ASTER AS A SOURCE FOR TOPOGRAPHIC DATA IN THE LATE 1990S

Topography is a fundamental earth characteristic that can be measured for studies of the land surface, The Advanced Spaceborne Thermal Emiss ion and Reflection Radiometer (ASTER) onboard the EOS-AM1 platform wil l acquire along-track stereo data for topographic mapping. ASTER is ca pable of recording 771 digital stereo pairs per day, each covering 60 x 60 km on the ground, at 15-m resolution, with a base-to-height ratio of 0.6, According to present plans, approximately 30 digital elevatio n models (DEM's), accurate to within +/-7 to +/-50 m (RMSEz) will be p roduced daily by processing facilities in Japan and the United States, The Land Processes Distributed Active Archive Center (LP-DAAC) at the United States Geological Survey's (USGS's) EROS Data Center (EDC) wil l emphasize the use of automated stereocorrelation procedures to produ ce absolute DEM's tied to ground control. During the six-year mission, ASTER has the potential to provide a coherent, digital stereo data se t covering all of the earth's land surface. At minimum, ASTER DEM's wi ll augment topographic data from other sources. Results of simulations of ASTER stereo data using existing satellite and aircraft data over validation sites in Huntsville, AL, and Iguala, Mexico, illustrate the value of high-resolution ASTER DEM's and how actual ASTER DEM's will be validated.