小波谱在舰船地震波场分析中的应用
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摘要
舰船地震波信号是一个非平稳过程,以傅里叶变换为基础的传统谱分析方法已经难以发挥作用。小波变换因其在时-频域都具有表征信号局部特征的能力而成为非平稳信号分析的有力工具。提出了小波谱、小波相干系数用于舰船地震波信号的处理方法。由于Morlet小波所具有的优势,选用Morlet小波作为母小波进行小波分析,得到舰船地震波信号的时频特征。通过对实验数据的分析对比体现出小波谱良好的时频定位能力,表明小波谱适于信号特征的提取,并优于传统谱分析。
Ship seismic-wave signal is a non-stationary random process.The traditional approaches based on Fourier transformation are usually hard to give fall play.But wavelet transformation is a powerful tool since it can make the local details of signal clear whether in time domain or in frequency domain.The application of wavelet spectrum and wavelet coherence in the ship's seismic-wave field is studied.Because of the advantages of Morlet wavelet,it is used in the wavelet transform as the mother wavelet.The time-frequency features of ship's wave field are obtained.Compared with the test data,this proposed method is suitable for extracting signal featares.
Ship seismic-wave signal is a non-stationary random process.The traditional approaches based on Fourier transformation are usually hard to give fall play.But wavelet transformation is a powerful tool since it can make the local details of signal clear whether in time domain or in frequency domain.The application of wavelet spectrum and wavelet coherence in the ship's seismic-wave field is studied.Because of the advantages of Morlet wavelet,it is used in the wavelet transform as the mother wavelet.The time-frequency features of ship's wave field are obtained.Compared with the test data,this proposed method is suitable for extracting signal featares.
引文
[1]陈云飞,吕俊军.航行舰船地震波及其在水中目标探测中的应用[J].舰船科学技术,2005,27(3):62—66.
[2]伊廷华,李宏男,李兵,孙丽.地震动信号小波谱分析与结构损伤评估[J].振动与冲击,2006,25(5):32—36.
[3]吴克俭,宋金宝,楼顺里.风浪局域小波谱峰的涨落[J].海洋学报,1998,20(3):1—5.
[4]胡广书,现代信号处理教程[M].北京:清华大学出版社,2001.
[5]李跃华,李兴国,小波谱估计用于雷达目标成像和识别红外与毫米波学报,1999,18(4):283—288.
[6]Walden T.Andrew&Percival P.Donald,Wavelet Methodsfor Times Series Analysis,Cambridge University Press,2000.
[7]Torrence C,Compo G P.Apractical guide to wavelet analysis,Bull.Am.Meteorol.Soc.,1998,79,61—78.
[8]Grinsted A,Moore J C,Jevrejeva S.Application of the crosswavelet transform and wavelet coherence to geophysical timeseries[J].Nonlinear Processes in Geophysics,2004,11:561—566.
[2]伊廷华,李宏男,李兵,孙丽.地震动信号小波谱分析与结构损伤评估[J].振动与冲击,2006,25(5):32—36.
[3]吴克俭,宋金宝,楼顺里.风浪局域小波谱峰的涨落[J].海洋学报,1998,20(3):1—5.
[4]胡广书,现代信号处理教程[M].北京:清华大学出版社,2001.
[5]李跃华,李兴国,小波谱估计用于雷达目标成像和识别红外与毫米波学报,1999,18(4):283—288.
[6]Walden T.Andrew&Percival P.Donald,Wavelet Methodsfor Times Series Analysis,Cambridge University Press,2000.
[7]Torrence C,Compo G P.Apractical guide to wavelet analysis,Bull.Am.Meteorol.Soc.,1998,79,61—78.
[8]Grinsted A,Moore J C,Jevrejeva S.Application of the crosswavelet transform and wavelet coherence to geophysical timeseries[J].Nonlinear Processes in Geophysics,2004,11:561—566.
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