APPENDIX A
VTG - Course over ground and ground speed
COG and SOG obtained by processing the GPS signals.
$GPVTG, x.x, T, x.x, M, x.x, N, x.x, K, p*hh<CR><LF> Positioning mode indicator*
Speed, km/h
Speed, knots
Course degrees magnetic
Course degrees true
*A = Autonomous, D = Differential, E = estimated(dead reckoning), M = Manual input, S = Simulator, N = Data not valid. The Mode indicator field supplements the Status field. The Status field shall be
set to V=invalid for all values of Operating Mode except for A=Autonomous and D=Differential. The positioning system Mode indicator and Status field shall not be null fields.
ZDA - Time and date
UTC, day, month, year and local time zone.
$GPZDA. hhmmss.ss, xx, xx, xxxx, xx, xx*hh<CR><LF>
Local zone minutes description, same sign as local hours Local zone description 00 h to ± 13 h (see note)
Year Month, 01 to 12
Day, 01 to 31
UTC
NOTE - Zone description if the number of whole hours added to local time to obtain GMT. Zone description is negative for east longitudes.
