Decomposing and mapping different scales of land subsidence over Shanghai with X- and C-Band SAR data stacks

Land subsidence can be observed with time-series of Interferometric Synthetic Aperture Radar (InSAR) data. However, existing approaches only reveal signals that are multi-scale mixed, which is not conducive to the systematic analysis different mechanisms. A deformation signal decomposition (DSD) method based on spectral used decompose extracted by InSAR into three classes signals. They refer large-scale related geological settings, medium-scale caused more group excavation, and small-scale along linear infrastructures. TerraSAR-X datasets for Shanghai spanning April 2013 September 2020, Sentinel-1A January 2016 2020 in this study. The results were cross-verified between datasets, validated against levelling measurements. Subsidence mechanisms automatically decomposed, facilitates a targeted diagnosis land detailed was conducted jointly at scales surface displacement, conditions, major construction activities, It indicated activities leading cause subsidence, suggests local authorities wish mitigate may benefit from primarily considering process.