Positioning Method For Underwater High Speed Target

Localization of underwater targets has always been an important task of underwater acoustic systems and an important application of underwater acoustic technology.With the development of acoustic vector technology and array signal processing technology,some new progress has been made in the acquisition of underwater target information.This paper mainly combines the characteristics of high-speed target movement,and analyzes the problems of less data and Doppler Effect caused by the characteristic of high movement speed.The MVDR algorithm,typical MUSIC algorithm and cross-spectrum algorithm are selected for analysis.Through modeling,theoretical derivation and simulation of line spectrum signals of high-speed targets are given,it is concluded that due to Doppler Effect,MVDR and MUSIC azimuth estimation error increases with the increase of target motion speed.Cross-spectral algorithm can overcome the energy broadening problem by choosing bandwidth.The high-speed target will get less fast beats,which will reduce the performance of MUSIC algorithm and cross-spectrum method.In this paper,G-MUSIC algorithm is used to solve the problem of performance degradation of MUSIC algorithm in the case of small fast beats.In order to solve the problem of locating moving targets,a passive bearing-only tracking method based on dual base stations is adopted,and a target motion analysis method is discussed under the conditions of synchronous arrival and random arrival of bearing sequence data.Research shows that the convergence speed of the method based on random arrival of bearing data is slow.This paper analyzes the factors that affect the azimuth intersection positioning error,mainly including angle error,base station spacing and target distance.The preliminary quantitative analysis of the station distribution conditions required to meet certain error requirements provides a certain reference for the design of multi-station positioning system.In addition,this paper also studies the problem that the localization algorithm based on time delay difference may fail when the target moves at high speed.Finally,the cross spectrum algorithm and the bearings-only location algorithm of double base stations are verified by Sanya sea trial data.The results show that the location error is less than 5%,which proves the effectiveness and practicability of the algorithm.