Leica TPS1200 series Technical Reference Manual page 1347

Examples
NMEA Message Formats
Field Description
x.x Altitude of position marker above/below mean sea level in metres. If no ortho-
metric height is available the local ellipsoidal height will be exported. If the
local ellipsoidal height is not available either, the WGS 1984 ellipsoidal
height will be exported.
M Units of altitude as fixed text M
x.x Geoidal separation in metres. This is the difference between the WGS 1984
earth ellipsoid surface and mean sea level.
M Units of geoidal separation as fixed text M
x.x Age of differential GNSS data, empty when DGPS not used
xxxx Differential reference station ID, 0000 to 1023
*hh Checksum
<CR> Carriage Return
<LF> Line Feed
User defined Talker ID = GN
$GNGGA,113805.50,4724.5248541,N,00937.1063044,E,4,13,0.7,1171.281,M,-
703.398,M,0.26,0000*42
TPS1200 1347