Analysis Of Acoustic Vector Signal Characteristics And Research On Spectral Estimation Algorithm

The research on the characteristics of sound field is an important part in the field of ocean acoustics.The research on the characteristics of acoustic vector signal is based on the simultaneous measurement of three orthogonal components of sound pressure scalar and particle velocity or particle acceleration at the same point.The joint processing of sound pressure and vibration velocity can obtain more information of sound vector field,which is conducive to the subsequent analysis of sound vector signal and parameter estimation.As a very important and widely used signal analysis and processing method,the parameter estimation technology of signal has been the focus and hotspot in the field of underwater acoustic signal processing.In this paper,the characteristics of acoustic vector field are analyzed,and a power spectrum estimation method based on fast orthogonal search is proposed.In this paper,the autocorrelation and cross correlation function,coherence function,phase spectrum,self spectrum and cross spectrum of acoustic vector signal are introduced.In addition,the autocorrelation method,the periodic graph method and the improved method in the classical power spectrum estimation method are described.Aiming at the problem that the resolution of classical spectral estimation method is limited,the parametric model spectral estimation method and the modern spectral estimation method with higher resolution are further discussed,and the performance of various spectral estimation methods is analyzed through the processing of simulation signals.In order to realize the multi parameter estimation of signal,the phase and amplitude of signal can be estimated at the same time of high frequency resolution.This paper proposes a power spectrum estimation method based on fast orthogonal search.In the aspect of experimental data processing,the characteristics of self power spectrum,cross power spectrum and phase difference of sound pressure and three velocity components are analyzed.By comparing the data processing effects of each channel,we can provide preprocessing for vector signal analysis and determine the time of signal appearance and duration.Next,the frequency of the signal is estimated by the fast orthogonal search algorithm.Simulation and experimental data processing results show that,compared with the traditional spectrum estimation method,the fast orthogonal search algorithm can estimate multiple parameters of underwater acoustic signal stably and accurately,and obtain the estimation results with high frequency resolution.