Application Of Sentinel-1A In Monitoring Surface Deformation Of High Slope

Radar technology,which has the characteristics of all-weather,all-time and wide monitoring range,is an important earth observation technology at present.Highway safety is closely related to the stability of highway high slope.In order to ensure road safety,the deformation of highway high slope should be monitored for a long time.In this paper,the Differential Interferometric Synthetic Aperture Rader(D-InSAR)technology is used to monitor the surface deformation of the "pig climbing rock" slope on the highway of Biwei,Guizhou(Bijie to Weining Expressway),combined with the C band data of sentinel 1A(Sentinel-1A)satellite.In this paper,the principle and technological process of InSAR and D-InSAR are described in detail,and the processing methods of D-InSAR are discussed.The method suitable for the study area is selected to extract deformation information of high slope.It shows that the differential interferometry of synthetic aperture radar is suitable for deformation monitoring of high slope of highway.The research contents and results are as follows:1.By comparing the interference processing results of VV polarization and VH polarization,the coherence coefficients of interference patterns of two polarization modes are discussed.It can be seen that better results can be obtained by using VV polarization mode in the study area.2.By comparing and analyzing the processing results of the filtering method and the phase unwrapping method,the optimal Goldstein filtering method and the optimal minimum cost flow unwrapping method are obtained.3.The monthly deformation results corresponding to 11 pairs of data in 2017 are obtained.The 6 and 11 groups of data are validated by the total station measurement results.The deviation between the two results is within the allowable range of the study.The relationship between monthly deformation results and rainfall is analyzed.It is concluded that the deformation of high slope is larger when the rainfall is more than that when the rainfall is less.4.By analyzing the deformation results of "pig climbing rock" high slope from October 27,2016 to December 21,2017,it is concluded that Sentinel-1A data and D-InSAR technology can carry out high-precision slope deformation monitoring.The subsidence information of the high slope of "pig climbing rock" is obtained.It is found that the high slope has settled 3-4 centimeters over the past year.The long-term deformation monitoring of the slope is carried out by using D-InSAR technology,so as to prevent an unrecoverable disaster.