Deformation Monitoring Of Landslide Based On Distributed Scatter Interferometric Synthetic Aperture Radar

China is a country with frequent geological disasters.The number of landslide disasters accounts for more than 70% of the total geological disasters,which brings huge losses to the national economy and seriously jeopardizes people's production and life.The traditional landslide deformation monitoring methods include leveling and Global Positioning System(GPS)monitoring.However,the former cannot perform large-scale high-density monitoring,and the latter is difficult to provide high-density deformation fields.The newly-developed Interferometric Synthetic Aperture(In SAR)has the advantages of large scope of observation,high accuracy of deformation measurement,and high degree of automation.Therefore,it has achieved good results in large-scale deformation measurement.Although this technique has achieved good application effects in large-scale deformation measurement,it is vulnerable to spatiotemporal correlation and atmospheric delay,and the accuracy is limited by the precision of phase unwrapping,moreover,various errors were introduced during processing,and the accuracy of the long-term time-series deformation monitoring solution is low.For the defects of In SAR technology,Persistent Scatterer In SAR(PS)technology is proposed.Since the PS technique only analyzes the Persistent Scatterer(PS)point in the image sequence,it is less affected by space-time decoherence and noise,and can provide reliable deformation field observations results for the deformation field.However,when using the PS technique to monitor the deformation of a mountainous area where prone to landslide,the PS point can hardly be extracted and the ground deformation information cannot be accurately obtained.In order to improve the density of landslide area of point target detection and strengthen deformation of surface displacement of spatial detail analysis,this paper carried out the DS target recognition and detection methods of research in landslide area,this topic mainly use DS-In SAR technology,by means of hypothesis test,with an appropriate hypothesis test method,selection and target pixels with the same statistical properties of point selection and screening of DS point,combined with the existing PS technique processing,use DS-In SAR technology for deformation monitoring of landslide area,the paper detailed work is as follows:(1)Selecting the appropriate DS target detection method,the core of this paper is to select the appropriate hypothesis testing method to identify the statistical consistency points.In this paper,we use the fast homogenous point selection algorithm,and in the context of gauss hypothesis,the traditional hypothesis testing problem is changed to a method of confidence interval estimation.Compared with the traditional method,this method occupies less memory,high in efficiency and spends less time.(2)Using 18 images of Sentinel-1A in shuibuya hydropower station in hubei province,the time span from March 5,2016 to April 5,2016.Using DS-In SAR technique to solve the temporal sequence deformation of the region.The annual average settlement rate was-44mm/yr~+38mm/yr,and the occurrence time of the landslide was between June and October,and eight landslide areas were detected.(3)In order to test and verify the reliability of method,experimental area is extracted in this paper,at the same time,using the PS method acquire deformation information as comparison,the results showed that the two methods to extract the spatial distribution and change trend of landslides in roughly the same;By looking at the local government reports and authoritative media information,and field investigation,this papers methods of deformation calculating results in conformity with the actual situation,and has high reliability.Theoretical studies and experimental results have shown that using the DS-In SAR technique based on the fast homogenous point selection algorithm for landslide monitoring can not only increase the target density in the landslide area,provide detailed deformation field details,but also effectively perform landslide warning and monitoring with high accuracy and reliability.