Research On Surface Deformation Monitoring Of Kunyang Phosphate Mine Integrating GPS And Time-series InSAR Technology

Our country is rich in mineral resources,with a wide variety of minerals and large reserves.Mining mineral resources will inevitably destroy the ecological environment of the mining area and cause landslides and other geological disasters.In order to prevent the occurrence of disasters,long-term continuous monitoring of mining areas is required.Synthetic Aperture Radar Interferometry(InSAR)technology is increasingly applied to deformation monitoring in mining areas.Open-pit mine is a special land use unit.In mining areas,there are often large deformation gradients,more bare land in mining areas,few artificial features,and dense vegetation around the mining area.Conventional time-series InSAR technology can obtain low density of monitoring points in the mining area.Introduce Distributed Scatterers(DS)InSAR technology to monitor the deformation of the mining area,and explore the suitability of DS-InSAR technology in the deformation monitoring of the mining area.A kriging interpolation method fused with GPS(Global Positioning System)data is proposed to solve the problem of null values in the InSAR monitoring results.The main research and results of the thesis are as follows:(1)Introduced DS-InSAR technology,processed the 29-period Sentinel-1A data for the whole year of 2019,and obtained the deformation rate information of Kunyang Phosphate Mine.The results show that DS-InSAR technology can monitor the spatial distribution of Kunyang Phosphate Deformation,and the phase estimation method based on the covariance matrix eigendecomposition can optimize the original differential interferogram and obtain more phase information.(2)Using the SBAS-InSAR technology to obtain the deformation rate information of Kunyang Phosphate Mine,and comparing the DS-InSAR monitoring results with the SBAS-InSAR monitoring results,it is found that the two results are linearly correlated,the monitoring results are more reliable,and the correlation coefficient is R =8.3;(2)The deformation gradient of Kunyang Phosphorus Mine's dump,the second,third,and fourth mining area is too large,resulting in decoherence in the monitoring results.The larger the deformation gradient,the more serious the decoherence phenomenon;(3)DS-InSAR monitoring The number of monitoring points in the results is more than that of the SBAS-InSAR monitoring results,which is about 1.5 times the relationship,indicating that the KS(Kolmogorov-Smirnov)test homogeneous point identification method can effectively identify distributed targets in the study area and increase the density of monitoring points.(3)Aiming at the problem of null values in the InSAR monitoring results,a kriging interpolation method fusing GPS data is proposed.Using GPS points and InSAR monitoring points located in the null area to perform joint interpolation,the complete annual average deformation rate and deformation time series of Kunyang Phosphate Mine are obtained.Through analysis,it can be seen that the effect of fusion and interpolation of the two kinds of data is better.It is restored and determined that the most severely deformed areas in Kunyang Phosphate Mine are dumps,second mining areas and other places.The interpolation results are verified with GPS points that are not involved in the interpolation processing,which proves that the results obtained by the kriging interpolation method fusing GPS data are more reliable.