Tandem-x Mission: Overview, Status and Outlook

TanDEM-X (TerraSAR-X add-on for Digital Elevation Measurement) opens a new era in spaceborne radar remote sensing [1]-[3], [9], [12]. Realized in the framework of a public-private partnership between the German Aerospace Center (DLR) and EADS Astrium GmbH, a single-pass SAR interferometer with adjustable baselines in acrossand in along-track directions was formed by adding a second (TDX), almost identical spacecraft to TerraSAR-X (TSX) and flying the two satellites in a closely controlled formation on average orbit height of 514 km. This allows the acquisition of highly accurate cross-track and along-track interferograms without the inherent accuracy limitations imposed by repeat-pass interferometry due to temporal decorrelation and atmospheric disturbances. With typical across-track baselines of 150 to 500 m a global Digital Elevation Model (DEM) with 2 m relative height accuracy at a 12 m posting is being generated.