Combination of stereo SAR and InSAR for DEM generation using TanDEM-X spotlight data

The objective of this work is to generate accurate digital elevation models (DEMs) from synthetic aperture radar (SAR) interferograms using the spotlight and staring spotlight modes during the TanDEM-X (TDX) science phase. We use stereo SAR with TDX or TerraSAR-X (TSX) to estimate absolute heights of natural or man-made reflectors for input to the unwrapped interferograms. The accuracy of the absolute heights in the DEMs was a few decimetres in flat regions and a few metres in the hilly and rugged terrain.