Multi beam joined estimation for persistent scatterer interferometry

The persistent scatterer interferometry (PSI) is a powerful technique to monitor the line of sight (LOS) deformation with Millimeter accuracy in urban areas. Nowadays, this technique is well established for the sensors ERS and Envisat/ASAR. Nevertheless, the availability of high resolution SAR sensors enables new applications which require new estimation principles. Application test cases for the sensor TerraSAR-X were demonstrated already. However, the high resolution data are not really fully exploited at the moment. This paper describes a newly developed PSI estimation principle which improves the spatial resolution by the support of distributed scatterers and increases the temporal sampling by the joined estimation of different beams. The prototyped technique needs to cope with the different projections of the horizontal and vertical deformation components onto the line of sight (LOS). Basically, this allows the inversion of the beam's observation equation and finally retrieves the vertical and horizontal deformation components.