Geometric Optics Approximation with Considering Interference for Reflection from Random Rough Surface

The geometrical optics ray-tracing approach is an effective and simple method of studying the radiative properties of rough surfaces. The conventional geometrical optics ray-tracing method does not consider the interference effect, and therefore limits its application. In this paper, the conventional geometrical optics ray-tracing method is updated by considering the effect of the interference. Two geometrical optics ray-tracing methods and a finite different time domain method are used to study the radiative properties of a one-dimensional random rough surface. By comparing the results of the different methods, the effect of interference is quantified and discussed under various conditions. The interference effect cannot be neglected for the case of strong roughness and oblique incidence. Compared with the conventional geometrical optics ray-tracing method, the improved geometrical optics ray-tracing method has a higher precision and wider application. The interaction between the surface roughness and multiple scattering is also discussed.