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DIRECTIVITY OF RECEIVED OCEAN NOISE.
BELL TELEPHONE LABS INC WHIPPANY N J
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At a point under the ocean the noise intensity received from ships and waves on the surface has a directivity pattern which could be observed by a directive receiving array. The report derives simple theoretical formulas for the mean noise intensity pattern or, equivalently, the average pattern over a long period of time. The derivations use ray propagation theory. They assume an ocean with plane surface and bottom and with propagation velocity depending on depth only. Noise sources have constant probability density over the surface. To use the formulas it is not necessary to trace rays, except to include the effect of dissipation of sound energy into heat. This dissipation, although small, has an important influence on the directivity pattern in some cases. A numerical example is included for a deep ocean that exhibits a sound channel at 666 fathoms. Author
APPROVED FOR PUBLIC RELEASE