ABSTRACT
Iterative techniques to solve the inverse scattering problem have gained tremendous attention in the past 25 years (Belkebir and Tijhuis, 2001; Chun et al ., 2005; Crocco et al ., 2005; Dubois et al ., 2005; Estataico et al ., 2005; Harada et al ., 1995; 1990; Isernia et al ., 2004; Rieger et al ., 1999; Wang and Chew, 1989) . Several iterative methods have been proposed but only a few of them have achieved some level of success . We will briefly examine the Born iterative method, distorted Born iterative method, conjugate gradient method, and the prior discrete Fourier transform method which serve as the basis for many other iterative methods and approaches .
