gps: global positioning system
24 satellites launched by U.S. DOD, originally for weapons systems targeting
Gives time & position anywhere in the world, although often only outdoors
Typical Position Accuracy:
- Civilian: Horiz 50m, Vert 78m, 3D 93m, 200ns
- Diff: Horiz 1.3m, Vert 2.0m, 3D 2.8m, 350ns
Military accuracy might be usable in 2000
http://www.trimble.com/gps/howgps/gpsfram2.htm
http://tycho.usno.navy.mil/gpsinfo.html