Globalsat EM-506 [11/17] Vtg course over ground and ground speed

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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 B-10 contains the values for the following example:

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

Table B-10 VTG 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

R= Coarse Position

S=Simulator

Checksum *23

<CR><LF> End of message termination

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

are geodetic WGS84 directions.

2. Position was calculated based on one or more of the SVs having their states derived from

almanac parameters, as opposed to ephemerides.