Avoiding Phase Unwrapping in DEM Generation by Fusing Multi Frequency Ascending and Descending Interferograms

This paper presents an approach to fuse an ensemble of interferograms of different wavelengths and viewing geometries to one common digital elevation model (DEM). Phase unwrapping and geocoding are performed on the fly and the different interferograms support each other. Propagation of phase unwrapping errors to large areas can no more occur which makes this method especially suitable for rugged mountains. The method is explained and a fusion of SRTM ascending and descending data with data with different wavelengths is demonstrated. The limits and possibilities are demonstrated by varying the number of interferograms and the viewing conditions. Furthermore a performance measure is given and compared with reference data