Research On Passive Detection Algorithm Of Underwater Diver

As the terrorist attack continually occurring in underwater area instead of on land,the detection of target invading from underwater area has became the new issue of attention.Withstanding the attack from underwater area also has becoming a challenging issue in the work of defending of naval vessels and harbor.The attacking pattern as diver has became the chief role of terrorist to the coastwise facility.The diver proceeded terrorist attacking mainly equip the open-circuit system and light diver-suit.The spectrum of acoustic signal being radiation from diver is broadband,the source of sound radiation is the breathing activity of diver.When the diver strike the surface of water or walking in the bottom of water or turning around,the transient interference signal will occur.Furthermore,the activity of lives around will also bring in transient interference.This dissertation mainly proceeded the researching on the algorithm for detection of diver.The algorithm is resisting the transient interference and based on passive sonar detection technique.The main content of researching in this dissertation is summarized as follow,1.The dissertation proceed the research on the mechanism of diver radiating the acoustic signal,the occurring of transient interference,and the characteristic in the domain of time and the spectrum.2.Utilizing the researching achievement relating to the issue,the dissertation accomplish simulation of diver’s breathing acoustic signal which has the general character of diver and add the white noise which spread in the whole frequency band to the signal.Then introduce the algorithm of reference detection for diver,algorithm of the referenceless detection for diver,the algorithm of detection for diver based on correlation spectrum of vector,the algorithm of detection for diver based on estimate of distance between two vectors,the algorithm of detection for diver based on cosine of angle.3.Add the pulse to the signal as the transient interference.Analysis the performance of the algorithm opposing the transient interference.4.Apply the algorithm to the trial of measuring the diver breathing acoustic signal.by the means of using the algorithm to data processing,the dissertation examine the performance of the algorithm.In the end,the dissertation compares the performance of different algorithm.