Assessment of the Potential of Terrasar-x with Respect to Mapping Applications Using Radargrammetric and Interferometric Techniques

The first German space mission TerraSAR-X was launched on June 15th, 2007. Within the TerraSAR-X science program of the German Aerospace Center (DLR), the Institute of Digital Image Processing of Joanneum Research (JRDIB) has gained a principal investigator status with respect to the assessment of the mapping potential of TerraSAR-X data using radargrammetric as well as interferometric techniques. As for topographic mapping, TerraSAR has initiated a new generation of high-resolution spaceborne SAR sensors, as it provides SAR images at very high resolution down to 1 meter, based on variable off-nadir looking angles. Thus, high resolution SAR stereo image pairs can be acquired in different imaging dispositions, 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 order to assess the potential of TerraSAR-X for 2D and 3D mapping applications, stereo-radargrammetric as well as interferometric techniques are investigated. Various types of underlying topography and terrain, like rural, urban and alpine areas, are considered. With respect to urban and rural areas it is analysed, whether and at which accuracy buildings and forest stands can be extracted by means of stereoscopic and/or interferometric mapping techniques. The analysis further refers to the impact of incidence angles inherent to the stereo images onto the mapping accuracy. Surface models and vegetation height models are generated for the individual test sites and by means of various processing workflows, i.e. stereo data as well as INSAR data processing. The quality of the achieved surface models is evaluated by a comparative analysis including reference ortho-images and reference surface models.