Study And Engineering Application On Permanent Scatterers Interferometric Synthetic Aperture Radar

With the rapid development of China’s high-speed railway,high-speed railway deformation monitoring has gradually received widespread attention.At present,China’s high-speed rail has a very fast speed and a large number of passengers,which causes the railway track to bear great pressure.Many high-speed railways are built on the viaduct.The bridge will withstand gravity and sway for a long time,which will inevitably cause deformation of the pier.China’s high-speed railways extend in all directions,and the geological conditions in different regions are different.Some metro areas are soft and easy to form railway settlement.All of the above problems will cause safety hazards in railway traffic,so railway deformation monitoring is very necessary.In recent years,the Interferometric Synthetic Aperture Radar(In SAR)technology has been continuously developed to provide long-term ground monitoring with all-weather,uninterrupted,wide-area and high spatial resolution,and is not affected by bad weather.It has a greater advantage in optical images.Based on this,the Differential Interferometric Synthetic Aperture Radar(DIn SAR)can be used to measure surface deformation,but it is difficult to improve the deformation measurement accuracy due to the influence of atmospheric delay and time-space baseline disassociation.Permanent Scatterers in Differential SAR Interferometry(PSIn SAR)uses permanent scatterers as research objects and is not affected by time-space baseline disassociation.It is widely used in the field of surface deformation monitoring and inherits the advantages of In SAR technology.High surface deformation monitoring accuracy.PSIn SAR technology can achieve millimeter-scale surface deformation monitoring accuracy and decimeter-level DEM elevation error estimation accuracy.This paper mainly studies PSIn SAR and DIn SAR data processing methods,and on the basis of theory,it applies engineering application for PSIn SAR and DIn SAR data processing.The main research work is as follows:1.A detailed understanding of the current situation of surface deformation in China and a focus on the application requirements of China’s high-speed railway for railway settlement monitoring and the feasibility of PSIn SAR for railway settlement monitoring.2.By analyzing the components of the interference phase,the basic principle of DIn SAR data processing is introduced.The data processing flow of DIn SAR is analyzed in detail and the source of error in the data processing process is analyzed to provide theoretical basis for subsequent engineering application.Finally,the surface deformation monitoring experiment of Jiuzhaigou earthquake on August 8,2017 is carried out in combination with the measured data of Sentinel-1A.The surface deformation results of the Jiuzhaigou earthquake zone and its vicinity.Proven the ability of DIn SAR in surface deformation monitoring.3.The PSIn SAR data processing principle and data processing flow are analyzed in detail,and the recognition and construction methods of permanent scatterers(PS)are studied.The existing PS points are compared through the measured data.The advantages and disadvantages of the method.On this basis,the settlement monitoring of Xi’an High-speed Railway North Station and its surrounding area was carried out through 36 Sentinel-1A measured data with a time span of 4 years,and the settlement rate field of the Xi’an section and surrounding area of Zhengxi high-speed railway was obtained.The results were analyzed in detail.4.With the continuous development of spaceborne interferometric synthetic aperture radar,the interference data available for data processing is rich and the amount of data is huge.To achieve efficient,fast and high-precision data processing,the PSIn SAR data processing system and DIn SAR data processing system are engineering.Application is very necessary.Starting from the differential interference processing,the PSIn SAR data processing system and the DIn SAR data processing system are divided into independent sub-links.Each link is designed with independent input and output and parameter setting interface.The whole software system is designed with a unified error reporting system,which improves the overall Software stability.