Long Period Fluctuations of CW Signals in Deep and Shallow Water.

• Main Authors: Clark,John G., Kronengold,Morton
• Other Authors: INSTITUTE FOR ACOUSTICAL RESEARCH MIAMI FLA
• Format: Text
• Language: English
• Published: 1974
• Subjects: Physical and Dynamic Oceanography; Acoustics; *Underwater sound signals; Phase studies; Sound transmission; Continuous waves; Variations; North Atlantic Ocean; MIMI project; North Atlantic
• Online Access: http://www.dtic.mil/docs/citations/AD0776654; http://oai.dtic.mil/oai/oai?&verb=getRecord&metadataPrefix=html&identifier=AD0776654

In July 1972 as part of the cooperative studies between the Miami and Michigan Project MIMI research groups, continuous fixed system underwater sound propagation tests at 406 Hz were commenced between a sound source off Eleuthera, Bahamas and receivers at Bermuda, a distance of 1250 kilometers, and at positions intermediate in range with respect to the 1250 kilometer path. Preliminary studies of long period cw transmission fluctuations at Bermuda and at one intermediate position have been completed. Phase fluctuations associated with the ocean tides are a marked feature of the data. With averages taken over two day time spans, significant variations in the statistical properties of transmission loss have been observed over a 5 month time period. Shorter period fluctuations in acoustic phase (time scale of a few minutes to a few hours) have similar characteristics in the deep and shallow water propagation ranges. (Modified author abstract)