Back-to-back approach to SAR interferometry

Abstract. Interferometric SAR (InSAR) techniques, particularly Persistent Scatterer Interferometry (PSI), have become essential for land deformation monitoring. However, phase unwrapping errors significantly impact the reliability of deformation measurements, especially in areas with high phase noise or rapid deformation. This paper introduces a back-to-back (B2B) approach that enhances PSI results through a direct phase integration of consecutive interferograms, combined with adaptive phase unwrapping error detection and correction. The methodology integrates coherence-based pixel selection, adaptive phase unwrapping with variable thresholds, spatial-temporal consistency checking, and interpolation. Validation across several mining sites confirms the method’s robustness. For example, at the Relave Talabre mine in Chile, the B2B approach increased measurement density by over 20% with respect to standard PSI, and improved temporal consistency between ascending and descending datasets. These results demonstrate that the B2B approach offers enhanced spatial coverage, more reliable phase unwrapping, and operational efficiency for large-scale deformation monitoring in mining environments.