Kongsberg EM 2040 MKII, Руководство по установке

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Rattle noise
Rattle noise may be caused by loose objects in the vicinity of the transducer, like fixing
bolts. The rattle may also come from loose objects inside the hull.
Interference
Interference from other hydroacoustic equipment on board the same vessel may be an
annoying source of disturbance. Unless the same frequency is used for more than one
piece of equipment only the transmitted pulse will contribute to the interference.
Ambient noise
Ambient noise is usually not a limiting factor to the performance of sonars and echo
sounders.
The ambient noise may be split up as follows:
•
Sea noise
: Air bubbles, seismic disturbances, waves, boundary turbulence, etc.
•
Biological noise
: Fish, mammals
•
Man made noise
: Other vessels, interference
•
Precipitation noise
: Heavy rain or hail
In some areas, where many vessels operate together, the engine and propeller noise from
other vessels may be disturbing. Interference from hydroacoustic instruments located
in other vessels may also be a limiting factor. The sea noise depends on the weather
conditions. In bad weather the sea noise can be quite high due to the waves.
Electrical self noise
Electrical or electronic self noise is picked up or generated in any other part of the
equipment than the transducer.
The most common source of electrical self noise is hum. The hum is normally generated
by a low quality power supply. It is then picked up by the transducer cables and/or
sensitive electronic circuitry. At higher frequencies – where rather wide bandwidths
are necessary – the noise from components, transistors or other analogue electronic
may be a limiting factor.
Preparing the installation