摘要
///Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) stereo images were used to automatically produce a digital elevation model (DEM) of a rugged karst area in southern China. The accuracy of the DEM was assessed by comparing elevation data at check points and along four transects with reference data derived from 1∶50 000 scale topographic maps. The quality of the DEM was significantly improved when the number of ground control points (GCPs) from the topographic maps was increased from 30 to 60 but only slightly improved when 90 points were used. The 90-point DEM had an elevation root mean square error (RMSE) of 42.7 m, which is higher than the accuracy specifications for the ASTER sensor, mainly due to the variable quality of GCPs and the rugged terrain of the study area. Topographic shadows also influenced the accuracy of the DEM, as indicated by check points in areas under shadow that had a higher RMS elevation error than those not in shadows.