TerraSAR-X and TanDEM-X: Global Mapping in 3D using Radar Marco Weber Infoterra GmbH, Germany Email: marco.weber@infoterra-global.com Abstract TanDEM-X (TerraSAR-X Add on for Digital Elevation Measurements) is a national proposal for a new generation SAR satellite operating at X-band in single pass SAR interferometry. The single pass SAR interferometric constellation is realised by two independent X-band satellites flying in formation and has the goal to deliver a global digital elevation model in a HRTI-3 specification. The economic revival of the Arabic countries requires appropriate and precise planning documents in all the three dimensions. However, a continuous and up-to-date acquisition by optical sensors is strongly limited by unfavorable weather conditions. Therefore, the easy access to the high-resolution radar missions TerraSAR-X and TanDEM-X gives the global remote sensing community the possibility to participate in one of the most ambitious space programs.