质点振速传感器直线阵超指向性波束形成

Superdirective beamforming of line arrays using particle velocity sensors

声矢量传感器及其组阵方式的研究已成为水声领域的热门课题。该文研究了当单自由度矢量传感器(质点振速传感器)的观测方向沿直线阵轴线方向时的空间均匀噪声场中两阵元的噪声相关系数,然后采用Gram-Schmidt模态波束分解与综合方法推导了高阶超指向性的最优解,得到了直线阵端射方向的指向性指数和稳健性水平。仿真研究表明,当d/λ<0.5(d为阵元间距,λ为波长)时,质点振速传感器直线阵(简称质点振速阵)采用超指向性方法在端射方向的指向性指数略高于声压传感器直线阵(简称声压阵);而当d/λ>0.5时,质点振速阵的指向性指数远远高于声压阵。该文的研究内容对水下声呐系统中质点振速传感器的有效组阵和实际应用具有一定的参考价值。

Research on acoustic vector sensors and their arrays has become a hot topic in the field of underwater acoustic engineering. In this paper, the noise correlation coefficients between the array elements in a spatially isotropic noise field are studied when the desired observation direction of the one-degree-of-freedom vector sensor (particle velocity sensor) is along the direction of the line array axis, and the optimal solutions of high-order super-directivity based on the Gram-Schmidt mode-beam decomposition and synthesis are introduced. Then the directivity index and robustness in the end-fire direction are derived. Simulation results show that the directivity index of the particle velocity sensor array is slightly higher than that of the acoustic pressure sensor array in the end-fire direction when d/λ< 0:5 (d is the spacing of two adjacent elements, is the wavelength);when d/λ> 0:5, the directivity index of the particle velocity array is much higher than that of the acoustic pressure sensor array. The research content of this paper provides a reference on how to effectively form a particle velocity sensor array in underwater sonar systems.