Acoustic nackscatter from a random rough water surface

• Main Authors: Ball, Ernest Charles, Carlson, John Algot
• Other Authors: Medwin, Herman
• Language: en_US
• Published: Monterey, California. U.S. Naval Postgraduate School 2012
• Online Access: http://hdl.handle.net/10945/11549

Approved for public release, distribution unlimited === Acoustic backscattering from a random rough water surface has been studied experimentally to test the application of two scattering theories, a statistical description and a resonance approach. The rough surface was created by wind agitation over an anechoic tank. The wave height distribution was measured with a resistive probe and the wave slope distribution by optical glitter detection using a photocell. The distributions of backscattered sound pressures were recorded for surface roughnesses and sound frequencies corresponding to a very wide range of roughness conditions. Both statistical and resonance theories have regions of applicability and regions where they fail to predict the backscatter. Backscattering may be considered to be due to these two mechanisms, since a summation of the predictions of the two theories fits the experimental data fairly well over the complete range of angles of incidence studied. A method of analysis is suggested to relate the doppler shifted continuous wave sound spectrum to the surface wave spectrum.