Operation Manual

Some devices report GPS information with multiple NMEA (National Marine Electronics Association) sentence formats:
GGA, RMC, and VTG. See the examples below. For more examples and information about NMEA sentences, see the
following websites:
http://aprs.gids.nl/nmea/
http://www.gpsinformation.org/dale/nmea.htm#nmea
GGA
$GPGGA – Essential fix data including 3D location and accuracy information
Example: $GPGGA,1753405,4916.450,N,12311.127,W,2,06,1.5,117.3,M,−26.574,M,6.0,0138*47
Sample
Data
Description
1753405 Time of fix – 17:34:05 UTC
4916.450,N Latitude 49 deg. 16.450 min North
12311.127,W Longitude 123 deg. 11.127 min West
2
Fix quality: 0 = fix not available; 1 = GPS fix; 2 = Differential GPS fix; 3 = PPS fix; 4 = Real Time
Kinematic; 5 = Float RTK; 6 = estimated (dead reckoning); 7 = Manual input mode; 8 = Simulation
mode
06 Number of satellites being tracked
1.5 Horizontal dilution of precision (HDOP) – relative accuracy of horizontal position
117.312,M Altitude in meters above mean sea level
-26.574,M
Geoidal separation: height of mean sea level above WGS-84 earth ellipsoid (negative value
means mean sea level is below ellipsoid)
6.0 Time in seconds since last update from differential reference stations
0138 Differential reference station ID number
*47 Checksum – used by program to check for transmission errors
RMC
$GPRMC – Recommended minimum specific GPS/transit data
Example: $GPRMC,225446,A,4916.45,N,12311.12,W,000.5,054.7,191194,020.3,E*68
Sample Data Description
225446 Time of fix – 22:54:46 UTC
176