NMEA-0183 message: HDT
Heading from True North
The heading computation in this message is computed from the moving baseline vector, which requires a two-antenna system.
An example of the HDT string is:
$GPHDT,123.456,T*00
                                                            
Heading from true north message fields
| Field | Meaning | 
|---|---|
| 0 | Message ID $GPHDT | 
| 1 | Heading in degrees | 
| 2 | T: Indicates heading relative to True North | 
| 3 | The checksum data, always begins with * |