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Adjusting for long term anomalous trends in NOAA's Global Vegetation Index datasets / L. Jiang in IEEE Transactions on geoscience and remote sensing, vol 46 n° 2 (February 2008)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 46 n° 2 (February 2008) . - pp 409 - 422 Titre : Adjusting for long term anomalous trends in NOAA's Global Vegetation Index datasets Type de document : Article/Communication Auteurs : L. Jiang, Auteur ; D. Tarpley, Auteur ; K. Mitchell, Auteur ; et al., Auteur Année de publication : 2008 Article en page(s) : pp 409 - 422 Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image [Termes IGN] correction [Termes IGN] erreur systématique [Termes IGN] image NOAA-AVHRR [Termes IGN] modèle météorologique [Termes IGN] Normalized Difference Vegetation Index [Termes IGN] occupation du sol [Termes IGN] sécheresse [Termes IGN] stabilité Résumé : (Auteur) The weekly 0.144° resolution global vegetation index from the National Oceanic and Atmospheric Administration (NOAA) National Environmental Satellite, Data, and Information Service (NESDIS) has a long history, starting late 1981, and has included data derived from Advanced Very High Resolution Radiometer (AVHRR) sensors onboard NOAA-7, -9, -11, -14, -16, -17, and -18 satellites. Even after postlaunch calibration and mathematical smoothing and filtering of the normalized difference vegetation index (NDVI) derived from AVHRR visible and near-infrared channels, the time series of global smoothed NDVI (SMN) still has apparent discontinuities and biases due to sensor degradation, orbital drift [equator crossing time (ECT)], and differences from instrument to instrument in band response functions. To meet the needs of the operational weather and climate modeling and monitoring community for a stable long-term global NDVI data set, we investigated adjustments to substantially reduce the bias of the weekly global SMN series by simple and efficient algorithms that require a minimum number of assumptions about the statistical properties of the interannual global vegetation changes. Of the algorithms tested, we found the adjusted cumulative distribution function (ACDF) method to be a well-balanced approach that effectively eliminated most of the long-term global-scale interannual trend of AVHRR NDVI. Improvements to the global and regional NDVI data stability have been demonstrated by the results of ACDF-adjusted data set evaluated at a global scale, on major land classes, with relevance to satellite ECT, at major continental regions, and at regional drought detection applications. Copyright IEEE Numéro de notice : A2008-072 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2007.902844 En ligne : https://doi.org/10.1109/TGRS.2007.902844 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29067 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
065-08021	RAB	Revue	Centre de documentation	En réserve L003	Disponible

A method for soil moisture estimation in Western Africa based on the ERS scatterometer / Mehrez Zribi in IEEE Transactions on geoscience and remote sensing, vol 46 n° 2 (February 2008)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 46 n° 2 (February 2008) . - pp 438 - 457 Titre : A method for soil moisture estimation in Western Africa based on the ERS scatterometer Type de document : Article/Communication Auteurs : Mehrez Zribi, Auteur ; C. André, Auteur ; B. Decharme, Auteur Année de publication : 2008 Article en page(s) : pp 438 - 457 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Traitement d'image [Termes IGN] Afrique occidentale [Termes IGN] analyse comparative [Termes IGN] diffusomètre [Termes IGN] humidité du sol [Termes IGN] image ERS [Termes IGN] Niger [Termes IGN] radiomètre à hyperfréquence [Termes IGN] réalité de terrain [Termes IGN] rugosité du sol Résumé : (Auteur) The analysis of feedback phenomena, which occur between continental surfaces and the atmosphere, is one of the keys to an improved understanding of African monsoon dynamics. For this reason, the monitoring of surface parameters, particularly soil moisture, is very important. This paper presents a new methodology for the estimation of surface soil moisture over Western Africa based on the data provided by the European Remote Sensing wind scatterometer instrument, in which an empirical model is used to estimate volumetric soil moisture. This approach takes into account the effects of vegetation and soil roughness in the soil moisture estimation process. The proposed estimations have been validated using different methods, and a good degree of coherence has been observed between satellite estimations and ground truth measurements over the Banizambou site in Niger. Moisture and rainfall estimations for the same site are shown to be strongly correlated. Comparison with the multimodel analysis product provided by the Global Soil Wetness Project, Phase 2, indicates that their estimations are well correlated, although land surface models provide slightly overestimated levels of soil moisture. Copyright IEEE Numéro de notice : A2008-073 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2007.904582 En ligne : https://doi.org/10.1109/TGRS.2007.904582 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=29068 [article]

Exemplaires(1)

Code-barres	Cote	Support	Localisation	Section	Disponibilité
065-08021	RAB	Revue	Centre de documentation	En réserve L003	Disponible