Accuracy of interferometric elevation models generated from DOSAR airborne data

Addresses the geometric aspects of DEM-generation from interferometric airborne SAR data. It explains realistic modelling of the interferometric imaging geometry and gives results from simulation of imaging geometry modelling errors. In principle geometric motion compensation can never be exact, therefore new methods are required to correct elevation errors in the DEM-generation process. With the help of one ground control patch, imaging geometry is determined and the phase differences calibrated. In order to obtain the highest possible precision in the generated DEM it is necessary to produce two differently filtered versions of the DEM. In this case singular heights of individual objects are better preserved in one DEM, whereas the elevation of large scale features is more precise in the other. As a result, the height resolution is approximately 1 m locally and the overall positioning precision lies near 2 m for the DOSAR test data, which is compared to the Swiss DHM25 and to individual ground features