EU navigation safety project Accseashas demonstrated automatic resilience against GPS jamming attacks in UK waters.
The trials used data from eLoran, based on one of the navigation systems used before GPS was invented, to provide back-up positional information.
Although accurate, GPS and its proposed European alternative Galileo, work on faint signals in a narrow band and are easily deliberately disrupted.
According to the project, GPS jammers are widely available, and for as little as £30 can cause complete outages across all receivers currently on the market. Space weather can also disrupt services.
“The more dependent we become on electronic systems, the more resilient they must be. Otherwise, we face a scenario where technology is actually reducing safety rather than enhancing it," said Martin Bransby, research and radio-navigation manager at Manager at the General Lighthouse Authorities (GLA), which carried out the trial on behalf of the project. "Demands on marine navigation are only getting tighter, yet electronic systems at sea are primitive compared to those used in air travel. This needs to change.”
Building on two previous trials conducted by the GLA in 2008 and 2010, which investigated the impact of GPS service denial, this latest demonstration is the first time that navigation of a ship was seamlessly transferred from satellite to terrestrial navigation.
"When GPS was deliberately jammed, the system switched automatically to eLoran and provided eLoran derived information to the connected bridge systems, allowing them to maintain operation and enabling the mariner to continue to navigate safely and efficiently," said the project.
Loran, and its rival Decca Navigator, provided navigation information in pre-GPS days by sending long-wave signals from fixed land-based stations.
Loran was pulse-based and the Decca system measured the relative phase of continuous-wave signals.
All three independent systems, Loran, Decca and GPS, use time-of-arrival differences between at least three transmitters of known position to calculate receiver position.
Loran systems still exist, and eLoran uses signals from many more than three Loran transmitters as well as other techniques to improve accuracy.
Accseas is taking advantage of the availability of the prototype eLoran transmitter at Anthorn (Cumbria) and eight other Loran stations around the North Sea.
Most recently, in January 2013, a differential Loran station was installed at Dover, one of the busiest shipping lanes in the world, enabling mariners to obtain port approach-level accuracies using eLoran within this area. A P&O Ferries vessel is evaluating this.
"By 2014, eLoran 'initial operational capability' is expected in seven major ports along the East Coast of the UK, with full operational capability covering all major ports expected by 2019," said the project.
Accseas (Accessibility for shipping efficiency advantages and sustainability) is a European Union part-funded project involving partners from across the North Sea Region. Its aim is to developing a practical e-navigation test bed to harmonise the exchange of electronic maritime information onboard and ashore.
Its partners are: General Lighthouse Authorities (UK); Chalmers University of Technology (Sweden); Danish Maritime Authority; Federal Waterways & Shipping Administration (Germany); Rijkwaterstaat, Minesterie Infrastructuur en Millieu (Netherlands); Swedish Maritime administration; Norwegian Coastal Administration; SSPA Sweden; Flensburg University of Applied Science (Germany); NHL Hogeschool, Leeuwarden, Maritiem Instituut Willem Barentsz (Netherlands); and World Maritime University (Sweden).
