GPS
NAVSTAR GPS
GNSS
space segment
constellation
control segment
user segment
channels
single frequency
dual frequency
almanac
ephemeris
C/A code
P code
Y code
pseudorange
trilateration
3D trilateration
selective availability (SA)
PDOP
multipath
DGPS
NDGPS
CORS
SBAS
WAAS
GLONASS
Galileo
Compass
EGNOS
MSAS
GPX
geocaching
geocoin
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