Image Reconstruction of the Buried Metallic Cylinder Using FDTD Method and Ssga

Abstract

Abstract-This paper presents an image reconstruction approach based on the time-domain and steady state genetic algorithm (SSGA) for a 2-D perfectly conducting cylinder buried in a half-space. The computational method combines the finite difference time domain (FDTD) method and the steady state genetic algorithms (SSGA) to determine the shape and location of the subsurface scatterer with arbitrary cross section. The subgirdding technique is implemented in the FDTD code for modeling the shape of the cylinder more closely. In order to describe a a unknown 2-D cylinder with arbitrary cross section more effectively, the shape function is expanded by closed cubic-spline function instead of frequently used trigonometric series. The inverse problem is reformulated into an optimization problem and the global searching scheme SSGA with closed cubic-spline is then employed to search the parameter space. Numerical results show that the shadowing effect for the inverse problem in a half space results in poor image reconstruction on the backside of the cylinder. We propose the two-step strategy to overcome the shadowing effect. It is found that good imaging quality could be attained based on the proposed strategy.

Computational Approach Based on a Differential Evolution with Self-Adaptive Concept for Microwave Imaging of Two-Dimensional Inverse Scattering Problem

“…For time-domain algorithms, where the shape reconstruction of conducting scatterers is a concern, PSO has been investigated, whereas the steady-state GA (SSGA) has been utilized in the reconstruction of metallic scatterers (Huang et al, 2008). In this case, the reported results indicate that PSO is a reliable tool for inverse scattering applications.…”

Shape reconstruction of 2D perfectly conducting cylinder targets using the particle swarm optimisation

“…Evaluate the population using objective function: the PSO algorithm evaluates the objective function (9) for each individual in the population.…”

“…[9][10][11][12][13][14][15][16][17][18][19] Among these techniques, the PSO is the most recent one and is never used to deal with the imaging problem of buried conducting cylinders to the best of our knowledge; an anti-noise study about the performances of PSO has not yet been reported with application to the electromagnetic inverse scattering problems.…”

Time Domain Image Reconstruction for Homogenous Dielectric Objects by Dynamic Differential Evolution

“…In general, they tend to get trapped in local minima when the initial trial solution is far from exact. Thus, some population-based stochastic methods, such as the genetic algorithm (GA) (Huang et al, 2007(Huang et al, , 2008bCaorsi et al, 2000;Zhong et al, 2007), particle swarm optimization (PSO) (Rekanos & Trochidis, 2007;Donelli & Massa, 2005;Huang et al, 2008a;Travassos et al, 2008), and differential evolution (DE) (Michalski, 2000;Qing, 2003), have been proposed to search the global extreme of the inverse problem to overcome the drawback of the deterministic methods. In the 2006, the dynamic DE (DDE) was first proposed to deal with the shape reconstruction of the conducting cylinder (Qing, 2006).…”