Investigation of the Stereo-Radargrammetric Mapping Potential of TerraSAR-X

The first German space mission TerraSAR-X was launched on June 15th, 2007. With respect to topographic mapping, this mission has initiated a new generation of high-resolution spaceborne SAR sensors, as it provides SAR images at very high resolution down to 1 meter in the Spotlight mode on the one hand, and variable off-nadir looking angles on the other hand. Thus, high resolution SAR stereo image pairs can be acquired at optimized imaging conditions, stimulating the traditional stereo mapping approach to be used for 3D mapping, either in parallel with or as an alternative to SAR interferometry as the evolving mapping technique of the last decade. In this paper, the stereo-radargrammetric potential of TerraSAR-X is investigated based on multiple Spotlight data sets for selected Austrian test sites. First, a-priori estimates of 3D mapping accuracy being feasible from TerraSAR-X stereo pairs are deduced based on control point measurements. Therefore, various stereo dispositions were analyzed. Second, surface models were generated by means of stereo mapping procedures and qualitatively validated by visual comparison to appropriate reference data.