Narrowing the radio spectrum
This story first appeared on June 6 as a Web Extra, New
rules endanger GPR.
On April 18, an Amtrak auto train was passing through Crescent City, Fla., on
its way to Washington when it derailed, killing four people and injuring more
than 160 others. Many investigators believe that waterlogged soil caused the tracks
to move around and derail the train. A group of geoscientists, led by Ernest Selig
and Gary Olhoeft, think they may have found a way to prevent future accidents
using ground penetrating radar (GPR) to measure the amount of water beneath
the rails. But a ruling by the Federal Communications Commission (FCC) to restrict
the use of GPR may stop them dead in their tracks when it goes into effect this
The use of GPR to create an automated, water-measuring system for the Federal
Railroad Administration is only one of this technologys many applications.
In his 30 years of GPR experience, including 20 years at the U.S. Geological Survey,
Olhoeft, now a geophysics professor at the Colorado School of Mines, has used
GPR for everything from studying agricultural pollution to finding lost utilities
to preventing damage from excavation to mapping archaeological sites prior to
At a congressional hearing on June 5, industry representatives and members of
Congress highlighted GPRs contributions in an effort to curb the coming
FCC regulations on ultra-wideband (UWB) technology, including GPR regulations
based on concerns about potential interference with military and transportation
This technology has too many promising applications to stifle it based on
unfounded, and unproven, concerns, said House Energy and Commerce Committee
Chairman Billy Tauzin (R-La.). GPR uses a large range of frequency in the radio
spectrum to look downward into the earth, water, ice or man-made materials to
see the unseen. The FCC regulates the nongovernmental use of the radio spectrum,
and the National Telecommunications and Information Administration (NTIA) handles
the frequency spectrum for federal agencies.
Until 1998, the wide use of GPR went largely unnoticed and unregulated. After
three companies applied to use new UWB devices, the FCC and NTIA decided it was
time to draft rules for their use. Now, after four years of discussion, the FCC
has issued frequency and application restrictions, and calls for GPR manufacturers
and users to obtain certification for their systems and to submit advanced notification
of use. According to the FCC rules, GPR systems can operate at frequencies below
960 megahertz and between 3.1 and 10.6 gigahertz, but its use in those ranges
is restricted to law enforcement, fire and rescue organizations, to scientific
research institutions, to commercial mining companies, and to construction companies,
banning use by independent geoscientists. All use is banned between 960 megahertz
and 3.1 gigahertz.
I think theyre being too conservative, because theyre going
to end up putting a lot of people out of business and unfortunately theyre
going to eliminate a bunch of applications like evaluating pavements, bridge decks,
concrete runways. Those all are using radars right in that frequency range,
These rules result from intense pressure from the Departments of Defense and Transportation
to protect infrastructures that rely on the radio spectrum to help provide national
security and public safety. These government agencies fear that unrestricted use
of certain bands of the radio spectrum will interfere with their use of the spectrum.
Even thinly spread UWB energy interferes with very low power signals from
distant sources, such as GPS [Global Positioning System] satellites, which are
over 12,000 miles away. In such a case, prudence is dictated because no one knows
for sure, testified Steven Price of the Department of Defense.
GPS runs right around 1 gigahertz and, Olhoeft says, the Department of Defense
is trying to protect both the current GPS system and the future system the agency
has proposed building. One of the biggest errors in geophysics is not knowing
where you are at, so we use the GPS too. And weve shown them that it doesnt
interfere. Indeed, at the congressional hearing, when questioned by Rep.
Tauzin, Julius Knapp of the FCC stated that in GPRs 30 years of use, there
have been no reported cases of interference from GPR.
Dennis Johnson of Geophysical Survey Systems Inc. (GSSI) testified on behalf of
GPR manufacturers and users. Having sold about 2,500 systems since the company
started in 1970, GSSI is the largest U.S. manufacturer of GPR. Johnson said the
GPR industry is worth $200 million in the United States alone. If the rules
are not changed, the outcome and consequences for the GPR industry are extremely
serious. Many companies will go out of business, and the publics access
to a very useful technology will be severely limited, if not eliminated,
A source at the FCC says that the agency plans to interpret the rules as broadly
as possible, granting a waiver to those who request one. In fact, he says that
the FCC has already met with several groups to get a jump-start on granting them
permission and certification for GPR usage. He does concede, however, that the
process is subject to the NTIAs corroboration. No one really knows what
will happen when the rules change this month.
In its rules, the FCC admits to its conservatism and says it will review the rulings
in six to 12 months, after extensive testing of GPR and other devices affected
by the ruling. Members of Congress at the hearing pressed both the FCC and the
NTIA to construct a strict timetable to promote a speedy resolution.
Lisa M. Pinsker
press release with links to the ruling
Radar Solutions International
Site about GPR and regulations