Centre dedocumentation
scientifique

Using thermal time and pixel purity for enhancing biophysical variable time series: An interproduct comparison / Grégory Duveiller in IEEE Transactions on geoscience and remote sensing, vol 51 n° 4 Tome 1 (April 2013)  

Public [article]  inIEEE Transactions on geoscience and remote sensing > vol 51 n° 4 Tome 1 (April 2013) . - pp 2119 - 2127 Titre : Using thermal time and pixel purity for enhancing biophysical variable time series: An interproduct comparison Type de document : Article/Communication Auteurs : Grégory Duveiller, Auteur ; Frédéreic Baret, Auteur ; Pierre Defourny, Auteur Année de publication : 2013 Article en page(s) : pp 2119 - 2127 Note générale : Bibliographie Langues : Anglais (eng) Descripteur : [Vedettes matières IGN] Applications de télédétection [Termes descripteurs IGN] analyse comparative [Termes descripteurs IGN] blé (céréale) [Termes descripteurs IGN] cohérence des données [Termes descripteurs IGN] Green area index [Termes descripteurs IGN] image à basse résolution [Termes descripteurs IGN] image Terra-MODIS [Termes descripteurs IGN] intensité lumineuse [Termes descripteurs IGN] Leaf Area Index [Termes descripteurs IGN] série temporelle [Termes descripteurs IGN] surveillance de la végétation Résumé : (Auteur) This paper presents a multiannual comparison at regional scale of currently available 1-km global leaf area index (LAI) products with crop-specific green area index (GAI) retrieved from 250-m spatial resolution imagery from the Moderate Resolution Imaging Spectroradiometer (MODIS). The crop-specific GAI product benefits from the following extra processing steps: 1) spatial filtering of time series based on pixel purity; 2) transforming the time scale to thermal time; and 3) fitting a canopy structural dynamic model to smooth out the signal. In order to perform a rigorous comparison, these steps were also applied to the 1-km LAI products, namely, MODIS LAI (MCD15) and LAI produced in the CYCLOPES (Carbon cYcle and Change in Land Observational Products from an Ensemble of Satellites) project. A simple indicator was also designed to quantify the increase in temporal smoothness that can thus be obtained. The results confirm that, for winter wheat, the 250-m GAI product provides a more realistic description of the time course of the biophysical variable in terms of reaching higher values, grasping the variability, and providing smoother time series. However, the use of thermal time and pixel purity also improves the temporal consistency and coherence of the 1-km products. Overall, the results of this study suggest that these techniques could be valuable in harmonizing remote sensing data coming from different sources with varying spatial and temporal resolution for enhanced vegetation monitoring. Numéro de notice : A2013-215 Affiliation des auteurs : non IGN Thématique : IMAGERIE Nature : Article nature-HAL : ArtAvecCL-RevueIntern DOI : 10.1109/TGRS.2012.2226731 En ligne : https://doi.org/10.1109/TGRS.2012.2226731 Format de la ressource électronique : URL article Permalink : https://documentation.ensg.eu/index.php?lvl=notice_display&id=32353 [article]