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 NCE has predicted and controlled the sonar self-noise on naval and
commercial vessels - both mono-hulled or SWATH. This is basically a two
step process to optimizing the acoustic operation of on-board sonars. The first
is to evaluate the radiated or platform noise of the vessel for various
operating conditions. The second is to compare this platform noise to
the allowable noise based on the sonar self noise goals and sonar system
processing capabilities. The self-noise goals account for the operating
characteristics of the various sonar suites or can also be derived based
on expected operating conditions, including speed, ocean depth, bottom
properties, etc.
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Another important design parameter is to ensure the sonars are not
located in the vicinity of any bubble sweep-down. Flow modeling of the
vessel will reveal the general nature of the flow around the hull and
can provide guidance in locating sonar equipment in areas expected to be
free from bubble sweepdown.
Machinery systems and propeller contribution calculation procedures,
based on the machinery, isolation system, and general arrangement
configuration of the vessel, are utilized to evaluate the vessel's
platform noise. Airborne, structureborne, fluidborne (hull grazing),
and hull-to-hull (for SWATH vessels) paths are all considered.
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NCE has utilize its predicted or measured sonar platform noise and
vibration database from many research vessels, including NOAA's FRV, R/V
KNORR, USN AGOR-24 Class vessels, the USCG ice breaker HEALY, a RAN
hydrographic survey vessel, and R/V PALMER and R/V GOULD.
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;)