GPS Changes Coming Earlier Than Some Expected

Updated 6:02 PM ET August 17, 1999By Tim Dobbyn

WASHINGTON (Reuters) - Boaters and other civilian users facing possible disruption in the Global Positioning System (GPS) this weekend need to be ready a few days earlier than previously anticipated, the U.S. military said Tuesday.

Although attention has been focused on the Aug. 21-22 reset of the GPS internal clock to zero, some users of the satellite-based navigation system may start to experience problems as early as Thursday, both the U.S. Air Force and the Coast Guard warned.

The reason is that a regular update of location information to the 27 satellites in the system beginning Aug. 19 also contains new time information that could cause some older GPS receivers to misinterpret which satellites they are "viewing."

GPS plays an increasingly important role in civilian life, including airline operations, truck fleet tracking, recreational boating and computer maps in cars.

The August date rollover for GPS occurs because the system was designed to ignore calendar dates, but keep precise time measured in seconds and weeks.

Only 1,024 weeks were allotted from Jan. 6 in 1980 before the system resets to zero. The event has been compared to GPS' own version of the Year 2000 computer glitch that arises because too little memory was allocated to the year in dates.

Most recently manufactured GPS receivers are capable of handling both the satellite update and the system's internal date rollover but some units made 1994 or earlier are in doubt.

Some receivers may not work at all, others will take more time to locate satellites and others may display inaccurate positions, times or dates.

"Users need to check their equipment regularly over the next few days," said Ronea Alger, chief spokeswoman at Los Angeles Air Force Base, that runs the GPS program.

The Coast Guard is urging boaters and other users that include private pilots to play safe and always have more than one navigation tool available. Boat/U.S., a boat owners' organization, said it was concerned by the recent emergence of Thursday as a problem after it had spent months sounding warnings about the Aug. 21-22 clock reset.

Spokeswoman Becky Squires said people on voyages expecting to get a few extra days out of their GPS equipment could be at risk. "I think that's a little disturbing," she said.

Boat/U.S. has advised its members that most GPS units made after 1994 are ready for the GPS date rollover.

Coast Guard Master Chief Petty Officer Rick Hamilton said the Aug. 19 problem could have the biggest impact on the increasing number of users who rely on the precise time information generated by GPS to coordinated communications networks.

"We're talking about cellular phone systems, fax and page systems and some power grids," said Hamilton. "We call it the invisible GPS community."

The Aircraft Owners and Pilots Association (AOPA) played down the risk to aviation from the GPS changes.

AOPA spokesman Drew Steketee said the control panel units used in instrument flight conditions were subject to government orders to be end-of-week compliant while hand-held GPS units sometimes used under visual flight rules were meant as backups only.

"People in the aviation industry have foreseen this date for some time, the press is just waking up to it this month," Steketee said.

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Ray

-- Ray (ray@totacc.com), August 17, 1999

Answers

http://infoseek.go.com/Content?arn=a3215reuff- 19990817&qt=GPS&sv=IS&lk=noframes&col=NX&kt=A&ak=news1486

-- Linkmeister (link@librarian.edu), August 17, 1999.

This morning I heard on my local news that they had to close the Cape Cod Cannel (Massachusetts) because a barge, carrying oil, ran aground. They didn't give a reason why or what caused it. Maybe there will be something in the paper tomorrow. I do wonder if they had an early GPS problem?

-- flb (fben4077@yahoo.com), August 17, 1999.

Ray, Thanks. I can't believe they didn't advise people of this earlier! There were some federal advisories even this week with no mention of this new data. Is that irresponsible and downright insane or what?

-- Mara Wayne (MaraWAyne@aol.com), August 17, 1999.

And... one more time...

Interesting little snippet from an article Linkmeister found...

Paris, Tuesday, August 17, 1999
The Internet May Be the Biggest Question Mark of Them All
By Thomas Fuller International Herald Tribune

http:// www.iht.com/IHT/TODAY/TUE/FPAGE/netbug.2.html

[snip]

Internet users may get a foretaste of Y2K confusion on Aug. 24, when, for reasons not directly related to the millennium bug, the clocks in some satellites that carry Internet traffic will reset themselves to zero. That could affect the way computers linked to the Internet register such things as financial transactions.

[snip]

-- Diane J. Squire (sacredspaces@yahoo.com), August 17, 1999.

Diane, does this mean E-commerce will crash big time?

-- Randolph (dinosaur@williams-net.com), August 17, 1999.

To the top. This is an important article. The GPS rollover, if it is noticeable, could cause problems as early as tomorrow.

-- Linkmeister (link@librarian.edu), August 18, 1999.

A new and quite thorough article about the GPS rollover by Lane Core Jr....

http://www.y2ktimebomb.com/Computech/Issues/lcore9933.htm

"The August 21-22 GPS Rollover: What It Is, And What It Is Not"

-- Linkmeister (link@librarian.edu), August 18, 1999.