies and security constraints are fully respected. GENESI-DR also gives access to Grid and Cloud computing resources allowing authorized users to run a number of different processing services on the available data. The GENESI

Assessing Feasibility and Acceptability of Web-Based Enhanced Relapse Prevention for Bipolar Disorder (ERPonline): A Randomized Controlled Trial.

PubMed

Lobban, Fiona; Dodd, Alyson L; Sawczuk, Adam P; Asar, Ozgur; Dagnan, Dave; Diggle, Peter J; Griffiths, Martin; Honary, Mahsa; Knowles, Dawn; Long, Rita; Morriss, Richard; Parker, Rob; Jones, Steven

2017-03-24

was no evidence of impact of ERPonline on clinical outcomes or medication adherence, but relapse rates across both arms were low (15%) and the sample remained high functioning throughout. One person died by suicide before randomization and 5 people in ERPonline and 6 in WL reported ideas of suicide or self-harm. None were deemed study related by an independent Trial Steering Committee (TSC). ERPonline offers a cheap accessible option for people seeking ongoing support following successful treatment. However, given high functioning and low relapse rates in this study, testing clinical effectiveness for this population would require very large sample sizes. Building in human support to use ERPonline should be considered. International Standard Randomized Controlled Trial Number (ISRCTN): 56908625; http://www.isrctn.com/ISRCTN56908625 (Archived by WebCite at http://www.webcitation.org/6of1ON2S0). ©Fiona Lobban, Alyson L Dodd, Adam P Sawczuk, Ozgur Asar, Dave Dagnan, Peter J Diggle, Martin Griffiths, Mahsa Honary, Dawn Knowles, Rita Long, Richard Morriss, Rob Parker, Steven Jones. Originally published in the Journal of Medical Internet Research (http://www.jmir.org), 24.03.2017.

Space-borne polarimetric SAR sensors or the golden age of radar polarimetry

NASA Astrophysics Data System (ADS)

Pottier, E.

2010-06-01

SAR Polarimetry represents an active area of research in Active Earth Remote Sensing. This interest is clearly supported by the fact that nowadays there exists, or there will exist in a very next future, a non negligible quantity of launched Polarimetric SAR Spaceborne sensors. The ENVISAT satellite, developed by ESA, was launched on March 2002, and was the first Spaceborne sensor offering an innovative dualpolarization Advanced Synthetic Aperture Radar (ASAR) system operating at C-band. The second Polarimetric Spaceborne sensor is ALOS, a Japanese Earth-Observation satellite, developed by JAXA and was launched in January 2006. This mission includes an active L-band polarimetric radar sensor (PALSAR) whose highresolution data may be used for environmental and hazard monitoring. The third Polarimetric Spaceborne sensor is TerraSAR-X, a new German radar satellite, developed by DLR, EADS-Astrium and Infoterra GmbH, was launched on June 2007. This sensor carries a dual-polarimetric and high frequency X-Band SAR sensor that can be operated in different modes and offers features that were not available from space before. At least, the Polarimetric Spaceborne sensor, developed by CSA and MDA, and named RADARSAT-2 was launched in December 2007 The Radarsat program was born out the need for effective monitoring of Canada’s icy waters, and some Radarsat-2 capabilities that benefit sea- and river ice applications are the multi-polarization options that will improve ice-edge detection, ice-type discrimination and structure information. The many advances in these different Polarimetric Spaceborne platforms were developed to respond to specific needs for radar data in environmental monitoring applications around the world, like : sea- and river-ice monitoring, marine surveillance, disaster management, oil spill detection, snow monitoring, hydrology, mapping, geology, agriculture, soil characterisation, forestry applications (biomass, allometry, height…), urban mapping etc�

Calibration of 2D Hydraulic Inundation Models with SAR Imagery in the Floodplain Region of the Lower Tagus River

NASA Astrophysics Data System (ADS)

Pestana, Rita; Matias, Magda; Canelas, Ricardo; Roque, Dora; Araujo, Amelia; Van Zeller, Emilia; Trigo-Teixeira, Antonio; Ferreira, Rui; Oliveira, Rodrigo; Heleno, Sandra; Falcão, Ana Paula; Gonçalves, Alexandre B.

2014-05-01

for the different land cover classes. Flood extent maps, derived from satellite-born Synthetic Aperture Radar (SAR), namely ERS SAR and ENVISAT ASAR imagery, provided the spatially distributed data needed for the calibration of the hydraulic models for the several floods. The flood extent maps obtained for each simulation were then compared with the flood extent maps derived from SAR imagery for each flood and the roughness coefficients changed accordingly. The models were also calibrated in terms of the stage at the gauging station Almourol, located 12km downriver from Tramagal. The combination of the calibration results for the several past floods provided 100 meters resolution Manning coefficient maps of the study area. An application of the obtained calibrated Manning coefficient maps was made for the largest flood of the 20th century (February 1979), for which no SAR imagery was available. In this case validation of the model was made in terms of the stage at the gauging station Almourol and at flood stage marks distributed throughout the floodplain.

