Software changes delay rollout of FAA satellite navigation system
- By Frank Tiboni
- Feb 22, 1999
The Federal Aviation Administration recently delayed by more than a year
the deployment of a $475 million satellite navigational system because it wants to further
refine the systems fourth and final software module.
FAA originally wanted to roll out the Wide Area Augmentation System in July, but it has
pushed the deployment back 14 months to September 2000.
The delay came after the final module proved to be a much greater challenge than
originally anticipated, said Steven Zaidman, FAAs associate administrator for
research and acquisition.
We will not commission Phase 1 of WAAS until we are satisfied this technical
challenge has been resolved, he said.
WAAS contractor Raytheon Co. has completed the first three WAAS operational modules.
The final module, the Correction and Verification System, will do monitoring, fixing and
The fourth module is an integrity check from the ground and goes to the heart of
the system, FAA spokesman Paul Takemoto said.
The module requires the interaction of more than 20 software algorithms for functions
such as alarm alerts and location checks for geostationary satellites, he said.
This is not a simple software fix, Takemoto said.
WAAS will augment the satellite data that FAA gets through the Defense
Departments Global Positioning System. It will correct the GPS signals received on
the civilian portion of GPS to ensure accuracy and data integrity for civil aviation
FAA has completed the hardware installations for Phase 1: 25 ground reference stations,
two master control stations, two geosynchronous satellite uplink stations and two
transponders on leased satellites.
After the rollout of the four modules during Phase 1, WAAS will give pilots en route
navigation and vertical guidance for precision approaches to runways in a limited portion
of the country. During subsequent phases, FAA will deploy WAAS nationwide.
The Johns Hopkins Applied Physics Laboratory in Laurel, Md., recently conducted an
independent risk assessment of the use of GPS data for civil aviation and will release its
FAA will use the assessment to determine if it can use WAAS as a primary navigation
tool for civil aviation.
FAA remains committed to the implementation of WAAS because of its safety
benefits for the aviation community and the flying public and because it is central to the
our overall efforts to modernize the National Airspace System, FAA administrator
Jane Garvey said.
The agencys WAAS team also is working with FAAs counterparts in Europe and
Japan to build a global satellite system for improving navigational data worldwide, Garvey