Oct/Nov 2008

Could GPS jamming – which has been possible for many years – be on the increase, posing a degree of threat to the accuracy of tracking systems? Originally a military issue, in the civilian world the problem is likely to be of most concern in stolen vehicle recovery, where thieves might try to disable a hidden tracking system to evade detection.

However, it is not clear how real the problem is, and how much the result of a perceived threat, and two suppliers are currently challenging each other on the issue.

Tracker, one of the UK's leading stolen vehicle tracking and recovery systems, this autumn published a warning of the potential dangers. According to company spokesman Mark Walls: 'Whilst GPS/GSM devices have their place in stolen vehicle recovery, there really shouldn't be sole reliance on this technology.' He adds: 'Jammers are frighteningly easy to build using publicly available information and basic components and are cheap to buy from numerous sites on the internet.'

Tracker uses a different technology involving VHF wireless signals, and says this is resistant to the kind of jamming that can affect GPS-based systems.

 

However, one of the company's main rivals, Trafficmaster's Trackstar business, which uses GPS, has been quick to dispute the idea that there is a problem. It says it is not aware of any incidence of its customers' vehicles not being recovered because of a jamming device blocking the GPS signal.

According to Pat Gallagher, the company's director of in-vehicle products: 'Trackstar has a 90 per cent recovery rate, which we believe is the highest recovery rate in the industry. We have seen no evidence of increased use of jamming devices, and in fact both Thatcham and the Police assure us that they do not see jamming devices as a concern.'

GPS jamming is illegal throughout the EU, and we at m.logistics have no intention of describing how it's done, but there's a wealth of material about it on the Internet, and it does appear to be fairly cheap to do, although its reliability might sometimes be suspect.

In any case, navigation devices can be 'jam-proofed' to a degree, either in software or through measures such as ensuring the GPS antenna views only the sky, not nearby jamming RF signals.

Recent interest in the issue does perhaps underline the benefits that could result in future from enhanced tracking systems, possibly using a mix of Europe's forthcoming Galileo satellite network, GSM cell tracking, and newer technologies such as Skyhook's Wi-Fi Positioning System.