Monitoring ground deformation of non-urban areas based on temporarily coherent targets

The ground deformation monitoring based on permanent scatterers interferometric synthetic aperture radar (PSInSAR) is limited by the spatial distribution density of the PS, especially in non-urban areas with sparse PS distribution. To address this, an improved algorithm is proposed based on temporarily coherent targets(TCT) which maintain high coherence of partial observation period and whose spatial distribution is rich in non-urban areas. After incorporating the seasonal characteristics of ground scatterers, the algorithm screens the interferometric pair to preserve the TCT which can be distinguished by dual-threshold method. After mining and separating the interferometric phase information by multi-differential process, the deformation velocity and elevation correction of TCT are inversed. Twenty-four Sentinel-1A SAR images, acquired between 2014-10-24 and 2016-05-09, are processed to extract the ground deformation of TCT in Jingbian County, Shaanxi Province. Compared with PSInSAR, the results provide evidence that multitemporal analysis method of temporarily coherent targets can significantly increase the spatial distribution density of monitoring targets, as well as effectively and reliably monitor the ground deformation in non-urban areas.