Assessment of Digital Elevation Models Derived Using Radar Interferometry

Interferometric synthetic aperture radar (InSAR) has been developed as a powerful technique to derive high quality digital elevation models (DEMs) from a pair of SAR images. (Honikel, 1998) This paper describes InSAR processing principle, the crucial steps in deriving high quality DEMs from the C-band ERS Tandem Mission data, and addresses possible error sources before and during the processing such as phase noise, orbit errors, and propagation effects. The greatest challenge in DEM quality assessment is to adjust the geographical information of the DEM to correspond with the actual geographical coordinates. This technique is called ‘georeferencing’, and it can be achieved by either referencing to the aerial orthophoto or the geographical information obtained from ground control points (GCPs). Therefore, two technical approaches are investigated and experimented, and the results are presented in the paper.