Accurate Azimuth Ground Deformation Estimation From Sentinel-1 Time Series

This letter proposes the exploitation of the overlapping areas between bursts of Sentinel-1 interferometric wide (IW) swath data for the estimation of ground azimuth deformation velocities from time series, which provides high sensitivity to the North–South direction. The availability of two separated Doppler spectral looks over these areas allows one to obtain high accurate estimates, overcoming the limited performance of classical correlation techniques with coarse resolution modes. Since the estimation is restricted to the (sparsely distributed) burst overlaps, its applicability is limited to geophysical phenomena characterized by a slow spatial variability, e.g., seismic scenarios. We demonstrate the suitability of this approach to time series over a region in Pakistan affected by post-seismic deformation. The estimated mean azimuth velocity performance from real data indicates an accuracy better than 7 mm/year over high long-term coherent areas for a three-year data stack.