Electromagnetic imaging for an imperfectly conducting cylinders

Abstract—This paper presents a computational approach to the imaging of an imperfectly conducting cylinder by the genetic al-gorithm (GA). A conducting cylinder of unknown shape and con-ductivity scatters the incident wave in free space and the scattered field is recorded outside. Based on the boundary condition and the measured scattered field, a set of nonlinear integral equations is derived and the imaging problem is reformulated into an opti-mization problem. The GA is then employed to find out the global extreme solution of the cost function. Numerical results demon-strated that, even when the initial guess is far away from the exact one, good reconstruction has been obtained. In such a case, the gra-dient-based methods often get trapped in a local extreme. In addi-tion, the effect of Gaussian noise on the reconstruction results is investigated. Numerical results show that multiple incident direc-tions permit good reconstruction of shape and, to a lesser extent, conductivity in the presence of noise in measured data. Index Terms—Conductors, electromagnetic scattering inverse problems, genetic algorithms, image reconstruction. I