used interferometric synthetic aper

used interferometric synthetic aperture radar (InSAR) to monitor surface deformation over permafrost. Because ice and water have different densities, the ground surface settles during the thaw and the amount of surface subsidence can be used to estimate the thickness of the active layer if the vertical distribution of pore water within the soil is known. Wang et al. [25] used multi-temporal TerraSAR-X backscatter intensity and interferometric coherence along with the relationship between vegetation cover and the permafrost as the basis for classifying and mapping permafrost landscape features. Chen et al. [26]proposed a method to estimate the active layer thickness using time-series P-band polarimetric synthetic aperture radar (SAR) observations, achieving retrieval with errors