Error Analysis And Imaging Processing In Ground-based Slope Stability Radar

Surface deformation disasters,such as landslie,slippery and debris flow,do great harm to people’s lives and property.Ground-based slope stability radar(GB SSR)can be used to forecast the disasters with advantages of continuity and high precision,which is of great importance to lower the risk of surface disasters doing to people’s lives and property.There are several kinds of GB SSR systems,ground-based synthetic aperture radar(GB-SAR)is one of them,and it synthesizes an aperture by exploiting the movement of the platform on which the antenna is mounted,and then synthetic aperture radar and differential interferometry are used to obtain the deformation information.With the enhancement of monitoring requirement,Multiple-input multiple-output(MIMO)radar technology is applied to GB SSR.This paper does some research on GB-SAR and GB-MIMO radar,detailed information is showed as follows:1: Performance analysis of GB-SAR’s imaging algorithmsIn consideration of GB-SAR system’s characteristics and applications,imaing algorithms applied to GB-SAR system should meet the following requirements:(1)wide range of application scope;(2)as little time as possible spent on imaging;(3)higher precision of deformation measurement.Based on above requirements,three imaing algorithms usually used in GB-SAR,which are BP(Back Procjection),KSD(Algorithm Based on Keystone and Subblock Dechirp)and FPFA(Far-Field Pseudopolar Format Algorithm),are analyzed from three aspects: application scope,computation burden and precision of deformation measurement.Theoretical analysis and experimental results shows that KSD algorithm is suitable for wide observed scenes.2.Quantization of GB SSR’s imaging resultsBecause of blurred details,imaging results of GB SSR systems show limited information of observed scene.This paper studies the statistical distribution of imaging results’ amplitude,proposes some qualtitative methods,and three evalution criteria of image quality are used to judge the quantized results.Experimental results show that LOGN method is more appropriate for GB SSR system,more information of the illuminated area is displayed,and finally observed scene and imaging result have a better match.3.Error calibration of GB-MIMO radar systemGB-MIMO radar obtains synthetic aperture by alternative operation of transmitting antennas and receiving antennas.Because of the introduction of MIMO radar system,several different errors,such as time delay error,the gain phase error and antenna position error,existe in GB-MIMO radar.According to whether the error is space-variant or not,this paper divides system errors into two groups: the first two are the first group,and the rest is the second group.For the two groups,this paper analyzes the characteristics of the system errors,studies the error models,provides correction methods based on external calibration,and simulatilon and experimental datasets are used to validate their effectiveness.