## 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**

**Abstract:**

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