高阶声场传感器的噪声空间相关性及其阵列超指向性方法

Spatial correlation of noise for high-order acoustic sensor and its superdirective beamforming method

为改善声呐对水下低频安静型目标的探测能力,本文提出采用高阶声场传感器阵列。本文通过特征波束分解与综合超指向性模型定义了以圆环阵作为单个高阶声场传感器的物理含义,分析了高阶传感器接收噪声的空间相关性,然后通过改进的Gram-Schmidt超指向性模型分析了高阶传感器直线阵在端射和舷侧方向的波束响应、指向性因子、稳健性水平等性能指标。仿真结果表明,高阶声场传感器直线阵在消除栅瓣、降低旁瓣、抑制左右舷模糊等方面具有很大的优势,由7个4阶传感器组成的直线阵的指向性指数在较宽的频带内高于传统声压阵8 dB以上。高阶声场传感器阵列及其超指向性方法对未来声呐阵列设计和探测低频水下目标提供了参考。

In order to improve the ability of sonar to detect underwater low-frequency quiet targets,a new idea is to use a high-order acoustic sensor array.In this paper,the high-order acoustic sensor is defined by the eigenbeam decomposition and synthesis model of circular arrays.The spatial correlation of the received noise of high-order acoustic sensor is analyzed,and then the improved Gram-Schmidt superdirectivity model is adopted to analyze beampatterns,directivity factors and robustness levels of the high-order sensor line array in the endfire and broadside directions.The simulation results show that the high-order sensor array has great advantages in eliminating grating lobes,reducing side-lobe levels,and suppressing left and right ambiguity.The directivity index of the line array composed of seven 4th-order sensors is 8 dB higher than that of the traditional pressure sensor array.The high-order acoustic sensor array and its superdirectivity model contribute to the design of sonar arrays and the detection method for underwater low-frequency targets in the future.