Hi Folks, Merry Chistmas. I have been using the Landsat ETM calibration tool in ENVI for the primary purpose of extracting surface temperature from the thermal band 6. The result has returned unusally low surface temp values. So: does the spectral radiance need to be processed further to get correct values? I have been calibrating just the thermal band, is this legitimate? Is it better to process the high gain (band 62) or the low gain (band 61) data? Some help with this and maybe some applied methodology would be much appreciated. Cheers Graeme