Coregistration between Sar Image Subsets Using Pointwise Targets

SAR image coregistration is a key procedure before starting InSAR time-series analysis. In this paper, we present a strategy to coregister SAR image subsets, instead of single SAR images, in attempt to improve InSAR time-series analysis. First, all potentially coherent image pairs are coregistered and divided into several image subsets, depending on a coregistration quality index or baseline information. Afterwards, offsets between point-wise targets, detected within the subsets, are estimated from incoherent mean amplitude maps. Then, these offsets are used to coregister the image subsets. The proposed method is implemented on two ENVISAT ASAR datasets and a clear coregistration improvement is found, which should lead to more accurate InSAR time-series analysis results.