DOT to maintain GPS backup

The Transportation Department will maintain backup navigation capabilities to the Global Positioning System, Transportation Secretary Norman Mineta announced March 7.

The decision follows a review released in September 2001 by the department's Volpe National Transportation Systems Center that found GPS is susceptible to disruptions from the atmosphere, blockage by buildings, communications equipment and tampering.

"We're keeping the older systems as needed as we address the vulnerabilities," said Bill Mosley, a DOT spokesman.

Mineta has endorsed all of Volpe's recommendations:

* Maintain old systems.

* Implement new civil signals.

* Transfer anti-jam technology from the military.

* Conduct industry outreach.

* Assess existing navigation capabilities.

GPS, a satellite-based radio-navigation system developed and operated by the Defense Department, allows land, sea and airborne users to determine their position anywhere in the world.

The Federal Aviation Administration plans to use GPS as part of the Wide Area Augmentation System, currently in production, to improve air traffic control.

"We're not going to rely solely on GPS for the near-term," Mosley said.

Industry officials took the announcement in stride.

"I'm not surprised," said Jack Ryan, vice president for air-traffic management at the Air Transport Association, a trade organization for the airline industry. "I think it's cautious."

Still, officials foresee a time when a GPS signal will have enough integrity — in the face of interference — to decommission old systems.

"There was a thought at some point that GPS could be the sole navigation system," Mosley said. But studies identified problems, and transportation never made a move to eliminate old capabilities, he added.

For now, the agency will implement the Volpe recommendations.

"We haven't put a cost figure on it," he said. "Generally, we believe this can be done on the budget we have."