NMEA-0183 message: DTM

Datum reference information

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

$GPDTM,W84,,0.0,N,0.0,W,0.0,W84*7D

DTM message fields

Field

Meaning

0

Message ID $GPDTM

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