MAPPING SURFACE ALBEDO IN THE EAST SLOPE OF THE COLORADO FRONT RANGE, USA, WITH LANDSAT THEMATIC MAPPER

An approach for obtaining surface albedo measurements from Landsat Thematic Mapper (TM) imagery and digital terrain data is presented. Digital terrain data are used for the geometric correction and image registration of satellite imagery, the correction of atmospheric effects, and the computation of solar irradiance. The visible, near-infrared and mid-infrared reflectance derived from Landsat TM spectral bands are combined into a measure of surface albedo by use of a weighted average scheme. The methodology has been applied in order to map the spatial distribution of surface albedo along an altitudinal transect in the east slope of the Colorado Front Range, U.S.A. Estimated values of albedo for selected surfaces compare favorably with published data for comparable surfaces and field measurements in the region. The results presented herein are part of a continuing research project specifically designed to map the spatial patterns of the net radiation load at the surface in high relief environments.