Research On Deformation Monitoring Of Urban Infrastructure Based On Spaceborne SAR

With the continuous development of urban construction,a large number of infrastructures have been built,such as high-rise buildings,subway,high-speed railway,bridges and so on.Urban infrastructure is an important guarantee of people's lives.On the one hand,due to the rapid development of cities,underground space development,groundwater exploitation and other causes of land subsidence and infrastructure deformation increasingly endanger the health of infrastructure,there is an urgent need for "physical examination".On the other hand,the traditional measurement methods for infrastructUre monitoring in urban areas are facing a series of problems,such as high cost,unsustainable monitoring and so on.As a new measurement technology,synthetic aperture radar(SAR)can continuously observe urban infrastructure with its characteristics of wide range,high precision and all-day.This paper relies on the national key research and development plan of "Precise emergency service system construction and demonstration through synergy obervation,airborne,and ground remote sensing".Taking Taiyuan City and Futian District of Shenzhen City as research areas,the urban infrastructures are monitored based on spaceborne synthetic aperture radar.The main research results and conclusions are as follows:Firstly,starting from improving the accuracy and rationality of PS points recognition,this paper optimizes PS points by using the concept of distance threshold and connectivity in graph theory based on the selection of coherence coefficients.Secondly,this paper studies the construction method of PS network,analyses the limitations of traditional Delaunay triangle network,constructs a free-connection network model,and optimizes PS network based on model correlation coefficient.This paper completes phase unwrapping with zero space matrix and integer programming in the phase unwrapping problem,then solves PS parameters by indirect adjustment,and analyses residual phase.A set of processing program is developed to realize automatic solution.Thirdly,taking Taiyuan City as an experimental area,this paper analyses the regional settlement of Taiyuan City,points out the four settlement funnels of Taiyuan City and explains its development trend,and illustrates the applicability of radar interferometry in deformation monitoring of infrastructure in traditional goaf.This paper analyses and evaluates the deformation of transportation infrastructure such as Shitai Passenger Dedicated Line.By theoretical analysis and experimental study,compared with the traditional PS-InSAR algorithm,the improved algorithm improves the estimation of atmospheric delay,phase unwrapping and redundancy of solving equation.Fourthly,taking Futian District of Shenzhen as an example,in the case of complex coastal atmospheric phase,land reclamation and soft soil foundation,the deformation of the important infrastructure in Futian District of Shenzhen City is monitored by using the proposed algorithm.The deformation of the subway,port and comprehensive transportation hub is accurately extracted,and the settlement of these infrastructure is explained.Using the strategy of building image pyramids and python,the visualization program of InSAR interpretation based on Google Earth is compiled to view the deformation monitoring results intuitively and conveniently.Fourthly,taking Futian District of Shenzhen as an example,in the case of complex coastal atmospheric phase,land reclamation and soft soil foundation,this paper uses the proposed algorithm to monitor the deformation of the important infrastructure such as subway,ports and comprehensive transportation hub in Futian District of Shenzhen,accurately extracts its deformation,and illustrates the settlement of these infrastructure.Using the strategy of building image pyramids and python,the visualization program of InSAR interpretation based on Google Earth is compiled to view the deformation monitoring results intuitively and conveniently.Through theoretical analysis and experimental research,it is proved that the improved algorithm in this paper can effectively suppress the noise and atmospheric delay in the deformation monitoring of urban infrastructure,and can accurately obtain the deformation field of infrastructure,so as to accurately extract its deformation.