Monitoring And Application Of Surface Subsidence In Mining Area Based On SAR Technology

As an important part of China’s energy resources,coal plays a key role in promoting national economic development.However,the surface subsidence caused by large-scale and high-intensity coal mining has caused great damage to the ecological environment of mining areas.By strengthening the monitoring of surface subsidence in mining areas and grasping the extent of surface damage and mining subsidence patterns,it is of great practical significance to ensure safe coal production,early warning of geological disasters and help ecological restoration.Interferometric Synthetic Aperture Radar(InSAR)technology has become a research hotspot in the field of mining subsidence monitoring with its high accuracy surface deformation monitoring capability.However,due to the large deformation gradient and abruptness of surface subsidence in mining areas,it is difficult to obtain large gradient deformation information in mining areas with InSAR based on phase unwrapping,and only small deformation information can be extracted of the basin edge,and the atmospheric delay error will reduce the accuracy and reliability of monitoring small deformation.The proposed offset-tracking technique solves the problem of acquiring large gradient deformation in the mine area,but it is difficult to meet the accuracy requirement of monitoring small deformation at the edge of the subsidence basin in the mine area.To address the above problems,this thesis focuses on the refined monitoring of surface subsidence in mining areas based on SAR technology,and combines the advantages of InSAR and offset-tracking techniques in monitoring deformation of different gradients to obtain a complete subsidence basin by fusing them.The main work and results are as follows:(1)The current research status of InSAR technology and offset-tracking technology in the field of surface deformation monitoring in mining areas is summarized.The principles and data processing processes of D-InSAR,SBAS-InSAR,Sta MPS-InSAR and offset-tracking technology are introduced in detail,and the error sources of surface deformation monitoring by D-InSAR technology and offset-tracking technology are analyzed on this basis.(2)Aiming at the problem of atmospheric delay error in InSAR technology,this thesis adopts external data GACOS-assisted D-InSAR,SBAS-InSAR and Sta MPSInSAR for atmospheric correction,and takes Wangjiata coal mine as an example for experimental verification.The results show that the GACOS-based atmospheric correction method can effectively improve the reliability of InSAR monitoring of small surface deformation;on this basis,by comparing the monitoring results of the three InSAR methods,it is concluded that the GACOS-based SBAS-InSAR method has higher accuracy and stability in the monitoring of small surface deformation at the edge of the subsidence basin.(3)The key parameters selection scheme and the external error correction method of the offset tracking technology are analysed with regard to the factors affecting the monitoring accuracy of the offset tracking technology.Taking Wangjata coal mine as the research object,the registration accuracy,stability and operational efficiency of multiple sets of experimental results are compared and analysed to determine the optimal parameter scheme.On this basis,the bilinear fitted surface method and the DEM-assisted refined look-up table method were used to weaken the influence of external error sources,further improving the monitoring accuracy of the offset tracking technique.Finally,the reliability of the optimised offset tracking technique for monitoring large gradient deformation in the mine area is confirmed by combining with the measured data.(4)To address the problem that it is difficult to obtain the complete deformation field of the mine area by a single SAR technique,this thesis adopts the method of fusing the optimized SBAS-InSAR and Offset-tracking techniques to obtain the complete subsidence basin of the mine area.Taking Wangjata coal mine as an example,the experimental results confirm the effectiveness and reliability of the method in extracting the full basin information of the mine area.On this basis,this thesis takes working face 2S201 of Wangjiata coal mine and working faces 15235 and 15225 of Jiulong mine as examples,and carries out research on the inversion of Probability integral parameters and the assessment of damage to buildings by mining subsidence based on the subsidence information obtained by the above fusion method,respectively,and achieves good application results.There are 38 figures,17 tables and 95 references in this thesis.