Scattering of optical radiation by a rough different-scale mirror surface

In the physical optics approximation, we consider the backscattering of light waves by a rough surface that has a one-dimensional relief of different-scale mirror fragments and that acts as a phase screen. Asymptotic angular distributions are obtained in the diffusion phase approximation, and the numerical phase jump method is used to take into account complex statistics of surface irregularities. For a periodically modulated rough surface, the results of numerical calculations by the phase jump method and by the tangent reflecting plane method are compared with available experimental data. Angular dependences of backscattering are presented that demonstrate the effect of the Rayleigh roughness distribution on the scattering intensity, and the narrowing of the range of backscattering angles under the influence of additional large-scale random surface profiling is shown.