Message ID

6

Value: 21

Identifier for Message 21

Repeat indicator

2

Value: TBD 

Used by the repeater to indicate how many times a message has been repeated. See § 4.6.1, Annex 2; 0-3; 0 = default; 3 = do not repeat any more

3

Source ID

30

Value: As received

Identity of the virtual ATON station

(see Article 19 of the RR and Recommendation ITU R M.585)

Type of aidsto-navigation

5

Value: As received

0 = not available = default; refer to appropriate definition set up by IALA; see Table 13

Name of Aidsto-Navigation

120

Value: As received in first 120 bits of corresponding Name field. Pad up to 120 bits if shorter (with zero).

Maximum 20 characters 6-bit ASCII, as defined in Recommendation ITU-R M.1371-5 Table 47

“@@@@@@@@@@@@@@@@@@@@” = not available = default.

The name of the AtoN may be extended by the parameter “Name of Aidto-Navigation Extension” below

Position accuracy

1

Value: 0

1 = high (≤10 m) 

0 = low (>10 m) 0 = default

The PA flag should be determined in accordance with Recommendation ITU-R M.1371-5 Table 50

Longitude 

28

Value: As received

Longitude in 1/10 000 min of position of an AtoN (±180°, East = positive,

West = negative

181 = (6791AC0h) = not available = default

Latitude

27

Value: As received

Latitude in 1/10 000 min of an AtoN (±90°, North = positive, South = negative

91 = (3412140h) = not available = default

Dimension/ reference for position

30

Value: 0

Reference point for reported position; also indicates the dimension of an

AtoN (m) (see Recommendation ITU-R M.1371-5 Fig. 41bis and § 3.19.1)

Type of electronic position fixing device

4

Value: 7

[0 = not available = default

1. = GPS
2. = GLONASS
3. = Combined GNSS
4. = Loran
5. = Chayka
6. = INS 
7. = manually input = surveyed or charted position. (The accurate position enhances its function as a radar reference target) 8 = Galileo
8. = BDS
9. & 11 = not used, reserved for future use
10. = integrated PNT system]
11. = inertial navigation system
12. = terrestrial radio navigation system 15 = internal GNSS

Time stamp

6

Value: 61

UTC second when the report was generated by the EPFS (0-59 or 60) if time stamp is not available, which should 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)

Off-position indicator

1

Value: 0

For floating AtoN, only: 0 = on position; 1 =  off position.

This flag should only be considered if time stamp is equal to or below 59. For floating it denotes that the AtoN exceeds the zone parameters set for on station. 

AtoN status

8

Value: As received

Reserved for the indication of the AtoN status, refer to IALA R0126.

00000000 = default

RAIM-flag

1

Value: 0

RAIM (Receiver autonomous integrity monitoring) flag of electronic position fixing device; 0 = RAIM not in use = default; 1 = RAIM in use see ITU-R M.1371-5, Table 50

Virtual  AtoN flag

1

Value: As received

0 = default = physical AtoN at indicated position; 1 = virtual AtoN, does not physically exist.

Assigned mode flag

1

Value: 0

0. =          Station     operating                   in                autonomous             and             continuous                mode        =                 default
1. = Station operating in assigned mode

Spare

1

Value: 0

Should be set to zero. Reserved for future use

Name     of       Aid-to-

Navigation

Extension

0, 6, 12, 18, 24, 30, 36, ... 84

Value: As received after first 120 bits of corresponding Name field. Excluded if Name is shorter.  

This parameter of up to 14 additional 6-bit-ASCII characters for a  2-slot message may be combined with the parameter “Name of Aid-to-Navigation” at the end of that parameter, when more than 20 characters are needed for the name of the AtoN. This parameter should be omitted when no more than 20 characters for the name of the A-to-N are needed in total. Only the required number of characters should be transmitted, i.e., no @-character should be used

Spare

0, 2, 4, or 6

Value: as required for byte alignment

Used only when parameter “Name of Aid-to-Navigation Extension” is used. Should be set to zero. The number of spare bits should be adjusted in order to observe byte boundaries

Number of bits

272-360

0

Default, Type of AtoN not specified

1

Reference point

2

RACON or Mobile AtoN

3

Fixed structures off-shore, such as oil platforms, wind farms.

(NOTE 1 – This code should identify an obstruction that is fitted with an AtoN AIS station)

4

Emergency Wreck Marking Buoy

Fixed AtoN

5

Light, without sectors

6

Light, with sectors

7

Leading Light Front

8

Leading Light Rear

9

Beacon, Cardinal N

10

Beacon, Cardinal E

11

Beacon, Cardinal S

12

Beacon, Cardinal W

13

Beacon, Port hand

14

Beacon, Starboard hand

15

Beacon, Preferred Channel port hand

16

Beacon, Preferred Channel starboard hand

17

Beacon, Isolated danger

18

Beacon, Safe water

19

Beacon, Special mark

Floating AtoN

20

Cardinal Mark N

21

Cardinal Mark E

22

Cardinal Mark S

23

Cardinal Mark W

24

Port hand Mark

25

Starboard hand Mark

26

Preferred Channel Port hand

27

Preferred Channel Starboard hand

28

Isolated danger

29

Safe Water

30

Special Mark

31

AIS Mobile Marker used to mark vehicles, platforms, objects such as Light Vessel/LANBY/Mobile offshore drilling units/Rigs, unmanned autonomous vehicles, debris, etc.