Treatment of light scattering by a rough surface in terms of three-dimensional spectrum

It is demonstrated that scattering by a rough surface can be described in terms of its 3-D spectrum and the coherent transfer function, which was first developed to describe the process of imaging. The three dimensional coherent transfer function for confocal imaging is presented for a high-angle theory. From this an effective transfer function for imaging of rough surfaces is developed, based on the Kirchhoff approximation. It is described how confocal imaging can be used to investigate various scattering mechanisms, and can be used for reconstruction of surface profiles in the Kirchhoff approximation.