Calculation of scattering from dielectric objects above half space

The scattering cross-section of a dielectric target located above half space is calculated using the reciprocity theorem (RT), steepest descent method (SDM), and spatial domain dyadic Greenʹs function (SDGF) obtained via the discrete complex image method with the generalised pencil of function method. Numerical results show that the RT and SDM results are in good agreement. However, the SDGF is able to provide accurate results on the scattered fields over most angles in the farfield region.