Application Of SAR/InSAR In Surface Deformation In Huizhou

Differential Interferometric Synthetic Aperture Radar(D-InSAR),by processing two SAR images acquired at different times and covering the same area,obtains the phase information in the image and measures the centimeter-level deformation of the surface.D-InSAR,with its unique advantages over traditional measurements,has gradually become an important technique for monitoring surface deformation,and it is widely used in surface deformation monitoring.However,on the one hand,its accuracy and reliability are susceptible to the unfavorable factors of interferometric disorientation and atmospheric delay,which limits its performance in the Applications in long slow surface deformation monitoring.On the other hand,in the case of large deformation gradients,the phase untangling error results in the inability to accurately obtain the deformation information at large numbers of levels.In the extraction of surface deformation information,in order to overcome and improve the disadvantages of D-InSAR in two types of ground subsidence applications,slow surface deformation and large gradient of deformation,the time-series InSAR technique is used to invert the slow ground settlement by extracting phase information of stable points and the offset tracking technique is used to obtain large gradient ground settlement based on amplitude information.At present,ground subsidence has brought a lot of harm to people's production and life.Subsidence monitoring has become a particularly important task.In this paper,the principle of SAR extraction of surface deformation and the main steps of data processing have been systematically introduced in view of the above two problems,and analyzed the accuracy of its monitoring and the sources of error that affect accuracy.Based on the introduction of the principles of both techniques,the key aspects of the optimized timing InSAR and offset tracking techniques are further investigated,and use the technology to accurately and effectively obtain the deformation monitoring results,to grasp the spatial and temporal distribution of ground subsidence,and analyze the subsidence mechanism.The main aspects of the study and the results achieved are as follows:(1)Integrate the advantages of(SBAS-InSAR,Small Baseline Subset Interferometry)and(IPTA,Interferometric Point Target Analysis)technologies to study the key technologies and processes of SBAS-IPTA technology.Using the Sentinel-1A data of 89 scenes from 2015.09 to 2019.03,the surface of Huizhou District,Huizhou City,which was slowly deformed for a long time,was monitored to obtain the time series results of the deformation of the area,the characteristics of the temporal and spatial changes of the settlement in the area were analyzed,and the deformation information was related to the relevant geology.The deformation information is combined with relevant geological data and optical images to investigate the cause of the settlement.Combining the leveling measurement results to verify its monitoring results,it is found that the two are consistent,which proves the reliability of the SBAS-IPTA technical monitoring results.(2)Using the idea of SBAS-InSAR technique,optimize the offset-tracking technique to get timing small Baseline offset-tracking technique.During the time series calculation,the deformation rate during the monitoring period is used to replace the average deformation rate to obtain the optimal solution of the time series deformation accumulation amount of the Shangwo stone mine in Longmen County,Huizhou City,which has the characteristics of large gradient settlement.And specific interpretation and analysis of the results,using geological data,rainfall and groundwater level data to analyze other sedimentation factors other than mining,mastering the basic sedimentation laws of the mine,providing a theoretical basis for ecological environmental management and disaster prevention and mitigation in mining areas.