Impact of surface emissivity and atmospheric conditions on surface temperatures estimated from top of canopy brightness temperatures derived from Landsat 7 data

The method to derive surface temperature from top of canopy brightness temperature developed by Olioso (1995b) [20] is tested over the Avignon-Crau-Camargue area (France) using Landsat-7 ETM+ images. The difference between surface temperature and brightness temperature depends on surface emissivity, incident atmospheric radiation and the temperature itself. Differences up to 2 K were obtained for a surface emissivity of 0.97. It can increase up to 7 K when surface emissivity was 0.91. The surface temperature derived from Landsat data were in agreement with the ground measurements when using local calibration of the surface emissivity derivation method and a modification of the calculation of atmospheric radiation as compared to [20]. The impact of error in emissivity derivation was higher than the impact of errors in deriving atmospheric radiation.