Identification of ground subsidence in goaf of Hancheng Mining Area based on PS-InSAR and DS-InSAR

Aiming at the shortcomings of traditional InSAR technology in monitoring surface subsidence in coal mine goaf, a monitoring method for coal mining subsidence combining PS-InSAR and DS-InSAR is proposed. The research mainly conducts interference processing on the Sentienl-1A data of 81 scenes covering Hancheng Mining Area from January 2018 to April 2021, and extracts the distribution of PS points with high scattering characteristics and DS points with medium scattering characteristics. The number of stable coherent points is increased, and the monitoring requirements of the coal mine subsidence area are met. The monitoring results show that the 12 deformation areas in this mining area correspond to the positions of the 12 coal mines in the Hancheng Mining Area one by one, and the comparison of the working face position of the coal mine with the InSAR deformation range shows that mining subsidence has occurred in the coal mining areas of the 12 coal mines. Among them, the three large coal mines, Sangshuping, Xiayukou and Xiangshan, have large coal mining subsidence ranges and large deformation levels. Other small coal mines are basically distributed with hidden dangers of subsidence in different ranges. Longyuan Coal Mine is in the monitoring period, and the surface is basically not deformed. The maximum annual average subsidence rate in Hancheng Mining Area reached 230 mm/a, and the maximum cumulative subsidence amount reached 740 mm, indicating that InSAR technology can play a certain role in the identification of surface subsidence in the goaf area of coal mines, and provide data support for post-mining management of the mining area.