将希尔伯特—黄变换(HHT)应用于天然地震信号处理中,通过对天然地震波信号进行HHT时频分析,获得该信号的三维Hilbert时频谱、边际谱、瞬时能量谱和Hilbert能量谱。通过分析,可以看出HHT方法能敏感地提取到地震波信号随时间和频率动态变化的不同阶段的主要特征,其图像清晰,能够反映能量突变点信息,其时频局部定位能力较强。边际谱、瞬时能量谱和Hilbert能量谱能提取出地震波信号其他新的特性,可对信号的时频分析起到补充作用。结果表明,HHT方法能准确描述地震信号的非线性时变特征,是地震信号时频分析的有效工具。

Hilbert-Huang transform( HHT) method is applied in time-frequency analysis of natural seismic wave in this paper,the authors obtain three-dimensional Hilbert time-frequency spectrum,marginal spectrum,instantaneous energy spectrum and Hilbert energy spectrum of seismic signal. It can be seen that HHT approach can sensitively extract to the main characteristics of seismic wave signal dynamic change over time and frequency,the time-frequency spectrum is clear,and can reflect the information with the energy's abrupt change points,the time-frequency local orientation ability is strong. Other new features of seismic wave signal can be extracted by marginal spectrum,instantaneous energy spectrum and Hilbert energy spectrum of seismic signal,which can play a complementary role. The results show that HHT approach can describe nonlinear time-varying characteristics of seismic signal and is an effective tool on time-frequency analysis of seismic signal.