DOT to preserve GPS backup

The Transportation Department will maintain backup navigation capabilities to the satellite-based 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 tampering, disruptions from the atmosphere, and blockage by buildings and communications equipment.

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

GPS, a radio-navigation system developed and operated by the Defense Department, allows land, sea and airborne customers to determine their positions anywhere in the world based on information received from satellites. It is a key technology in battlefield and navigation systems, as well as other critical applications across government.

The Federal Aviation Administration plans to use it to help guide airplane landings as part of the Wide Area Augmentation System (WAAS), a network of ground stations that correct GPS signals and broadcast them to receivers on aircraft. It is currently in development.

Despite support for satellite-based navigation by potential WAAS users, "we're not going to rely solely on GPS for the near term," Mosley said.

Industry officials took the news in stride. "I'm not surprised," said Jack Ryan, vice president of 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 be reliable enough — in the face of interference — to decommission old systems.

That was the plan all along, according to Ryan. "We kind of envisioned that you could use GPS as the sole means of navigation. At least that was our hope."

DOT officials asked the Volpe Center to assess threats to systems that receive GPS signals from DOD's 28-satellite constellation after the President's Commission on Critical Infrastructure Protection recommended the study.

"There was a thought at some point that GPS could be the sole navigation system," Mosley said, but DOT never made a move to eliminate old capabilities.

For now, the agency will implement those recommendations. "We haven't put a cost figure on it," Mosley said. "Generally, we believe this can be done on the budget we have."

The actions shouldn't affect WAAS or the FAA's Local Area Augmentation System, which provides similar navigation information at airports, said Tammy Jones, an FAA spokeswoman.

Since it began in December 1994, WAAS has faced cost overruns, leading some to question its feasibility. The Bush administration has requested $107.7 million in funding for fiscal 2003 — a 42 percent increase. Raytheon Co., which is slated to deliver the initial system in 2003, declined to comment on Mineta's announcement.

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Action Plan

Transportation Secretary Norman Mineta has endorsed all of the recommendations for the Global Positioning System, including:

* Maintaining old systems.

* Implementing new civil signals.

* Transferring anti-jam technology from the military.

* Encouraging industry outreach.

* Assessing existing navigation aids.