Division 3.4.1 Table 3.2 Position report

United Kingdom

Table 3.2

Position report

Parameter	Number of bits	Description
Not applicable within the Union for the purpose of this Regulation
Knots shall be calculated in km/h by external on-board equipment.
Shall only be evaluated if the report is coming from an Inland AIS mobile station and if the information is derived by automatic means (direct connection to switch).
Message ID	6	Identifier for this message 1, 2 or 3
Repeat indicator	2	Used by the repeater to indicate how many times a message has been repeated 0-3; Default = 0; 3 = do not repeat any more
User ID (MMSI)	30	MMSI number
Navigational Status	4	0 = under way using engine; 1 = at anchor; 2 = not under command; 3 = restricted manoeuvrability; 4 = constrained by her draught; 5 = moored; 6 = aground; 7 = engaged in fishing; 8 = under way sailing; 9 = reserved for future amendment of Navigational Status for a high-speed craft; 10 = reserved for future amendment of Navigational Status for Wing In Ground (WIG); 11 = power-driven vessel towing astern (regional use)^f1 12 = power-driven vessel pushing ahead or towing alongside (regional use); 13 = reserved for future use; 14 = AIS-SART (active); 15 = not defined = default (also used by AIS)
Rate of turn ROT AIS	8	0 to + 126 = turning right at up to 708° per min or higher 0 to – 126 = turning left at up to 708° per min or higher Values between 0 and 708° per min coded by ROTAIS = 4.733 SQRT(ROTsensor) degrees per min where ROTsensor is the Rate of Turn as input by an external Rate of Turn Indicator. ROTAIS is rounded to the nearest integer value + 127 = turning right at more than 5° per 30 s (No Turn Indicator available) – 127 = turning left at more than 5° per 30 s (No Turn Indicator available) – 128 (80 hexadecimal) indicates no turn information available (default). ROT data should not be derived from COG information
Speed over ground	10	Speed over ground in 1/10 knot steps (0-102,2 knots) 1 023 = not available; 1 022 = 102,2 knots or higher^f2
Position accuracy	1	The position accuracy (PA) flag should be determined in accordance with ITU-R M. 1371 1 = high (=< 10 m) 0 = low (> 10 m) 0 = default
Longitude	28	Longitude in 1/10 000 min (± 180o, East = positive (as per 2's complement), West = negative (as per 2's complement), 181= (6791AC0 hexadecimal) = not available = default)
Latitude	27	Latitude in 1/10 000 min (± 90o, North = positive (as per 2's complement), South = negative (as per 2's complement), 91= (3412140 hexadecimal) = not available = default)
Course over ground	12	Course over ground in 1/10o (0-3599). 3 600 (E10 hexadecimal) = not available = default; 3 601 — 4 095 shall not be used
True heading	9	Degrees (0-359) (511 indicates not available = default).
Time stamp	6	UTC second when the report was generated by the electronic positioning fixing system (EPFS) (0-59, or 60 if time stamp is not available, which shall also be the default value, or 61 if positioning system is in manual input mode, or 62 if Electronic Position Fixing System operates in estimated (dead reckoning) mode, or 63 if the positioning system is inoperative)
Special manoeuvre indicator: blue sign	2	Indication if blue sign is set^f3 0 = not available = default, 1 = not engaged in special manoeuvre = blue sign not set 2 = engaged in special manoeuvre = blue sign is set yes, 3 is not used
Spare	3	Not used. Should be set to zero. Reserved for future use.
RAIM-flag	1	Receiver autonomous integrity monitoring (RAIM) flag of electronic position fixing device; 0 = RAIM not in use = default; 1 = RAIM in use. RAIM-flag should be determined in accordance with ITU-R M. 1371
Communication state	19	Communication state should be determined in accordance with ITU-R M. 1371
Total	168	Occupies one slot

Annotations

Footnotes

f1: Not applicable within the Union for the purpose of this Regulation
f2: Knots shall be calculated in km/h by external on-board equipment.
f3: Shall only be evaluated if the report is coming from an Inland AIS mobile station and if the information is derived by automatic means (direct connection to switch).