An algorithm is formulated for reconstructing a dielectric cylinder with the use of the T-matrix and the singular value decomposition (SVD) and is discussed through numerical examples under noisy conditions. The algorithm consists of two stages. At the first stage the measured data of scattered waves is transformed into the T-matrix. At the second stage we reconstruct the cylinder from the T-matrix. The singular value decomposition is applied in order to separate the radiating and the nonradiating currents, and the radiating current is directly obtained from the T-matrix. The nonradiating current and the object are reconstructed by decreasing a residual error of the current in the least square approximation, where linear equations are solved repeatedly. Some techniques are used in order to reduce the calculation time and to reduce the effects of noise. Numerical examples show us that the presented approach is simple and numerically feasible, and enables us to reconstruct a large object in a short time.

The applicability of a boundary matching technique is presented for reconstructing the refractive-index profile of a circularly symmetric cylinder from the measurement of the scattered wave when the cylinder is illuminated by an H-polarized plane wave. The algorithm of reconstruction is based on an iterative procedure of matching the scattered wave calculated from a certain refractive-index distribution with the measured scattered-wave. The limits of reconstruction for strongly inhomogeneous lossless and lossy cylinders are numerically shown through computer simulations under noisy environment, and are compared with those in the E-wave case.

We present a novel algorithm to reconstruct the refractive-index profile of a circularly symmetric object from measurements of the electromagnetic field scattered when the object is illuminated by a plane wave. The reconstruction algorithm is besed on an iterative procedure of matching the scattered field calculated from a certain refractive-index distribution with the measured scattered field on the boundary of the object. In order to estimate the convergence of the reconstruction, the mean square error between the calculated and measured scattered fields is introduced. It is shown through reconstructing several examples of lossy dielectric cylinders that the algorithm is quite stable and is applicable to high-contrasty models in situations where the Born approximation is not valid.