Research On Passive Positioning Technology Under The Deep Ocean Based On Vector Hydrophone

With the gradual maturity of our country’s shallow-sea sonar technology research,deepsea ocean technology has gradually become the focus of scholars’ research.The unique sound velocity profile distribution and sound field propagation characteristics of the deep sea cause the detection and positioning performance of the offshore surface sonar to decline or even invalid.The sound propagation mode of the reliable sound path provides the feasibility of passive positioning in the deep sea,but the array is required to be arranged within the depth margin,which is difficult to implement and very costly.This paper combines deep-sea sound propagation characteristics and vector signal processing technology to study the passive positioning technology of deep-sea single-vector hydrophones.The main research work is as follows:First,the ray theory is explained,the relationship between the multi-path channel and the intrinsic sound ray along with the reflection conditions of different media surfaces are introduced;then construct the deep-sea acoustic vector field model base on the ray theory.The correlation between the sound pressure and the vibration velocity signal is analyzed,and the direction finding method and processing gain based on the average sound intensity and complex sound intensity are studied.The influence of the receiver in different depths on the deep-sea propagation characteristics and detection range is analyzed through simulation.The multi-way arrival structure and its characteristics are analyzed to provide a theoretical basis for the positioning algorithm described later.The deep-sea joint passive positioning algorithm based on single vector hydrophone is studied.Use the single vector MUSIC algorithm to estimate the target elevation angle,perform computer simulation and performance analysis of the algorithm,and give the reasons for the error;combined with the change of the elevation angle with the sound source position,give the fuzzy plane of the distance estimation,analyze the error influence factors and the influence of the search grid on the results;based on the virtual source theory,the interferometric structure of the deep-sea acoustic vector field is deduced,the functional relationship between the oscillation period and the depth in the interferometric structure is analyzed,and the target depth is calculated by extracting the oscillation period.Then compare the depth estimation performance of single vector hydrophone and single sound pressure hydrophone under different signal-to-noise ratio environmental conditions.The application of the passive positioning technology of the single vector hydrophone time reversal mirror in the deep sea is studied.The sound pressure time reversal mirror and vector time reversal mirror are introduced,and the time reversal mirror method based on complex sound intensity is given;then conduct simulation and performance analysis,different type of time reversal techniques under deep sea conditions are simulated,the spatial correlation characteristics of the vector time mirror technology are analyzed,the reason for the appearance of the virtual front is explained,and the method of joint estimation with distance is proposed to obtain the accurate positioning result;the more suitable vector time reverse algorithm under different environmental conditions is given;then analyze the influence of signal-to-noise ratio conditions,search grid and sound velocity profile adaptation on the accuracy of different algorithms.