Land surface emissivity and temperature determination in the whole HAPEX-Sahel area from AVHRR data

Most of the developed methods for land surface temperature retrieval have been derived for mid-latitude atmospheres and their application in tropical areas is very limited. The aim of this paper is to discuss the applicability of a global split-window method, developed by the authors, in a tropical environment as well as to analyse the accuracy in determining LST in tropical areas. The accuracy of this split-window method is about 2degK, which is a reasonable value taking into account the large atmospheric attenuation in tropical environments. We have performed this study in the framework of the Hydrologic Atmospheric Pilot Experiment in the Sahel (HAPEX-Sahel), showing the results for the whole HAPEX-Sahel area (13 -14 N; 2-3 E). To complete the study, an intercomparison of the existing split-window methods has also been carried out in this area.