Advanced Displacement Estimation for PSI using High Resolution SAR Data

The Persistent Scatterer (PS) technique is a well known method for estimating object and/or surface deformation from space with high accuracy and high spatial coverage and sampling by analyzing estimation frameworks generated from stacks of interferograms [1]. It is especially suitable for urban areas which, in general, show a high density of PS to detect movements with a wide area deformation pattern as well as changes within small scales, e.g. subsidence of isolated buildings. The new high resolution class satellites like TerraSAR-X, Radarsat-2 or Cosmo-SkyMed put forth new potentials and challenges as the density of PS increases dramatically. As several PS can be found on one single object like a building or a bridge, a advanced motion estimation for this group of points can be introduced, accounting for the coupled movement. In this paper we show how the estimation can be carried out restricting the movement to certain models we employ in order to increase the accuracy of the displacement for the whole group of PS. The results obtained for the proposed estimation technique are based on simulated data to thoroughly investigate the potentials of this approach. They are the basis for real datasets available from TerraSAR-X.