TanDEM-X: A Satellite Formation for High Resolution SAR Interferometry

This paper analyses the potential of TanDEM-X to acquire highly accurate digital elevation models (DEMs) on a global scale. For this, an appropriate mission concept will be introduced. This concept is based on an add-on satellite almost identical to the TerraSAR-X satellite, orbiting in close formation with it. Radar images of these two satellites allow for the generation of a world-wide DEM according to the emerging HRTI-3 standard within less than three years. The achievable height accuracy will be derived from a detailed performance analysis taking into account major system and scene parameters. Critical issues will be identified on both the system and mission level. Furthermore, additional applications as demanded by user requirements will include regional DEMs according to HRTI-4 standard or new techniques such as digital beamforming, bi-static observations or polarimetric interferometric SAR. A mission scenario is presented, which fulfils these requirements within the three year mission time