Accession Number : AD0715132

Title :   Remote Sensing of Underwater Sound.

Descriptive Note : Final rept.,

Corporate Author : GEORGIA INST OF TECH ATLANTA ENGINEERING EXPERIMENT STATION

Personal Author(s) : Rivers,Wayne K.

Report Date : 15 OCT 1970

Pagination or Media Count : 22

Abstract : The work performed on a research program investigating interaction mechanisms for sensing underwater sound from a platform above the sea is reviewed. Two mechanisms were studied: the modulation of the electric permittivity of the salt water by the acoustic pressure and the free-surface vibration. The effects of these two mechanisms on the earth's atmospheric electric field and on an electromagnetic wave reflected from the sea surface were considered. The magnitudes of the modulations produced were compared with the internal receiver noise background and with external background modulations produced by the environment. The conclusion is that at present even the most hopeful of the mechanisms, Doppler modulation of electromagnetic waves, is not useful for the stated purpose because of both technological limitations and adverse requirements on operational parameters. (Author)

Descriptors :   (*UNDERWATER SOUND, DETECTORS), DOPPLER RADAR, RADAR REFLECTIONS, ELECTROMETERS, MODULATION, SEA WATER, CONDUCTIVITY, DIELECTRIC PROPERTIES, ACOUSTIC PROPERTIES, VIBRATION

Subject Categories : Physical and Dynamic Oceanography
      Acoustics

Distribution Statement : APPROVED FOR PUBLIC RELEASE