Archaeology > Global Positioning Satellites
GLOBAL POSITIONING SATELLITES
GPS is a modern version of the age-old technique of triangulation, using
high-precision instruments to measure angle, distance, and time. The system uses an array of satellites,
referred to as a constellation, located in synchronized orbits around the earth. The position of each
satellite is known to an extremely precise level. Radio signals transmitted by the satellites are used
to calculate the location of the GPS receiver equally precisely.
The position can then be translated
to any common coordinate system and map projection, such as State Plane or UTM (Universal Transverse Mercator),
the latter used for U.S. Geological Survey topographic maps.