Navigational aid
A navigational aid (NAVAID), also known as aid to navigation (ATON), is any sort of signal, markers or guidance equipment which aids the traveler in navigation, usually nautical or aviation travel. Common types of such aids include lighthouses, buoys, fog signals, and day beacons.
"ATON" redirects here. For other uses, see Aton.Definition[edit]
According to the glossary of terms in the United States Coast Guard Light list, an aid to navigation (ATON) is any device external to a vessel or aircraft specifically intended to assist navigators in determining their position or safe course, or to warn them of dangers or obstructions to navigation.
AIS AtoNs[edit]
AtoNs can be integrated with automatic identification system (AIS). AIS transmitted form an actual aid (buoy, lighthouse etc.) is termed a "real AIS AtoN".[11]
If it is impractical to equip the AtoN with an AIS transponder an AIS shore station can be assigned to transmit AIS messages on behalf of the AtoN. This is known as a "synthetic ATON". Synthetic AtoNs can be either "monitored synthetic AtoNs" or "predicted synthetic AtoNs". The former have a link between the AtoN so that the AIS station can confirm the AtoNs status. The latter have no link and the AIS system just predicts that the AtoN is where it should be.[12]
If there is no real AtoN (such as for the short term marking of a wreck) then a "virtual AIS AtoN" is used.[12]
Each AIS AtoN must have a unique Maritime Mobile Service Identity (MMSI) number. Synthetic and virtual AIS AtoNs mark their messages as repeats to indicate that the location of the transmitter is not the location of the AtoN.[13]