Research Of Target Positioning Method Based On Sound Field HBT Interference

With the development of marine resources and military electronic technology,underwater acoustic positioning technology has become a research trend.Due to the characteristics of good concealment and strong anti-interference ability of passive location technology,it is more and more widely used in military and civil applications.The existing method has problems such as large positioning error and long calculation time in silent target positioning,which brings severe test to the accuracy of passive positioning.Research on long-distance underwater passive positioning algorithm has become a hot topic in the industry.The theoretical analysis,simulation and experiment were carried out to study on underwater target passive location algorithm with low signal-to-noise ratio(SNR),so as to achieve target location with low SNR.The main research contents are as follows:Firstly,the Hanbury Brown-Twiss(HBT)interference principle is introduced into the sound field according to the characteristics of the current passive localization algorithm.,and the HBT interference localization model is established according to the sound field HBT interference principle.it would be a theoretical support for the subsequent simulation and experiment.Secondly,according to the HBT interferometric positioning model,the detection effect of the sensor array topology and HBT interferometric positioning method under different environmental parameters is simulated and analyzed,and the influence of different errors on the positioning effect is analyzed.The simulation results showed that :(1)The obtuse triangle array is better than linear array and isosceles triangle array;When the number of arrays is greater than or equal to 2,accurate positioning at 5000 meters can be achieved.(2)When the number of different frequencies and the SNR of the sound source is 0.04,the remote multi-sound source location can be realized.(3)Sensor array Angle offset,sensor delay is proportional to the positioning error,the Angle deviation within 0.1°,sensor delay within 25 us,error less than 3%,The gain has little effect on the positioning error.Finally,according to the results of theoretical and simulation analysis,the overall scheme of the experiment is designed.The test results showed that :(1)The air location experiment result showed the target with the sound source level 85 dB,42 meters distance was accurately positioned and the error was lower than 0.1m.(2)In the lake water location experiment,a low SNR positioning experiment of single-frequency and multi-frequency sound source signals at 215 meters was realized.The experimental results were consistent with the simulation.It provides a new idea for the study of the long-range target location in sound transmission medium(air,water,etc).