Exact content, location, and times of broadcast will be announced in future local notices
In the near future, the U.S. Coast Guard and other authorized agencies and organizations (i.e., U.S. ArmyCorps of Engineers, National Oceanic and Atmospheric Administration, Marine Exchange of Alaska) willbegin transmitting AIS ATON messages and marine safety information via AIS for testing and evaluation. The exact content, location, and times of these broadcasts will be announced in future Local Notices toMariners.
AIS is an internationally adopted radio communication protocol that enables the autonomous andcontinuous exchange of navigation safety related messages amongst vessels, lifeboats, aircraft, shorestations, and aids to navigation (AIS ATON).
AIS ATON stations broadcast their presence, identity (9-digitMarine Mobile Service Identity (MMSI) number), position, and status at least every three minutes or asneeded. These broadcasts can originate from an AIS station located on an existing physical aid tonavigation (Real AIS ATON) or from another location (i.e., AIS Base Station).
An AIS Base Station signalbroadcasted to coincide with an existing physical aid to navigation is known as a Synthetic AIS ATON. Anelectronically charted, but non-existent as a physical aid to navigation, is identified as a Virtual AIS ATON.
How an AIS ‘Isolated Danger’ ATON will potentially be potrayed per IHO and IEC standards on paper charts/ RNCs, radar and ENCs
Other examples of how AIS ATON will be potrayed on future (IEC 62288, Ed.2 compliant) radars
The latter two can be used to depict an existing aid to navigation that is off station or not watching properlyor to convey an aid to navigation that has yet to be charted.
All three variants can be received by anyexisting AIS mobile device, but they would require an external system for their portrayal (i.e., AIS message21 capable ECDIS, ECS, radar, PC).
How they are portrayed currently varies by manufacturer, but thefuture intention is for the portrayal to be in accordance with forthcoming International Standards (i.e., IEC62288 (Ed. 2), IHO S-4 (Ed. 4.4.0)).
Mariners capable of receiving and displaying these test AIS messages are encouraged to providefeedback and report any anomalies to the USCG NAVCEN Website: http://www.navcen.uscg.gov
Source: NAVCEN Notice