Civilian GPS: Long on promise, short on funds

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

different."

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.