Cylindrical-Wave Approach for Line-Source Electromagnetic Scattering by Buried Dielectric Cylinders

An analytical-numerical model for the electromagnetic characterization of GPR scenarios, with a line-source illumination field, is proposed. Solution is given in the spectral-domain, in the case of a two-dimensional geometry with dielectric scatterers buried in a semi-infinite medium. The source and scattered fields are represented by means of cylindrical-wave expansions; the concept of plane-wave spectrum of a cylindrical wave is used to describe the interaction of the fields with the air-soil interface, following the fundamentals of the Cylindrical Wave Approach. The proposed model has been implemented in a Fortran code and numerical results are presented. The electromagnetic field can be calculated both in the near and far region, for arbitrary size and position of the scatterers, and the method can deal with both the fundamental transverse-electric and transverse-magnetic polarization states.