An iterative inversion algorithm for the reconstruction of buried dielectric objects

Presents an iterative inversion algorithm of reconstructing two-dimensional buried dielectric objects in a cross-well geometry. We define a cost functional as the norm of the discrepancy between the measured scattered field and the calculated one for an estimated object function. Note that the object function is related to the refractive index of the object. Then the inverse scattering problem reduces to an optimization problem where the object function is determined by minimizing the functional. Applying the conjugate gradient method to the optimization problem, one can derive an iterative formula for deriving the object function. Numerical results are presented for a lossy and homogeneous dielectric circular cylinder. The results demonstrate that the proposed algorithm yields high-quality reconstructions even for cases where the Born or the Rytov approximation breaks down.