Car thief gangs have begun using imported GPS jammers to allow them to escape tracking technology.
Illicit kit imported into Europe from China operates on the same frequency as GPS satellites to drown out timing signals and confound in-car devices. Because of this in-vehicle systems are unable to either determine their position or report in to vehicle tracking centres in cases where cars or lorries registered with GPS-based tracking technology are stolen.
Vehicles "disappear from the radar" when the GPS jamming technology is deployed, Professor David Last of the University of Wales at Bangor told The Guardian. Professor Last has acted as an expert witness for prosecutors in recent prosecutions involving the seizure of illegal GPS jamming kit.
GPS jammers also have the potential to drown out mobile signals locally, a factor that has reportedly been applied to stop truckers contacting the police in lorry heists in Germany, as well as other applications. Experts reckons some German motorists have used the devices in attempts to avoid GPS-based road charging, introduced for trucks in 2005.
Ownership of the technology is a legal grey area even though it is against the law in both the UK and Germany to either sell or use jamming devices. GPS satellite signals are low power, so jamming devices need not be powerful.
Bob Cockshott, a GPS expert who works for the Technology Strategy Board, a public sector body funded by the Department of Business, explained that a "jammer with an output of about 2 watts [can] swamp any signal from the GPS satellites over an area of a few metres".
More powerful jammers in the 20w range could potentially disrupt the GPS signals over a river estuary or at airports. The UK government has allocated a £2.2m grant to a consortium including Chronus Technology to build GPS-jamming detection systems, currently at the prototype stage of development.
Although the risk of GPS jamming has been understood for years, its misuse by crooks is far more recent, dating back perhaps only 18 months. "We need to make users of GPS aware of the threat," Cockshott told The Guardian.
He added that the use of systems that triangulate positions based on the strength of signals from mobile phone masts, or similar technology, needs to be deployed as a complement and backup to GPS-based vehicle tracking and recovery services. ®