Research On Micro-doppler Suppression In ISAR Image Based On The Theory Of Matrix Filling

For Inverse Synthetic Aperture Radar,the micro-Doppler effect on the target can not only cause the difficulty on parameter extraction and motion error compensation,but will cause the defocused image,forming the interference brand of direction,seriously affecting the image quality.So studying the problem of micro-Doppler control has important meaning for high precision imaging of the ISAR,at the same time in the competition of target recognition with high precision,it has important application value.This paper aimed at the ISAR image's micro-Doppler control problem in the actual application to establish a reasonable and effective mathematical model,and based on the theory of matrix reconstruction to realize the micro-Doppler control study in ISAR image.The main content and innovation points of the paper are as follows:Firstly,the micro-Doppler suppression study plan based on matrix filling theory was set up.Based on analyzing the application background and main affects of the micro-Doppler suppression study in detail,which combined the main methods of the micro-Doppler suppression study;Analyzing the single ISAR image gotten,no matter in the real domain or complex domain the image of micro-Doppler suppression both had the characteristic of low rank,and putting forward the study plan of single ISAR image's micro-Doppler suppression in the real domain and ISAR image's micro-Doppler suppression in the complex domain based on low rank matrix decomposition.In addition,this paper solved the problem of micro-Doppler suppression from another view: firstly,a series of ISAR image came into being,rearranging them into new observation matrix,according to the difference threshold value detecting the low rank and sparse,having sparse and low-rank decomposition,the target and micro-Doppler were divided to achieve the effect of micro-Doppler suppression.The two research plans laid the foundation for the study of the whole paper.Then,analyzing the effect of micro-Doppler based on rotary table RD image shaking and rotating.Aiming at lacking of "point target" model in the early period to represent the situation of target's micro drive information,taking rotary table of airplane as an example to set up the model of rotary table of ISAR image;Combined with the classical RD imaging algorithm,the micro-Doppler effect of vibration and rotation were analyzed in detail;Implementing the echo signal analysis of the micro scattering point and simulation of micro-Doppler effect interference,giving the micro-Doppler effect's result based on the actual measured data,which is the problem resolution of micro-Doppler control study in the below paper.ISAR micro-Doppler suppression based on low rank matrix decomposition was put forward again.Analyzing the micro-Doppler suppression with single scattering point in the complex domain of airplane propeller and the modulus low rank of micro-Doppler suppression image;Focusing on the sparse of ISAR image sparse and low rank of micro-Doppler image to analyze the effective rank of matrix,having SVD low rank fitting for the micro-Doppler ISAR image to guarantee the low rank of micro-Doppler;Combined with Robust principal component analysis(RPCA)and APG to realize the treatment of modulus RPCA and RPCA in the complex domain for ISAR image,and correcting the APG in the complex domain,rebuilding the contraction operator in the complex domain.Then,analyzing and comparing the simulation value of RPCA and treatment effect of complex RPCA in the simulation and measured data Through simulation and measured data treatment,the validity of ISAR micro-Doppler suppression was verified based on low rank matrix decomposition method.Combined with the analysis of image signal-to-noise ratio and coherence coefficient,introducing that the method used in this paper had a good control effect on ISAR image micro-Doppler effect.In the end,in a certain small angle,continuous imaging a series of ISAR images to ensure that the target was not rotated at all,but in this period,the micro Doppler had great change.Therefore,changing each image in a series of images into a one dimensional vector to form a new observation matrix,through the difference threshold to detect and getting the target of low rank matrix,micro-Doppler was sparse matrix,and having low-rank matrix decomposition based on IALM and APG,and having comparative analysis for the experimental results.