Inversion of ground constant offset loop-loop electromagnetic data for a large range of induction numbers

A novel approach for interpreting ground loop-loop electromagnetic data demonstrates that constant offset measurements, combined with multifrequency soundings, can effectively image subsurface electrical conductivity without requiring extensive multioffset data collection. This method, validated using synthetic and field data from Provins, Franceshows strong agreement with borehole and geological information. The technique involves two key steps: converting in-phase and out-of-phase data into robust apparent conductivities across all induction numbers, followed by 1D and 2D inversion to derive true ground conductivity distributions. This approach offers a time-efficient alternative for geophysical surveys while maintaining accuracy, as validated by Maxwell theory simulations.

Guillemoteau, J., Sailhac, P., Boulanger, C., & Trules, J. (2014). Inversion of ground constant offset loop-loop electromagnetic data for a large range of induction numbers. Geophysics, 80(1), E11–E21. https://doi.org/10.1190/geo2014-0005.1