8.7 Format of the NMEA 0183 String (GGA)
The NMEA (GGA) String is a sequence of characters starting with the ‘$GPRMC’ character and ending with
the characters CR (carriage return) and LF (line-feed). The format is:
$GPGGA,hhmmss.ss,bbbb.bbbbb,n,lllll.ll,e,A,vv,hhh.h,aaa.a,M,ggg.g,M„0*cs<CR><LF>
The letters printed in italics are replaced by ASCII numbers or letters where as the
other characters are part of the time string. The groups of characters as defined below:
$ Start character, ASCII Code 24h
sending with one bit accuracy at change of second
hhmmss.ss the current time:
hh hours (00..23)
mm minutes (00..59)
ss seconds (00..59, or 60 while leap second)
ss fractions
of seconds (1/10 ; 1/100)
A Status (A = time data valid)
(V = time data not valid)
bbbb.bbbbb latitude of receiver position in degrees
leading signs are replaced by a space character (20h)
n latitude, the following characters are possible:
‘N’ north of equator
‘S’ south d. equator
lllll.lllll longitude of receiver position in degrees
leading signs are replaced by a space character (20h)
e longitude, the following characters are possible:
‘E’ east of Greenwich
‘W’ west of Greenwich
A Position fix (1 = yes, 0 = no)
vv Satellites used (0..12)
hhh.h HDOP (Horizontal Dilution of Precision)
aaa.h Mean Sea Level altitude (MSL = altitude of WGS84 - Geoid Separation)
M Units, meters (fixed value)
ggg.g Geoid Separation (altitude of WGS84 - MSL)
M Units, meters (fixed value)
cs checksum (EXOR over all characters except ‘$’ and ‘*’)
<CR> Carriage Return, ASCII Code 0Dh
<LF> Line Feed, ASCII Code 0Ah
34 Date: 17th September 2019 SyncBox N2X
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