Derivation of land surface temperatures and emissivities from satellite IR window measurements

This presentation consideres the retrieval of land surface temperatures (LST) and surface spectral emissivities epsilon(v) from NOAA infrared radiance measurements in the 10.5-12.5 mu m atmospheric window. The proposed retrieval technique makes use of combined AVHRR (channels 4,5) and HIRS/2 (channel 8) measurements in order to separate the effects of varying emissivities and LST in satellite data and then to retrieve both the epsilon(v) and LST. The first step is the estimation of epsilon(v) based on the temperature independent spectral indices analysis. The second step is the estimation of LST from AVHRR data using an appropriate version of the split window method. The data set of collocated AVHRR/HIRS and ground based observations for the central region of Russia has been compiled for the summer periods of 1993-1995 and then was used for testing the proposed technique. The verification of remotely sensed LST's against specially constructed ground temperature true values gives RMS errors in the range 2.0-3.0 degrees C. (C) 1998 COSPAR. Published by Elsevier Science Ltd.