Insight into the radiotolerance of the life support bacterium Rhodospirillum rubrum S1H by means of phenotypic and transcriptomic methods

NASA Astrophysics Data System (ADS)

Mastroleo, Felice; Monsieurs, Pieter; Leys, Natalie

The MELiSSA life support system from the European Space Agency is targeting the produc-tion of oxygen, water and food by recycling organic waste. Among different types of pro-cesses, MELiSSA uses several interconnected bioreactors inhabited by microorganisms and higher plants (Hendrickx et al., 2006; Mergeay et al., 1988). Because this loop is foreseen to be functional in space where it will be exposed to higher doses and different spectra of ionizing radiation, it was decided to screen the radiotolerance of the organisms used. In this study, the radiotolerance (i.e. tolerance to ionizing radiation) of the photosynthetic bacterium Rho-dospirillum rubrum S1H was investigated. In this test, first the effect of low energy Cobalt-60 gamma rays, were tested. To assess the radiotolerance of bacterium S1H, the survival rate after increasing exposure was determined. R. rubrum S1H appeared relatively radiosensitive, as the radiation dose at which 90% of the population was killed (D10 value) was 4 times lower than the model bacterium Escherichia coli. It was demonstrate that the culture medium has an impact on radiation tolerance. This survival curve also permitted to select a number of sub-lethal ionizing radiation doses (¡ D10 ), that were used to analyze the gene expression response of R. rubrum S1H after gamma irradiation. The microarray transcriptome analysis results ob-tained from different doses and different culture medium showed a significant response of the bacterium to sublethal doses. Potential marker genes for ionizing radiation stress in R. rubrum S1H were identified. By quantitative PCR, it was shown that the expression of these marker genes increased with the recovery time after exposure to ionizing radiation. In other words, the radiation tolerance and the response of R. rubrum S1H to low energy Cobalt-60 gamma ionizing radiation was characterized. Therefore to ensure MELiSSA process robustness during extended space exploration mission, it is advised that

Summer Sea ice in the Pacific Arctic sector from the CHINARE-2010 cruise

NASA Astrophysics Data System (ADS)

Ackley, S. F.; Xie, H.; Lei, R.; Huang, W.; Chinare 2010 Arctic Sea Ice Group

2010-12-01

The Fourth Chinese National Arctic Research Expedition (CHINARE) from July 1 to Sep. 23, 2010, the last Chinese campaign in Arctic Ocean contributing to the fourth International Polar Year (IPY), conducted comprehensive scientific studies on ocean-ice-atmosphere interaction and the marine ecosystem’s response to climatic change in Arctic. This paper presents an overview on sea ice (ice concentration, floe size, melt pond coverage, sea ice and snow thickness) of the Pacific Arctic sector, in particular between 150°W to 180°W to 86°N, based on: (1) underway visual observations of sea ice at half-hourly and automatic cameras recording (both side looking from the icebreaker R.V. Xuelong) every 10 to 15 seconds; (2) a downward-looking video mounted on the left side of the vessel at a height of 7 m above waterline recording overturning of ice floes; (3) on-site measurements of snow and ice thickness using drilling and electromagnetic instrument EM31 (9.8 kHz) at eight short-term (~3 hours each) and one 12-day ice stations; (4) six flights of aerial photogrammetry from helicopter, and (5) Satellite data (AMSE-E ice concentration and ENVISAT ASAR) and NIC ice charts) that extended the observations/measurements along beyond the ship track and airborne flights. In the northward leg, the largest ice concentration zone was in the area starting from ~75°N (July 29), with ice concentration of 60-90% (mean ~80%), ice thickness of 1.5-2m, melt ponds of 10-50% of ice, ridged ice of 10-30% of ice, and floe size of 100’s meters to kms. The 12-day ice station (from Aug 7-19), started at 86.92°N/178.88°W and moved a total of 175.7km, was on an ice floe over 100 km2 in size and ~2 m in mean thickness. There were two heavy and several slight snowfall events in the period (July 29 to Aug 19). Snow thickness varies from 5cm to 15 cm, and melted about 5cm during the 12-day ice camp. In the southward leg, the largest sea ice concentration zone was in the area between 87°N to 80�

Persistent Scatterer InSAR monitoring of Bratislava urban area

NASA Astrophysics Data System (ADS)

