A sound ray correction method and system based on an underwater acoustic ultra-short baseline positioning system

Abstract

The invention provides a sound ray correction method based on a water sound ultrashort baseline positioning system. The method comprises the following steps: obtaining an initial glancing angle theta0 through a quaternary cross-shaped stereoscopic water sound ultrashort baseline positioning system; measuring the sound velocity profile through a sound velocity profiler; carrying out the sound ray correction iteration on the basis of the sound velocity profile in a mode of layer adding according to the initial glancing angle theta0 through the quaternary cross-shaped stereoscopic water sound ultrashort baseline positioning system, so as to solve the coordinates of each detection point relative to a measurement ship. According to the invention, the method obtains a phase difference estimation value according to a quaternary stereoscopic water sound ultrashort baseline array, and the iteration is carried out through employing an adaptive layered adding method, thereby solving the coordinates of each detection point relative to the measurement ship. Compared with a conventional mean sound velocity algorithm, the method greatly improves the range finding precision, effectively corrects a curved propagation path of sound rays in an underwater complex environment, and improves the underwater range finding and positioning precision of the water sound ultrashort baseline positioning system.

Description

technical field [0001] The invention relates to the technical field of marine surveying, in particular to a sound ray correction method and system based on an underwater acoustic ultra-short baseline positioning system. Background technique [0002] The ultra-short baseline positioning system is widely used in the field of underwater positioning due to its small size, light weight, and easy portability. The positioning principle is to use the phase difference (or delay difference) between the underwater response signal to the receiving unit and the slant distance between the underwater measurement target and the ultra-short baseline array to achieve positioning. The sound source at a certain depth from the sea surface emits an acoustic signal downward at a certain angle. When an underwater target is found, the target will reflect the acoustic signal to the receiver, and then obtain the distance from the target to the sound source according to the signal propagation time and ...

AI Technical Summary

Problems solved by technology

Because the parameters such as temperature, salinity and pressure of seawater at different depths are different, this leads to the propagation of the acoustic signal in the seawater not only along the curve, but also the sound speed in each layer is not the same, and finally makes the use of acoustic signals to analyze water Lower target positioning produces refraction errors

If you directly use the triangular relationship to simply calculate the depth and horizontal displacement of each point, it will bring a large error to the final position calculation. In order to ensure high positioning accuracy, sound ray correction must be performed

However, the traditional average sound velocity algorithm can only effectively reduce the positioning error, and the positioning estimation is not accurate enough.

Wang Yan et al proposed an iterative method for sound ray correction of long baseline underwater acoustic positioning system based on the bending of sound ray when the sound velocity propagates underwater, which improves the positioning accuracy, but this method has a large amount of calculation and is only suitable for long baseline The hydroacoustic positioning system encountered certain difficulties when applied to the short baseline plane formation

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