Low-frequency electromagnetic modeling and retrieval of simple orebodies in a conductive Earth
Résumé
As relevant in mineral exploration of the Earth using inductive electromagnetic means, (diffusive) scattering by a perfectly conducting ellipsoidal anomaly placed in a homogeneous conductive medium and illuminated by a time-harmonic magnetic dipole, is considered by means of a low frequency expansion in positive integral powers of (jk), k complex wavenumber of the exterior medium. The aim is to construct a simple yet robust model of the fields to identify the anomaly when magnetic fields are collected nearby. The approach is illustrated by field calculations and inversions of both synthetic and experimental data.