Iterative Angular-Mode Inversion of a Conducting Cylinder

Abstract

For the iterative reconstruction of the shape function of a two-dimensional conducting object, the angular modal representation of the scattered field gives effective choice of measurement points especially in the presence of noise in the scattered field. It is shown that the object center and its initial shape may be estimated from the effective propagating modes of the measured scattered field. By employing N effective propagating modes excluding the exponentially small higher-order modes, numerical calculation shows that the reconstruction of the shape function with 2N unknowns is possible. When the noise is present, the characteristics of the cost function show that the effective propagating modes with multiple incident waves eliminating the shadow region of the object are needed for the stable inversion. (C) 1995 John Wiley & Sons, Inc.