Research On Acoustic Measurement Technology Of Multi-target Water Entry Point

The acoustic signals generated by the target entering the water from high speed into the water can be used to locate the water entry targets.Based on this feature,this paper uses multiple distributed measurement nodes and target underwater acoustic signals to carry out the research on the acoustic measurement technology of multi-target water entry point position.The main contents include the measurement method of target water entry point position,multi-target data association algorithm and the design and implementation of multi-target water entry point positioning software function.Firstly,this paper studies the position measurement method of target water entry point,including the azimuth only intersection location algorithm using the target azimuth information,the intersection location algorithm using the delay difference of the target underwater acoustic signal to each measurement node,and the azimuth delay difference joint location algorithm using the azimuth and delay difference information.Aiming at the problem of redundant measurement information when multiple measurement nodes work at the same time,this paper studies a high-precision positioning algorithm using redundant information.The simulation results show that the positioning algorithm using redundant information can further improve the positioning accuracy on the basis of the original positioning algorithm.In the part of multi-target data association algorithm,this paper studies multi-target azimuth data association and data association based on azimuth delay difference information.In the multi-target azimuth data association algorithm,firstly,all possible association sets are listed,the geometric distance between points in any two intersection sets is calculated,and the final Association set is determined by setting the decision threshold.For the situation that the number of DF lines and the number of measurement nodes may be different in the association combination,the effectiveness of data association is judged by setting the confidence degree.In the data association algorithm based on the combination of azimuth delay difference information,this paper first uses the azimuth only intersection location algorithm to calculate the delay difference between the target signal and the two measurement nodes,then compares it with the actually measured delay difference,and considers the association combination with the lowest evaluation function value as the optimal Association combination,On this basis,the data association method using the measurement information of redundant measurement nodes as the judgment solution is also studied.Simulation results show that the above two multi-target data association algorithms can achieve multi-target batch division.In the design and implementation of multi-target water entry point positioning software,this paper adopts the idea of modularization,and divides the display and control software into several relatively independent modules.This paper focuses on the communication module with the functions of data reception,analysis and distribution,the human-computer interaction module that can realize command interaction and provide visual interface,and the multi-target falling point positioning solution module with the functions of multi-target batch division and target positioning.The correctness and stability of the software are proved by the laboratory electric coupling and lake test combined with the simulation data.