Estimating three dimensional positions of persistent scatterers and developing a PS-InSAR analysis system

This paper presents a method for estimating the three dimensional (3D) position of Persistent Scatterers (PSs) for Persistent Scatterer Interferometric SAR (PS-InSAR) and a PS-InSAR analysis system. PSs are useful to monitor deformation of manmade structures with accuracy of millimeter range. However, SAR images include geometric distortions such as layovers or foreshortenings. These distortions cause errors in estimating the 3D positions (latitude, longitude and altitude) of PSs in the SAR images. Foreshortenings are corrected by conventional methods based on ortho-rectification. On the other hand, layovers still remain to be solved. In our method, both foreshortenings and layovers are corrected through estimating possible 3D positions of each PS (referred as “PS candidates”) by using Digital Surface Model (DSM) and the position of a satellite. The results by PS-InSAR analysis system show the validity of the proposed method.