3aAO15. Investigation of frequency-angular resonances of sound reflection coefficients from the bottom.

Session: Wednesday Morning, December 4

Time: 11:45

Author: Margarita S. Fokina
Location: Inst. of Appl. Phys., Russian Acad. of Sci., 46, Ulyanov St., 603600, Nizhny Novgorod, Russia


Features of the behavior of exact frequency-angular dependencies of the reflection coefficients V(fd,tet) (f---frequency, d---thickness of a sediment layer, tet---angle of slid) from a structure and the acoustic properties of various types of the marine bottom are investigated. Angular and frequency resonances of reflection coefficients and change of position of resonance depending on a ratio of acoustic parameters of sediment layers and half-space are revealed. For exact calculations of a reflection coefficients, a matrix propagator was used. Resonant formalism was expanded on the layered elastic bottom case, in terms of the Breit--Wigner variables. The comparisons of resonance and exact calculations of reflection coefficients for two types of resonances show good agreement of the results. Calculations of exact and resonant reflection coefficients for real parameters of the shallow sea bottom was carried out. The relation between resonance position and width and parameters of environment was ascertained. [Work supported by RFFI Project N 96-02-18944.]

ASA 132nd meeting - Hawaii, December 1996