Date of Award


Document Type

Open Access Master's Thesis

Degree Name

Master of Science in Geophysics (MS)

Administrative Home Department

Department of Geological and Mining Engineering and Sciences

Advisor 1

Wayne D. Pennington

Advisor 2

Roohollah Askari

Committee Member 1

Roger M. Turpening


We evaluate the performance of the Margrave deconvolution and spectral ratio methods using the Gabor, S-, and modified S transforms in highly attenuating media, where the quality factor changes with depth dramatically. Our results substantiate that the modified S-transform deconvolution is more robust in terms of generating fewer artifacts and providing better estimates of reflectivities than the Gabor transform. The results also show that using the modified S-transform in the spectral ratio method produces better Q estimates than the S-transform and the Fourier transform that is conventionally used in the spectral ratio method. This improvement in the estimates of reflectivities and Q using the modified S-transform is due to the enhancement of the time-frequency decomposition obtained by substituting the frequency in the Gaussian window with a linear frequency function. The coefficients of this linear function control the time frequency localization by expanding the Gaussian window at low frequencies and tightening it at high frequencies, in turn providing a better time-frequency decomposition. We demonstrate the efficiency of the modified S-transform deconvolution and Q estimation through the analysis of both synthetic and field data.