Multi-image DEM reconstruction

ERS multi-pass SAR interferometry has been successfully applied to the generation of large scale DEM with a few meters vertical accuracy. It is shown that residual atmospheric artifacts on DEM are concentrated at very low spatial frequencies, so fusion with low resolution DEMs obtained with other techniques can improve the elevation accuracy. Once such a precise DEM is available together with precise orbital data, a data-base of Permanent Scatterers (PS) can be generated starting from several interferometric SAR images taken in a long period of time (several seasons). PS can be used to further improve the DEM accuracy and to monitor possible terrain deformations in poorly coherent areas