多小孔径基阵宽带源声被动定向方法

Acoustic Passive Directional Method of Broadband Source Using Multiple Small Aperture Subarray

提出了一种基于多个小孔径子阵的宽带声定位方法,并成功应用于低空多目标的无源定向中。该方法将目标源辐射的低频宽带噪声通过相干处理,然后构造近似的降秩估计器对目标进行方位估计,有效地解决了通常单个小孔径基阵难以满足的多目标分辨和定向精度要求。由于所构造的估计器不需要各子阵之间的位置信息,从而避免了伪峰和位置估计误差对方位估计的影响。仿真和试验结果表明,该方法提高了多目标的定向精度,给出了稳定的信号方位估计,能较好地实现大气声定位中对近距离多目标的分辨。

An approach for the direction of arrival （DOA） estimation of multiple broadband sources was presented by using multiple small aperture subarrays, and a novel signal model used in rank reduction estimator （RARE） was used to deal with the information from multiple small aperture subarrays. Then approximate RARE estimator was built to estimate DOA of multiple broadband sources. Source resolution and directional precision were increased by extending array aperture. Moreover, false peak that appears in the conventional methods based on eigen subspace was removed from spatial spectrum effectively with the proposed method, and sensitivity to position error was reduced by robust RARE estimator. Simulative and experimental results show that the method achieves better statistical stability and lower threshold of signal to noise ratio （SNR）. Correct DOA estimation can also be obtained in the case of large intersubarray displacement error.