Kongsberg cNODE MiniS, Instruction Manual

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General acoustic
considerations
Take this information into consideration when deploying the transponders.
Acoustic range
The term depth rating should not be confused with the term acoustic range . The acoustic
range is dependent on many factors, and some of the factors are outside the control of
the user.
Vessel system
The directivity and coverage area for the vessel system is different, depending on which
system you are using. Some systems have high directivity and omnidirectional coverage,
while other systems has reduced coverage and less directivity. The transponder should
always be within the coverage cone of the vessel system.
Transducer type
There are different types of transducers used with the transponders depending on
operational needs. An omnidirectional transducer, such as TD180, covers a large area,
but has less acoustic power compared to a focused transducer, such as TD30V. A focused
signal gives less footprint/coverage. The vessel should always be within the signal
footprint of the transponder.
Tx Power
The ability to detect signals depends on the signal strength. The transmission power can
be adjusted, both for the vessel system and for the transponder.
Acoustic noise
Acoustic noise is present at all vessels. At given conditions, the noise level can
be excessive. A vessel’s propellers and thrusters produce acoustic noise during
manoeuvring, and in certain instances onboard machinery and pumps may also produce
acoustic noise when in use. Heavy propeller/thruster use as well as waves can generate
air bubbles, which can get in front of the vessel’s transducer and block the acoustic signal.
cNODE MiniS Instruction Manual