Making A Noise/Speed Curve To Determine Vessel Noise - Kongsberg Simrad MF90 Installation Manual

• Check for interference from other hydroacoustic systems.
• Check for environmental noise, such as other vessels in the vicinity or animal life.

Making a noise/speed curve to determine vessel noise

The performance of the MF90 system will always be limited by different noise sources.
During this test, noise measurements are done for different vessel speeds. The weather and
sea conditions for the noise measurements will be those at the time of the test.
Prerequisites
The MF90 system is turned on and operates normally. The vessel is at sea. Recommended
minimum depth is 100 metres. If the MF90 system is operated from any other compartment
than the bridge, an open two-way oral communication channel with the bridge is required.
You need the following equipment:
• Personal computer
• Spreadsheet program
If you wish to do the test with a "silent ship" the following prerequisites must be met:
• The water must be as deep as possible. Recommended minimum depth is 100 metres.
• There must be no other vessels in the vicinity.
• As much machinery as possible must be turned off. It is particularly important to turn
off electrical motors, as well as cooling systems and hydraulic pumps that may cause
electric noise.
• To prevent interference, all other hydroacoustic instruments must be turned off.
If you do this tests in a busy harbour, or with noise sources present, the sensitive receivers
will detect all the noise in the nearby waters.
Context
To measure the noise, observe the noise values provided on the
dialog box. Since the noise will vary with each ping, you must make five measurements
for each vessel speed, and then calculate the average noise.
Tip
If you record all the raw data during the noise test, you can repeat the test later using
the replay file.
You may wish to make the noise/speed curve under realistic conditions. This means that
all relevant vessels systems are in normal use. If you experience very high noise levels,
476671/B
Setting to work
page in the
Noise Diagnostics
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