NMEA-0183 message: GGA

Related Topics

Time, position, and fix related data

An example of the GBS message string is:

$GPGGA,172814.0,3723.46587704,N,12202.26957864,W,

2,6,1.2,18.893,M,-25.669,M,2.0,0031*4F

Note – The data string exceeds the NMEA standard length.

GGA message fields

Field Meaning
0 Message ID $GPGGA
1 UTC of position fix
2 Latitude
3 Direction of latitude:

N: North

S: South

4 Longitude
5 Direction of longitude:

E: East

W: West

6 GPS Quality indicator:

0: Fix not valid

1: GPS fix

2: Differential GPS fix, OmniSTAR VBS

4: Real-Time Kinematic, fixed integers

5: Real-Time Kinematic, float integers, OmniSTAR XP/HP or Location RTK

7 Number of SVs in use, range from 00 through to 24+
8 HDOP
9 Orthometric height (MSL reference)
10 M: unit of measure for orthometric height is meters
11 Geoid separation
12 M: geoid separation measured in meters
13 Age of differential GPS data record, Type 1 or Type 9. Null field when DGPS is not used.
14 Reference station ID, range 0000-4095. A null field when any reference station ID is selected and no corrections are received1.
15

The checksum data, always begins with *

Note – If a user-defined geoid model, or an inclined plane is loaded into the receiver, then the height output in the NMEA GGA string is always the orthometric height (height above a geoid). The orthometric height is output even if no user-defined geoid is loaded (there is a simplified default geoid in the receiver), or if a user-defined geoid is loaded, or if an inclined plane is used.