Surface Collapse Deformation Monitoring of Urban Underground Distribution Network Based on Time Series InSAR

Due to the noise from different sources in the original SAR image data, the error in calculating the surface collapse deformation is relatively large. Therefore, a method for monitoring the surface collapse deformation of urban underground distribution network based on time series InSAR is proposed. At the initial stage of extracting surface deformation, baseline estimation processing was carried out for the surface SAR image data of the original urban underground distribution network. After the residual terrain in the interferogram was eliminated by DEM de leveling method, speckle noise in the surface SAR interferogram was removed by frequency domain filtering, The phase unwrapping of the surface SAR interference fringe pattern of the urban underground distribution network is realized through the regional growth method, and the surface collapse deformation data is determined by accumulating the residual of the interference fringe of each surface SAR image in the time series. In the test results, the error between the monitoring results and the actual measured data of the ground subsidence in the planned area of the underground medium voltage distribution network is always within 0.45mm. Compared with the control group, it has obvious advantages in accuracy and reliability.