Estimation Of Ground Deformation In Transmission Corridor Area Using Time Series InSAR

With the rapid development of the economy,the demand for electricity has grown explosively.However,China's land area is huge and its geographical environment is very different.Some power transmission corridor are forced to meet the needs of the actual situation and need to pass through some areas with complex geological conditions.During the course of operation,they need to be monitored in real time.However,in areas with complex geological conditions,conventional monitoring methods are time consuming and costly.Synthetic Aperture Radar(SAR)is a new type of active microwave sensor that can achieve all-time,all-weather observations of the earth.It plays a decisive role in the field of remote sensing.The SAR interferometry technology is an emerging technology that uses the SAR image phase information to extract surface deformation.Among them,time-series InSAR technology can overcome some difficulties in traditional SAR interferometry,and is widely used in the field of surface subsidence monitoring,seismic coseismic deformation field inversion and other fields,reaching millimeter-level accuracy.However,the traditional time-series InSAR technology requires a large number of SAR images in the same area.Due to topographical factors,reliable monitoring results cannot be obtained in some areas.The research content of this paper is mainly to use improved timing InSAR technology to extract the surface deformation of the power transmission corridor,and the results are compared and verified.Most of the transmission corridors in the Southwest China are in remote mountainous areas with complex geological conditions and diversified vegetation types.The ground objects have unstable backscattering characteristics.Therefore,general InSAR technology cannot effectively monitor surface deformation.In this paper,timing InSAR technology has been deeply studied.The permanent scatterer interferometry technology and small baseline interferometry technology have been jointly used.16 high-precision,single-polarity TerraSAR-X images have been used to achieve surface deformation monitoring of the transmission corridor in the mountainous area.This paper first analyzes and studies the SAR interferometry technology and SAR differential interferometry technology.Then,the current status and practical application of timing InSAR technology are summarized and analyzed.Combining the advantages of permanent scatterer SAR interferometry and small baseline SAR interferometry,the series of SAR images acquired in the same target area was used to successfully extract the annual average surface deformation rate.This technology makes it possible to extract the terrain deformation of transmission corridors in a complex area of the earth's surface.In this paper,on the premise of reducing the number of images and data processing time,a sufficient density of high coherence points is selected within the target area.After that,the two types of high-coherence points acquired are jointly processed,phase unwrapping is completed,and various error terms are separated from the differential interference phases to obtain the annual average surface deformation rate of the target region.Finally,this article projects the acquired results to Google Earth and uses other information to interpret the surface deformation results obtained.Due to the lack of measured data from the ground,this paper uses the data processing results of current mainstream business software as a reference,and compares the data processing results of this paper with the verification of the results.The results show that the improved timing InSAR technology is used in this paper to realize the monitoring of the surface deformation of the transmission corridor in a complex terrain area.