Study gives OK to satellite-based navigation

The Federal Aviation Administration today announced that an independent study confirmed that existing satellite-based technology would, if modified, be reliable enough to serve as the primary navigation service for aircraft.

For several years, the FAA has been developing "augmentation" systems that refine Global Positioning System satellite signals so that aircraft can use GPS as a navigation tool.

The six-month GPS risk assessment study—conducted by the Johns Hopkins University Applied Physics Laboratory—set out to determine, among other things, whether the FAA needs an independent backup system for its satellite-based navigation programs and how much such a system might cost.

If appropriately augmented, GPS "can satisfy the required navigation performance as the only navigation system installed in the aircraft and the only navigation service provided by the FAA," according to the study, which was co-sponsored by the FAA, the Air Transport Association and the Aircraft Owners and Pilots Association.

The results of the study will help the agency make some important technical and program decisions about its Wide-Area Augmentation System program. WAAS will use a network of ground stations to refine GPS signals so that the signals are reliable enough for navigation across the country and for precision approaches to airports.

Jane Garvey, the FAA's administrator, said in a news release that she is "encouraged" by the findings. "It tells us we're on the right course and GPS navigation is achievable." Garvey added that "a significant amount of cooperative effort with the aviation community, including the Department of Defense, and additional investments will be required to make the needed changes."

Last year a report on critical infrastructures released by a presidential panel cautioned the FAA not to rely on GPS as its sole navigation system. According to the panel, GPS is vulnerable to jamming, lacks redundancy and may not be wholly reliable, leaving aircraft vulnerable to flying blindly.

The study is available on the World Wide Web at www.jhuapl.edu/transportation/aviation/gps.