The purpose of the Area Notice is to transmit information that pertains to a region or area, for example a security zone, an area of fog, or dredging operations. The areas that are being defined can be circles, rectangles, polygons, or sectors. They can also be defined as a simple point or series of points (polyline). The Area Notice message can be made up of multiple subareas in which case the total area is the union of the subareas. This message can also be used to convey advisory lines or tracks (using the polyline subarea); however, the Route Information message should be used for recommended or directed routes.
An Area Notice should be used to broadcast dynamic information (i.e., information that is time- dependent). These messages are to be used for a specific time period, and will automatically timeout at the end of the period. If the Area Notice must be in place longer, then a new Area Notice must be transmitted with a new start and end time. It should be only used to convey pertinent time-critical navigation-safety information to mariners or authorities, and not as a means to convey information already provided by official nautical charts or publications.
Usage Notes
Areas should be displayed as graphical overlays along with accompanying text.
Dr. Gregory Johnson, gwjohnson@alionscience.com(link sends e-mail)
Parameter | # of bits | Description | |||
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Standard Message Header | Message ID | 6 | Identifier for Message 8; always 8. | ||
Repeat Indicator | 2 | Used by the repeater to indicate how many times a message has been repeated. (See ITU-R M.1371-3, Annex 2, § 4.6.1).0 – 3; 0 = default; 3 = do not repeat any more. Set to 0 (default). | |||
Source MMSI | 30 | MMSI number of source station. This varies according to the transmitter ID. | |||
Spare | 2 | Not used. Set to zero | |||
Binary Data | Designated Area Code | 10 | Designated area code (DAC). (See Rec. ITU-R M.1371-3 § 2.1, Annex 5). Set to 366 (US). | ||
Function Identifier | 6 | Function identifier. Set to 22 | |||
Application Data | Message Linkage ID | 10 | A source specific running number, unique across all binary messages equipped with Message Linkage ID. Used to link additional information to the message by a Text Description message. The Message Linkage ID and the first six digits of the source MMSI uniquely identify the sent message. 1 – 1,023; 0 = not available = default. | ||
Notice Description | 7 | Notice Description as per Table 11. Set to 0 – 127 according to description. If 127, there must be associated text (see Table 10). |
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Start time of Area | UTC month | 4 | UTC month of the Area start. 1 – 12; 0 = UTC month not available = default; 13 – 15 (reserved for future use). | ||
UTC day | 5 | UTC day of the Area start.1 – 31; 0 = UTC day not available = default. | |||
UTC hour | 5 | UTC hour of the Area start. 0 – 23; 24 = UTC hour not available = default; 25 – 31 (reserved for future use). | |||
UTC minute | 6 | UTC minute of the Area start.0 – 59; 60 = UTC minute not available = default; 61 – 63 (reserved for future use.) | |||
Duration | 18 | Minutes until end of Area Notice, measured from start time of Area Notice. Maximum duration is 262,142 minutes (182.04 days).0 = cancel Area Notice; 1 – 262,142; 262,143 = undefined = default. | |||
Sub-area 1 | 90 | Area description, structured as in Table 5 – Table 10. A short text description may be associated with the areas using Sub-area 5: Associated text. 2-slot message. |
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Sub-area 2 | 90 | Optional additional area, structured as in Table 5 – Table 10. 2-slot message. |
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Sub-area 3 | 90 | Optional additional area, structured as in Table 5 – Table 10. 3-slot message. |
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Sub-area 4 | 90 | Optional additional area, structured as in Table 5 – Table 10. 3-slot message. |
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Sub-area 5 | 90 | Optional additional area, structured as in Table 5 – Table 10. 3-slot message. |
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Sub-area 6 | 90 | Optional additional area, structured as in Table 5 – Table 10. 4-slot message. |
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Sub-area 7 | 90 | Optional additional area, structured as in Table 5 – Table 10. 4-slot message. |
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Sub-area 8 | 90 | Optional additional area, structured as in Table 5 – Table 10. 5-slot message. |
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Sub-area 9 | 90 | Optional additional area, structured as in Table 5 – Table 10. 5-slot message. |
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Sub-area 10 | 90 | Optional additional area, structured as in Table 5 – Table 10. 5-slot message. |
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Spare | 1-7 | From 1 to 7 spare bits, added to make the total message length an even number of bytes. Set all spare bits to 0. | |||
Total | 208 – 1016 | 2-5 slot message |