| Conformal array is designed to fit the shape of the carrier surface and conform to aerodynamics.It has broader application prospects in radar,sonar,and wireless communication due to its excellent aerodynamic performance and better parameter estimation effect.In contrast,polarization sensitive arrays have a higher application value than conventional scalar arrays due to their strong anti-interference ability,robust detection capability and high resolution.The research on array parameter estimation algorithms is abundant,but the excellent performance is mostly based on accurately known array manifolds.However,in the process of practical engineering applications,the ideal array conditions without errors cannot be completely satisfied,and various errors are difficult to avoid,which affects the actual array manifold to some extent.Most of the existing array error correction algorithms analyze and derive errors of a single type.This paper focuses on the parameter estimation problem of non-ideal array in the spatial-polarization domain and studies the parameter estimation problem when multiple types of errors coexist.The main work of this article is as follows:Firstly,the theoretical basis of signal processing of conformal polarization sensitive array is introduced,including the modeling of the output signal of PSA and the modeling of various array errors.At the same time,a comprehensive error model expression is given based on the characteristics of multiple coexisting errors.For the polarization sensitive array,a joint spectrum estimation algorithm of the fractional-dimension in the spatial-polarization domain is introduced,and the influence of amplitude and phase error on parameter estimation is discussed.Secondly,several classical error correction algorithms are introduced for single type of array error.Considering the introduction of polarization domain and the special nature of correction algorithms,existing correction algorithms are transplanted into vector arrays,fully utilizing the structure of vector arrays for correction.The effectiveness of the correction algorithm is demonstrated through simulation experiments in various scenarios.Thirdly,for non-ideal polarization sensitive arrays with orientation-dependent amplitude and phase error,an offline calibration algorithm based on manifold separation technology is proposed.The manifold separation technology based on non-ideal arrays is studied,and the method of solving the sampling matrix of the effective aperture distribution function is analyzed.The manifold separation technology is applied to polarization-sensitive arrays,and the 2D-PESMUSIC algorithm is proposed for parameter estimation of non-ideal arrays.On this basis,an improved 2D-FFT-MUSIC algorithm is proposed,which significantly reduces the computational complexity.Simulation experiments demonstrate the effectiveness of the algorithm for joint estimation of spatial-polarization domain parameters for non-ideal arrays.Finally,two online calibration algorithms are proposed for non-ideal polarization-sensitive arrays with orientation-dependent amplitude and phase error.One is a rotation calibration algorithm based on the maximum likelihood criterion,which makes full use of the rotation angle of the carrier platform as a prior condition to achieve accurate direction finding of nonideal arrays.The other is an online correction algorithm based on instrumental sensors,which utilizes several precisely known auxiliary sensors to estimate the source direction of non-ideal arrays.Simulation experiments compare the parameter estimation performance of these two algorithms,which show the effectiveness of the algorithms. |
