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You could really say that Geophex, Ltd., of Raleigh,
North Carolina, has a lot of sense--or maybe, sensors. Through
Small Business Innovation Research (SBIR) funding from
NASA's Stennis Space Center, Geophex devised a new design for
broadband electromagnetic sensors. NASA's original goal was to
find an advanced airborne electromagnetic remote sensor to monitor
various coastal environments. To meet this goal, Geophex developed
a patented sensing technology, capable not only of coastal monitoring,
but also a variety of other functions, including environmental
pollution characterization, groundwater contamination detection,
archaeological study, and mineral detection. The new technology
is offered in several of the company's products--the GEM-2, GEM-2A,
and the GEM-3.
The Geophex
products consist of two primary electromagnetic coils, which
are stimulated by alternating currents that generate a magnetic
field in the object targeted for investigation. An electromagnetic
sensing coil that measures the magnetic field induced in the
target is also needed. While other apparatuses have been constructed
with these same general components, Geophex's sensor has been
drastically compacted, and yet still contains the needed specifications
of a sensor instrument.
In the Geophex
version of sensing technology, the coils are situated in close
proximity of each other. Previously, the coils were placed as
far apart as possible, making for a rather large instrument.
This distance was thought to be necessary in order to prevent
the excitatory magnetic field of the primary coil from overwhelming
the relatively weak field of the sensing coil. Geophex's compact
size is achieved through the use of a concentric design where
the smaller sensing coil is placed within the larger primary
coils, creating a magnetic cavity at the center of two concentric
loops, allowing for the accurate detection of weaknesses in electromagnetic
fields.
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| The GEM-2A airborne sensor is commercially
used for surveying large areas of land, in search of minerals,
metals, and hydrocarbons. |
Geophex creates products of unrivaled
accuracy and efficiency in a wide range of Earth-related fields.
For instance, the GEM-2 is a handheld, lightweight, programmable,
digital device. It consists of a broadband electromagnetic sensor,
a rechargeable battery, and operating software. Characteristics
like its advanced sensing ability and compact size make the GEM-2
ideal for smaller geological and environmental surveys. In one
noted case, the GEM-2 was used to rediscover decades-old radioactive
waste that had been buried in Tennessee.
The same sensing
capabilities are offered in the GEM-2A, an airborne version of
the sensor. Suspended from a helicopter, the GEM-2A is used to
search for mineral deposits and to survey large tracts of land.
One Australian mining company succeeded in its search for diamond
deposits and other precious and base metals by employing the
GEM-2A.
The third version
of this technology is exhibited in the GEM-3. Like the other
GEM products, it can be used for environmental site characterization,
but it also has another unique function. The GEM-3 is capable
of detecting buried landmines and other active munitions. While
other products are able to perform similar functions, the GEM-3
goes above and beyond their capabilities by identifying landmines
by their brand names. Because each landmine has its own unique
electromagnetic response to the broad frequency band emitted
by the GEM-3, bomb identification and disposal strategies are
made easier.
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The GEM-3 can be used for
detecting and identifying buried unexploded ordnance and landmines.
Each landmine shows a distinct electromagnetic response in
a broad frequency band, which can be used as a fingerprint
to identify it by its brand name. |
While Geophex
has enormous success with these products, more is yet to come.
It is hoped, future applications of this technology will allow
for the detection and identification of concealed weapons. Medical-related
applications include using tomography to image the conductivity
of the body. This technology also has the potential for detecting
water and other fundamental resources necessary for establishing
human colonies on other planets. Based on the success of the
GEM family of sensors, NASA's Jet Propulsion Laboratory has awarded
Geophex a contract for the development of an electromagnetic
sensor to be mounted on a Martian rover. Sensor technology will
help us map out opportunities in space, as we continue to map
out those here on Earth.
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