Results from the Shuttle Radar Topography Mission (SRTM) are presented. The SRTM C-band and X-band digital elevation models (DEMs) are evaluated with regard to elevation accuracies over agricultural fields, forest areas and man-made features in Norway. High-resolution digital maps and satellite images are used as background data. In general, many terrain details can be observed in the SRTM elevation datasets. The elevation accuracy (90% confidence level) of the two SRTM systems is estimated to less than 6.5 m for open agricultural fields and less than 11 m considering all land surface covers. This is better than specifications. Analysis of dense Norwegian forest stands shows that the SRTM system will produce elevation data that are as much as 15 m higher than the ground surface. The SRTM DEM products will therefore partly indicate canopy elevations in forested areas. We also show that SRTM data can be used to update older DEMs obtained from other sources, as well as estimating the volume of rock removed from large man-made gravel pits.

In this paper, 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.Index Terms-SRTM, SAR, digital elevation model.