Two-dimensional Deformation Monitoring And Analysis Of Landslide Based On Ascending And Descending SAR Data

China is a country with frequent occurrences of geological disasters,and landslides are one of the most harmful geological disasters.Monitoring and studying the formation mechanism and deformation characteristics of landslides is a prerequisite for landslide disaster warning,and it is also very meaningful.Traditional monitoring methods such as leveling,GPS measurement and other technologies are constrained by the disadvantages of low monitoring efficiency,high monitoring cost,and high cost,which are increasingly unable to meet actual needs.Synthetic Aperture Radar Interferometry(InSAR)technology is a satellite earth observation technology developed in recent decades.This technology is characterized by high resolution and accuracy,wide monitoring coverage,low cost,and weather-free all-weather Time observation is a good supplement to traditional monitoring technology.With the development of technology,it is increasingly used in various surface deformation monitoring including landslides.However,the traditional D-InSAR technology is easily affected by factors such as time-space decoherence,DEM error,and atmospheric effects,and the results are not reliable enough.In addition,since the surface deformation monitored by InSAR technology based on single-track SAR data is a singledirectional line-of-sight(LOS)deformation,it cannot truly describe the three-dimensional deformation characteristics of the deformed body.This paper focuses on these two issues.The main research contents are as follows:(1)Through literature analysis,the geometric models and basic principles of InSAR and DInSAR technology are summarized,and the error sources of D-InSAR technology are analyzed and studied.Introduced two time series methods-the technical principles of the small baseline set(SBAS)technology and the permanent scatterer(PS-InSAR)technology,as well as the principle of different error term removal,and summarized the data processing procedures of the two time series technologies;(2)Analyze and summarize the advantages and disadvantages of SBAS technology and PSInSAR technology and their respective applicable fields.The landslide in Voda Village,Changdu,Tibet and its surrounding area are selected as the research area,and the point target analysis(IPTA)technology that combines the advantages of SBAS technology and PS-InSAR technology is used for data processing,and the LOS direction of the lifting orbit data in the research area is obtained.Deformation,the law of landslide deformation is analyzed by selecting characteristic points and characteristic sections.The precipitation data in the study area was collected to analyze the correlation between deformation and precipitation,and the causes and deformation laws of landslides were preliminarily explored.(3)The principle and data processing steps of using multi-track SAR data to reconstruct the two-dimensional or three-dimensional deformation of the deformed body are studied,and the twodimensional velocity deformation field of the landslide and the two-dimensional time series deformation of the landslide are reconstructed using the sentinel data of the lifting rail covering the study area Field,the landslide deformation was reduced to the sliding direction of the landslide,the deformation process of the landslide was inverted more realistically,and the technical feasibility was confirmed.The R/S analysis method based on fractal theory is introduced to analyze the stability of the landslide,and the feasibility of the R/S analysis method in landslide deformation prediction and stability analysis is verified through experiments.