Illegal GPS Jammers Are Widespread, Study Finds

Illegal systems which jam GPS are widely used in the UK, and could cause accidents, according to a new study conducted in secret.

The Sentinel study, a£1.5m government project run by a consortium that includes the police and the National Physical Laboratory, found 60 violations in six months by monitoring just 20 roadside locations, according to a paper presented at the GNSS Vulnerability 2012: Present Danger, Future Threats conference held at the National Physical Laboratory yesterday.

Signals from Space

Global Positioning System (GPS) is used by transport, military, and financial sectors for navigation and coordination. given this country’s reliance (some would say over-reliance) on GPS, disrupting the satellite signal could cause serious problems for airports, mobile phone networks and even the stock market. GPS uses signals from an array of satellites, by which receivers on the ground can determine their position via triangulation. Because GPS is nothing more than radio waves, these waves can be jammed, but most of the GPS-enabled devices we use are one-way receivers that cannot transmit on the frequency used by the GPS system.

Until recently, GPS jammers were built mainly for military purposes, for instance, to confuse the enemy or disrupt missile targeting systems. Last year, the Ministry of Defence even had to stop a major naval exercise, as the use of military jamming could endanger local fishermen and disrupt mobile communications. However, there are a few civilian uses for jamming GPS signals including the ability to conceal a person or a vehicle if it is transmitting its location based on information from GPS.

Logistics and other companies often install GPS trackers which transmit their vehicles’ location, based on GPS data, so the company can follow the movements of its vehicles, and prevent use of company cars for personal purposes. Trackers are also used in vehicles carrying valuable loads. Expensive cars can be tagged with GPS trackers, to help locate them if they are stolen.

GPS jammers effectively allow tracked vehicles to get off the grid, while blocking the signal from other users, in a range from about 10 meters to 32 kilometers.

The Sentinel research project used a network of 20 roadside monitors to detect jammer use. In one location, the study recorded more than 60 GPS jamming incidents in six months, reports the BBC.

Today we not only use GPS to navigate in our cars but we also rely on signals from space as a timing indicator. It is used to synchronise a wide range of computer based systems,  and even ensures accurate timing for some computerised stock market transactions.

In a jam

Sentinel is a 24 month project which aims to establish the extent to which Global Navigation Satellite System (GNSS) signals, including GPS, can be trusted by users on an everyday basis.

It will focus on “research into techniques for real-time detection, characterisation, discrimination and location of natural and deliberate interference phenomena and threats enabling trust by ensuring system integrity is not discredited with false alarms,” states the description of the study on the GPS World website.

The Sentinel consortium, responsible for the project, is led by Chronos Technology – a specialist company in the field of Positioning, Navigation and Timing (PNT). Other members of the consortium include Association of Chief Police Officers, General Lighthouse Authorities, National Physical Laboratory, University of Bath and vehicle security company Thatcham.

The £1.5m project replaces similar GAARDIAN program which ran from 2008 to 2011. The consortium enjoys complete government support, with the funds provided by the Technology Strategy Board (which, in turn, is sponsored by the Department for Business, Innovation and Skills) and the Engineering and Physical Sciences Research Council.

But illegal GPS jammers are not the only focus of the study. Jamming can occur naturally due to extreme weather conditions or solar flares. Accidental jamming as a result of the nature of the GPS radio signal is also an issue. One of the aims of the project is to distinguish between different kinds of jamming. Knowing why it happens will be useful in preparing a response and contingency actions.

Despite being dangerous and illegal to use (but not own), GPS jammers are available to buy online at dedicated websites like www.jammer4u.co.uk, and a basic model costs just around £60.

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