'Jammers' pose threat to naval navigation - expert


“JAMMERS” WHICH can be purchased via the internet pose a security risk to GPS navigation systems on land and at sea, according to an Irish technology specialist.

Such “jammers” interfere with GPS receivers by broadcasting a competing signal on the same frequency. They can now be purchased for several hundred dollars on the web, GPS positioning consultant Gary Delaney says.

The prevalence of such illegal devices must give added impetus to moves to provide an alternative navigation system, such as the terrestrial-based eLoran, Mr Delaney says.

Internet and mobile phone systems are now so dependent on “GPS time” that these communication networks are very vulnerable to degradation.

Mr Delaney says that a one watt “jammer” could affect GPS sets, internet and mobile phone coverage within a 50km radius.

The Naval Service says that it is aware of the issue, but has not come across such devices during drug interdiction activities.

The US-run GPS system has long been known to be vulnerable to deliberate or inadvertent interruption.

Two years ago in California, a US navy training exercise jammed GPS signals and interrupted mobile phone services for up to 10 miles inland.

It is understood that a device capable of interfering with GPS systems was discovered on a yacht seized almost three years ago in these waters on suspicion of drug-related activities, but the device had not been activated.

The Commissioners of Irish Lights (CIL), which is responsible for lighthouses and other navigational warning equipment around this coastline, says it supports development of an alternative navigation system to satellite, despite last month’s decision by the US coastguard to shutdown its Loran-C network.

US president Barack Obama said that the ground-based network was “obsolete” and was no longer needed in an age when GPS devices were almost ubiquitous in ships, planes and cars.

The US decision has been criticised by navigational experts, and the “father” of GPS Bradford Parkinson has said that a terrestrial system like Loran has to provide a critical back-up for safety and security reasons.

The EU has been working on a satellite network, named Galileo, which would complement the existing US-led GPS, and satellite systems run by Russia (Glonass), India and China. However, the EU system is way behind schedule and as vulnerable, potentially, as GPS to degradation.

CIL endorses development of an enhanced form of Loran, known as eLoran, as part of moves towards an independent European communications network.

The lighthouse authority has said that it does not want to be “totally reliant on satellites, which are subject to error”, and Capt Kieran O’Higgins of CIL has described eLoran as a very capable system.

Mr Delaney said eLoran would not require many transmission masts, and he did not envisage one would be located in Ireland, given the security issues attached to such structures.