A Method for Measuring Underwater Acoustic Velocity Based on Phase Difference

Abstract

The invention discloses a water sound speed measuring method based on phase difference. The method includes the steps: synchronously acquiring pre-sampling transmitting signals x1(t) and pre-samplingreceiving signals x2 (t) by the aid of double-path AD sampling modules to obtain tow-path discrete sampling sequences x1 (n) and a x2(n); performing cross-spectrum treatment and cross-correlation calculation on the tow-path discrete sampling sequences x1 (n) and a x2(n); dividing measurement of signal propagation time of sound wave signals in a distance d into phase difference in a single period and the sum of full-period numbers. According to the method, the calculation accuracy of the phase difference in the single period is improved, the measuring accuracy of the propagation time of the sound wave signals can be improved, and the method has the advantages that the phase difference of the sound wave signals in the single period and the full-period numbers are accurately calculated to obtain the propagation time of the sound wave signals. The method is based on ensuring of real-time measurement, measuring processes are simple, measuring accuracy is high, and cost is low.

Description

technical field [0001] The invention relates to a method for measuring underwater sound velocity, in particular to a method for measuring underwater sound velocity based on phase difference. Background technique [0002] At present, the conventional measurement methods of underwater sound velocity mainly include empirical formula method and direct measurement method. The empirical formula method measures the temperature, salinity and depth in the ocean environment, and calculates based on these measured parameters to obtain the sound velocity of water. Although the empirical formula method has a high accuracy in measuring sound velocity, in this method, corresponding instruments must first be used to obtain the temperature, salinity and depth in the marine environment, and then these parameters can be obtained from these instruments. For calculation, the measurement process is complicated, and it takes a long time to obtain the sound velocity. The hysteresis is obvious, and...

AI Technical Summary

Problems solved by technology

However, in this method, the accuracy of the digital measurement of the propagation time directly restricts the accuracy of the sound velocity

Although increasing the acquisition frequency of the analog-to-digital converter can improve the measurement accuracy of the propagation time to some extent, the higher the acquisition frequency, the higher the cost of the analog-to-digital converter, and the acquisition frequency of the analog-to-digital converter at the current technical level is relatively limited , so the measurement accuracy of improving the speed of sound in this way is relatively limited

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