For many of us, GPS devices make our lives
easier. They help us find the best route to a meeting, a nearby Starbucks, or even
help us avoid a nasty accident that is stopping traffic on the freeway.
However, as GPS devices become more widely used, the potential for danger from
a GPS jammer is becoming increasingly common. For instance, some emergency
networks, power stations, and airports rely upon accurate timing of GPS signals.
Should one of these signals become compromised by a GPS jamming signal, there
could be serious consequences.
GPS jammers are used in potentially less harmful
circumstances as well. In Germany, some drivers are reportedly using GPS
jamming devices in order to avoid GPS-based road charges. Although it's illegal
to sell or use these types of jammers in Germany as well as in the UK, the law
isn't necessarily stopping people from doing so. Since a GPS jamming device
that puts out approximately 2 watts is sufficient to disrupt a GPS signal in a
vehicle that's within 10 feet of the device, it's conceivable that GPS jammers
could be used to render stolen vehicles undetectable by law enforcement and
other services such as OnStar.
For the military, GPS jamming devices present even greater
threats. Some soldiers are using consumer grade GPS devices instead of the
secure units provided by the military. These consumer grade devices are easily
compromised by jammers, and the information could be used against the soldier carrying
the unit, as illustrated in this video:
All is not lost, however. As the video also points out,
there are secure GPS channels as well as unsecure ones. In addition, a system
is currently in prototype stages in the UK that would detect jammers. Such a
system could be deployed in airports, harbors, and other locations that depend
on the accurate timing of GPS signals.