Backward scattering of electromagnetic waves by the rough surface of a medium whose dielectric permittivity has an exponential profile

Within the framework of the Born approximation and the method of small perturbations we obtain analytic expressions for the radar scattering cross section of the rough surface of a layer embedded in a uniform half-space whose dielectric permittivity has an exponential profile. We numerically investigate the effect of stratification of the underlying medium on the scattering properties of the roughness