Pseudo-AIS targets

Introduction/Additional information: 

This message should be used to transmit VTS targets. This message should be variable in length, based on the amount of VTS targets. The maximum of VTS Targets transmitted in one International FM 16 should be seven (7). Because of the resulting effects of VDL channel loading, the transmission of International FM 16 should be no more than necessary to provide the necessary level of safety.
Attributes: broadcast, VTS transmitting, no acknowledgement.

Registrant: 
IMO Circ. 236
Message number: 
8
DAC: 
1
FI: 
17
State: 
deprecated
Number of slots (max): 
3
Permitted as from: 
19/05/2004
Not to be used after: 
01/01/2013
Details: 
Parameter No. of bits Description
 Message ID   6  Identifier for Message 8 ; always 8
 Repeat Indicator   2  Used by the repeater to indicate how many times a  
       message has been repeated.  
 Source ID   30  Name of source station  
 Spare   2  Not used. Should be set to zero.  
 IAI   16  DAC =001
FI=17
VTS Target 1 120 Refer to table below; occupies 2 slots
VTS Target 1 120 Optional; refer to table below; occupies 2 slots
VTS Target 1 120 Optional; refer to table below; occupies 3 slots
VTS Target 1 120 Optional; refer to table below; occupies 3 slots
Total Number of bits Max 536 3 slots

 

 Parameter    Bits    Description  
 Type of target identifier   2  Identifier type
 0 =The target identifier should be the MMSI number 
1 =The target identifier should be the IMO number 
2 =The target identifier should be the call sign 
3 =Other (default)  
 Target ID   42  Target identifier. The target ID should depend on type of target identifier above. When call sign is used, it should be inserted using 6-bit ASCII. If target identifier is unknown, this field should be set to zero. When MMSI or IMO number is used, the least significant bit should equal bit zero of the target ID  
 Spare   4  Spare. Should be set to zero  
 Latitude   24  Latitude in 1/1 000 min  
 Longitude   25  Longitude in 1/1 000 min  
 COG   9  Course over ground (degrees) (0-359)
 360 =not available =default 
 Time stamp   6  UTC second when the report was generated (0-59, or 60 if time stamp is not available, which should also be the default value)  
 SOG   8  Speed over ground in knots
 0-254
255 =not available =default  
 Total   120