PROCESSING AND ACCURACY OF LANDSAT THEMATIC MAPPER DATA FOR LAKE SURFACE-TEMPERATURE MEASUREMENT

Processing of Landsat-5 TM thermal images for lake surface temperature determination is addressed. A specific preprocessing algorithm to red uce sensor noise is presented and calibration and atmospheric correcti on is discussed. The atmospheric impact on thermal radiation measureme nts is modelled using Lowtran-7 utilizing radiosonde data. Comparing g round truth measurements acquired for 21 images between 1987 and 1994 with satellite derived temperatures yielded a mean square error of 0.5 3 deg K. A systematic overestimation or underestimation of Landsat der ived temperatures was not found. The emissivity effect upon the accura cy of the derived surface temperature is discussed as well as effects of using alternate atmospheric profile data.