Low-frequency electromagnetic characterization of buried obstacles by differential evolution with strategy of communication between groups and multi-resolution

Abstract

The characterization of conductive obstacles in a resistive subsoil in the induction regime is investigated. Validated by numerical experimentation, a simple model is proposed to calculate all electromagnetic quantities of interest, the interaction between obstacles being taken in account. It is based on the extended Born approximation, Lax-Foldy multiple diffraction theory, and introduction of equivalent ellipsoidal obstacles. Those are retrieved via a hybrid algorithm of Differential Evolution using a communication strategy between groups, which in particular enables separation of nearby coupled ones. The different steps of the algorithm are detailed. The resolution of the standard algorithm and the hybrid algorithm are compared. The effect of taking in account the interaction between obstacles in the model is analyzed.