| With the vigorous development of China's transportation field,roads and railways have become an increasingly important way for people to travel and transport goods.However,due to the impact of natural disasters and human activities on the environment,several hazards to linear traffic engineering such as road landslides,roadbed instability,road surface collapse and regional surface inhomogeneous deformation have gradually become an important hidden danger to ground traffic safety.Therefore,in order to ensure the safe construction and normal operation and maintenance of linear traffic projects such as roads and railways,the efficient and non-contact remote sensing monitoring of surface deformation along both sides of the line has become an important research topic.Traditional monitoring methods,such as leveling,total station measurement,and GNSS survey,all use point-shaped targets as the monitoring objects.Not only the monitoring period is long but also the relative cost is high,it is difficult to comprehensively analyze the overall deformation along the line.The In SAR technology effectively made up for these defects.This thesis relies on the National Key Research and Development Plan " Precise emergency service system construction and demonstration through Space-Sky-Land and remote sensing synergy obervation ",based on PS-In SAR technology,this thesis carries out the refined deformation research on the interferometric measurement of ground high-coherence targets along the traffic line in Jiangbei District of Ningbo City.The content and results are as follows:(1)Compared with D-In SAR technology,PS-In SAR technology,which takes high SNR PS points as research object,not only overcomes the limitations of space-time decorrelation and APS,improves the accuracy of deformation monitoring,but also can obtain the time-series deformation information of a single scatterer with a high time sampling rate,which provides a new In SAR monitoring and fore-warning data processing technology for the linear traffic project that traverses the complex terrain and large span.(2)Taking the selection of a single main image and the extraction of PS points as entry point,a single main image optimization selection model was established through the principle of maximum comprehensive correlation coefficient and verified by examples.Based on the conventional PS point selection algorithm,a phase noise-based stability identification algorithm for the PS point refinement extraction was proposed and the automatic selection of PS points through the program was realized,on this basis,the thesis focused on the analysis of time-series surface deformation interference mathematical model,as well as the 3D spatiotemporal phase unwrapping algorithm.(3)Taking Jiangbei District of Ningbo City as an example,the 21 scenes 1m high resolution Terra SAR-X data in the study area was subjected to time series interference processing to successfully extract the time series deformation information from July 31,2013 to April 3,2017.The cumulative deformation of PS points and the annual average deformation rate of PS points in the radar line of sight in the study area were obtained.The visualization program of PS points was written in Python based on Google Earth software,and the historical surface deformation in the study area was inverted.(4)Introduced the deformation of the surface and road network in the study area,studied in detail the three-dimensional deformation rate and cumulative deformation time series analysis along the key road network,established a 3D visualization model of deformation and combined with historical image investigation,obtained traffic intuitively cause along the line. |
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