Research On Locating And Tracking Technologies Of Targets Based On Interference Spectrum

Passive detection and location in underwater acoustic has become one of the research focus in the field of underwater acoustic, especially with the prominent of underwater application problem. How to detect the quiet underwater vehicle in long range becomes difficult in recent research. Towed line array sonar is the major alarm, which is one of the important sonar developing directions. However, the problem of passive ranging is still waited to be settled.The stable interference structure can be observed in the low-frequency sound field. This paper will study the target passive ranging with the waveguide invariant theory.It is mainly focused on the continuous spectrum interference structures in the low-frequency sound. Firstly, to analyze the acoustic normal mode theoretical, and in the layered medium conditions, Kraken method uses the finite difference method to solve normal mode field. Waveguide invariant describes the dispersion characteristics of sound field and pattern of constructive interference and decretive interference, which reflects the relationship about the distance, frequency and slope of the interference striations, with the theoretical analysis and simulation.The interference striations of the LOFARgram satisfy some kind of equation in the continuous spectrum sound field. The image processing of Hough transform are proposed to the waveguide invariant, and the parameter information of the target signal, such as the rate of the range of the closest point of approach and the linear velocity and the target course angle.The parameter estimation with the corresponding passive ranging algorithm is under two scenarios that is whether there is closest point of approach have been validated by the simulation researches. In addition, the approach of passive ranging based on guide source with passive ranging algorithm and the simulation researches is studies. Finally, from the point of view of application, the GUI design of targeting passive ranging based on VC is given briefly.