Affiliations: [a] Electrical Engineering Department, Tamkang University,
Tamsui, Taipei County, Taiwan | [b] Electronic Engineering Department, De Lin Institute of
Technology Tu-Cheng, Taipei, Taiwan | [c] Department of Computer and Communication Engineering,
Taipei College of Maritime Technology, Danshui Town, Taipei County,
Taiwan
Abstract: This paper presents the studies of time domain inverse scattering
for a two dimensional homogeneous dielectric cylinder buried in a half-space
which are based on the finite difference time domain (FDTD) method and the
dynamic differential evolution (DDE). For the forward scattering, the FDTD
method is employed to calculate the scattered E fields, while for the inverse
scattering the DDE scheme is utilized to determine the shape, location and the
permittivity of the buried cylindrical scatterer with arbitrary cross section.
The subgirdding technique is implemented for the FDTD code in order to model
the shape of the cylinder more smoothly. In additions, in order to describe an
unknown cylinder with arbitrary cross section more effectively during the
course of searching, the closed cubic-spline expansion is adopted to represent
the scatterer contour instead of the frequently used trigonometric series.
Numerical results demonstrate that, even when the initial guess is far away
from the exact one, good reconstruction can be obtained. In addition, the
effects of Gaussian noise on the reconstruction results are investigated.
Numerical results show that even the measured scattered fields are contaminated
with Gaussian noise, DDE is able to yield good reconstructed quality.
