A Base Station Report is used for reporting UTC time and date and, at the same time, position. It is also is used by AIS stations for determining if it is within 120 NM for response to Messages 20 and 23.
Message 11 is only transmitted from a mobile station as a result of a UTC request message (Message 10).
|
Parameter |
Number of bits |
Description |
|---|---|---|
|
Message ID
|
6 | Identifier for this Message 4 or 11 4 = UTC and position report from base station: 11 = UTC and position response from mobile station |
|
Repeat indicator
|
2 | Used by the repeater to indicate how many times a message has been repeated. Refer to § 4.6.1, Annex 2; 0-3; 0 = default; 3 = do not repeat any more. |
|
User ID
|
30 | MMSI number |
|
UTC year
|
14 | 1-9999; 0 = UTC year not available = default |
|
UTC month
|
4 | 1-12; 0 = UTC month not available = default; 13-15 not used |
|
UTC day
|
5 | 1-31; 0 = UTC day not available = default |
|
UTC hour
|
5 | 0-23; 24 = UTC hour not available = default; 25-31 not used |
|
UTC minute
|
6 | 0-59; 60 = UTC minute not available = default; 61-63 not used |
|
UTC second
|
6 | 0-59; 60 = UTC second not available = default; 61-63 not used |
|
Position accuracy
|
1 | 1 = high (£10 m) 0 = low (>10 m) 0 = default |
|
Longitude
|
28 | Longitude in 1/10 000 min (±180°, East = positive (as per 2’s complement), West = negative (as per 2’s complement); 181 = (6791AC0h) = not available = default) |
|
Latitude
|
27 | Latitude in 1/10 000 min (±90°, North = positive (as per 2’s complement), South = negative (as per 2’s complement); 91 = (3412140h) = not available = default) |
|
Type of electronic position fixing device
|
4 | Use of differential corrections is defined by field position accuracy above: 0 = undefined (default) 1 = global positioning system (GPS) 2 = GNSS (GLONASS) 3 = combined GPS/GLONASS 4 = Loran-C 5 = Chayka 6 = integrated navigation system 7 = surveyed 8 = Galileo 9-14 = not used 15 = internal GNSS |
|
Transmission control for long-range broadcast message
|
1 | 0 = default – Class-A AIS station stops transmission of Message 27 within an AIS base station coverage area. 1 = Request Class-A station to transmit Message 27 within an AIS base station coverage area. Base station coverage area should be defined by Message 23; If Message 23 is not received, the AIS station which is allowed to transmit on CH75 and 76 should ignore this bit and transmit Message 27. |
|
Spare
|
9 | Not used. Should be set to zero. Reserved for future use |
|
RAIM-flag
|
1 | RAIM (Receiver autonomous integrity monitoring) flag of electronic position fixing device; 0 = RAIM not in use = default; 1 = RAIM in use see Table 50 |
|
Communication state
|
19 | SOTDMA communication state |
|
Number of bits
|
168 |
(Source: International Telecommunications Union Recommendation ITU-R M.1371-5)