Directional Multi-target Passive Acoustic Detection Technique

In modern air battlefield, multiple armed helicopter cooperate with each other is the main operational mode.Anti-Helicopter Mine is one of the most important smart mine in the air defense system. It can locate or even destroy the target which flying in a low altitude by acoustic detection system and other composite detection technology. But when the number of the armed helicopter is increasing, this kind of Anti-Helicopter Mine will work inefficiency. Using the spatial spectrum estimation technology, orientation system by the technique of passive acoustic detecting for multiple targets has been studied in this paper.Firstly, confirmed the useful spectrum characteristics by analyzed the sound field characteristics of helicopter noise signal and influence factors of helicopter noise spread in the air. Then in base of the spatial spectrum estimation technology, established the mathematical model that sensor array receiving target source. Secondly, analyzed the multi-target directional algorithm under complex environment, studied the modified multiple signal classification algorithm that suit for the orientation system by the technique of passive acoustic detecting for multiple targets. Through the MATLAB simulation, verified the superiority in terms of accuracy of coherent target source. Finally, completed the software and hardware design of the orientation system by the technique of passive acoustic detecting for multiple targets. The experiments verified the feasibility of the system and the directional performance of the modified multiple signal classification algorithm.The research provides a certain theoretical basis for the arbitrary array acoustic detection system, and it also provides a theoretical basis for the multi-target Anti-Helicopter Mine.