Standard symbols for AIS ATON have been developed
The United States Coast Guard (USCG) has announced that a testing ofvirtual aids to navigation, i.e., Automatic Identification System (AIS) Aids to Navigation(ATON) messages is being conducted in several ports around the US.
Standard symbols for AISATON have been developed by the International Hydrographic Organization (IHO) and will bedisplayed on the Electronic Chart Display and Information System (ECDIS) or radar.
However,unlike regular aids to navigation, the new “AIS ATON” may appear to be coming from an aid tonavigation – but that ATON may or may not be physically present. To assist mariners, theNational Oceanic and Atmospheric Administration (NOAA) will add new symbols to upcomingaffected NOAA nautical charts
AIS ATON stations broadcast their presence, identity (9-digit Marine
Mobile Service Identity(MMSI) number), position, and status at least every three minutes or as needed. Thesebroadcasts can originate from an AIS station located on an existing physical aid to navigation(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 AISATON.
An electronically charted, but non-existent as a physical aid to navigation, is identifiedas a Virtual AIS ATON. The latter two can be used to depict an existing aid to navigation that isoff station or not watching properly or to convey an aid to navigation that has yet to be charted.All three variants can be received by any existing AIS mobile device, but they would require anexternal system for their portrayal (i.e., AIS message 21 capable ECDIS, radar, personalcomputer (PC)). How they are portrayed currently varies by manufacturer, but the futureintention is for the portrayal to be in accordance with forthcoming International Standards (i.e.,IEC 62288 (Ed. 2), IHO S-4 (Ed. 4.4.0)).
Ship Masters are encouraged to provide feedback and report any anomalies to the USCGNAVCEN at: http://www.navcen.uscg.gov | Contact Us Tab | Subject: AIS | Category: AISTesting. |
AIS ATON Symbols
Depending on the purpose of the virtual aid, NOAA charts and NOAA Electronic NavigationCharts (ENCs) will use the following depictions (which can also be found on the NOAA websiteat http://www.nauticalcharts.noaa.gov/mcd/updates/ais_aton.html)
Example of USCG Local Notice to Mariners Chart Corrections for AIS ATONs