NavCom Sapphire Rev.J - Manual (Page 327)

Sapphire Technical Reference Manual Rev. J
327
2.73 NMEAVTG (ASCII)
SF-3050 Sapphire SF-3040
Supported Output Rate: OFF ONCE OnChange OnTime
OnChange = based on [PROCESSRATE]
OnTime = highest rate licensed
This output message reports velocity and course over ground information, and is in compliance
with NMEA-0183 Standards version 3.0.
Table 160: VTG Message Output Format
Output Format: $GPVTG,track,T,track,M,speed,N,speed,K,mode*checksum
Field# Field Name Description
F1 track True track (course over ground) in degrees (0 to 359.9)
F2 T True track orientation (T=true north)
F3 track Magnetic track in degrees (0 to 359.9)
F4 M Magnetic track orientation (M=magnetic north)
F5 speed Speed over ground in knots (0 to 1000)
F6 N Speed over ground units (N=knots)
F7 speed Speed over ground in kilometers (0 to 1852)
F8 K Speed over ground units (K=km/h (kilometers/hour))
F9 mode
Position mode indicator
A = autonomous
D = DGPS
E = Estimated (dead reckoning)
S = Simulator
N = Data not valid
P = Precise (NMEA v4.1 only) (see note 1)
F10 *CRC Checksum
Example: $GPVTG,0.0,T,,M,0.03,N,0.06,K,D*0D

1
The IEC 61162 4
th
Edition adds a new mode indicator field, P for Precise, in order
to distinguish Precise solution from DGPS solution.
- P is used for all Dual Frequency StarFire and RTK related solutions
- D is used for all other DGPS solutions including: WAAS, RTCM Code, and StarFire
Single.