Analysis of X-SAR SRTM elevation data to estimate surface cover heights over land areas

We present the first results of the SRTM AO-038 project in Norway. The SRTM X-SAR elevation data are evaluated with respect to digital reference maps and surface cover types like agricultural fields, forest, lakes and infrastructure. Optical satellite images, aerial photos and field observations are used to aid in the analysis of the SRTM elevation data. The X-SAR SRTM DEM gave better elevation accuracies over many open agricultural areas as compared to the 1:50000 topographic DEM commonly used in Norway. The SRTM DEM gave surface cover elevations rather than ground elevations in areas of dense forest. These SRTM elevation offsets in forested areas may be used further to categorize the forest cover type.