Research Of The High-Precision Dual-Channel Sound Velocity Of Seawater Measurement System

With the further exploitation of marine resources, marine monitoring has become the urgent demand. The acoustic velocity of seawater is one of the important parameters in the process of marine monitoring. Seawater velocity measurement is widely used in the error measurement of underwater acoustic equipment like single beam echo sounder, multi beam echo sounder, side scan sonar. The research aim of this thesis is to establish a set of high accuracy dual channel acoustic velocity of seawater measurement system which based on transit time method, the system can finish accurate measurement of acoustic velocity in seawater which at different marine environment. The main work of this paper includes the following aspects:(1) This paper studies the principle and characteristics of measuring sound velocity by three empirical formulas and a variety of direct measurement method. After analyses the advantages and disadvantages of various methods of sound velocity measurement, this paper proposes seawater velocity measurement by transit time method.(2)According to the characteristics of velocity measurement system, establishes the mathematical model of velocity measurement system, and finish the simulation analysis of seawater velocity measurement by transit time method.(3)This paper makes a detailed introduction for dual channel water sound velocity measuring system, including the hardware and software two parts. The hardware part mainly gives the method and function description of the design, which contains control module, time measurement module, power supply module, and communication module.the software part contains the main program flow chart and time measuring core modules. In order to improve the robustness of the system, this paper uses the software programming method to realize anti-jamming. Through the design of hardware system and software system, this paper has improved velocity of the measurement of sound.(4)Establishing the experimental platform of sound speed measurement. The system analyses the dual channel measurement results by experiments of measuring sound velocity. Then it analyses the distance measurement accuracy, echo, sound attenuation, sound delay and so on. These factors all can effect measurement results. This system proves the stability of seawater velocity measurement system.