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Auteur G. Venkataraman |
Documents disponibles écrits par cet auteur (2)
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Accuracy assessment of MODIS/Terra snow cover product for parts of Indian Himalayas / Hari Prasad Chelamallu in Geocarto international, vol 29 n° 5 - 6 (August - October 2014)
[article]
Titre : Accuracy assessment of MODIS/Terra snow cover product for parts of Indian Himalayas Type de document : Article/Communication Auteurs : Hari Prasad Chelamallu, Auteur ; G. Venkataraman, Auteur ; M. V. R. Murti, Auteur Année de publication : 2014 Article en page(s) : pp 592-608 Note générale : bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] analyse spatio-temporelle
[Termes IGN] Himalaya
[Termes IGN] image Terra-MODIS
[Termes IGN] Inde
[Termes IGN] manteau neigeux
[Termes IGN] ruissellementRésumé : (auteur) Snow cover mapping is important for snow and glacier-related research. The spatial and temporal distribution of snow cover area is a fundamental input to the atmospheric models, snowmelt runoff models and climate models, as well as other applications. Daily snow cover maps from Moderate Resolution Imaging Spectroradiometer (MODIS) Terra satellite were retrieved for the period between 2004 and 2007, and pixels in these images were classified as cloud, snow or snow-free. These images have then been compared with ground snow depth (SD) measurements from the four observatories located at different parts of Himalayas. Comparison of snow maps with in situ data showed good agreement with overall accuracies in between 78.15 and 95.60%. When snow cover was less, MODIS data were found to be less accurate in mapping snow cover region. As the SD increases, the accuracy of MODIS snow cover maps also increases. Numéro de notice : A2014-416 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10106049.2013.819041 En ligne : http://www.tandfonline.com/doi/full/10.1080/10106049.2013.819041 Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=73952
in Geocarto international > vol 29 n° 5 - 6 (August - October 2014) . - pp 592-608[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 059-2014031 RAB Revue Centre de documentation En réserve L003 Disponible Snow permitivity retrieval inversion algorithm for estimating snow wetness / G. Singh in Geocarto international, vol 25 n° 3 (June 2010)
[article]
Titre : Snow permitivity retrieval inversion algorithm for estimating snow wetness Type de document : Article/Communication Auteurs : G. Singh, Auteur ; G. Venkataraman, Auteur Année de publication : 2010 Article en page(s) : pp 187 - 212 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection
[Termes IGN] constante diélectrique
[Termes IGN] image Envisat-ASAR
[Termes IGN] modèle d'inversion
[Termes IGN] neige
[Termes IGN] prévention des risques
[Termes IGN] rétrodiffusion
[Termes IGN] surveillance hydrologique
[Termes IGN] traitement d'imageRésumé : (Auteur) The environmental satellite (ENVISAT) advanced synthetic aperture radar (ASAR) offers the opportunity for monitoring snow parameters with dual polarization and multi-incidence angle. Snow wetness is an important index for indicating snow avalanche, snowmelt runoff modelling, water supply for irrigation and hydropower stations, weather forecasts and understanding climate change. We used a first-order scattering model that includes both volume and air/snow surface scattering based on a developed inversion model to estimate snow dielectric constant, which can be further related for estimating snow wetness. Comparison with field measurement showed that the correlation coefficient for snow permittivity estimated from ASAR data was observed to be 0.8 at 95% confidence interval and model bias was observed as 2.42% by volume at 95% confidence interval. The comparison of ASAR-derived snow permittivity with ground measurements shows the average absolute error 2.5%. The snow wetness range varies from 0 to 15% by volume. Numéro de notice : A2010-266 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1080/10106040903486130 Date de publication en ligne : 18/02/2010 En ligne : https://doi.org/10.1080/10106040903486130 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=30460
in Geocarto international > vol 25 n° 3 (June 2010) . - pp 187 - 212[article]Exemplaires(1)
Code-barres Cote Support Localisation Section Disponibilité 059-2010031 RAB Revue Centre de documentation En réserve L003 Disponible