TanDEM-X: Mission Overview and Status

TanDEM-X (TerraSAR-X add-on for Digital Elevation Measurement) opens a new era in space borne radar remote sensing. A single-pass SAR-interferometer with adjustable baselines in acrossand in along-track directions is formed by adding a second (TDX), almost identical spacecraft, to TerraSAR-X (TSX) and flying the two satellites in a closely controlled formation. TDX has SAR system parameters which are fully compatible with TSX, allowing not only independent operation from TSX in a mono-static mode, but also synchronized operation (e.g. in a bi-static mode). With typical across-track baselines of 200-400m DEMs with 2m relative height accuracy at a 12 m posting will be generated. The HELIX concept provides a save solution for the close formation flight with vertical separation of the two satellites over the poles and adjustable horizontal baselines at the ascending/descending node crossings.