Bakon, Matus; Perissin, Daniele; Papco, Juraj; Lazecky, Milan

2014-05-01

) technique, covering the target area with 57 Envisat ASAR images from Ascending Track No. 229 (32) and Descending Track No. 265 (25) captured between years 2002 and 2010. Processing involves Sarproz (Copyright (c) 2009 Daniele Perissin) a powerful software solution for obtaining differential interferograms and performing PSInSAR methodology. The area of interest to investigate the deformation phenomena is covering approximately 16 by 16 kilometers (256 sqkm). For evaluation of PSInSAR potential to detect and monitor ground displacements, PS derived time series of deformation signal were compared to the field GNSS data from three GNSS stations coded PIL1, BRAT and GKU4. By the detailed look on the deformation maps the investigated urban area of Bratislava is relatively stable with the deformation rates within the few (±5) millimeters. The comparison of PSInSAR derived time series with GNSS data indicates good correlation and confirms achievable precision and applicability of InSAR measurements for ground stability monitoring purposes. Data for this work were provided by European Space Agency within the Category-1 project ID 9981: "Detection of ground deformation using radar interferometry techniques". The authors are grateful to the Tatrabanka Foundation and The National Scholarship Programme of the Slovak Republic for the opportunity to work together. Data have been processed by the Sarproz (Copyright (c) 2009 Daniele Perissin) and visualised in Google Earth. This paper is also the result of the implementation of the project: the National Centre of Earth's Surface Deformation Diagnostic in the area of Slovakia, ITMS 26220220108 supported by the Research and Development Operational Programme funded by the ERDF and the grant No. 1/0642/13 of the Slovak Grant Agency VEGA.

Towards monitoring of geohazards with ESA's Sentinel-1 C-band SAR data: nationwide feasibility mapping over Great Britain calibrated using ERS-1/2 and ENVISAT PSI data

NASA Astrophysics Data System (ADS)

Cigna, Francesca; Bateson, Luke; Dashwood, Claire; Jordan, Colm

2013-04-01

the major limitation over most of Britain, and areas of layover and shadow for each satellite mode do not exceed 1% of the entire landmass. Although the results from the landuse feasibility mapping confirm that landcover has stronger control on the potential of these technologies over Britain, the overall number of monitoring targets that might be identified over the entire landmass for each acquisition mode exceeds 12.8M. Based on the results of the feasibility mapping, we identified three categories of landsliding in Britain, over which we will carry out SAR-based ground motions studies with ERS-1/2 SAR and ENVISAT ASAR data covering the past 20 years, based on combination of change detection, SAR Interferometry (InSAR), PSI and Small Baseline (SBAS) approaches. Selected test sites include South Wales Coalfield, the Cotswold Escarpment, the Pennines, the North York Moors, as well as landsliding affecting transport/infrastructure and coastal sites in eastern and southern England. The results of our study act as milestones for future SAR applications and operational uses for a wide range of geohazards in Britain, including landslides, land subsidence/uplift due to groundwater abstraction/recharge, shrink-swell clays, as well as structural deformation of critical infrastructure, and show the potential of future nationwide monitoring of the entire landmass with the new Earth explorers of the Sentinel-1 constellation. Reference: Cigna F., Bateson L., Jordan C., Dashwood C. (2012), Feasibility of InSAR technologies for nationwide monitoring of geohazards in Great Britain. Remote Sensing and Photogrammetry Society Annual Conference, RSPSoc 2012, Greenwich (UK), 12-14 September 2012. Available at: http://nora.nerc.ac.uk/19876/

DInSAR time series generation within a cloud computing environment: from ERS to Sentinel-1 scenario

NASA Astrophysics Data System (ADS)

Casu, Francesco; Elefante, Stefano; Imperatore, Pasquale; Lanari, Riccardo; Manunta, Michele; Zinno, Ivana; Mathot, Emmanuel; Brito, Fabrice; Farres, Jordi; Lengert, Wolfgang

2013-04-01

requests of processing resources linked to disaster events. This work aims at presenting a parallel computational model for the widely used DInSAR algorithm named as Small BAseline Subset (SBAS), which has been implemented within the cloud computing environment provided by the ESA-CIOP platform. This activity has resulted in developing a scalable, unsupervised, portable, and widely accessible (through a web portal) parallel DInSAR computational tool. The activity has rewritten and developed the SBAS application algorithm within a parallel system environment, i.e., in a form that allows us to benefit from multiple processing units. This requires the devising a parallel version of the SBAS algorithm and its subsequent implementation, implying additional complexity in algorithm designing and an efficient multi processor programming, with the final aim of a parallel performance optimization. Although the presented algorithm has been designed to work with Sentinel-1 data, it can also process other satellite SAR data (ERS, ENVISAT, CSK, TSX, ALOS). Indeed, the performance analysis of the implemented SBAS parallel version has been tested on the full ASAR archive (64 acquisitions) acquired over the Napoli Bay, a volcanic and densely urbanized area in Southern Italy. The full processing - from the raw data download to the generation of DInSAR time series - has been carried out by engaging 4 nodes, each one with 2 cores and 16 GB of RAM, and has taken about 36 hours, with respect to about 135 hours of the sequential version. Extensive analysis on other test areas significant from DInSAR and geophysical viewpoint will be presented. Finally, preliminary performance evaluation of the presented approach within the Sentinel-1 scenario will be provided.

