The 24 satellites which make up the global positioning system (GPS) network are scheduled to reset Saturday, August 21, causing possible glitches for owners of GPS handheld equipment.
Considered a small-scale Y2K-type glitch for satellites, the event on Saturday is called the GPS Week 1024 rollover. GPS satellites have a clock that counts the weeks of operation since they became active up to week 1,023 -- but then the clock rolls back to zero.
It is similar to a car's odometer that resets to zero after 100,000 miles. As the satellites are nearing the reset week, there has been some concern that older GPS receivers might not be able to cycle back to zero or that they would search for where the satellites were back in 1980 and experience operating delays.
While most recent GPS receivers and in-car navigation systems have been designed to handle the rollover, published reports claim that receivers manufactured prior to 1993 may have problems turning on.
John Lovell, director of quality at Trimble, claims that even newer GPS units may experience some problems. "There are receivers sold within the last year that could have some degree of difficulty. It depends when the firmware was written and you could have a fairly new receiver with older firmware. There is no one date where you can draw the line."
Since most GPS receivers in use have been sold in the past few years, most will be unaffected, by most supplier accounts. Of those affected, most receivers will require only a few extra minutes to an hour to turn on and locate the satellites and will operate normally thereafter, said suppliers. In rare cases, the unit's ROM may have to be upgraded, said Lovell.
Companies such as Garmin and Trimble are offering software downloads via their websites to take care of any potential glitches, while others say they have tested their products and no problems are expected.
Trimble has more than 300 products posted on its website and is encouraging consumers to call or visit the website to find out about their specific products. "We are expecting no catastrophes, but minor hiccups," said Lovell, noting "The big thing that we've seen in the last week is people calling to get upgrades or information."
GM's OnStar, TravRoute and Alpine said they do not expect customers to experience any problems as a result of the rollover.
A spokesman for OnStar noted, "It will not affect us. We have tested for it and we should not experience any problems at all. Our first sale was in the fall of '96 and my understanding is most of the GPS receivers that will be affected were manufactured before that."
Alpine assistant VP of navigation and telematics market development Mark Karnes said of the company's navigation system, "We incorporated software late in 1997 that would take into account the rollover and treat it just like a virus and restart so its not an issue for us. I doubt there are many systems out there in general that will have problems.