Accession Number : AD0741108

Title :   Amplitude Modulation of an Acoustic Wave Propagating Near the Ocean Surface.

Descriptive Note : Master's thesis,

Corporate Author : NAVAL POSTGRADUATE SCHOOL MONTEREY CALIF

Personal Author(s) : Smith,Wilton Jeremain , Jr

Report Date : DEC 1971

Pagination or Media Count : 87

Abstract : Sixty kHz CW sound was propagated parallel to and near the ocean surface adjacent to an array of four thermistors, a salinometer, a sound velocimeter, a turbulent velocity probe, and a wave-height probe in order to investigate the statistics and environmental causes of amplitude modulation. The temporal variations of the sound amplitude were studied during four twenty-minute runs over a range of 2 meters at varying depths from near the surface to 14 meters during sea-state one conditions in water of 16 meters-depth. Analysis indicated mean percentage amplitude modulation of approximately 5% with a variance of approximately 10-3. (Author)

Descriptors :   (*UNDERWATER SOUND, SOUND TRANSMISSION), (*SOUND TRANSMISSION, AMPLITUDE MODULATION), SURFACE PROPERTIES, STATISTICAL ANALYSIS, POWER SPECTRA, BUBBLES, OCEAN WAVES, THERMISTORS, SALINOMETERS, HYDROPHONES, NETWORKS, PROBES, MICROSTRUCTURE, THESES, NAVAL RESEARCH

Subject Categories : Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE