SOUND-PROPAGATION WITH A LINEAR SOUND-SPEED PROFILE OVER A ROUGH-SURFACE

The distribution of an acoustic field propagating at grazing angles ov er a hard rough surface is described by an integral equation that resu lts from the Helmholz integral in the parabolic approximation. The Gre en's function corresponding to the case when the sound speed varies li nearly with distance from the surface is found. The integral equation is solved analytically for the case of a flat surface. The field distr ibution in the space above the surface, obtained by numerical methods, is presented for a flat surface and for a rough surface. In both case s, the sound speed varies linearly with distance from the surface.