Globalsat ET-314 GPS Engine Board [13/22] Vtg course over ground and ground speed

ET-314AC

High Performance GPS Engine Board

2010/4/1

- 13 -

are geodetic WGS84 directions relative to true North.

VTG - Course Over Ground and Ground Speed

Note – Fields marked in italic red apply only to NMEA version 2.3 (and later) in this NMEA

message description

Table A-7 contains the values for the following example:

$GPVTG,309.62,T,,M,0.13,N,0.2,K,A*23

Table A-7 RMC Data Format

Name Example Units Description

Message ID $GPVTG VTG protocol header

Course 309.62 degrees Measured heading

Reference T True

Course degrees Measured heading

Reference M Magnetic

Speed 0.13 knots Measured horizontal speed

Units N Knots

Speed 0.2 Km/hr Measured horizontal speed

Units K Kilometers per hour

Mode A A=Autonomous, D=DGPS, E=DR

N=Output Data Not Valid

Checksum *23

<CR><LF> End of message termination

SiRF Technology Inc. does not support magnetic declination. All “course over ground” data are

geodetic WGS84 directions.