IALA

VTS targets (targets derived by means other than AIS)

Introduction/Additional information:

This IFM 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 IFM 16 should be seven (7). Because of the resulting effects of VDL channel loading, the transmission of IFM 16 should be no more than necessary to provide the necessary level of safety.

A VTS target should only be used when the position of the target is known. However, the target identity and/or course and/or time stamp and/or speed over ground may be unknown.

Details:

 Parameter  Number of bits  Description
 VTS target 1 120  See Table 44; occupies 2 slots
 VTS target 2 120  Optional;  see Table 44;  occupies 2 slots
 VTS target 3 120  Optional;  see Table 44;  occupies 2 slots
 VTS target 4 120  Optional;  see Table 44;  occupies 2 slots
 VTS target 5 120  Optional;  see Table 44;  occupies 2 slots
 VTS target 6 120  Optional;  see Table 44;  occupies 2 slots
 VTS target 7 120  Optional;  see Table 44;  occupies 2 slots
 Total number of bits  Maximum 840

Table 44

 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