Timed circular notice
Note: This message can be broadcast with a timetoexpire of 0 to indicate that a region is known to not have a currently active notice.
Note: Proposed transmission scheme for areatype=0 (right whale acoustic): A notice will be sent every 3 minutes for each buoy. Messages will be sent with timetoexpire of 0 when no acoustic detection has occured in the last 24 hours. When an acoustic detection, the system will send an separate broadcast for that buoy as soon as possible in addition to the normal 3 minute schedule.
Note: The (lat,lon,areatype) provide the key/id for each message. Any system is expected to overwrite any prior message message with a new message when it is received. This provide the mechanism to cancel out of date messages before they expire or extend the messages further into the future.
| Name | NumberOfBits | ArrayLength | Type | Units | Description |
|---|---|---|---|---|---|
| MessageID | 6 | uint | AIS message number. Must be 8 | ||
| RepeatIndicator | 2 | uint | Indicated how many times a message has been repeated 0: default 3: do not repeat any more |
||
| UserID | 30 | uint | Unique ship identification number (MMSI) | ||
| Spare | 2 | uint | Reserved for definition by a regional authority. | ||
| dac | 10 | uint | Designated Area Code - 366 for the United States | ||
| fid | 6 | uint | Functional IDentifier - 63 | ||
| month | 4 | uint | Start time of most recent notice UTC month | ||
| day | 5 | uint | Start time of most recent notice UTC day of the month 1..31 | ||
| hour | 5 | uint | Start time of most recent notice UTC hours 0..23 | ||
| min | 6 | uint | Start time of most recent notice UTC minutes | ||
| longitude | 28 | decimal | degrees | Center of the area/zone East West location | |
| latitude | 27 | decimal | degrees | Center of the area/zone North South location | |
| timetoexpire | 15 | uint | Minutes | Minutes from the start time until the notice expires. Max is aprox 23 days 0: No detection or notice not active in region |
|
| radius | 14 | udecimal | m | Distance from center of detection zone (lat/lon above). Distance in increments of 10 meters | |
| areatype | 8 | uint | What does this circular area represent 0: Right whale detection 1: Restricted Area 2: Prohibited Area (no unauthorized entry) 4: Diving operations 5: Underwater obstruction 6: Fishing nets 7: Oil in water 9: Towing prohibited 10: Anchorage area (large vessels) 11: Anchorage area (small vessels) 12: Anchorage area (general) 13: Anchorage area (deep water) 14: Anchorage area (tanker) 15: Anchorage area (24h max) 16: Anchorage area (explosives) 17: Sea-plane landing area 18: Anchorage area (sea planes) 20: Anchoring prohibited 21: Fishing prohibited 23: Actively dumping explosives 24: Actively dumping 30: Firing danger area 31: Military area, entry prohibited 32: Mine-laying practice area 33: Submarine transit and exercise area 34: Mine field 61: Fast ice 62: Sea ice 63: Logs 65: Dredging area 66: Cargo transhipment area 67: Incineration area 70: SAR - Region of search (what SAR keys should there be?) 71: SAR - Man Overboard 80: Debris, Generic 90: Restricted visibility 91: Restricted visibility, fog 92: Restricted visibility, smoke 100: Autonmous Underwater Vehicle (AUV) operations 101: Remotely Operated Vehicle (ROV) operations - teather in water 102: Diving operations 103: Swimmers in water 111: LNG security zone |