Electromagnetic imaging of separable obstacle problem.

The practical problem of imaging scatterers that are separable from the known obstacles is addressed. Using such a priori information, the obstacle is regarded as a known scatterer rather than part of the background and can be excluded from the retrieving process by reformulating the cost function. As a result, the proposed method transforms the problem into an inverse scattering problem with homogeneous background, and avoids the computationally intensive calculation of Green's function for inhomogeneous background (bases of the physical model of the problem). Meanwhile, the factors that influence the imaging quality for such kind of problem are also analyzed. Various difficult numerical examples are presented to show the good performance of our method. In addition, a data set of scattering experiments from the Institut Fresnel is tested to verify the validity of our method.