2 about your ais receiver, 1 about ais, About your ais receiver – Seiwa Si-Tex MDA2 User Manual
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About your AIS receiver
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2
About your AIS receiver
2.1
About AIS
The marine Automatic Identification System (AIS) is a location and vessel information reporting system. It allows vessels equipped with
AIS to automatically and dynamically share and regularly update their position, speed, course and other information such as vessel
identity with similarly equipped vessels. Position is derived from the Global Positioning System (GPS) and communication between
vessels is by Very High Frequency (VHF) digital transmissions.
There are a number of types of AIS device as follows:
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Class A transceivers. These are similar to class B transceivers, but are designed to be fitted to large vessels such as cargo ships
and large passenger vessels. Class A transceivers transmit at a higher VHF signal power than class B transceivers and therefore
can be received by more distant vessels. They also transmit more frequently. Class A transceivers are mandatory on all vessels over
300 gross tonnes on international voyages and certain types of passenger vessels under SOLAS regulations.
•
Class B transceivers. Similar to class A transceivers in many ways, but are normally lower cost due to the less stringent
performance requirements. Class B transceivers transmit at a lower power and at a lower reporting rate than class A transceivers.
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AIS base stations. AIS base stations are used by Vessel Traffic Systems to monitor and control the transmissions of AIS transceivers.
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Aids to Navigation (AtoN) transceivers. AtoNs are transceivers mounted on buoys or other hazards to shipping which transmit
details of their location to the surrounding vessels.
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AIS receivers. AIS receivers will generally receive transmissions from class A transceivers, class B transceivers, AtoNs and AIS
base stations but do not transmit any information about the vessel on which they are installed.
This product is an AIS receiver.