Roughness factor

This figure shows the roughness factor for a rough reflection surface in terms of the angle of incidence. The roughness factor reduces the amplitud of the specular component, resulting in the scattering factor of a rough reflection surface. The roughness factor is computed according to Beckmann and Spizzichino (The scattering of electromagnetic waves from rough surfaces, Macmillan, New York, 1963) for three different values of standard deviation of the roughness degree for comparison.