Programmatic overview of GMES Space Component and implementation status

NASA Astrophysics Data System (ADS)

Aschbacher, Josef; Milagro, Maria Pilar

2010-05-01

provide almost 10 times the data obtained by Envisat's ASAR instrument. A pair of Sentinel-2 satellites will routinely provide high resolution (10-60 m) optical images globally with frequent revisits tailored to the needs of GMES land and emergency services. Sentinel-2 aims at ensuring continuity of SPOT and LANDSAT type data, with improvements to allow service evolution. A pair of Sentinel-3 satellites will provide global near real time ocean, ice and land monitoring. It continues observations of ERS, Envisat and SPOT/Vegetation. Sentinel 4 and 5 will be dedicated to monitor atmospheric trace gases from geostationary and low Earth orbit respectively. A Sentinel-5 precursor satellite will be launched at the end of 2014 to fill the gap until the arrival of Sentinel-5 on board post-EPS. The Contributing Missions are satellite missions operated by national agencies or commercial entities of Member States, EUMETSAT or other third parties, which do not replace nor duplicate the capacities of the dedicated Sentinel missions but rather complement them. The GMES data will feed the different services: Land, Marine, Atmosphere, Emergency and Security. Data from the former 3 services will also feed Climate Change applications. Some of these services will become fully operational in the next years. As part of the ESA led GMES Space Component, ESA and the EC are working together to define the principles and implementation scheme of the Sentinel Data Policy. The new data policy aims at providing free-of-charge access to all Sentinel data, both for public, commercial and scientific use. These "free and open" data policy principles have been approved by ESA Member States. EU approval is expected in the course of 2010.

A novel multi-temporal approach to wet snow retrieval with Sentinel-1 images (Conference Presentation)

NASA Astrophysics Data System (ADS)

Marin, Carlo; Callegari, Mattia; Notarnicola, Claudia

2016-10-01

by training the proposed method with examples extracted by [1] and refine this information by deriving additional training for the complex cases where the state-of-the-art algorithm fails. In addition, the multi-temporal information is fully exploited by modelling it as a series of statistical moments. Indeed, with a proper time sampling, statistical moments can describe the shape of the probability density function (pdf) of the backscattering time series ([3-4]). Given the description of the shape of the multi-temporal VV and VH backscattering pdfs, it is not necessary to explicitly identify which time instants in the time series are to be assigned to the reference image as done in the bi-temporal approach. This information is implicit in the shape of the pdf and it is used in the training procedure for solving the wet snow detection problem based on the available training samples. The proposed approach is designed to work in an alpine environment and it is validated considering ground truth measurements provided by automatic weather stations that record snow depth and snow temperature over 10 sites deployed in the South Tyrol region in northern Italy. References: [1] Nagler, T.; Rott, H., "Retrieval of wet snow by means of multitemporal SAR data," in Geoscience and Remote Sensing, IEEE Transactions on , vol.38, no.2, pp.754-765, Mar 2000. [2] Storvold, R., Malnes, E., and Lauknes, I., "Using ENVISAT ASAR wideswath data to retrieve snow covered area in mountainous regions", EARSeL eProceedings 4, 2/2006 [3] Inglada, J and Mercier, G., "A New Statistical Similarity Measure for Change Detection in Multitemporal SAR Images and Its Extension to Multiscale Change Analysis," in IEEE Transactions on Geoscience and Remote Sensing, vol. 45, no. 5, pp. 1432-1445, May 2007. [4] Bujor, F., Trouve, E., Valet, L., Nicolas J. M., and Rudant, J. P., "Application of log-cumulants to the detection of spatiotemporal discontinuities in multitemporal SAR images," in IEEE Transactions on

Spatial distribution of soil moisture obtained from gravimetric and TDR methods for SMOS validation, at the Polesie test site SVRT 3275, in Poland

NASA Astrophysics Data System (ADS)

Usowicz, B.; Marczewski, W.; Lipiec, J.; Usowicz, J. B.; Sokolowska, Z.; Dabkowska-Naskret, H.; Hajnos, M.; Lukowski, M. I.

