Time Series Analysis of Scansar Interferograms using the Small Baseline Subset Technique

We generate a deformation time series by applying the Small BAseline Subset (SBAS) InSAR processing algorithm to ScanSAR (burst mode) data synthesized from ERS-1/2 stripmap SAR data. Careful selection of interferometric image pairs based on short spatial and temporal baselines mitigates higher levels of decorrelation observed in low-resolution ScanSAR data. We simulate burst mode data from 40 ERS-1/2 stripmap raw datasets over Phoenix, Arizona by omitting raw data lines. Interferograms are formed for varying amounts of burst overlap to reflect a realistic ScanSAR scenario and the effect of loss of resolution and coherence on accuracy of time series solution due to varying amounts of burst overlap is investigated. Comparison of ScanSAR SBAS results with stripmap SBAS results shows a mean error of 0.01-0.1 cm/year in velocity estimates and 0.4-2.1 cm error in displacements.