### ASA 127th Meeting M.I.T. 1994 June 6-10

## 4pUW7. Matched-field tracking of acoustic sources in shallow water.

**Homer Bucker
**

**
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*NCCOSC, RTDE Div., Code 541, San Diego, CA 92152-5001
*

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A simple matched-field tracking algorithm is proposed for transit
detection of acoustic sources in shallow water. Let A and B represent the end
points of a track. A track correlation function, C[sub AB], is calculated using
the formula C[sub AB]=(summation)[sub f](summation)[sub t]{(Re (summation)[sub
l](gamma)[sub l](gamma)[sub l][sup *])/[((summation)[sub l](gamma)[sub
l](gamma)[sub l][sup *])((summation)(gamma)[sub l](gamma)[sub l][sup *])]}. In
the equation above, the indices f, t, and l are for different frequencies, time
periods, and sensor pairs, respectively, and the * denotes complex conjugate.
The term (gamma) is the short period time average of the j,k element of the
covariance matrix. That is, (gamma)[sub l]=, where
F[sub j] is the signal received at sensor j. In a similar manner, (gamma)[sub
l]=, where F[sub j] is the expected field if the
acoustic source followed the track AB. Realistic simulations will be shown for
detection of sound sources by a vertical line of sensors in a shallow water
area with a sloping bottom.