Chaotic Acoustic Positioning

Because of rich natural resources,ocean has brought a huge economic and social benefits.so there is a growing emphasis on the development and utilization of ocean.Currently,the sonar is usually used to detect,identify and track the underwater target.With the development of the marine enterprise,sonar is widely used in military and civilian fields.However,the active sonar emits sinusoidal acoustic waves,so its concealment and security is relatively poor.Meanwhile,underwater acoustic environment demonstrates multipath characteristic,because of the surface and bottom reflection,as well as complex noise.These effects are obstacles to get high precision target positioning.To solve these problems,a new method using chaotic signal generated by a hybrid system is proposed fur underwater target positioning.The method sends broad band chaotic signal,which is similar to the background noise,so it is difficult to be detected.Meanwhile,the method uses bistatic sonar which has advantage of active sonar and passive sonar,as well as the characteristics of good concealment and strong anti-interference ability.Therefore,the method overcomes the drawback of poor concealment of the active sonar.In addition,combining the chaos matched filter and traditional matched filter.the method can estimate the echo delay,and then can estimate the distance more precisely.Finally,using the distance between the transmitter and the target and the total distance from the transmitter after reflection of goal to the receiver can locate the target.Simulation results show that,compared with traditional methods and some existing methods,the proposed chaotic sonar positioning method can effectively reduces the effects of noise and multipath propagation.Our proposed method wan effectively improve positroning accuracy and has good tenvironmental compatibility.