Vtg - course over ground and ground speed – Rainbow Electronics GM862-GPS User Manual
Page 104
GM862-GPS Software User Guide
1vv0300729 Rev. 5 - 05/07/07
Reproduction forbidden w ithout Telit Communications S.p.A. w ritten authorization - All Rights Reserved
page 104 of 120
5.4.6
VTG - Course Over Ground and Ground Speed
This sentence reports the actual course and speed relative to the ground.
Table I contains the values for the following example:
$GPVTG,309.62,T, ,M,0.13,N,0.2,K,A*23
Table I: VTG Data Format
Name
Example
Units
Description
Message ID
$GPVTG
VTG protocol header
Course
309.62
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
Checksum
*23
<CR> <LF>
End of message termination
NOTE:
SiRF Technology Inc. doe s not support magnetic declination. All “course over ground” data are
geodetic WGS84 directions.