矢量水听器扩展孔径线阵方位估计技术

矢量水听器由声压水听器和质点振速水听器复合而成,可以同时测量声场中的声压和质点振速的正交分量,将矢量水听器布成阵列对目标方位进行估计.在不增加阵元个数的情况下,可以把阵布成稀疏阵来增加阵孔径,提高对目标方位的估计精度.按照耐奎斯特空间采样定理,阵元间距超过半波长将会带来方位估计的周期性模糊.该研究利用扩展孔径矢量线阵对目标进行方位估计,以及研究如何去掉方位估计中的周期性模糊,最终获得目标方位的高精度无模糊估计.研究结果表明,在相同的信噪比条件下,利用扩展孔径矢量线阵可获得比具有相同输出路数的声压阵更好的方位估计性能.

DOA estimation using extended-aperture uniformly linear vector-hydrophone array

A vector-hydrophone is the combination of a traditional pressure hydrophone and velocity hydrophones which simultaneously measures the acoustic pressure and three orthogonal components of acoustic particle velocity in a sound field. Direction of arrival(DOA) estimation of a source can be obtained by a vector-hydrophone array. An array aperture with enlarged aperture size by sparsely spacing vector hydrophones generally offers enhanced array resolution and direction-finding precision. Extending the uniform intersensor spacing beyond a half-wavelength would lead to a set of cyclically ambiguous direction-of-arrival estimates, in accordance with the spatial Nyquist sampling theorem. This study used an extended aperture vector-hydrophone linear array to enhance the direction-finding precision of sources and investigated how to remove the cyclically ambiguous of direction-of-arrival estimation. The results indicate that higher resolution for DOA estimation can be obtained by using a vector- hydrophone uniform linear array rather than a pressure hydrophone uniform linear array which had the same output channels.