Phase unwrapping strategy and assessment for the high resolution DEMs of the TanDEM-X mission

The next milestone in the TanDEM-X mission is the generation of high-resolution DEMs for selected areas. New scenes with lower heights of ambiguity are being acquired to fulfill the goal on the relative height accuracy of 0.8 m. To enable a reliable phase unwrapping in a finite time, a processing concept based on the usage of the final global TanDEM-X DEM has been developed. Since the global DEM provides an up-to-date measurement of the terrain height with an unprecedented high accuracy, it is of great help for the phase unwrapping procedure. This paper proposes an adaption of the Integrated TanDEM-X Processor, which is used operationally for the generation of the global DEM data, so that it can process DEMs of higher resolution from interferometric bistatic data with very low height of ambiguity and better resolution by making good use of the finalized global DEM. The final paper will focus more particularly on the assessment of the unwrapping results.