2009-04-01

The purpose is obtaining trustful ground based measurement data of SM (Soil Moisture) for validating SMOS, respectively to spatial and temporal distribution and variations. A use of Time Domain Reflectometric (TDR) method is fast, simple and less destructive, to the soil matter, than a usual standard gravimetric method. TDR tools operate efficiently, enable nearly instant measurements, and allow on collecting many measurements from numerous sites, even when operated manually in short time intervals. The method enables also very frequent sampling of SM at few selected fixed sites, when long terms of temporal variations are needed. In effect one obtains reasonably large data base for determining spatial and temporal distributions of SM. The study is devoted to determining a plan on collecting TDR data, in the scales of small and large field areas, and checking their relevance to those available from gravimetric methods. Finally, the ground based SM distributions are needed for validating other SM distributions, available remotely in larger scales, from the satellite data of ENVISAT-ASAR, and from SMOS (Soil Moisture and Ocean Salinity Mission) when it becomes operational. The ground based evaluations are served mainly by geo-statistical analysis. The space borne estimations are retrieved by image processing and physical models, proper to relevant Remote Sensing (RS) instruments on the orbit. Finally, validation must engage again the geo-statistical evaluations, to assess the agreement between direct and remote sensing means, and provide a measure of trust for extending the limited scales of the ground based data, on concluding the agreement in scales proper to the satellite data. The study is focused mainly on trustful evaluating data from the ground, provided independently on satellite data sources. SM ground based data are collected permanently at 2 selected tests sites, and temporary in areas around the tests sites, in one day sessions, repeated several times per

e-Infrastuctures interoperability: the Geohazards Exploitation Platform for the use of satellite earth observations in Geosciences

NASA Astrophysics Data System (ADS)

Caumont, Herve; Brito, Fabrice; Mathot, Emmanuel; Barchetta, Francesco; Loeschau, Frank

2015-04-01

We present recent achievements with the Geohazards Exploitation Platform (GEP), a European contribution to the GEO SuperSites, and its interoperability with the MEDiterranean SUpersite Volcanoes (MED-SUV) e- infrastructure. The GEP is a catalyst for the use of satellite Earth observation missions, providing data to initiatives such as the GEO Geohazard Supersites and Natural Laboratories (GSNL), the Volcano and Seismic Hazards CEOS Pilots or the European Plate Observing System (EPOS). As satellite sensors are delivering increasing amounts of data, researchers need more computational science tools and services. The GEP contribution in this regard allows scientists to access different data types, relevant to the same area and phenomena and to directly stage selected inputs to scalable processing applications that deliver EO-based science products. With the GEP concept of operation for improved collaboration, a partner can bring its processing tools, use from his workspace other shared toolboxes and access large data repositories. GEP is based on Open Source Software components, on a Cloud Services architecture inheriting a range of ESA and EC funded innovations, and is associating the scientific community and SMEs in implementing new capabilities. Via MED-SUV, we are making discoverable and accessible a large number of products over the Mt. Etna, Vesu- vius/Campi Flegrei volcanic areas, which are of broader interest for Geosciences researchers, so they can process ENVISAT MERIS, ENVISAT ASAR, and ERS SAR data (both Level 1 and Level 2) hosted in the ESA clusters and in ESA's Virtual Archive, TerraSAR-X data hosted in DLR's Virtual Archive, as well as data hosted in other dedicated MED-SUV Virtual Archives (e.g. for LANDSAT, EOS-1). GEP will gradually access Sentinel-1A data, other space agencies data and value-added products. Processed products can also be published and archived on the MED-SUV e-Infrastructure. In this effort, data policy rules applied to the

Large networks of artificial radar reflectors to monitor land subsidence in natural lowlying coastal areas

NASA Astrophysics Data System (ADS)

Tosi, Luigi; Strozzi, Tazio; Teatini, Pietro

2014-05-01

Deltas, lagoons, estuaries are generally much prone to land subsidence. They are also very sensitive to land lowering due to their small elevation with respect to the mean sea level, also in view of the expected eustatic sea rise due to climate changes. Land subsidence can be presently monitored with an impressive accuracy by Persistent Scatterer Interferometry (PSI) on the large megacities that are often located on lowlying coastlands, e.g., Shanghai (China) on the Yangtze River delta, Dhaka (Bangladesh) on the Gange River delta, New Orleans (Louisiana) on the Mississippi river delta. Conversely, the land movements of the portions of these transitional coastlands where natural environments still persist are very challenging to be measured. The lack of anthropogenic structures strongly limits the use of PSI and the difficult accessibility caused by the presence of marshlands, tidal marshes, channels, and ponds yield traditional methodologies, such as levelling and GPS, both time-consuming and costly. In this contribution we present a unique experimental study aimed at using a large network of artificial radar reflectors to measure land subsidence in natural coastal areas. The test site is the 60-km long, 10-15 km wide lagoon of Venice, Italy, where previous PSI investigations revealed the lack of radar reflectors in large portions of the northern and southern lagoon basins (e.g., Teatini et al., 2011). A network of 57 trihedral corner reflectors (TCRs) were established between the end of 2006 and the beginning of 2007 and monitored by ENVISAT ASAR and TerraSAR-X acquisitions covering the time period from 2007 to 2011 (Strozzi et al., 2012). The application has provided general important insights on the possibility of controlling land subsidence using this approach. For example: (i) relatively small-size (from 0.5 to 1.0 m edge length) and cheap (few hundred euros) TCRs suffice to be clearly detectable from the radar sensors because of the low backscattering

Stability and subsidence across Rome (Italy) in 2011-2013 based on COSMO-SkyMed Persistent Scatterer Interferometry

