Comparação entre modelos digitais de elevação gerados por sensores ópticos e por radar.

The aim of this paper is to compare the quality and accuracy of Digital Elevation Models (DEM) generated from different sources. Three different DEMs, covering the same geographic area (region of Uberaba, MG), are tentatively evaluated in this work. The first is a DEM derived from radar interferometry, through the Shuttle Radar Topographic Mission (SRTM). The other two are DEMs generated from optical stereoscopic images: one from the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), and the other from the CCD sensor onboard of the China-Brazil Earth Resources Satellite (CBERS II). The SRTM and the ASTER DEMs show an impressive match as regards elevation. The CBERS-II image shows larger problems between the stereopair, a problem that requires additional registration with a more accurate dataset, and further with the other DEMs, before comparisons can take place. Preliminary results show that the DEMs evaluated can provide a fast and an accurate description of the topography in scales varying from 1:50.000-1:250.00.