A microwave imaging technique based on particle swarm optimization (PSO) and asynchronous particle swarm optimization (APSO) are proposed for the electromagnetic inverse scattering. In this article, the finite-difference time-domain (FDTD) method is employed for the analysis of the forward scattering part, while PSO and/or APSO schemes (combining with FDTD) are applied to tackle the inverse scattering part. These two schemes aim for the simultaneous reconstruction of the location, shape, and permittivity of the dielectric scatterer in a slab medium. The reconstruction is based on the minimization of a cost functional, which evaluates the difference between measured and estimated values of the electric field. These two schemes are tested by several numerical examples, and the numerical results indicate that APSO outperforms PSO in terms of reconstruction accuracy and convergence speed. Both techniques have been tested in the case of simulated measurements contaminated by additive white Gaussian noise.
Research in Nondestructive Evaluation 26(4), pp.208-224