Abstract: Eddy currents generated within damaged, conductive structures are cast in a wave formalism so that coil-recorded fields appear radiated by Huyghens sources within the defect. This leads to wave-imaging techniques, with limitations due to strong decay with depth of the magnitude of the probing field in the structure. Here, we aim at imaging 2-D anomalies in a metal half- space from the anomalous electromagnetic field above, for a time-harmonic source. We discuss (1) a direct Diffraction Tomography algorithm such that attenuation is accounted for via introduction of imaginary frequencies; (2) an iterative simulated annealing method which builds up a two-valve solution (zero or one, whether an elementary cell consists of air or metal) associated with the global minimum of a cost function linked with the discrepancy between existing and retrieved defect.!9
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