WHERE AM I ?
Trying to figure out
where you are
and
where you're going
is probably
one of man's oldest problem...
There are been many solutions:
Historical ones:
Landmarks, maps
Dead Reckoning, compass, sextant...
Celestial
Modern ones:
OMEGA, LORAN (Radio beacons)
SatNav (Satellite Doppler measuraments)
GPS: Global Positioning System