The Research On Multichannel Interferometric SAR Height Reconstruction Method

Synthetic Aperture Radar Interferometry(InSAR)is based on SAR imaging technology and interferometric measurement technology,which can acquire high-precision three-dimensional terrain data in all-weather conditions day and night.It has been applied in many fields such as terrain mapping,surface deformation monitoring,forest mapping and so on.Based on traditional single-baseline interferometric SAR measurement techniques,the multichannel InSAR measurement technology has been developed and has a very broad application prospects.Elevation reconstruction is an important application research direction in the multichannel InSAR measurement techniques.The research of this dissertation is summarized below:This paper analyzes the phase precision of the multichannel InSAR in detail.Since the accuracy of elevation reconstruction is closely related to the accuracy of interferometric phase precision,error analysis was performed on four approximations and assumptions for the currently widely used ECS self-registration imaging algorithm:the equivalent error analysis of relative velocity between radar and diffuser;the quadratic approximate error analysis of distance difference of two antennas with nonlinear self-registration:the second-order Taylor approximation error analysis in nonlinear scaling;the flat ground assumption error analysis in imaging processing.The error analysis provide some guidance for further optimizing the phase retention accuracy in the interferometric SAR imaging,which is very meaningful for the subsequent elevation reconstruction work.To improve computational efficiency of multichannel InSAR elevation reconstruction,a rapid elevation reconstruction method based on the optimal estimation of remainder was proposed.Firstly,after the removal of the flat-earth effect,the wrapped interferometric phase of each pixel was drawn and congruence equations of interferometric phase fuzzy number were constructed.Secondly,the optimal estimation method was used to solve the optimal estimation of the common remainder with noise,and the elevation of each target was solved.Finally,the improved method was used to get higher precision reconstruction results.Experimental results show that the algorithm significantly improves the computational efficiency of multichannel InS AR elevation reconstruction.