TANDEM-X MISSION STATUS

Abstract. TanDEM-X (TerraSAR-X add-on for Digital Elevation Measurements) is an innovative formation flying radar mission that opens a new era in spaceborne radar remote sensing. Its primary objective is the acquisition of a global Digital Elevation Model (DEM) with unprecedented accuracy (12 m horizontal resolution and 2 m relative height accuracy). This goal is achieved by extending the TerraSAR-X synthetic aperture radar (SAR) mission by a second TerraSAR-X like satellite, TanDEM-X (TDX). Both satellites fly in close orbit formation of a few hundred meters distance, and the resulting large single-pass SAR interferometer features flexible baseline selection enabling the acquisition of highly accurate cross-track interferograms not impacted by temporal decorrelation and atmospheric disturbances. Beyond the global DEM, several secondary mission objectives based on along-track interferometry as well as new bistatic and multistatic SAR techniques have been defined. Since 2010 both satellites have been operated in close formation to map all land surfaces at least twice and difficult terrain even up to four times. While data acquisition for the DEM generation will be concluded by the end of 2014 it is expected to complete the processing of the global DEM in the second half of 2016.