NASA Astrophysics Data System (ADS)

Francesca, Cigna; Lasaponara, Rosa; Nicola, Masini; Pietro, Milillo; Deodato, Tapete

2015-04-01

Ground stability of the built environment of the city of Rome in central Italy has been extensively investigated in the last years by using Interferometric Synthetic Aperture Radar (InSAR), with focus on deformation of both the monuments of the historic centre (e.g., [1-2]) and the southern residential quarters (e.g., [3]). C-band ERS-1/2 and ENVISAT ASAR time series deformation analyses brought evidence of overall stability across the town centre, except for localized deformation concentrated in areas geologically susceptible to instability (e.g. western slope of the Palatine Hill), whereas clear subsidence patterns were detected over the compressible alluvial deposits lying in proximity of the Tiber River. To retrieve an updated picture of stability and subsidence across the city, we analysed a time series of 32 COSMO-SkyMed StripMap HIMAGE, right-looking, ascending mode scenes with an image swath of 40 km, 3-m resolution and HH polarization, acquired between 21 March 2011 and 10 June 2013, with repeat cycle mostly equal to 16 days. Persistent Scatterer Interferometry (PSI) processing was undertaken by using the Stanford Method for Persistent Scatterers (StaMPS) as detailed in [4], and more than 310,000 radar targets (i.e. PS) were identified, with an average target density of over 2,800 PS/km2. The performance of StaMPS to retrieve satisfactory PS coverage over the urban features of interest was assessed against their orientation and visibility to the satellite Line-Of-Sight, as well as their conservation history throughout the biennial investigated (2011-2013). In this work we discuss effects due to local land cover and land use by exploiting the Global Monitoring for Environment and Security (GMES) European Urban Atlas (IT001L) of Rome at 1:10,000 scale, thereby also evaluating the capability of the X-band to spatially resolve targets coinciding with man-made structures in vegetated areas. Based on this assessment, our PSI results highlight those environmental

Assimilation of Sentinel-1 estimates of Precipitable Water Vapor (PWV) into a Numerical Weather Model for a more accurate forecast of extreme weather events

NASA Astrophysics Data System (ADS)

Mateus, Pedro; Nico, Giovanni; Catalao, Joao

2017-04-01

In the last two decades, SAR interferometry has been used to obtain maps of Precipitable Water Vapor (PWV).This maps are characterized by their high spatial resolution when compared to the currently available PWV measurements (e.g. GNSS, radiometers or radiosondes). Several previous works have shown that assimilating PWV values, mainly derived from GNSS observations, into Numerical Weather Models (NWMs) can significantly improve rainfall predictions.It is noteworthy that the PWV-derived from GNSS observations have a high temporal resolution but a low spatialone. In addition, there are many regions without any GNSS stations, where temporal and spatial distribution of PWV areonly available through satellite measurements. The first attempt to assimilate InSAR-derived maps of PWV (InSAR-PWV) into a NWM was made by Pichelli et al. [1].They used InSAR-PWV maps obtained from ENVISAT-ASAR images and the mesoscale weather prediction model MM5 over the city of Rome, Italy. The statistical indices show that the InSAR-PWVdata assimilation improves the forecast of weak to moderateprecipitation (< 15 mm/3-h). The second and last attempt, was performed by Mateus et al. [2]. They used the same satellite mission and the Weather Research and Forecast (WRF) model over the city of Lisbon, Portugal, during a light rain event not forecast by the model.Results showed that after data assimilation, there is a bias correction of the PWV field and an improvement in the forecast of the weakto moderate rainfall up to 9 h after the assimilation time. We used, for the first time, the Weather Research and Forecast Data Assimilation (WRFDA) model, at micro-scale resolutions (3 km), over the Iberian Peninsula (focusing on the southern region of Spain) and during a convective cell associated with a local heavy rainfall event, to study the impact of assimilation PWV maps obtained from SAR interferometric phase calculated using images acquired by the Sentinel-1 satellite. It's worth noting that, in

GlobVolcano pre-operational services for global monitoring active volcanoes

NASA Astrophysics Data System (ADS)

Tampellini, Lucia; Ratti, Raffaella; Borgström, Sven; Seifert, Frank Martin; Peltier, Aline; Kaminski, Edouard; Bianchi, Marco; Branson, Wendy; Ferrucci, Fabrizio; Hirn, Barbara; van der Voet, Paul; van Geffen, J.

