Scattering characteristics analysis of conformal array based on sound field prediction method

基于声场预报的共形体积阵散射特性分析

School of Marine Science and Technology, Northwestern Polytechnical University, Xi’an 710072, China

Received: 3 September 2021

Abstract

In order to study the problem that the array manifold of conformal arrays deviates from the ideal value due to the sound scattering caused by the rigid baffles of arrays, in this paper, the influence of the scattering phenomenon caused by the rigid baffle on the receiving response of array is analyzed by using sound field prediction method based on a conformal array-semi-cylindrical volume array. The sound field distribution of conformal array at different angles is calculated by using the sound field modeling and simulation. Based on the above distribution, an actual array manifold is constructed under consideration of rigid barrier, and its variation under the influence of scattered sound is analyzed. The variation is described by two physical quantities defined in this paper: the first-order response composed of amplitude and phase and the second-order response composed of cross-correlation. Simulation shows that compared with the ideal model, the scattered signals generated by rigid baffles on conformal array varies with the azimuth and signal-to-noise ratio(SNR), which further leads to the deviation of each hydrophone of conformal array. The experimental data verifies that the simulation results are basically consistent with the actual situation. The effect of the scattering on the conformal array should be considered when designing and performing in practice.

摘要

针对刚性障板引起的声散射现象导致的共形体积阵阵列流形偏离理想值这一问题, 以一类特殊形状的共形体积阵——半圆柱体积阵为模型, 运用声场预报方法, 分析了刚性障板引起的散射现象对阵列接收响应的影响。通过声场建模仿真, 计算了不同角度下共形体积阵的声场分布; 利用该分布构建了考虑刚性障板影响的基阵阵列流形, 分析了其在散射声场影响下的变化规律, 该变化规律采用文中定义的2个物理量描述: 幅度相位构成的一阶响应和互相关构成的二阶响应。仿真结果表明, 相较于理想条件下的透声模型, 体积阵阵列接收到的由障板等刚性物体产生的散射声信号随方位、信噪比的不同而变化, 进一步导致各个阵元的接收响应出现随方位变化而变化的偏差。通过对实验数据的分析, 验证了仿真结果与实际情况基本吻合; 在实际中设计这类基阵时, 应该考虑散射现象对其阵处理性能的影响。