3D Airborne Electromagnetic Inversion in the Areas with High Conductivity Contrasts and Rugged Topography
M.S. Zhdanov and L. Cox
Event name: Near Surface Geoscience 2014 - 20th European Meeting of Environmental and Engineering Geophysics
Session: Modelling and Inversion I
Publication date: 08 September 2014
Info: Extended abstract, PDF ( 763.16Kb )
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This paper introduces an approach to 3D modeling and inversion of the airborne electromagnetics (AEM) that is suited to arbitrarily complex earth models with very high conductivity contrasts and rugged topography, yet is fast enough to consider large surveys. We use a hybrid FE-IE method, which directly avoids errors associated with numerical differentiation and interpolation of the electric vector potentials at the edges of the elements containing the receiver. This approach is stable and accurate and for conductivity contrasts in excess of 10⁸:1, as is typically required for practical AEM interpretation. We incorporate the moving sensitivity domain method into this modeling framework to increase the modeling speed for an entire survey by several orders of magnitude. A case study for the 3D inversion of 90 line km of DIGHEM data from the Reid-Mahaffy test site is presented to demonstrate the efficacy of our method.