On the Generation of Late ERS Deformation Time Series Through Small Doppler and Baseline Subsets Differential SAR Interferograms

In this letter, we investigate the potential of the small baseline subset (SBAS) differential synthetic aperture radar interferometry (DInSAR) technique to produce consistent deformation time series by using data sets of SAR images with high Doppler centroid (DC) frequencies. To cope with this issue properly, we exploited an archive of SAR scenes acquired by the European Remote Sensing 2 (ERS-2) sensor after the February 2000 three-gyroscope navigation mode failure. Our approach is oriented toward the long-term investigation of large-scale displacements with low spatial resolution (about 100 × 100 m) by processing sets of SAR images without discarding scenes depending on their DC values. Our analysis involves a set of descending SAR data frames from 1992 to 2007 relevant to the Napoli (Italy) bay area. Comparison with contemporaneous Global Positioning System measurements clearly confirms the effectiveness of the proposed approach.