Dispersion Analysis Method Of Channel Waves Seismic Data And Its Application

The principle and even the advantages and disadvantages of various methods for extracting the dispersion curve are studied in detail,including moving time window method,phase difference method,frequency-wavenumber domain algorithm,?-p transform,the short-time Fourier transform(STFT),wavelet transform(WT),S-transform(ST)and generalized S transform(GST),Wigner-Ville distribution(WVD),Pseudo Wigner-Ville distribution(PWVD),smooth pseudo Wigner-Ville distribution(SPWVD),Hilbert-Huang transform(HHT).Using S-transformation and generalized S-transformation,WVD,PWVD,and SPWVD methods,the physical simulation data is initially processed,and the effects are compared,and then the four methods that need to be used are selected:Wigner-Ville distribution,short-time Fourier transform,generalized S transform,frequency-wavenumber domain and Hilbert-Huang transform method.These four methods are used to extract the dispersion curve from the same transmission channel waves numerical simulation data and the same field measured transmission channel waves data.Based on the previous analysis and research,further analysis and comparison were carried out,and the four methods were evaluated for the advantages and disadvantages of resolution?energy aggregation?continuity of dispersion curve and correctness of Airy phase velocity.The dispersion curve Airy phase's velocity and frequency obtained by several methods are correct.WVD and HHT have high resolution and good energy aggregation and HHT aggregation is the highest.But there is cross-term interference in WVD.The dispersion curve extracted by HHT is poor in continuity and the calculation takes a little longer.STFT needs to determine the window function through experiments.When the window function is determined,the resolution is fixed,the dispersion curve has good continuity,and the Airy phase is clear,and the energy aggregation is general.The GST window function has multi-resolution,the dispersion curve has good continuity,the Airy phase is clear,the time-frequency aggregation and energy aggregation are strong,and the GST has higher time resolution in the high-frequency part than the STFT.The low frequency part has a higher frequency resolution.