Open AccessAsymptotic Theory For Diffusive Electromagnetic Imaging
Author(s) -
Virieux Jean,
FloresLuna Carlos,
Gibert Dominique
Publication year - 1994
Publication title -
geophysical journal international
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.302
H-Index - 168
eISSN - 1365-246X
pISSN - 0956-540X
DOI - 10.1111/j.1365-246x.1994.tb04022.x
Subject(s) - inversion (geology) , perturbation (astronomy) , electrical resistivity and conductivity , mathematical analysis , wave propagation , perturbation theory (quantum mechanics) , physics , mathematics , optics , geology , quantum mechanics , paleontology , structural basin
SUMMARY We propose an asymptotic theory for diffusive electromagnetic imaging. Three steps are required to perform this imaging. (1) A high‐frequency solution is first constructed which mimics the one usually found in wave‐propagation phenomena. (2) This solution, valid for a smooth continuous description of the resistivity in the medium, is used in a first‐order Born approximation leading to a linear relation between the resistivity perturbation of the subsurface and the perturbation of the electric signal obtained at the free surface. (3) This linear relation is asymptotically inverted by using an iterative quasi‐Newtonian inversion based on a least‐squares criterion developed by Jin et al. (1992). Although the extension to smooth heterogeneous reference medium is possible, we have only tested the inversion scheme for homogeneous reference media as Zhdanov & Frenkel (1983) previously did with another method.