paper 150112082717

Abstract

Subspace migration is a stable and effective non-iterative imaging technique for approaching the inverse scattering problem. However, for the successful imaging of thin elec- tromagnetic inhomogeneities, a priori information about tangential and normal directions to unknown targets must be known. If this a priori information is not known, good results cannot be obtained using subspace migration. For this reason, various test vectors are applied to the imaging functional. However, this involves large computational costs, and the results may still be poor. With this as motivation, we derive the structure of single-frequency subspace migration, without any knowledge of shape information for unknown targets, and explore some proper- ties thereof. This is based on the fact that measured far-field can be written as an asymptotic expansion formula. Some numerical results are then demonstrated, in support of our derivation.

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Won-Kwang Park