Green's theorem based eigenfunction formulations for PEC-enclosed electromagnetic imaging

The design of electromagnetic imaging systems, and the choice of basis expansion used in forward solvers that model these systems, can alter the performance of electromagnetic imaging algorithms. PEC-enclosed imaging systems naturally lend themselves to eigenfunction expansions for the electromagnetic fields. If the unknown contrast functions are also expanded in an eigenfunction basis, imaging algorithms can be formulated without using a mesh to discretize the computational domain. In this work we summarize some options for eigenfunction-based formulations for use in electromagnetic imaging.