$GPVTG

Summary
NMEA 0183 standard Course Over Ground and Ground Speed.

Syntax
$GPVTG,<1>,<2>,<3>,<4>,<5>,<6>,<7>,<8>,<9>*hh<CR><LF>

Fields
<1>    Course Over Ground, degrees True, to the nearest 0.1 degree
<2>    T = True
<3>    Course Over Ground, degrees Magnetic, to the nearest 0.1 degree
<4>    M = Magnetic
<5>    Speed Over Ground, knots, to the nearest 0.1 knot
<6>    N = Knots
<7>    Speed Over Ground, km/hr, to the nearest 0.1 km/hr
<8>    K = km/hr
<9>    Mode indicator:
           A = Autonomous mode
           D = Differential mode
           E = Estimated (dead reckoning) mode
           M = Manual input mode
           S = Simulator mode
           N = Data not valid