Global Positioning System

GPS can give your wearable computer position (lattitude/longitude), time, and altitude information, providing the receiver can "see" enough of the positioning satellites that orbit the earth. Accuracy depends on number of satellites "acquired," level of encryption the military is using at any given time, and if differential GPS is being used. Cheap (~$300) receivers can be gotten in PCMCIA card or small boxes with serial interfaces. These systems can be good enough, depending on conditions, to see the lane changes of a car. For more information, see below. More recently, Ashtech has announced a system that integrates the Russian and US systems to get 15m accuracy. See the Ashtech entry.

GPS Overview (by Peter H. Dana, U. Texas)
Navtech Information and Equipment listings
NAVSTAR Global Positioning System (up to date status on satellites, service, etc.)
Mac and PC Ham Radio/GPS tracking program
Ashtech's 15m accuracy combo US-Russian system

Last modified: Tue Nov 28 14:39:15 1995