Reference Information
LD8 Operations Manual
AB- V-MA-00635_RevA6
32
5.3.1 GGA Sentence
The NMEA GGA sentence contains time and position fix related data for a GPS system. It includes basic
quality information, which is limited to ‘Fix Quality’, ‘Number of Satellites in Use’, ‘HDOP’ and ‘Age of
Corrections’.
GGA Sentence Structure & Example
$GPGGA, hhmmss.ss, ddmm.mmmmm, a, dddmm.mmmmm, b, q, xx, p.p, a.b, M, c.d, M, x.x, nnnn *hh
$GPGGA, 123519.00,
4807.03787, N,
01131.00547, E, 1, 15, 0.9, 545.4, M, 46.9, M, 14.0, 0281 *47
GGA Sentence Defined
Field
Content
GGA
Global Positioning System Fix data
hhmmss.ss
UTC of position
ddmm.mmmmm
Latitude of position
a
N or S, latitude hemisphere
dddmm.mmmmm
Longitude of position
b
E or W, longitude hemisphere
q
GPS Quality indicator (0 = invalid, 1 = GPS SPS, 2 = DGNSS fix, 4 = Fixed RTK, 5 =
Float RTK / PPP, 6 = Dead Reckoning), 7 = Manual Input Mode, 8 = Simulation Mode
xx
Number of satellites in use
p.p
HDOP (Horizontal dilution of precision)
a.b
Antenna altitude above/below mean -sea-level
M
Units of antenna altitude, meters
c.d
The relationship between the geoid and the WGS84 ellipsoid
M
Units of meters
x.x
Age of differential GNSS data
nnnn
Differential reference station ID, 0000 to 1023
*hh
Checksum
[CR][LF]
Sentence Terminator
NOTE
The number of decimal places in the GGA message Latitude and Longitude values is configurable,
see section
for details. If making changes from 5 decimal places the
sentence will no longer conform with NMEA v3.01.