Rapid emergence of empirical Green's functions from cross-correlations of ambient sound on continental shelfa).

Applications of acoustic noise interferometry to passive remote sensing of the ocean rely on retrieval of empirical Green's functions (EGFs) from cross-correlations of ambient sound at spatially separated points. At ranges of tens of ocean depths, obtaining stable and accurate EGF estimates usually requires noise averaging periods of hours or days. Using data acquired in the Shallow Water 2006 experiment on the continental shelf off New Jersey, it is found that at ranges of 40-70 ocean depths, the EGFs can be retrieved with noise averaging times as short as 64 s.