Image reconstruction of defects in metallic plates using a multifrequency detector system and a discrete geometric approach

We present an inversion procedure for the image reconstruction of defects in metallic plates, using a multifrequency eddy-current system. The solution of the eddy-current forward problem is achieved by means of a discrete geometric approach, while the inverse problem is resolved with an iterative linearization algorithm based on sensitivity data. In particular, we propose a suitable measurement point on the region under test using a probe coil exited by means a multifrequency signal, in order to improve the amount of usable data and the accuracy of the inverse procedure. Index Terms--Discrete geometric approach, inverse problems, multifrequency eddy currents, sensitivity analysis.