Research On Target-before-detect Of Underwater Multi-target

The detection and tracking of underwater multi targets is one of the hotspots in modern sonar research.In recent years,the new method on underwater target detection and tracking is the tracking before detection method(TBD).This method accumulates and processes the multi frames of echo data without threshold or low threshold directly.Applying this method to sonar detection,we can make full use of the original sonar data and improve the performance of sonar in low SNR environment.This paper first studies the basic contents of multi-target tracking in underwater acoustic environment,including the principles and key issues of underwater multi-target tracking,summarizes the underwater multi-target tracking methods and classical algorithm,and analyzes the advantages of TBD compared with DBT and the difficulties of TBD technology.The problem of data association is described in detail which is called the core technology in MHT-TBD,and the target motion models and simulation evaluation index used in the simulation part are given.Then,this paper introduces the principle of Multiple Hypothesis Tracking based on Tracking Before Detection(MHT-TBD),and gives the flow chart of the algorithm,and verifies the feasibility of the algorithm through MATLAB simulation.The improved interactive multimode MHT-TBD(IMM-MHT-TBD)algorithm is used to optimize the efficiency and improve the practicability of the algorithm.Finally,this paper introduces a dynamic programming based on Tracking Before Detection(DP-TBD).First,we analyze the situations of underwater single target,and get the corresponding conclusion by modeling and simulation.The algorithm has the limitations of difficult threshold setting,large energy loss and bad performance in the environment with low SNR.In this paper,an improved dynamic programming algorithm is adopted to solve the problem of limitations in the process of underwater single target tracking.In order to carry out the detection and tracking of underwater multi targets by using the DP-TBD algorithm,the DP-TBD must be improved.The simulation results show that the maximum regional method(MR-DP-TBD)method can effectively track and detect the underwater multi targets.