A Method for Underwater Control Point Location Considering Surface Sound Velocity and Coordinate Prior Information

Abstract

The invention provides an underwater control point positioning method considering surface sound velocity and coordinate prior information, and belongs to the technical field of underwater positioning. The invention proposes to take into account the surface sound velocity and coordinate prior information, by analyzing the sound velocity error of the circular navigation method and the acquisition of the control point plane coordinate prior information, the control point coordinates and the water depth value measured by the pressure sensor are regarded as random quantities, and According to experience, the a priori variance of the observed water depth is 0.1% of the water depth, and finally the generalized least squares principle is used to solve the coordinates of the control points. By simulating 50m and 1500m water depth positioning experiments, it is proved that under the condition of not using the sound velocity profile, only considering the surface sound velocity and coordinate prior information, can also obtain high-precision positioning results, which can effectively save ship time and improve operation efficiency. The invention has strong practicability, stable and reliable results and high efficiency, and is mainly used for the transmission of the absolute coordinate reference of the underwater control network.

Description

technical field [0001] The invention belongs to the field of underwater positioning, and in particular relates to an underwater control point positioning method in consideration of surface sound velocity and coordinate prior information. Background technique [0002] The seabed control network is the basis of ocean geodesy, which is of great significance for detecting and monitoring ocean plate movement and crustal deformation. In the process of absolute position calibration of control points, the traditional method is to use ship-borne GPS and underwater ranging equipment to intersect to determine the coordinates of seabed control points. But there are disadvantages: the ranging accuracy is greatly affected by the sound velocity error, and a small sound velocity error will cause a sharp drop in positioning accuracy, especially in deep sea positioning, the positioning error caused by the sound velocity error cannot be ignored. In order to weaken the influence of the sound v...

AI Technical Summary

Problems solved by technology

But there are shortcomings: the distance measurement accuracy is greatly affected by the sound velocity error, and a small sound velocity error will cause a significant drop in positioning accuracy, especially in deep sea positioning, the positioning error caused by the sound velocity error cannot be ignored

In order to weaken the influence of the sound velocity error and improve the positioning accuracy and operation efficiency, some scholars have proposed the circular navigation method. Due to the symmetry of the survey ship trajectory, the influence of the sound velocity error can be effectively weakened when the least squares is used to solve the control point coordinates. However, this method has the problem of low accuracy of vertical solution and instability

[0003] The accuracy of the vertical solution of control points depends on accurate distance measurement, and accurate sound velocity profile is the key to accurate distance measurement, however, the sound velocity profile is related to water temperature, salinity and pressure, and changes irregularly with time and space , so it is difficult and time-consuming to obtain an accurate sound velocity profile

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