Atmospheric phase screen-estimation for PSInSAR applied to TerraSAR-X high resolution spotlight-data

The PSInSAR technique, invented by Ferretti et. al. ten years ago, meanwhile has proven it's capability for very precise measurement of surface deformations. To achieve this, the influence of the atmospheric phase screen (APS) has to be removed. We investigated the APS for two series of TerraSAR-X high resolution spotlight data of a scene in Bavaria. Our approach was to consider the APS as composed of a phase ramp, a part stratified with height and a turbulent component. We estimated the turbulent component via kriging. The variograms show for short distances a regime which is not visible for lower resolutions. In this paper we discuss the choice of appropriate variogram models with respect to our data.