Research On Passive Location Of Near Small Target Based On Bearings-only TMA

Bearings-only passive positioning technology is one of the earliest and the most studied and the most widely used method.Use the method of solving triangle to get the target's distance and position by the target azimuth data obtained through multi-arrays hydrophone.Positioning accuracy is related to measurement error of bearing data,the target position,the target distance,the array aperture,the baseline length of the measurement error,the accuracy of the array installation and other factors,The measurement of bearing data is the key facter.The high-precision estimation of bearing is the key to improve the positioning accuracy.This paper studies passive positioning performance for short-range small target by multi-arrays joint bearings-only passive positioning technology.Firstly,the problem of the testability of bearings-only TMA based on multi-arrays is analyzed,dual arrays can be measured everywhere except the vicinity of the baseline,the four-arrays has no unmeasured area through the redundant matrix of the weighted synthesis.The high-precision estimation of bearing is the key to improve the positioning accuracy.Bearing estimation of a single vector hydrophone is analyzed through the theoretical and the follow-up simulation.Obtained the relationship of bearing estimation error and the ratio of signal to noise,it provides a theoretical basis for the pure bearign target passive positioning technology based on multi-element submarine array.Then,the calculation formulas of dual-array and quaternion array are given.Simulation analysis the main factors affecting the positioning accuracy and target positioning accuracy in different positions of the array are simulation analyzed which provide basis for dispose the follow-up experimental data.Smooth(rlowess)method is used to preprocess the azimuth data,positioning accuracy get more increase.For post-processing,"round filter" filter and Kalman filter method is used.Theoretical studies that under the condition of samples above 50%,this method can filter all the flaws.Subsequent matlab simulation and experimental data processing verify the applicability of the method.Finally,sea trial data processing result are compared to the GPS data with high accuracy.The results show that In short-range passive positioning,horizontal linear motion targets within the baseline that the distance between the target and the base is about 100m,positioning error within 5%.