一种用于水下小尺度运动阵列的目标波达方向估计方法

Novel Target Direction-of-arrival Estimation Method for Underwater Small-scale Moving Array

为解决水下小尺度运动阵列对目标定位的孔径和样本不足问题,采用合成孔径方法实现孔径的扩展。通过分析相干信源情况下不同阵元数与样本数之比时样本协方差矩阵的谱分离特性,提出采用小快拍的主特征空间目标波达方向估计方法。研究结果表明:仿真实验中,阵元数与样本数之比为5时,该方法依然可以正确分辨4个目标;水池试验中,阵元数与样本数之比为4.8时,该方法同样可以准确分辨3个相邻目标。该方法不需要先验信息如信源个数等,解决了小尺度运动阵列在实际应用时所暴露的孔径和样本方面的固有局限,可满足实际应用需求。

The underwater small-scale moving array is limited by its small aperture and sample size for direction of arrival（ DOA） estimation of coherent target. The passive synthetic aperture technique is used to solve the problem of insufficient aperture. The spectral separation of sample covariance matrix is studied in the case of coherent target. A DOA estimation method for coherent target based on main feature space is proposed,which uses small snapshots. In the simulation,the proposed method can still distinguish the four targets correctly when the ratio of the number of sensors to the number of samples is 5; in the water tank experiment,the above ratio is 4. 8,and it can identify three adjacent targets clearly. The proposed method can achieve better resolution for coherent targets in small samples,which meets the application needs of small-scale motions array of targeting,and requires no priori information of signal source number.