General Acoustic Considerations - Konsberg cNODE Micro Instruction Manual

cNODE Micro Instruction Manual
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 of the vessel's system varies depending on the
system's components and their specifications. 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
Several types of transducers can be used with the transponders to suit 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's 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.
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