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Evaluation of modified four-component scattering power decomposition method over highly rugged glaciated terrain / G. Singh in Geocarto international, vol 27 n° 2 (March 2012)  

Public [article]  inGeocarto international > vol 27 n° 2 (March 2012) . - pp 139 - 151 Titre : Evaluation of modified four-component scattering power decomposition method over highly rugged glaciated terrain Type de document : Article/Communication Auteurs : G. Singh, Auteur ; Yasushi Yamaguchi, Auteur ; S. Park, Auteur ; R. Avtar, Auteur Année de publication : 2012 Article en page(s) : pp 139 - 151 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image radar et applications [Termes IGN] décomposition d'image [Termes IGN] décomposition spectrale [Termes IGN] glace [Termes IGN] Himalaya [Termes IGN] image radar moirée [Termes IGN] polarimétrie radar Résumé : (Auteur) In recent years, there has been increased utilization of fully polarimetric synthetic aperture radar (POLSAR) data to study glaciated terrain features for glaciological and climate change modelling. This article is concerned with more accurate results and appropriate analysis of POLSAR data over a highly rugged glaciated area in Himalayan region. For this purpose, the modified Yamaguchi four-component scattering power decomposition (4-CSPD) method with a rotation concept of 3 x 3 coherency matrix [T] about line of sight is evaluated. It has been found that the modified Yamaguchi 4-CSPD method significantly improved the decomposition results as compared with the original 4-CSPD by minimizing the cross-polarized Horizontal-Vertical (HV) components. This modified 4-CSPD leads to enhancement in the double bounce scattering and surface scattering components and also avoids the overestimation problem in the volume scattering component as compared with the original 4-CSPD from the sloped terrain. The significant reductions of the negative power occurrence in the surface scattering (3.9%) and the double bounce scattering (19.7%) components have also been noticed as compared with the original 4-CSPD method over the glaciated area in this part of the Indian Himalaya. Numéro de notice : A2012-127 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10106049.2011.626082 Date de publication en ligne : 20/10/2011 En ligne : https://doi.org/10.1080/10106049.2011.626082 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=31575 [article]

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Impacts of hydrologic soil properties on drought detection with MODIS thermal data / S. Park in Remote sensing of environment, vol 89 n° 1 (15/01/2004)  

Public [article]  inRemote sensing of environment > vol 89 n° 1 (15/01/2004) . - pp 53 - 62 Titre : Impacts of hydrologic soil properties on drought detection with MODIS thermal data Type de document : Article/Communication Auteurs : S. Park, Auteur ; J.J. Feddema, Auteur Année de publication : 2004 Article en page(s) : pp 53 - 62 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes IGN] humidité du sol [Termes IGN] image Terra-MODIS [Termes IGN] image thermique [Termes IGN] Kansas (Etats-Unis ; état) [Termes IGN] Normalized Difference Vegetation Index [Termes IGN] sécheresse [Termes IGN] système d'information géographique [Termes IGN] zone humide Résumé : (Auteur) Remote sensing data from the Moderate Resolution Imaging Spectroradiometer (MODIS), a climatic water budget model, and the STATSGO database were used within a GIS environment to determine the influences of hydrologic soil properties on soil moisture and thermal emission in western-central Kansas for a dry year, 2000. Two important variables, waterholding capacity (WHC) and hydrologic soil group (HSG), were controlled in our water budget experiment to evaluate their impacts on soil moisture content (SMC) changes throughout the period. Results showed that HSG affected drought detection and occurrence very little, but WHC variations explained most local variations of soil moisture content. As a strong indicator of relative soil moisture deficit, the Standardized Thermal Index (STI) patterns were also influenced by WHC. Generally, the earlier the soil moisture content drops below 40%, the earlier the STI reaches a threshold value of 0.2 or higher. Vegetation responses to thermal detection lagged behind the STI by up to 8 weeks, which was computed by comparing the STI and Normalized Difference Vegetation Index (NDVI) deviation from a 10-year mean. The spatial pattern of lagtimes was not apparent, but lagtimes were correlated with a WHC component. Numéro de notice : A2004-009 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1016/j.rse.2003.10.003 En ligne : https://doi.org/10.1016/j.rse.2003.10.003 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=26537 [article]