Details - Reflection and scattering of acoustic rays computed for parabolic ice keel models

Reflection and scattering of acoustic rays computed for parabolic ice keel models

Title

Reflection and scattering of acoustic rays computed for parabolic ice keel models

Related Titles

Series: Technical report (Naval Ocean Systems Center (U.S.)), 1217

By

Gordon, D. F.

Naval Ocean Systems Center (U.S.)

Type

Book

Material

Archival material

Publication info

Ft. Belvoir, Defense Technical Information Center, 1988

Notes

"April 1988."

Coefficients are computed for ray reflection and scattering from a model of a set of keels. The model is a collection of parallel ice keels that are of parabolic cross section. The size of the keels and the spacing between them are drawn from random distributions. The keels are also widened by a random factor to simulate oblique incidence on nonparallel keels. Rays are permitted to reflect from and refract through keels according to the interface properties between fluids and elastic solids. A large number of rays are directed toward the keel model and, upon emergence, are sorted into angular bins to determine scattering strength versus direction. Scattering coefficients have a dominant lobe near the secular direction. This is shown to result from the shape of the curve of reflection versus grazing angle. Very little backscatter occurs, a result of the limited slope angle of the parabolic keel models. Keywords: Arctic acoustics; Acoustic propagation; Ray theory; Sea ice; Reflection coefficients; Scattering coefficients; Ice keels.