Extended Abstract (8.0K)3.3
First results of the EOS-Terra ASTER observations over Marseille during the UBL/CLU-ESCOMPTE experiment
Benedicte Dousset, University of Hawaii, Honolulu, HI
Knowledge of land surface emissivity is critical to derive accurate land surface temperatures and to study the surface energy budget. Little information exists on urban surfaces emissivities, the values of which are < 1, and spectraly variable. Given the heterogeneity of urban surfaces, in-situ measurements of emissivity lack spatial resolution, whereas estimates of emissivity derived from land-cover types lack accuracy. As part of the UBL/CLU-ESCOMPTE experiment (http://medias.obs-mip.fr/escompte), two images were sensed over the Marseille region, by the Advanced Spaceborne Thermal Emission and Reflection radiometer (ASTER). The ASTER instrument aboard the sun-synchronous near-polar EOS Terra satellite, collects high spatial resolution (15-90 m) multi-spectral data (14 bands, VNIR to TIR) for local and regional processes studies. The five thermal bands of ASTER enable direct estimates of surface emissivities and accurate temperatures, at a 90 m resolution. First results of the ASTER observations over Marseille are presented. The surface emissivities and temperatures data are analyzed separately, and then correlated. A land-cover classification is derived from the ASTER VNIR bands, at a 15 m resolution. The interpretation of surface emissivities and temperatures as a function of land-cover type is facilitated by the data combination to a common 90 m grid. A significant negative correlation effect is observed in between the surface temperature and the vegetation index, derived from the ASTER VNIR bands.
Session 3, Urban field projects: ESCOMPTE/CLU & BUBBLE
Monday, 20 May 2002, 1:30 PM-3:15 PM
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