Improved inverse scattering for dielectric homogeneous cylinders

A method for the reconstruction of the shape and of the permittivities of homogeneous cylindrical objects is described. It is based on a rigorous integral method and a conjugate gradient algorithm requiring the solution of only two direct problems at each step. The number of scatterers is directly estimated from the data and remains fixed during the iterative process. To ensure the stability of the method, some smoothness of the boundary is required. This is achieved through the in-process control of the number of Fourier coefficients in the representation of the boundary. Numerical examples showing the versatility of the approach are given.