基于协方差矩阵拟合的小平台共形阵稳健波束形成技术

Robust Beamforming Technologies for Conformal Array of Small-Scale Platform Based on Covariance Matrix Fitting

针对无人水下航行器等小尺度平台机动且阵列孔径有限条件下的稳健探测需求,依据应用于小平台U形共形平面阵设计多种波束形成算法。分析快拍数、输入信噪比及导向向量误差等对波束形成方法稳健性的影响。虽然最小方差无畸变波束形成方法具有高阵增益的优点,但其在存在基阵导向向量误差和协方差矩阵估计误差的条件下性能下降较为严重,基于此提出了协方差矩阵拟合波束形成方法和双约束稳健最小方差无畸变响应波束形成方法,并通过数值仿真分析与其他多种波束形成方法对比验证稳健波束形成方法应用于水下小平台共形阵的稳健性。最后在考虑阵元位置误差时通过消声水池实验对多种波束形成方法的实际性能进行进一步对比验证。

To achieve robust detection on small-scale platforms like unmanned undersea vehicles(UUVs),which arecharacterized by their limited maneuverability and array apertures,various beamforming algorithms were designed byleveraging U-shaped conformal planar arrays specifically tailored for small-scale platforms.The impact of factors such assnapshot rate,input signal-to-noise ratio,and steering vector errors on the robustness of these beamforming technologies wasanalyzed.Although the minimum variance distortionless response(MVDR)method is noted for its superior array gain,itsperformance significantly deteriorates in the presence of steering vector errors and inaccuracies in the covariance matrixestimation.To mitigate these issues,the covariance matrix fitting-based beamforming method and the dual-constraint robustMVDR method were introduced.The robustness of the robust beamforming methods applied in conformal arrays ofunderwater small-scale platforms was validated through numerical simulations and comparison with various beamformingtechnologies.Finally,the actual performance of various beamforming technologies was further compared and verified by anechoic pool experiments with the array element position error considered.