NMEA-0183 message: DTM

Related Topics

Datum reference information

The DTM message string identifies the datum used. An example of the GPDTM message string is:

$GPDTM,xxx,x,xx.xxxx,x,xx.xxxx,x,,xxx*hh<CR><LF>

DTM message fields

Field Meaning
1 Local datum code (xxx):
W84 – WGS84
W72 – WGS72
S85 – SGS85
P90 – PE90
999 – User defined
IHO datum code
2 Local datum sub code (x)
3 Latitude offset in minutes (xx.xxxx)
4 Latitude offset mark (N: +, S: -) (x)
5 Longitude offset in minutes (xx.xxxx)
6 Longitude offset mark (E: +, W: -) (x)
7 Altitude offset in meters. Always null
8 Datum (xxx):
W84 – WGS84
W72 – WGS72
S85 – SGS85
P90 – PE90
999 – User defined
IHO datum code
9 Checksum