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Accession Number:
ADA167421
Title:
Vertical Directionality of Ambient Noise: 150-300 Hz.
Descriptive Note:
Technical memo.,
Corporate Author:
SCRIPPS INSTITUTION OF OCEANOGRAPHY LA JOLLA CA MARINE PHYSICAL LAB
Report Date:
1986-02-07
Pagination or Media Count:
74.0
Abstract:
Measurements of the vertical directionality of ambient noise in the 150-300 Hz region have been reported. The 48 element NORDA VEKA array cut for 300 Hz and centered on the sound axis 750 m was used to collect the data. Three features of the data are striking 1 short term stability and long term fluctuations of the vertical structure, 2 asymmetry in the levels observed by the upward and downward looking beams, and 3 the existence of an underlying boxcar characteristic to the vertical structure on top of which are substantial fluctuations often taking the form of horns at or - 10-14 degrees with a significant notch in the or - 9-10 degrees region. Keywords Acoustic arrays Fast fourier transforms Contrack VIII exercise.
Distribution Statement:
APPROVED FOR PUBLIC RELEASE