White House dramatically improves international GPS accuracy

President Clinton has ended the Pentagon’s practice of intentionally degrading the signal available to civil users of the satellite-based Global Positioning System (GPS).

The change enables civilian GPS users “to pinpoint locations up to 10 times more accurately than they do now,” the president said.

GPS consultants said the move will have “huge implications” for GPS users worldwide, including the nascent car navigation market. The White House itself pegged the value of the GPS market at US$8 billion and predicted it would double to US$16 billion in three years.

When the Department of Defense started launching GPS satellites in the 1980s, it provided two classes of service: signals with an accuracy of 10 to 20 metres for military users and a degraded signal available to civil users with accuracy of 100 metres. That policy was meant to prevent potential adversaries from using the GPS technology to launch attacks against U.S. forces or targets.

Clinton’s decision means that, from now on, civil users will benefit from the same GPS accuracy as military users – a change that a White House briefing paper said “will bring instant benefits to millions of GPS users.”

Clinton said the decision to discontinue degradation of the civil GPS signal was based on a “threat assessment” that providing increased accuracy to non-military users worldwide “would have minimal impact on national security.” He added that the Pentagon “has demonstrated our capability to selectively deny GPS signals on a regional basis when our national security is threatened.”

“The significance of this decision is huge,” said Richard Langley, a GPS consultant and professor of geodesy at the University of New Brunswick. “It will affect a large number of GPS application areas.”

Langley said automobile navigation systems, which feed GPS signals into a moving map display, will quickly show the results of the improved signal.

“Right now, with 100-metre (accuracy), you might not even be positioned on the right map in the display,” he said. “With the (degradation) turned off, those kind of map-matching errors will be significantly reduced.”

Langley added that the decision to provide highly accurate GPS signals to civil users could also improve the U.S. position at the multinational administrative radio conference, which is scheduled to run through next month.

“This move definitely puts the U.S. in a more favourable light” in the global battle for spectrum with mobile satellite service providers and the European Union-backed Galileo proposal for a satellite positioning system, Langley said.

Clinton’s move “will be absolutely great for our business,” said Ann Ciganer, vice-president for public policy at Trimble Navigation Ltd., a maker of GPS receivers in Sunnyvale, Calif. “It will improve sales because it will provide greater accuracy to GPS users…everywhere across the spectrum, from hikers to surveyors.”