Application of Hilbert-Huang transform in time-frequency analyisis of array acoustic signals

Array acoustic logging signal is a non-linear and non-stationary signal.Hilbert-Huang transform(HHT) is a new method developed for non-linear and non-stationary signal.The key step of this method is to apply the empirical mode decomposition(EMD)on signal,decomposing the signal into several intrinsic mode functions(IMF),and then time-frequency spectrum of the signal can be obtained.The HHT is applied to array acoustic logging signal processing,and EMD is used to decompose the signal into several IMF,and then the smooth pseudo Wigner-Ville distribution is obtained.Through the analysis,the difference between the water bearinglayer and drylayer can be obtained.