Standard search and rescue aircraft position report

msg_ID: 
9
Description: 
Position report for airborne stations involved in SAR operations, only
Priority: 
1
Access scheme: 
SOTDMA
RATDMA
ITDMA
Communication state: 
SOTDMA
ITDMA
Transmitted by: 
Mobile station

This message should be used as a standard position report for aircraft involved in SAR operations. Stations other than aircraft involved in SAR operations should not transmit this message. The default reporting interval for this message should be 10 s.

TABLE 59[1]
Parameter Number of bits Description
Message ID 6 Identifier for Message 9; always 9
Repeat indicator 2 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
User ID 30 MMSI number
Altitude (GNSS) 12 Altitude (derived from GNSS or barometric (see altitude sensor parameter below)) (m) (0-4 094 m) 4 095 = not available,
4 094 = 4 094 m or higher
SOG 10 Speed over ground in knot steps (0-1 022 knots)
1 023 = not available, 1 022 = 1 022 knots or higher
Position accuracy 1 1 = high (£10 m)
0 = low (>10 m)
0 = default
The PA flag should be determined in accordance with Table 50
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)
COG 12 Course over ground in 1/10 = (0-3 599). 3 600 (E10h) = not available = default; 3 601-4 095 should not be used
Time stamp 6 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)
Altitude sensor 1 0 = GNSS
1 = barometric source
Spare 7 Not used. Should be set to zero. Reserved for future use
DTE 1 Data terminal ready (0 = available 1 = not available = default)
(see § 3.3.1)
Spare 3 Not used. Should be set to zero. Reserved for future use
Assigned mode flag 1 0 = Station operating in autonomous and continuous mode = default
1 = Station operating in assigned mode
RAIM-flag 1 RAIM flag of electronic position fixing device; 0 = RAIM not in use = default; 1 = RAIM in use see Table 50
Communication state selector flag 1 0 = SOTDMA communication state follows
1 = ITDMA communication state follows
Communication state 19 SOTDMA communication state (see § 3.3.7.2.1, Annex 2), if communication state selector flag is set to 0, or ITDMA communication state (see § 3.3.7.3.2, Annex 2), if communication state selector flag is set to 1
Number of bits 168  
 
 


[1]   1 Nautical mile = 1 852 metres.
    1 knot = 1 852 m/h.