基于深海海底反射区匹配到达结构的声源深度估计方法

Matched arrival pattern-based method for estimating source depth in deep sea bottom bounce areas

针对近海面水平阵在深海海底反射区估计声源深度的难题,本文基于虚源理论推导了海底反射区的声波到达结构,解释了到达结构与声源-接收器深度之间的正弦调制关系。定义了匹配到达结构的非相干模糊度面,提出了基于匹配到达结构的声源深度估计方法,该方法与传统匹配场方法相比,无需考虑环境参数引起的失配问题,仿真分析验证了此方法实现深度估计与深度辨识的可行性。通过仿真分析发现:输入信噪比越低,深度估计所需的基阵孔径越大;当处理带宽过小时,深度估计模糊度面受到海面处旁瓣的干扰严重,难以准确估计真实的声源深度;基于水平阵估计深海海底反射区声源深度的匹配到达结构方法的适用距离为6倍海深。

To solve the problems in estimating source depth in deep sea bottom bounce areas using near-surface horizontal arrays,this study derives the arrival patterns of acoustic waves in bottom bounce areas on the basis of virtual source theory and explains the sinusoidal modulation relation between arrival patterns and source-receiver depth.A method based on matched arrival pattern processing is also proposed for source depth estimation,and the incoherent ambiguity surface of matched arrival patterns is defined.Relative to the traditional matched field method,the proposed method does not require the consideration of the mismatch caused by environmental parameters.Simulation analysis results verify the feasibility of the proposed method for depth estimation and recognition.Through simulation analysis,this work raises the following points:(1)the lower the input signal-to-noise ratio is,the larger the array aperture required for depth estimation;(2)when the processing bandwidth is too small,the depth estimation of the ambiguity surface is seriously disturbed by the sidelobe at the sea surface,thereby hindering the accurate estimation of the real source depth;(3)the maximum applicable distance of the proposed method based on horizontal arrays is six times the sea depth.