TanDEM-X acquisition plan and DEM performance in the third year of operation

TanDEM-X is a SAR mission with the goal to acquire a global digital elevation model of the Earth with an up to now unprecedented accuracy. This paper gives an overview on the actual status of the TanDEM-X mission in terms of acquisition strategy and planning of the third year of operation. The dedicated phases for the acquisition of Antarctica as well as for difficult terrain regions with shadow or layover and deserts are reviewed and explained in detail. In addition, the performance achieved with the first two global coverages is presented and discussed. Finally, the steps undertaken to calibrate the bi-static system and its actual stability is described.