Coregistration of Interferometric Stacks of Sentinel-1 TOPS Data

The coregistration of synthetic aperture radar images is of fundamental importance for the generation of interferograms. The high azimuth coregistration requirements imposed by the TOPS acquisition mode imply that an advanced approach for the coregistration of stacked time series images is needed due to temporal decorrelation effects. In some scenarios, the conventional approach of estimating the shifts pairwise with respect to the same master might result insufficient. Therefore, a joint estimation is proposed here, which exploits jointly all interferograms in order to retrieve more accurate results. Simulated data and Sentinel-1A images acquired in IW mode are used to validate this procedure, demonstrating the better performance of the joint approach when compared to the standard single-master approach.