3-D Deformation Fields Construction Based on Spatial and Temporal Continuity for GNSS-Based InBSAR: Verified and Enhanced by GB-SAR

The 3-D deformation monitoring can be achieved by associating different monitoring results from different navigation satellites in Global Navigation Satellite System (GNSS)-based interferometric bistatic synthetic aperture radar (InBSAR) system. However, the whole scene monitoring accuracy is limited by the low signal-to-noise ratio (SNR) and the differences among synthetic aperture radar (SAR) images from different GNSS satellites. In this article, a modified 3-D deformation fields construction algorithm based on the spatial and temporal continuity is proposed for GNSS-based InBSAR system. First, based on the spatial continuity, the persistent scatterers (PSs) that can be observed by more satellites are used to filter the initial scene deformation monitoring results. Second, the model is established according to the temporal continuity of deformation to refine the optimal regularization parameters. Third, with the intersystem fusion concept, 1-D deformation with sub-millimeter accuracy of ground-based SAR (GB-SAR) is introduced to further improve the 3-D deformation monitoring accuracy of GNSS-based InBSAR. Finally, the experimental data verify the proposed algorithm for the GNSS-based InBSAR system, achieving millimeter-level deformation monitoring accuracy. The proposed algorithm enables the system have great potential in applications such as geological disaster warning and building health monitoring.