Federal navigation plan released

Federal Radionavigation Plan

The latest Federal Radionavigation Plan, released March 26 by the departments of Transportation and Defense, sticks to the government's commitment to move to satellite-based systems and supports plans to keep the existing ground-based systems as backup.

The FRP, mandated under the Defense Authorization Act of 1998, "continues the commitment to transition to satellite-based services," said Mike Shaw, director of radionavigation at DOT. The departments released the last plan in 2000.

The department plans to continue modernizing the civil global positioning system (GPS) and phasing down dependence on existing ground-based systems. The government and the private sector use these systems as navigation aides, including to track and guide ships and planes.

DOT will stick with the 2003 and 2005 launch dates for the two additional coded signals that will provide significant upgrades to the system for civil use, Shaw said. The new coded signals will provide better protection against disruptions in service and more accurate signals, he said.

The plan does revise the schedule for some of the systems that are intended to bridge the gap between existing systems and the new GPS capabilities, such as the Federal Aviation Administration's Wide Area Augmentation System (WAAS), which will build a network of ground stations that correct GPS signals and broadcast them to receivers on aircraft.

But the launch dates are not dependent on the deployment of those systems, and "we're going to bring the full [satellite] capability online regardless of the augmentations," Shaw said.

The 2001 plan also marks the first time officials have split the policy and technical features into two documents to make it easier to read and understand for users and to maintain for the departments, Shaw said. Officials can more easily update the policy and planning section as they receive the evaluation on the current level of backup for GPS, he said.

DOT's Volpe National Transportation Systems Center released a report in September 2001 describing GPS' susceptibility to tampering and unintentional disruptions. Between that review and the homeland security concerns raised by Sept. 11, the department quickly launched a study to define what backup infrastructure is available during the phase down.

Earlier this month, DOT Secretary Norman Mineta announced the department will maintain backup capabilities as long as necessary. When the study is done, likely by the end of this year, the department will incorporate the recommendations on backup and redundancy needs into its radionavigation policy, which will become the basis for the 2003 FRP, Shaw said.

"Any good navigator never relies on one system, no matter what it is," he said. "We're trying to find a balance between 'everything goes' and 'everything stays.' "

Transportation is also talking with DOD on using DOD-developed technology to increase reliability, although some of the technology will likely be classified and not available to everyone using GPS, Shaw said.