Hi Guys,
A quick example on what $GPVTG messages are. Keep in mind that the sentence Identifier can also be displayed as $GNVTG. The message is the same but some GNSS receivers use this format.
$GPVTG
Track Made Good and Ground Speed.
eg1. $GPVTG,360.0,T,348.7,M,000.0,N,000.0,K*43
eg2. $GPVTG,054.7,T,034.4,M,005.5,N,010.2,K
054.7,T True track made good
034.4,M Magnetic track made good
005.5,N Ground speed, knots
010.2,K Ground speed, Kilometers per hour
eg3. $GPVTG,t,T,s.ss,N,s.ss,K*hh
1 = Track made good
2 = Fixed text ‘T’ indicates that track made good is relative to true north
3 = not used
4 = not used
5 = Speed over ground in knots
6 = Fixed text ‘N’ indicates that speed over ground in in knots
7 = Speed over ground in kilometers/hour
8 = Fixed text ‘K’ indicates that speed over ground is in kilometers/hour
9 = Checksum
The actual track made good and speed relative to the ground.
$–VTG,x.x,T,x.x,M,x.x,N,x.x,K
x.x,T = Track, degrees True
x.x,M = Track, degrees Magnetic
x.x,N = Speed, knots
x.x,K = Speed, Km/hr