The normal-mode theory of air-to-water sound transmission in the ocean

Abstract

The normal-mode theory is presented for the transmission of sound from a stationary source in a homogeneous, stationary, air layer into an arbitrarily stratified ocean. Transmission loss calculations are performed for a Pekeris-type shallow-water environment consisting of an isospeed water layer over a uniform elastic solid seabed. Notable features of the results are: the sensitivity of transmission loss to bottom type, the weak dependence of incoherent transmission loss upon source height, and a 25 log r range dependence of average transmission loss in the mode-stripping region. Finally, some approximate intensity-range relations are proposed for shallow-water propagation.