RECONSTRUCTION OF A LARGE AND HIGH-CONTRAST PENETRABLE OBJECT BY USING THE GENETIC AND LEVENBERG-MARQUARDT ALGORITHMS

A large and high-contrast two-dimensional dielectric object is reconst ructed from the measured scattered fields by using a hybrid optimizati on algorithm combining the genetic algorithm and the Levenberg-Marquar dt algorithm. Ill-posedness is filtered out by using the effective ang ular modes excluding the evanescent modes, and multiple incidences of plane waves of multifrequencies are used to reconstruct a dielectric o bject of its size, 3 x 3 wavelengths, and its relative permittivity 4. 0 in presence of 10% Gaussian noise in the scattered fields. Object si ze is enlarged by using the large discretized cells up to 0.5 waveleng th divided by the square root of relative permittivity. (C) 1997 John Wiley & Sons, Inc.