WAVE TRANSFORMS OF TRANSIENT ELECTROMAGNETIC FIELD IN CONDUCTIVE EARTH
G.A. Gretskov1, M.I. Epov1,2, E.Yu. Antonov1
1A.A. Trofimuk Institute of Petroleum Geology and Geophysics, Siberian Branch of the Russian Academy of Sciences, pr. Akademika Koptyuga 3, Novosibirsk, 630090, Russia
2Novosibirsk State University, ul. Pirogova 2, Novosibirsk, 630090, Russia
Keywords: TEM soundings, wave transform, regularization
Abstract
The study aims at finding a stable method for transformation of time-domain electromagnetic diffusion field to an electromagnetic wavefield. Two ways of transformation are considered: singular-value decomposition (SVD) and Tikhonov’s regularizations. Transformation is applied to TEM responses of a conductive half-space, a conductive S film, and to a series of horizontally layered models. The wave transforms are used to plot travel-time curves and to estimate the velocity of EM field propagation.
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