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Separation and Extraction of Multi-modal Attenuation Coefficients from Surface Wave Data
- Publisher: European Association of Geoscientists & Engineers
- Source: Conference Proceedings, 78th EAGE Conference and Exhibition 2016, May 2016, Volume 2016, p.1 - 5
Abstract
In this paper, a method based on velocity difference to separate and extract attenuation coefficients of multi-modes is proposed. Its strategy is picking region of each mode in super-resolution dispersion curve by a defined parameter “picking width”, then mapping them to complex wavenumber pseudospectrum to search local maxima, realizing better human-computer interaction. As phase velocity and attenuation coefficient are determined simultaneously in this method, the attenuation coefficients of multi-modes can be separated by different velocity regions and extracted respectively. The side effects of mode and noise interference which may lead to wrong mode assignment can be avoided in this way, getting more accurate attenuation coefficient curves of multi-modes which are basis of satisfactory inversion. The computation cost can also reduce greatly in searching period using this method.
The results for the simulation data testified the feasibility of the method, and results for practical data are promising because produced reliable phase velocity can prove the accuracy of attenuation coefficient.