基于互相关法的海水声速测量方法研究

发布时间：2018-06-26 07:21

本文选题：声速测量 + 互相关法　；参考：《天津理工大学》2017年硕士论文

【摘要】：精准的声速能够及时有效地为测深仪、测距仪、声纳仪等水声设备校正测量误差提供准确的声速数据,良好地反应海洋环境状况,对海洋研究、海洋监测有重大意义,是当今水文研究领域不可或缺的重要参数。本文主要对水中声速测量算法进行研究,实现对水中声速值的精确测量。论文从以下几个方面展开:(1)对海水声速分布特点以及主要影响因素进行分析总结,归纳了温度、盐度以及压力对声速的影响规律。对声速间接测量方法、直接测量原理及特点分析总结,重点阐述了时差法声速测量原理、特点以及现有测量技术的研究概况。(2)针对超声波发射信号与接收信号之间相关性强,与随机噪声相关性弱的特点,采用互相关法获取超声波传播时间,利用双光束激光干涉仪测量超声波传播距离,实现对声速的直接测量。(3)超声波信号在传播过程中受外界噪声干扰,为提高时间测量精度,对采集的接收信号数据开展了小波阈值去噪技术的研究,互相关法求超声波传播时间后进行抛物线插值,提升了超声波传播时间测量精确度。(4)利用恒温水槽、高精度铂电阻温度计及精密测温电桥、高分辨率数据采集系统等建立实验系统,分别在海水和纯水中进行声速测量实验。对测量环境数据、超声波传播距离以及传播时间测量不确定度进行评定,验证了基于互相关法的声速测量方法的可行性。
[Abstract]:Accurate sound speed can provide accurate sound velocity data for the correction and measurement errors of bathymetry, rangefinder, sonar and other underwater acoustic devices in time and effectively, and can well reflect the marine environmental conditions. It is of great significance to ocean research and ocean monitoring. It is an indispensable and important parameter in the field of hydrological research. In this paper, the algorithm of acoustic velocity measurement in water is studied, and the accurate measurement of sound velocity in water is realized. The main contents of this paper are as follows: (1) the characteristics of the velocity of sound in seawater and the main influencing factors are analyzed and summarized, and the influence of temperature, salinity and pressure on the velocity of sound is summarized. This paper analyzes and summarizes the indirect measurement method of sound velocity, the principle and characteristics of direct measurement, and emphatically expounds the principle, characteristics and research situation of the existing measurement technology. (2) aiming at the strong correlation between the ultrasonic emission signal and the received signal, Because of the weak correlation with random noise, the ultrasonic propagation time is obtained by cross-correlation method, and the ultrasonic propagation distance is measured by using a dual-beam laser interferometer. To realize the direct measurement of sound velocity. (3) the ultrasonic signal is disturbed by external noise in the process of propagation. In order to improve the accuracy of time measurement, the wavelet threshold de-noising technology is developed for the collected received signal data. After calculating ultrasonic propagation time by cross-correlation method, parabola interpolation is carried out to improve the accuracy of ultrasonic propagation time measurement. (4) using constant temperature flume, high precision platinum resistance thermometer and precision temperature measuring bridge, A high resolution data acquisition system was established to measure the sound velocity in seawater and pure water respectively. The uncertainty of measuring environmental data, ultrasonic propagation distance and propagation time is evaluated, and the feasibility of the method based on cross-correlation is verified.
【学位授予单位】：天津理工大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：P733.2;TB566

【相似文献】