SBAS-InSAR monitoring method of ground subsidence in mining areas by fusion with measured data

In recent years, the depth of underground mining in coal mines in China has gradually increased.Under the subcritical mining conditions, the surface subsiding amounts of the mining area are small and the surface subsiding duration is long.Sentinel-1 A with small baseline subset(SBAS) can be used to obtain the deformation information of the mine ground with high temporal and spatial resolution.The incoherence problems in InSAR monitoring result in that in some subsidence areas, the effective deformation information cannot be obtained.By fusing the actual measured data, the SBAS-InSAR method was improved to monitor the surface subsidence.The 26 sentinel 1 A data and part of the actual measured data in the Wannian mine were acquired as the experimental data.Incoherent InSAR data of some subsidence areas covered by heavy vegetation were solved by inverse distance weighted interpolation(IDW),and the laws of ground subsidence of the insufficiently mined working faces 132153 and 132157 were analyzed.The IDW interpolation for the decoherent region along the trending direction of the working face 132157 was carried out by combining some actual measured data, and the complete and continuous InSAR monitoring data for the ground subsidence area were obtained.The InSAR monitoring results and actual measured results in the same period were selected and compared, their standard errors were ±6.0 mm, ±4.4 mm and ±9.8 mm respectively.The research results show that the application of SBAS-INSAR based on the combinations of measured data and IDW interpolation is highly reliable in the time-series monitoring of ground subsidence in the deep mining area, and the monitoring accuracy meets the requirements of relevant engineering technology.