Transmission of 56-kc Sound in Shallow Water Over a Sand Bottom.
NAVY ELECTRONICS LAB SAN DIEGO CALIF
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This report presents the results of 46 transmission runs made in 15-fathom water over a sand bottom at 56 kc. The following preliminary results are offered. 1 on the average the transmission anomaly increased linearly with range regardless of the thermal structure. The average rate of increase of the anomaly the attenuation coefficient was 13.2 or - 0.2 db per 1000 yards for MIKE thermal structure and 15.7 or - 0.1 db per 1000 yards for NAN structure, 2 There was no significant difference between the attenuation coefficient measured by a hydrophone at a depth of 16 feet and by one at a depth of 50 feet and 3 The average attenuation coefficient when the data were not grouped according to thermal structure was 14.7 or - 0.6 db per 1000 yards.