环境噪声场中二阶组合水听器的空间相关性

Acoustic dyadic sensor's correlation in ambient noise fields

二阶组合水听器同步测量空间一点处的声压、振速和振速梯度,由此得到的信息有利于改善声纳的检测和估计性能。对各向同性噪声场中振速梯度的自相关特性,及其与声压、振速的互相关特性进行了研究。推导了各向同性噪声场中二阶组合水听器输出相关性的理论表达式;并分析了一种简单的各向同性噪声的数值模拟方法。利用该方法仿真出的二阶组合水听器的输出相关曲线与理论值基本吻合,验证了理论结果和模拟方法的有效性。该结果对二阶组合水听器阵列设计、性能分析和系统仿真有应用价值。

An acoustic dyadic sensor can be used to measure pressure, particle velocity and velocity gradient at a single point in space. The obtained information is very useful for improving detection and estimation of a sonar. Here, the auto-correlation of velocity gradient, the cross-correlation between pressure and velocity gradient, and that between particle velocity and velocity gradient in a 3-D spherical isotropic noise field were investigated. Noise covariance matrix was derived, and a simple simulation method of an isotropic noise field was analyzed. The numerical simulation results utilizing this method agreed well with the theoretical values. It was indicated that the theory and the simulation method proposed are effective.