Mapping out potential GPS threats

The Transportation Department is waiting for the results of a study on how

to protect systems that use the Global Positioning System from hackers intent

on knocking out or distorting positioning data.

DOT asked the Volpe National Transportation System Center to study threats

to systems that receive GPS signals from the Defense Department's 28-satellite

constellation, said Joseph Canny, deputy assistant secretary for navigation

systems policy at DOT. The President's Commission on Critical Infrastructure

Protection, in conjunction with 1998's Presidential Decision Directive 63,

which called for agencies to develop ways to protect critical information

systems, recommended DOT conduct the study.

Volpe completed the first phase of the study in July 1999 by documenting

the threats of interference to GPS systems for railroad, maritime, aviation

and intelligent transportation system users, Canny said. The second phase,

expected to be completed this summer, will look at how to protect GPS from

those threats.

Protecting the system is critical to safeguarding commercial aviation.

The FAA is designing a ground- and space-based GPS augmentation system for

commercial and private pilots to use. The agency originally planned to phase

out all ground-based navigation systems as it transitioned to satellite

navigation. But "recognition of uncertainties about the vulnerability of

GPS" led to FAA's decision to retain a basic backup network of nonsatellite-based

navigational aids, Canny said.

The study will be a "guide to future policy development and decision-making

on retention of other navigation systems and the development of [GPS] augmentation

systems," Canny said.