Coastal Surface Deformation Based On DS-InSAR

With the rapid development of economy and over exploitation of underground resources,the settlement phenomenon of surface is gradually obvious.Therefore,the surface subsidence monitoring is particularly important.Most of the traditional methods of surface subsidence monitoring are synthetic aperture radar interferometry,but there are some restrictive factors in a long time,which is difficult to meet the actual needs of monitoring.Therefore,it is very important to study time series synthetic aperture radar interferometry based on distributed targets(DS-InSAR).Through the research on the key technology of DS-InSAR —— DS point selection and phase optimization,this paper compares BWS test and Fa SHPS algorithm in order to select DS points better.On this basis,the method of DS point phase optimization ——maximum likelihood estimation method is verified.Finally,the method is used to monitor the surface deformation in Caofeidian coastal area,and the results of surface subsidence in the study area and its influence on the surface subsidence are obtained land surface changes in space and time.Therefore,the research results are as follows: in terms of selection efficiency and computational efficiency,Fa SHPS algorithm has more advantages than BWS test;the phase optimization method of DS points —— maximum likelihood estimation,can effectively optimize the phase,and the coherence after optimization is also improved to a certain extent;based on DS-InSAR technology,the surface deformation of Caofeidian coastal area from August 2018 to April 2019 is monitored by Sentinel-1A data,and the temporal surface deformation results of the area are obtained: Firstly,there are two areas of serious subsidence and uplift in Caofeidian coastal area,which are Caofeidian Industrial Zone and Tangshan Bay eco city.The overall subsidence rate of Caofeidian Industrial Zone is-26.36 ? 22.38mm/a,while that of Tangshan Bay Eco city is-26.15 ?22.33mm/a;secondly,combined with the changes of surface features based on objectoriented classification during the study period,the paper focuses on the analysis of the specific settlement conditions and the causes of deformation in the two serious settlement areas of Caofeidian Industrial Zone and Tangshan Bay Eco city.For the government departments in view of Caofeidian faced with the comprehensive planning and earthquake prevention and mitigation work to provide relevant supporting materials and basis.Figure 37;Table 5;Reference 53...