希尔伯特-黄变换地震信号时频分析与属性提取

Seismic signal time-frequency analysis and attributes extraction based on HHT

地震信号属于非线性和非平稳信号,传统的分析方法主要包括短时傅立叶变换、小波变换和Cohen类时频分布等等;希尔伯特-黄变换是分析非平稳信号的新方法,该方法的关键部分是信号的经验模态分解,通过经验模态分解,复杂的信号可以分解为有限的数量很少的几个固有模态函数,从而可以得到信号的希尔伯特时频谱;将该方法应用于单个的地震道数据,可以对地震道进行经验模态分解并得到希尔伯特谱,应用于地震剖面,可以得到意义更加明确的瞬时频率和瞬时振幅等地震属性,模型试算和实际应用表明了该方法的有效性.

Seismic data are nonlinear and nonstationary signals, traditional analysis methods include short-time Fourier transform, wavelet analysis, Cohen＇s class time-frequency analysis and so on; Hilbert-Huang transform is a new kind of method to analyze nonstationary signals, the key part of the method is the empirical mode decomposition （EMD） method with which any complicated data set can be decomposed into a finite and often small number of intrinsic mode functions （IMFs） that admit well-behaved Hilbert transforms. Use it to a seismic trace, the EMD decomposes trace into several IMFs and instantaneous frequency of the trace are required; Use it to a seismic section, it provides instantaneous frequency and instantaneous phase seismic attributes which are more meaningful than before; Model test and actual application have shown the validity of this method.