Studies of absorption and reflection cooffiaienta of high frequency sounds were made in deep water off the New London area in July 1935.nThe apparatus and technique are satisfactory for accurate quantitative data but the water conditions in the area were variable. There are relatively large horizontal and vertical temperature gradients which limited the range and consistency of the results. Values of the absorption coefficient were found that lie between a = 0.0005 and a = 0.0020. n Data are given on the background of noise on the SEMMES as a function of speed, frequency, and bearing of the transceiver.n A range chart is given showing the possible gain in range to he obtained by increasing the initial sound output, by lowering the noise level, or by selecting a frequency to give a low value of absorption.
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