Comprehensive vertical accuracy analysis of freely available DEMs for different landscape types of the Rur catchment, Germany

This study evaluates the vertical accuracy of nine freely available digital elevation models (DEMs) with a medium spatial resolution for a typical mid-latitude flat to hilly landscape in the Rur catchment in Germany. All datasets were evaluated with two reference datasets, a 1 m DEM and a highly precise set of elevation control points. The accuracy was evaluated with regard to different slopes, landforms and land use. The results reveal in flat areas an average error of 2-4 m which increases about two to three times in undulated terrain. Areas with dense tree cover show a mean error of 6-10 m. The highest accuracies were achieved by the SRTM DEM, followed by other DEMs that mainly implemented SRTM data. TanDEM-X and Copernicus DEM showed ambivalent results showing a higher ratio of existing errors in the elevation product for vegetation and water areas that prevent a higher overall accuracy of these DEMs.

Automated summary

This study evaluates the vertical accuracy of nine freely available digital elevation models (DEMs) in the Rur catchment in Germany, finding differing accuracy levels based on slopes, landforms, and land use. The SRTM DEM showed the highest accuracy, while TanDEM-X and Copernicus DEM had ambivalent results affected by vegetation and water areas.