Research On Key Techniques Of High Resolution Azimuth Estimation For Conformal Array

With the widespread application of array signal processing in practice,the practical application of high-resolution azimuth estimation of signals is also increasing.Based on external field experiments,the three main problems affecting the resolution of azimuth estimation during the experiment are: the deviation between the actual array element position and the ideal position;the array received signals are coherent signals;the azimuth estimation algorithm itself does not have good azimuth resolution ability.In this paper,three factors that affect the resolution of the azimuth estimation algorithm are taken as the main goal,and the conformal array is used as the signal receiving medium.The key technologies that affect the high-resolution azimuth estimation of the signal are studied: conformal array correction and conformal array reception,decoherent processing and high-resolution bearing estimation algorithms.Firstly,in order to solve the problems of inaccurate azimuth estimation and low algorithm resolution caused by array errors,this paper corrects the array errors.Active correction and self-correction methods have been used to correct the array errors,and the maximum likelihood correction method has been focused on.Secondly,the existence of coherent signals will cause inaccurate azimuth estimation,and most of the decoherence algorithms are only applicable to uniform linear arrays,and cannot be directly used on co-arrays.In order to solve this problem,this paper introduces the virtual array transformation preprocessing,transforms the conformal array into a uniform linear array,and uses the decoherence algorithm accordingly.Finally,the MUSIC algorithm with high-resolution performance is not stable enough,and the stable conventional beamforming does not have high-resolution performance.The use of deconvolution beamforming can solve the above contradictions,but the traditional deconvolution beamforming is only applied to It cannot be directly applied to the conformal array in the change formation.Therefore,referring to the idea of decoherence of the conformal array,this paper performs deconvolution beamforming after virtual transformation preprocessing.Array element position correction based on maximum likelihood method,decoherent processing and deconvolution beamforming after virtual array change preprocessing are the main research contents of this paper.The feasibility of the above method was verified by simulation and the lake test data processing,and three main problems affecting the high resolution of the conformal array were solved,laying a foundation for subsequent experiments.