Survey of Literature on Reflection and Scattering of Sound Waves at the Sea Surface

The problem of diffraction of waves at uneven surfaces has received increasing attention in the past 15–20 years. This has resulted in a large number of reports and papers in the open literature. In this review article most of the publications dealing with sound waves and pressure release surfaces (both theoretical and experimental) that appeared up to the beginning of 1969 are mentioned as references. They are classified by subject, and the main currents in the literature (Rayleigh and Uretsky method for sinusoidal boundaries, Eckart theory with Kirchhoff approximation for random surfaces, experiments at sea) are analyzed and discussed. General trends, relations between studies, agreements, and contradictions are mentioned. It is found that nearly all of the publications cover only part of the problem: although the wave diffraction at rough surfaces is a function of three basic quantities simultaneously (i.e. time, frequency of incident wave, and geometry), most of the papers deal with only one or another of these three variables. Possible directions of future research are indicated.