### ASA 125th Meeting Ottawa 1993 May

## 5aUW9. Gaussian mixture statistical model of arctic noise.

**R. Myers
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B. Sotirin
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*Ocean and Atmospheric Sci. Div., Code 541, NRaD, San Diego, CA 92152-5000
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Arctic ambient noise is often stationary and Gaussian for significant
periods of time. However, during periods of local ice activity, the ambient
noise can become highly non-Gaussian, nonstationary, and exhibit substantial
variability in spectral shape. During these periods, the task of characterizing
the statistics of the ambient noise is greatly complicated. In many cases,
however, the distribution of the noise during the periods of intense ice
activity can be modeled as a two-state Gaussian mixture, where the mixture
parameters are estimated from the data by searching for the maximum of the
likelihood function. A statistical analysis of selected ambient noise collected
over a 10-day period during which long-range ambient noise was interspersed
with intense, brief periods of local ice noise indicates that the ambient noise
was highly Gaussian except during the periods of ice activity. During the
periods of ice activity, the distribution of the ambient noise was modeled
quite well as a two-state Gaussian mixture.