John B. Chester
Raymond J. Christian
NUWC Div. Newport, New London Detachment, New London, CT 06320
A comprehensive low-frequency (<1000-Hz) low grazing angle (<30(degrees)) sea surface acoustic scatter experiment was conducted during February/March 1992 in the Gulf of Alaska. During data collection, wind speeds ranged from 3--17.5 m/s and sea states from 2--6. cw waveforms less than 500 ms in length at 250, 380, 900, and 935 Hz were transmitted by three collinear vertical towed source arrays. Surface scattered energy was received in 17 cosine-spaced beams by a horizontal source-ship-towed line array. This experimental geometry allowed measurement of surface scattering strength as a function of mean grazing angle, frequency, and horizontal bistatic angle. Analysis of these measurements in terms of these dependencies is presented along with comparison to current surface scattering strength model predictions.