Comparative accuracy of the AW3D30 DSM, ASTER GDEM, and SRTM1 DEM: A case study on the Zaoksky testing ground, Central European Russia
ABSTRACT Quasi global, medium resolution land surface models the Shuttle Radar Topography Mission digital elevation model (SRTM1 DEM) the Advanced Spaceborne Thermal Emission and Reflection Radiometer Global DEM (ASTER GDEM) and the Advanced Land Observing Satellite World 3D digital surface model (AW3D30 DSM) are widely used in geosciences. We carried out a comparative analysis of accuracy for these models exemplified by the Zaoksky testing ground, Central European Russia. First, we extracted related portions from the SRTM1 DEM, ASTER GDEM, and AW3D30 DSM for the study area. In the further analysis, we used 69 ground control points (GCPs) within the testing ground, as well as a reference DEM photogrammetrically generated from aerial stereo images. For each GCP, we determined an elevation value in four models and a related vertical error. For each model, we carried out a statistical analysis of vertical errors. To visualize the spatial distribution of vertical errors, we calculated matrices of residuals between the reference DEM and the quasi global models. The results demonstrate that the AW3D30 DSM can be considered the most accurate quasi global, medium resolution land surface model. We do not recommend the use of the ASTER GDEM because it is marked by high errors with chaotically distributed hummock like patterns.