An Improved Multi-Platform Stacked D-InSAR Method for Monitoring the Three-Dimensional Deformation of the Mining Area

The acquisition of information on fine surface three-dimensional deformation in a goaf is of great significance for the in-depth understanding of the law of mining subsidence and guiding the safe production and ecological restoration of the mining area. In this paper, three platform SAR satellite images are used for stacked D-InSAR processing to obtain the information on surface deformation in three line-of-sight directions. An improved three-dimensional decomposition model is proposed based on the difference between the COSMO-SkyMed and TerraSAR-X satellite heading angles, which are very small. The proposed method is verified by evaluating the three-dimensional deformation of the ground surface during the mining process at the 132610 working face in Fengfeng Mining District, Handan City, Hebei Province. The accuracy of the three-dimensionally decomposed vertical settlement results is verified with the leveling data of the same period. The accuracy of 0.82 cm is achieved, and the maximum subsidence is approximately 16 cm. Combining the high-precision terrain information obtained from the unmanned aerial vehicle photogrammetry data and the deformation law of inclined coal seam mining, the horizontal movement of the 132610 working face is analyzed to prove the feasibility of the proposed method.