Waveguide invariant estimation based on correlation coefficient of tonal acoustic intensity interference fluctuation

利用线谱声强干涉起伏相关系数估计波导不变量

¹ School of Marine Science and Technology, Northwestern Polytechnical University, Xi'an 710072, China
² Shaanxi Key Laboratory of Underwater Information Technology, Xi'an 710072, China
³ College of Information Science and Electronic Engineering, Zhejiang University, Hangzhou 310058, China

Received: 22 August 2022

Abstract

The waveguide invariant is usually not extracted from the striation pattern of broadband continuous spectrum in the low frequency analysis and recording spectrum at low signal-to-noise ratio. In this paper, the correlation coefficient of multi-tonal acoustic intensity interference fluctuation is utilized to estimate waveguide invariant. Since the proportional relationship between the reference intensity interference fluctuation and the scaled intensity interference fluctuation is dependent on waveguide invariant, the waveguide invariant estimation can be done. Firstly, the tonal intensity interference fluctuation has been resampled in the new time domain under the radial and non-radial motion models respectively. Then, the similarity degree between the resampling reference tonal intensity interference fluctuation and the scaling tonal intensity interference fluctuation can be described by correlation coefficient, and the peak of correlation coefficient is corresponding to the true value. Finally, the numerical results and the experimental results prove the proposed method's effectiveness.

摘要

针对低信噪比时难以利用低频分析记录谱中宽带连续谱条纹状干涉图样提取波导不变量的问题, 提出了一种利用线谱声强干涉起伏相关系数估计波导不变量方法。该方法根据参考线谱声强干涉起伏与经过尺度伸缩变换的线谱声强干涉起伏之间存在的正比关系包含波导不变量这一事实, 构造线谱声强干涉起伏相关系数以实现波导不变量估计。讨论在声源相对水听器径向和非径向2种运动模型下, 将原始采样时刻代换为新的采样时刻, 得到重采样后的线谱声强干涉起伏; 利用相关系数表示重采样后的参考线谱声强干涉起伏与经过尺度伸缩变换后的线谱声强干涉起伏之间的相似程度, 得到不同波导不变量搜索值下的相关系数, 其峰值对应的搜索结果就是波导不变量真值。仿真实验和实测数据处理结果表明, 所提方法能有效实现波导不变量估计。