The main purpose of TanDEM-X – a German SAR (Synthetic Aperture Radar) interferometric satellite mission – is to produce a world-wide consistent and reliable digital elevation model (DEM) with accuracy to the HRTI-3 (High-Resolution Terrain Information) specifications. To reach this goal, the existing TerraSAR-X Mission will be extended by a second radar satellite, which is almost similar to the already flying one. A world-wide network of receiving stations is necessary to downlink the acquired SAR-data with a volume of 350 TB in two and a half year. In addition, also the Payload Ground Segment must be updated to manage the new workflows and the high amount of data up to 2000 TB to produce the global DEM with a volume of approximately 15 TB
