The Reflection Coefficients Measurement Method for the Underwater Acoustic Materials Based on the Single Vector Hydrophone

单矢量水听器水声材料声反射系数自由场大样测量方法

¹ Acoustic Science and Technology Laboratory, Harbin Engineering University, Harbin 150001, China
² Key Laboratory of Marine Information Acquisition and Security(Harbin Engineering University), Ministry of Industry and Information Technology, Harbin 150001, China
³ College of Underwater Acoustic Engineering, Harbin Engineering University, Harbin 150001, China

Received: 2 September 2018

Abstract

In order to obtain the normal acoustic reflection coefficients of underwater acoustic materials in the free field with the wideband pulse signal, a new measuring method with a single vector hydrophone and the post-processing inverse filtering is put forward. Numerical simulations had been conducted to comparatively analyze the measurement performances of the measuring method. The simulation results show that the present method should be established on the high ratio of signal to the noise and it is not sensitive to the system error. The experiment result shows that the post-processing inverse filtering measuring method is more effective comparing with the method without the post-processing inverse filtering, especially the measurement consequence of the post-processing inverse filtering measurement method tends to the theoretical value when the frequency is higher than 2.5 kHz, because limitation of the transducer.

摘要

为了实现水声材料法向声反射系数的自由场宽带测量，将单矢量水听器作为测量系统的核心设备，结合脉冲声发射技术与后置逆滤波信号处理技术，提出了基于单矢量水听器的水声材料法向声反射系数自由场宽带测量方法，通过矢量水听器电子旋转技术实现直达声与反射声的有效分离。讨论了测量系统误差以及接收信号的信噪比等因素对测量结果的影响，该方法对信噪比有一定要求，但对测量系统误差不敏感。实验测试结果表明：与未经后置逆滤波处理的实验测试结果相比，文中所述方法显著提高了测量性能，但受发射换能器低频发射能力限制，实验结果在2.5 kHz以上与理论值吻合较好。