Spatial coherence of acoustic reverberation and its possible use for characterization of the environment.

Abstract

Cross‐correlation function of diffuse noise fields generated by random sound sources distributed on a surface or in a volume contains valuable information about the propagation environment. It was recently demonstrated [Godin et al. Geophys. Res. Lett. 37, L13605 (2010)] that this information can be successfully retrieved and used for passive ocean acoustic tomography. However, long averaging times are typically required for underwater noise to become sufficiently diffuse and for coherent features to become pronounced. In a waveguide with rough boundaries, one might expect that waves scattered by random roughness and waves that would be generated by random sources distributed on the boundaries have similar statistics. This paper investigates the possibility of using rough surface reverberation in an underwater waveguide, instead of the ambient noise, as a source of information about physical properties of the water column. Two‐point correlation function of the surface‐scattered waves is calculated in the ...