Application Of Adaptive Signal Processing In Underwater Acoustics

At present , Adaptive technique is widely applied in Acoustic Signal Processing field . Adaptive filter technique becomes an important part of statistical signal processing . It can improve its performance for Signal Processing through contact of itself with environment . Usually the system is time-variant nonlinear system , and can automatically match with (i. e. "adaptation" ) variational environment. In the case of environment which statistic is unknown , an adaptive filter offers more attractive solution to the problem than a fixed conventional filter does. Furthermore , the use of Adaptive Filters provides new signal-processing capabilities that would not be possible otherwise.First the thesis discusses adaptive signal processing's basic theory , on thebasis of it, introduce an adaptive filter-Adaptive Linear Enhancer(ALE) thatis most often used now , and its several improvement: Adaptive Linear Enhancer that has Coherent Accumulator two input Adaptive Linear Enhancer and fast Adaptive Linear Enhancer .Second discusses Adaptive Filter's application in measuring frequency of CW sonar pulse signal and in Towed Linear Array sonar signal processing . Simulation is made about adaptive filter's application . Simulation result shows that Adaptive Filter is very powerful tool for underwater acoustic signal processing .