The Study On Q Value Extraction And Inverse Q Filtering Of Seismic Wave Based On Improved Generalized S Transform

When seismic waves propagate through the earth subsurface,the anelasticity and inhomogeneity of the subsurface media will cause the dissipation of the seismic wave energy and the velocity dispersion,which will lead to the reduction of seismic data resolution.With the exploration precision demand becoming higher and higher,Q-value extraction and inverse Q filtering will become an important part of seismic data processing.In the frequency domain,the used methods of Q extraction commonly have limitations,such as spectral ratio method,the spectral matching method and centroid frequency method,because they can not meet the requirements of Q value extraction.The conventional Q filter is prone to the phenomenon of over compensation.Due to the obvious frequency dispersion effect of seismic wave propagation,the method of Q value extraction and inverse Q filtering based on time-frequency analysis method have a good application prospect.In this paper,five kinds of time-frequency analysis methods are analyzed,such as short-time Fourier transform,wavelet transform,S transform,generalized S transform and improved generalized S transform.Compared with the first four time-frequency analysis methods,the time window size of the improved generalized S transform can be changed by frequency,and it has a good time-frequency aggregation and can keep a certain low-frequency signal.Therefore,basis on the improved generalized S transform,the Q value extraction and inverse Q filtering method are derived.By the means of numerical simulation data and the actual seismic data,it is proved that the method based on improved generalized S transform of the Q value extraction and inverse Q filtering is superior and practical.