Stochastic Theory of Edge Diffraction: Its Physical Reading

In a recent paper we presented a new formulation for the electromagnetic field diffraction by a knife edge with random roughness. By using this approach, that we termed “stochastic theory of edge diffraction” (STED), mean value and variance of the field scattered by a half plane with a randomly rough edge were analytically evaluated under the assumptions that the observation distance r is much larger than the wavelength λ, and that the roughness standard deviation σ is not large with respect to λ. In the present paper, we provide an original geometrical/physical interpretation of those results that allows a better illustration of the relation between STED and the classical uniform geometrical theory of diffraction (UTD).