基于子矩阵波束形成输出直流响应加权的目标检测方法

Target detection method based on beamforming output DC response of sub-covariance matrix

针对同一单频带内未知目标检测中强、弱目标不能同时被检测问题,依据不同子矩阵波束形成输出直流响应值不同,提出一种基于子矩阵波束形成输出直流响应加权的目标检测方法。首先,利用特征分析技术对线列阵接收数据协方差矩阵进行特征分解;然后,对各特征向量进行共轭相乘得到相应子矩阵,并对子矩阵进行波束形成,利用各子矩阵波束形成输出直流响应值的差异形成加权因子;最后,利用该加权因子对各子矩阵波束形成输出结果进行加权统计得到最终合成结果,提升弱目标子矩阵波束形成输出结果在最终合成结果的比重,实现对同一单频带内未知目标的有效检测。理论分析、数值仿真和实测数据处理结果均证明了,在仿真条件下,相比常规波束形成和常规子空间重构法,所提方法使弱目标子矩阵波束形成输出结果在最终合成结果的比重由0.09%变为45.36%,降低了背景噪声和强目标对未知目标检测的影响,减小了目标间输出直流响应值的差异,改善了对同一单频带内未知目标的检测性能。

Aiming at the problem that strong and weak targets can not be detected at the same time in the same single frequency band, according to the differences of beamforming output DC response of every sub-covariance matrix, a target detection method based on sub-matrix beamforming output DC response weighting was proposed. Firstly, the eigen-analysis technique was used to decompose the covariance matrix of the linear array received data. Secondly, the corresponding sub-covariance matrix for every eigenvector was obtained by conjugate multiplication, the sub-matrices were beam-formed, and the difference of beamforming output DC response formed by each sub-matrix was utilized to form the weighting factor. Finally, the weighting factor was used to weight the output of each sub-matrix beamforming to obtain the final result, and the proportion of the weak target sub-matrix beamforming output in the final result was improved, and the unknown targets were effectively detected in the same single frequency band. The results of theoretical analysis, numerical simulation and measured data processing show that under the simulation conditions, compared with the conventional beamforming and conventional subspace reconstruction method, the proposed method increases the proportion of the weak target sub-matrix beamforming output in the final result from 0.09% to 45.36%, which reduces the influence of background noise and strong target on unknown target detection, reduces the difference of output DC response between targets, and improves the detection performance of unknown targets in the same single frequency band.