Research On Bearings-only Target Motion Analysis And Time-Reversal Passive Location Technology With Vector Hydrophone

As one of the indispensable technologies for ocean target detection,underwater acoustic positioning has always been the focus of marine research.Underwater acoustic passive localization mainly uses the target radiation signal to locate and track the target.With the advantages of well concealed and difficult to expose,it is also drawn much attention by many researchers from various countries.Under the precondition of ensuring the detection performance of the system,how to reduce the size of the array to improve the mobility of the system has always been the research objective of underwater acoustic researchers.Compared with sound pressure hydrophone,vector hydrophone can measure more comprehensive information of sound field,which attracts the attention of underwater acoustic researchers.The study and the development of signal processing technology based-on the acoustic vector sensor lays the foundation for the development of vector passive location technology.In this paper,we mainly study two problems of vector passive location technology:Bearings-only target motion analysis and time-reversal passive location,aiming to realize the passive location of vector hydrophone and its vertical array to target.1.Method of DOA estimation by single vector hydrophone is studied.Firstly,studied the theoretical basis of pressure-particle velocity combined signal processing of the vector hydrophone,explored acoustic intensity averager and complex acoustic intensity method,and analyzed the applicable of the two methods.Then,analyzed the statistical method for azimuth information of frequency point and studied the bar graph approach and the weighed bar graph approach.Studied an azimuth estimation method based DEMON(detection of envelope modulation on noise)spectral analysis of ship-radiated noise,modeling and simulation of ship-radiated noise.The computer simulations of each azimuth estimation method are given.The data of the lake test is processed and the performance of the DOA estimation algorithm is analyzed.The source number estimation method by single vector hydrophone is studied and simulated.The performance of source number estimation method based on different criterions is analyzed.2.Target motion analysis of single observer is studied.Firstly,bearings-only target motion analysis is introduced.System modeling,system observability analysis,estimation algorithm establishment and computer simulation are studied for static single observer and single moving observer.For the static single observer,the pseudo-linear estimate(PLE)method is used to estimate the target motion parameter.For the single moving observer,theKalman filter algorithm is used to estimate the target motion parameter.The performance of various algorithms,such as convergence time,tracking probability and other parameters are analyzed.3.Time-reversal passive location technology with vector hydrophone is studied.Firstly,the theoretical basis of time reversal mirror(TRM)processing is analyzed.Then,a sound field modeling software is studied: BELLHOP.According to the acoustic parameters of ocean,the virtual channel of sound field is estimated.In this paper,we study the time-reversal passive location algorithm of single pressure hydrophone,single vector hydrophone,pressure vertical array and vector vertical array.Through simulating various TRM algorithm in computer,the advantage of TRM processing with vector hydrophone,compared with pressure hydrophone is analyzed.We analyze the relationship between the inverse gain and the parameters such as the SNR,the number of array elements and the spacing between elements.By using the dipole directivity of single vector hydrophone,time-reversal passive location to multi-target is realized.Finally,the data of the lake test is processed to verify the performance of the algorithm.