2010-05-01

), Stromboli and Volcano (Italy), Hilo (Hawai), Mt. St. Helens (United States), CTM (Coherent Target Monitoring): Cumbre Vieja (La Palma) To generate products either Envisat ASAR, Radarsat 1or ALOS PALSAR data have been used. Surface Thermal Anomalies Volcanic hot-spots detection, radiant flux and effusion rate (where applicable) calculation of high temperature surface thermal anomalies such as active lava flow, strombolian activity, lava dome, pyroclastic flow and lava lake can be performed through MODIS (Terra / Aqua) MIR and TIR channels, or ASTER (Terra), HRVIR/HRGT (SPOT4/5) and Landsat family SWIR channels analysis. ASTER and Landsat TIR channels allow relative radiant flux calculation of low temperature anomalies such as lava and pyroclastic flow cooling, crater lake and low temperature fumarolic fields. MODIS, ASTER and SPOT data are processed to detect and measure the following volcanic surface phenomena: Effusive activity Piton de la Fournaise (Reunion Island); Mt Etna (Italy). Lava dome growths, collapses and related pyroclastic flows Soufrière Hills (Montserrat); Arenal - (Costa Rica). Permanent crater lake and ephemeral lava lake Karthala (Comores Islands). Strombolian activity Stromboli (Italy). Low temperature fumarolic fields Nisyros (Greece), Vulcano (Italy), Mauna Loa (Hawaii). Volcanic Emission The Volcanic Emission Service is provided to the users by a link to GSE-PROMOTE - Support to Aviation Control Service (SACS). The aim of the service is to deliver in near-real-time data derived from satellite measurements regarding SO2 emissions (SO2 vertical column density - Dobson Unit [DU]) possibly related to volcanic eruptions and to track the ash injected into the atmosphere during a volcanic eruption. SO2 measurements are derived from different satellite instruments, such as SCIAMACHY, OMI and GOME-2. The tracking of volcanic ash is accomplished by using SEVIRI-MSG data and, in particular, the following channels VIS 0.6 and IR 3.9, and along with IR8.7, IR 10

Organic compounds in hydrothermal systems on the Russian Far East: relevance to the origin of life

NASA Astrophysics Data System (ADS)

Kompanichenko, Vladimir

In 70th of the last century L. Mukhin with co-authors (1) explored amino acids in the hot springs and water-steam mixture from the boreholes in Kamchatka peninsula of eastern Rus-sia. According to their results, 12 amino acids of biological origination were detected in hot springs inhabited by thermophiles and hyperthermophiles. Only a single amino acid -glycine -was found in the lifeless condensate of water-steam mixture. These authors proposed its abiotic genesis. Our research is devoted to exploration of moderately volatile organic com-pounds in the hot springs and water-steam mixture in Kamchatka peninsula, Kuriles and intracontinental part of eastern Russia. Samples were taken from hot springs far from poten-tial sources of contamination by human populations, and from boreholes 60 to 1200 meters in depth. The temperature ranged from 175C (sterile water-steam mixture) to 55C (hot water with thermophile populations). The samples were analyzed by the gas chromatomass-spectrometer Shimatsu (GCMS-QP20105). Lifeless condensate of water-steam mixture (t = 108-175C) con-tains aromatic hydrocarbons (naphthalene, 1,2-methylnaphtaline biphenyl, phenathrene, fluo-rene,squalene, 1,3-diethylbenzene, and trichlorobenzene)., n-alkanes (decane, dodecane, tride-cane, tetradecane, pentadecane, hexadecane, and geptadecane), aldehyde (oktadekanal), ketone (2-geptadekanon), and alcohol (2-undetsenol-1). 10 homologous series have been found in hot solutions (t = 55-99C) inhabited by thermophilic and hyperthermophilic microorganisms hav-ing low concentrations: aromatic hydrocarbons, n-alkanes, alkenes, aldehydes, dietoxyalkanes, naphthenes, fatty acids, methyl ethers of fatty acids, monoglycerides, and steroids. Especially diverse organic substance is detected in alkaline lower-temperature solutions (pH 9-9.5, t up to 72C). The source of these compounds is not yet established. They may represent pre-existing organic material that has been chemically degraded by pyrolysis. For

Geomorphological analysis, monitoring and modeling of large rock avalanches in northern Chile (Iquique area) for regional hazard assessment.

NASA Astrophysics Data System (ADS)

Yugsi Molina, F. X.; Hermanns, R. L.; Crosta, G. B.; Dehls, J.; Sosio, R.; Sepúlveda, S. A.

2012-04-01

mapped characterized by well defined lateral levees and clear internal morphological features (ridges and furrows, hummocks). Rock avalanche run out simulations have been carried out to back analyze the sites using DAN 3D and a 3 m pixel resolution digital elevation model (DEM) obtained from stereoscopic Geoeye-1 images to assess parameters that controlled propagation mechanism and impact area extent of the events. The older lobes were dated by radiocarbon methods. Results indicate ages higher than 40,000 yr BP for the northern site. The second site could only be dated relatively with an underlying terrace that resulted older than the age limit of radiocarbon dating (43.500 yr BP). All the deposits are positioned well above (40-70 m) the present sea level rise, and at the reported uplift rates for the area, they could be associated to events older than some hundreds of thousand years. A more complete record of the failure history of the sites will be obtained when results of cosmogenic nuclides (CN) and luminescence dating will become available later this year. Several other smaller rock avalanches have been mapped in the study area. Satellite-based radar interferometry (InSAR) was performed using ERS-1 and ERS-2 scenes from 1995-2000 as well as ENVISAT ASAR scenes from 2004-2010. Both datasets show only small deformation in the area. This deformation includes sliding of small surficial slope deposits and subsidence apparently due to local groundwater withdrawal. No deformation of bedrock along the escarpment edge is observed. Results show that only major rock avalanches could reach the main access roads to Iquique and currently no large slope segments show signs of large displacement rates. Moreover, there is no strong correlation between M > 8 earthquakes return periods and age of the dated deposits, which implies that large rock avalanches could have been triggered by other factors. Hence, from a hazard and risk perspective, it is unlikely that large rock avalanches

