### ASA 125th Meeting Ottawa 1993 May

## 2aUW14. Effects of ambient noise on the scattering from cylinders and
spheres.

**Rebecca L. Honeycutt
**

**
Steven J. Johnson
**

**
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*Code 1945, Carderock Div., Naval Surface Warfare Ctr., Bethesda, MD
20084-5000
*

*
*
The sound scattering due to an ambient noise field, approximated by a
squared cosine function, is considered for infinite rigid and elastic cylinders
and rigid spheres. For the cylinders, it is assumed that the acoustic wave
front is parallel to the axis of the cylinder (normally incident). For this
assumption, a closed-form expression for the scattered sound field-to-incident
ambient noise field (signal-to-noise) ratio is obtained not only for the cosine
squared directivity, but for any arbitrary directivity that can be expressed in
terms of a Fourier series. For the sphere, it is assumed that the noise is
circumferentially symmetric, which leads to a closed-form expression for the
signal-to-noise ratio due to a cosine-squared directivity.