Horizontal spatial coherence of ocean reverberation

Reverberation from the ocean surface, bottom, and volume is discussed in the context of the point scatterer model, with uniform spatial distributions. It is shown that, for sufficiently narrow beamwidths or bandwidths, the covariance factors into a product of spatial and temporal covariances. The spatial covariance is shown to vanish for separations larger than the horizontal width of the transmitting array. This prediction is found to be in reasonable agreement with the experimental results of Wilson and Frazer and with our own sea surface reverberation data reported here.