Research On The Configuration Of Underwater Multistatic Sonar System

With the increasing improvement of marine information technology,the traditional monostatic sonar with combined transmitter and receiver has been gradually replaced by the new system of multi-static sonar due to its small coverage,low detection accuracy and poor concealment performance.As the core of multistatic sonar system,how to optimize its spatial array structure to further improve the system performance is crucial.Firstly,the optimal array of bistatic sonar system is researched.Based on the energy relationship,the functional relationship of the detection range of bistatic sonar in polar coordinates is derived.On this basis,the area and distance characteristics of the bistatic system in the dominant region are simulated and analyzed.And then,various advantageous spatial formations were provided for different target motion scenarios.Secondly,in the target location scenario,the optimal deployment of bistatic and tri-static sonar system is researched.For one thing,the Cramer-Rao bound(CRB)of bistatic sonar is derived based on the time-only localization(TOL)algorithm.Aiming at the cooperative localization scenario in which the system timing error is subject to zero mean Gaussian white noise,the optimal array structure of the bistatic sonar system is designed with the bistatic Cramer-Rao lower bound(CRLB)as the optimization objective.Besides,deriving a mathematical expression of timing error with distance,so that the CRB of bistatic sonar system is modified in the cooperative positioning scenario.Therefore,the more perfect configuration design of bistatic sonar system is completed.For another,aiming at the problem of the configuration design of the tri-static sonar system,the mathematical expression of geometric dilution of precision(GDOP)of the multistatic sonar is derived based on the TOL algorithm.On this basis,the influence of baseline angle,baseline length and external auxiliary angle on target positioning performance in the system layout is mainly explored,which the multistatic sonar system configuration strategy based on target motion direction is summarized.At the same time,performance simulation analysis and verification of the deployment structure and pattern of the tri-static sonar system using multiple positioning algorithms in two simulation scenarios.Finally,aiming at the problem of warning and surveillance in the assured sea area,the optimal configuration of the multistatic sonar system under the fixed array structure is researched.On the one hand,the objective functions with the largest coverage and improving overall positioning accuracy are established respectively.The placement position of sonar nodes is determined by genetic algorithm(GA),so that the optimal configuration structure is obtained.On the other hand,in view of the problem that the basic GA is easy to fall into the local optimum and leads to too slow solution speed,an adaptive genetic algorithm(AGA)is proposed to obtain the global optimum solution faster.