Enhancing Resolution of Seismic Traces Based on the Changing Wavelet Model of Seismograms

We present a mathematic expression of the changing wavelet model of the seismograms (CWMS). Based on this expression, we study the content and structure of spectra of seismic traces produced in two cases, i.e. the reflectivity does not meet the white assumption and seismic wavelets change during traveling in subsurface. And we analyze why the spectral‐whitening and conventional deconvolution methods cannot yield good results in these two cases. Then based on CWMS, we propose a new method to enhance the resolution of seismic traces. Firstly, we divide the seismic signal into proper segments by Gabor molecule‐windows produced adaptive to the signal, where each segment is regarded stationary, and then transform it into the Gabor domain. Secondly, we deal with the amplitude spectrum for each segment to expand the frequency band of the spectrum in the Gabor domain. Finally, taking inverse Gabor transform on the modified time‐frequency plane, we get the high‐resolution result. Compared with the spectral‐whitening and conventional deconvolution methods, our method has the following advantages: (1) It can work well even when the reflectivity does not satisfy the white presumption. (2) It can preserve relative local energy relationship with the original seismic trace, which may be important for seismic data interpretation. Tests on synthetic and real data show that our method is much better than the spectral‐whitening method in expanding frequency band and preserving local energy relationship of seismograms.