TerraSAR-X is a German satellite for Earth Observation, which was launched on July 14, 2007. The mission duration was foreseen to be 5 years. TerraSAR-X carries an innovative high resolution x-band sensor for imaging with resolution up to 1 m.
TerraSAR-X carries as secondary payload an IGOR GPS receiver with GPS RO capability. GFZ provided the IGOR and is responsible for the related TOR experiment (Tracking, Occultation and Ranging). TerraSAR-X provides continuously atmospheric GPS data in near-real time. These data from GFZ are continuously assimilated in parallel with those from GRACE-A by the world-leading weather centers to improve their global forecasts. TerraSAR-X, together with TanDEM-X also forms a twin-satellite constellation for atmosphere sounding and generates an unique data set for the evaluation of the accuracy of the GPS-RO technique.