Compasses for the Next Millennium
GPS systems communicate with a network of satellites to display the users’ current location on the surface of the earth. First developed for the military, GPS systems have become very popular with boaters, pilots, hikers, hunters, fishermen, and travelers. The systems produce extremely accurate locations and greatly simplify navigation on land, sea, and in the air. GPS is also used by commercial airlines and trucking companies. Train operators, however, have yet to buy in.

About the EOW Rollover
The EOW rollover rolls around every 1,024 weeks or about once every 20 years. GPS systems keep time by counting the number of weeks since January 6, 1980. Once they reach week 1,024, the systems’ week counters reset, or "rollover" to zero. This EOW rollover will happen at midnight between August 21 and 22, 1999 Universal Time Coordinated (UTC) – 8:00 p.m. Eastern Daylight Time. After the EOW rollover, GPS receivers not built to standards could display inaccurate information.

The Department of Defense says the rollover will not impact the GPS satellites or the DoD’s GPS ground station, but might impact consumer GPS systems.

What Could Go Wrong
Users of non-compliant GPS receivers could experience one or more of these problems after the EOW rollover:

• Unable to locate satellites
• Receiver takes a long time to locate satellites
• Display will appear normal, but locations, times, or dates will be incorrect

Getting Help
The Department of Transpiration suggests GPS owner call their system manufacture's help line to find out if their system is EOW-rollover compatible. And, while you have them on the line, ask about Y2K, as well. Can't find your GPS makers phone number? The US Coast Guard Navigation Center has a list of receiver manufacturers and contacts on their web site at:
www.navcen.uscg.mil/gps/geninfo/y2k/default.htm