Early biomarker response and patient preferences to oral and intramuscular vitamin B12 substitution in primary care: a randomised parallel-group trial.

PubMed

Metaxas, Corina; Mathis, Deborah; Jeger, Cyrill; Hersberger, Kurt Eduard; Arnet, Isabelle; Walter, Philipp

2017-04-19

HoloTc 1269 pmol/l [103-2435]). Hcy and MMA levels showed a significant decrease compared with baseline (group O-oral: Hcy 13.8 µmol/l [10.7-16.8] and MMA 168 nmol/l [134-202]; group I-IM: Hcy 8.5 µmol/l [7.1-9.8] and MMA 156 nmol/l [121-190]). HoloTc and MMA levels were normalised in all patients after 4 weeks of treatment, whereas normalisation of VB12 and Hcy was reached by all patients in group I-IM only. Response of VB12, HoloTc and Hcy was more pronounced in group I-IM (p <0.01) and the primary hypothesis that oral VB12 treatment would be noninfe-rior to IM treatment was rejected. Average adherence to thera-py was 99.6 ± 1.1% and days with 2 dosing events reached 5.6%. Before randomisation, preference was in favour of oral treatment (45.9%, n = 17) over IM administration (21.6%, n = 8). Twelve patients (32.4%) had no preference. Nine (24.3%) patients changed their preference after treatment. Patients who obtained their preferred route of administration main-tained their preference in the case of oral treatment and changed their preference after IM treatment. Differences in VB12 levels between groups were higher than expected. Therefore, noninferiority of oral treat-ment had to be rejected. However, normalisation of HoloTc and MMA was reached by all patients after a 1-month treatment period. The clinical benefit of the exaggerated biomarker re-sponse after IM treatment within a typical primary care popula-tion is questionable. Midterm biomarker effects and patient preferences should be considered when a therapeutic scheme is chosen. Initial rating in favour of either IM or oral therapy can change over time and justifies repeated re-evaluation of patient preferences. (ClinicalTrials.gov ID NCT01832129).

Countermeasure development : Specific Immunoprophylaxis and Immunotherapy of Combined Acute Radiation Syndromes.

NASA Astrophysics Data System (ADS)

Popov, Dmitri; Maliev, Slava

healthy mammals induces development of lymphocytosis, leukocytosis, trombocytosis, and ac-tivation of blood coagulation cascade. Administration of SRT (IV or IM) to radiation naive animals induces leukopeina, thrombopenia, lymphopenia as a result of clonogenic programmed cell death. Blood coagulation cascade suppression is registered. Materials and Methods: Cows, horses, rabbits, rats, mice were used for different stages of our experiments. Animals were quarantined at laboratory conditions for three weeks prior to experimentation. Isolation of the SRT was provided from the central lymphatic duct of irradiated cows. Immunization of horses and rabbits to obtain Antiradiation Antibodies (Specific Antiradiation Antidote -SAR) was provided. Animals: cows, mice, rats were irradiated in the VSRI (Kazan), Academy of Vet-erinary Medicine (Moscow), Scientific Research Institute of Radiobiology (Gomel), Scientific Research Nuclear Center (Dubna). Equipment for gamma-irradiation: " Pyma", "Panorama" -Co gamma radiation source. Irradiation was performed by different doses corresponding to induction of severe forms of the Acute Radiation Syndromes (ARS). Mice and rats were re-ceiving the combined radiation and thermal injury. Model of the thermal injury: Burns -10% of total body surface. Third grade of burns was used as a model. Thermal Injury was given after irradiation. Preparations of Antiradiation Vaccine -contained a toxoid form of Radiation Toxins were used for immune-prophylaxis. Preparations of Antiradiation Antidote IgG con-tained antibodies to Radiation Toxins was used for immune-therapy. Scheme of experiments: I. Control: Group A. Animals with the ARS not received any treatment. Group B. Animals with the thermal injury not received any treatment. Group C. Animals with combined forms of the ARS not received any treatment. II. Specific Immune-prophylaxis with Antiradiation Vaccine (AV): Group D. Animals undergone immune-prophylaxis by AV. Irradiation was provided 24 days after