DEM correction and mean surface displacement rate retrieval from a stack of wrapped multi-temporal DInSAR interferograms

In this work, a new technique for the correction of a digital elevation models (DEM) and the retrieval of the ground mean displacement rate of an investigated area, which relies on the analysis of a sequence of wrapped multi-master differential SAR interferograms, is presented. The method consists in finding the solution of a non-linear optimization problem that does not require the preliminary execution of any phase unwrapping operation. Therefore, the achievable estimates are not disturbed by phase unwrapping (PhU) errors. Noteworthy, the estimation of the ground displacement rate may reveal (in most cases) particularly suitable for retrieving geophysical information on the sources responsible for the observed deformations. Furthermore, the estimates of the DEM errors and the ground displacement rate can be used within advanced DInSAR processing chains for the retrieval of surface deformation time-series, with the aim to facilitate phase unwrapping operations and discriminate the desired signals (due to deformation) from residual phase artifacts. The first experimental results, carried out by applying the proposed method to stacks of simulated interferograms, demonstrate the validity of the proposed approach.