ABSTRACT

Reverberation is defined as that portion of the sound received at a hydrophone that is scattered by the ocean boundaries or by volumetric inhomogeneities. Accordingly, reverberation-producing scatterers in the sea can be grouped into three classes: sea surface, sea floor and ocean volume. Surface and bottom reverberation both involve a 2D distribution of scatterers and therefore can be considered jointly as boundary reverberation. Volume reverberation is produced by the marine life and inanimate matter distributed within the sea, and also by fine-scale features of the ocean itself. Useful reviews of oceanic scattering and reverberation have been provided by Farquhar (1970), Andersen and Zahuranec (1977), Ellis et al. (1993) and Pierce and Thurston (1993). A collection of papers dealing with highfrequency acoustics in shallow water (Pace et al., 1997) addressed issues relating to scattering and reverberation in shallow water. Love et al. (1996) noted that variability is the principal feature of volume reverberation in littoral waters.