Research On DOA Estimation Algorithm For Polarization Sensitive Array Coherent Sources Based On Uniform Circular Array

Spatial spectrum estimation technology is one of the main research contents in the field of DOA estimation.It has attracted the attention of a large number of researchers,because of the significant advantages in many aspects such as estimation accuracy and antenna formation adaptive ability,etc.Subspace algorithms such as Multiple Signal Classification(MUSIC)can detect Multiple signals in the same beam.But in the actual situation,there are often a large number of coherent signals in the direction-finding environment,which greatly reduces the performance of this kind of algorithm.The electromagnetic environment of modern battlefield is becoming more and more complicated,which puts forward higher requirements for electronic countermeasure technology.In order to improve the decoy resistance and direction finding performance of the passive radar direction finding system,the polarization information is introduced into the system to form the polarization sensitive passive direction finding system.By introducing the polarization information into the antenna array,the spatial information and polarization information of the incident signal can be detected simultaneously,which can effectively improve the overall direction-finding performance of the system.In this paper,according to the characteristics of the layout of the missile-borne array antenna,the uniform circle array model is adopted.The uniform array model can achieve omnidirectional two-dimensional direction finding of azimuth and pitch Angle.But for the coherent signals,the antenna receiving data matrix is very complex due to the placement of the uniform round array model,which leads to very complicated data processing in direction finding.In this paper,uniform circular arrays are processed by means of moving to solve the problem that ordinary scalar circular arrays cannot find the direction accurately when coherent signals are incident.The uniform circular array coherent algorithm is introduced into the polarization sensitive array,and the polarization information can be used to improve the angular resolution and effectively distinguish the radar signal and the decoy signal,so that the algorithm is more suitable for the direction finding system of the missile-borne radar.In this paper,the uniform circular array coherent resolution algorithm is introduced into a single dipole polarization-sensitive uniform circular array and a single dipole oblique moving coherent resolution algorithm is proposed.Firstly,the polarization information is introduced into the uniform array model.Secondly,the coherent signal is decoherence processed by the oblique movement of a single dipole uniform circular array.Then the rank-deficit MUSIC algorithm is used to estimate the Angle of coherent signals.Simulation results show that the single dipole uniform circular array skew moving algorithm is effective.Considering the direction-finding system of missile-borne radar,in order to make the direction-finding array model more suitable for radar seeker,a single dipole uniform circular array radial motion coherence algorithm is proposed,and the influence of the array velocity on the correlation coefficient of incident signal is analyzed.The coherent resolution algorithm of uniform circular array is combined with polarization-sensitive array,that is,The coherent signals are decoherence processed by the radial movement of a single dipole uniform circle array.Then,the rank deficit MUSIC algorithm is also used to detect the Angle and polarization information of coherent signals.On this basis,a single dipole uniform circular array curve moving algorithm is proposed.Furthermore,a single dipole uniform circular array curve moving algorithm is proposed,which can effectively resolve the coherence even when the Angle between multiple incident signals and the initial moving direction of the array moving is the same.