REGULARIZED QUASI-NEWTON METHOD FOR INVERSE SCATTERING PROBLEMS

We study the weak scattering case of a 3-D inverse scattering problem. The iterative sequence is defined in the framework of a Quasi-Newton method. Using the measurements of the scattering field from the carefu lly chosen set of directions, we are able to recover (finitely many) F ourier coefficients of the sought parameters of the model. In this met hod, the linearized (Born) approximation is just the first iteration, and further iterations improve the identification by an order of magni tude. A special regularization for the Frechet derivative's inverse pr ovides a significant improvement in the algorithm's performance. Numer ical experiments for the scattering from coaxial circular cylinders wi th exact data are presented.