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Acoustic reflection from a sea bottom with linearly increasing sound speed.
- Source :
- Journal of the Acoustical Society of America; 1979, Vol. 66 Issue 6, p1836-1841, 6p
- Publication Year :
- 1979
-
Abstract
- We calculate the acoustic reflection coefficient for plane waves, in a homogeneous fluid half-space, incident at arbitrary angle upon an underlying half-space of unconsolidated bottom sediments. The lower half-space, treated here as a fluid, has constant density and a sound speed that increases linearly with depth. An exact formal expression is found for the complex reflection coefficient R, in terms of a modified Bessel function. With no absorption, | R | is unity for all angles except at normal incidence, as would also be expected from ray theory. Assuming bottom absorption, we derive an analytical approximation for R, valid for incident angles [variant_greek_theta] (measured from the interface normal) in the range 10°<=[variant_greek_theta]<=70°, for acoustic frequencies f>=10 Hz, and to about 80° for f>=70 Hz. A high-frequency limit and a small-angle approximation are found. Use of a pseudolinear gradient, suitable at large angles, could extend [variant_greek_theta] to 90°. A more realistic model having layers in the upper part of the bottom is discussed briefly. [ABSTRACT FROM AUTHOR]
Details
- Language :
- English
- ISSN :
- 00014966
- Volume :
- 66
- Issue :
- 6
- Database :
- Complementary Index
- Journal :
- Journal of the Acoustical Society of America
- Publication Type :
- Academic Journal
- Accession number :
- 75079633
- Full Text :
- https://doi.org/10.1121/1.383615