  No surface is perfectly planar at all scales. The notion of flatness of a
surface therefore depends on the size of the probe used to observe it. As a
consequence rough interfaces are abundant in nature. Here the old, but still
active field of rough surface scattering of electromagnetic waves is addressed.
This topic has implications and practical applications in fields as diverse as
observational astronomy and the electronics industry. This article reviews the
theoretical and computational foundation and methods used in the study of rough
surface scattering. Furthermore, it presents and explains the physical origin
of a series of multiple scattering surface phenomena. In particular what is
discussed are: the enhanced backscattering and satellite peak phenomena,
coherent effects in angular intensity correlation functions and second harmonic
generated light (a non-linear effect).
