Civilian GPS: Long on promise, short on funds
- By Cheryl Gerber
- Mar 12, 2000
Despite the growth of GPS in the civilian market, there is still no national
GPS infrastructure or budget in place to support it.
One effort has made headway. The Air Force turned over its decommissioned
Ground Wave Emergency Network (GWEN) system to the Transportation Department
to reuse for a national civilian GPS infrastructure called the Nationwide
Differential GPS (NDGPS). GWEN consists of 60 broadcast towers, transmitters
and generators located throughout the United States.
As the NDGPS sponsor, the DOT's Federal Railroad Administration established
the operating requirements for all GPS land surface applications, said Richard
Shamberger, program sponsor at the FRA. The Coast Guard and Federal Highway
Administration are other key players in the effort.
Unfortunately, competing for congressional dollars pitted the FAA's
WAAS and the NDGPS against one another, although one system is for air and
the other is for land. "The GWEN tower differential system is a phenomenally
cost- effective way of getting one-meter accuracy across the country," said
Charles Trimble, chairman of the GPS Industry Council and founder of Trimble
Navigation Ltd. in Sunnyvale, Calif. "It came close to being killed, though,
because people were afraid it showed up WAAS. In fact, the systems are vastly
The FAA's WAAS will cost $3 billion to run for 15 years, whereas the
NDGPS will cost only $100 million over 15 years, said Len Allen, chief of
the Coast Guard Navigation Center's Operations Planning Division. Still,
Congress has been slow to allocate funds for the NDGPS. President Clinton's
fiscal 2001 budget proposes to spend $18.7 million on it.
The telecommunications industry also has an interest in the NDGPS, said
Ed Butterline, a consultant with Symmetricom, San Jose, Calif. The FCC mandated
that carriers must be able to locate cell phones within 125 meters by 2001.
In an emergency, cell phone users will dial 911, and their coordinates will
be passed to an emergency center, which will pinpoint users' locations.