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Cyber Threats Prompt Return of Radio For Ship Navigation (reuters.com)
Jonathan Saul reports via Reuters: The risk of cyber attacks targeting ships' satellite navigation is pushing nations to delve back through history and develop back-up systems with roots in World War Two radio technology. Ships use GPS (Global Positioning System) and other similar devices that rely on sending and receiving satellite signals, which many experts say are vulnerable to jamming by hackers. About 90 percent of world trade is transported by sea and the stakes are high in increasingly crowded shipping lanes. Unlike aircraft, ships lack a back-up navigation system and if their GPS ceases to function, they risk running aground or colliding with other vessels. South Korea is developing an alternative system using an earth-based navigation technology known as eLoran, while the United States is planning to follow suit. Britain and Russia have also explored adopting versions of the technology, which works on radio signals.
Cyber specialists say the problem with GPS and other Global Navigation Satellite Systems (GNSS) is their weak signals, which are transmitted from 12,500 miles above the Earth and can be disrupted with cheap jamming devices that are widely available. Developers of eLoran - the descendant of the loran (long-range navigation) system created during World War II - say it is difficult to jam as the average signal is an estimated 1.3 million times stronger than a GPS signal. To do so would require a powerful transmitter, large antenna and lots of power, which would be easy to detect, they add.
Cyber specialists say the problem with GPS and other Global Navigation Satellite Systems (GNSS) is their weak signals, which are transmitted from 12,500 miles above the Earth and can be disrupted with cheap jamming devices that are widely available. Developers of eLoran - the descendant of the loran (long-range navigation) system created during World War II - say it is difficult to jam as the average signal is an estimated 1.3 million times stronger than a GPS signal. To do so would require a powerful transmitter, large antenna and lots of power, which would be easy to detect, they add.
I'm surprised, but not really surprised, that modern commercial shipping doesn't have reliable backup systems - that's what the article seems to imply. I mean, how does a commercial sea-going ship's captain get certified without knowing some basic navigation skills - dead-reckoning, anyone?
Fair enough, dead-reckoning probably wouldn't suffice to avoid collisions in a major shipping channel, but still, you should be able to avoid the dry bits without having to rely on GPS. You can always turn on lots of flashing lights if you've lost communications - someone will come to help.
They sentenced me to twenty years of boredom
> the descendant of the loran (long-range navigation) system created during World War II
Nope. That was LORAN, later known as Loran-A. eLORAN is a slightly upgraded Loran-C, which was entirely post-war. They are similar in name only and worked on entirely different techniques and frequencies.
> Unlike aircraft, ships lack a back-up navigation system
Really? Ships had pretty reliable means of open sea navigation for at good 1000++y before GPS and even before the first aircraft, gradually improved trough the centuries. Paper maps, magnetic compass, more or less accurate clocks, tools for optical measurements? Whatever happened to them?
LORAN is good, but it is just as vulnerable as GPS and is pretty much the same basic technology, having infrastructure on the ground instead of space.
OTOH, sun/star/compass-based navigation can be improved by modern technology and still work autonomously on the ship. The fog and the clouds, preventing optical measurements by naked eye are almost non-issue in infrared. And more, now we have modern laser gyroscopes and precise accelerometers for a good inertial add-ons.
> This old but effective technology
As a pilot that used NDB, it would agree with the "old" but not "effective". Flying an approach against NDBs in the bumps while dodging snow squalls was an experience that made even my cast-iron stomach start to turn. Modern electronics could fix this by doing the work for you, but at an expense level far beyond GPS.
The idea of using any locallized transmitter is a non-starter for budget reasons, and one in the VHF moreso due to the required antenna sizes. NDB is dead, and good riddance.
LORAN-C depends on transmission stations, a lot of which are gone (although some aren't). The US and Canadian stations were shut down in 2010. Since they have to build new stations anyways, why not incorporate improvements? There's been a lot of advances since the 1970s.
> just pump enough energy into the air- and the closer you are to the target, the easier it is
But that's just it... in the case of GPS everyone is very far from the broadcasters and it is very easy for the jammer to be closer to its target than the transmitter, and very easy to generate more power than the weak signals from the satellite.
In the case of eLoran this arrangement is highly unlikely. For one thing, your target is likely to be closer to at least one of the transmitters than you are, and the power levels are so much higher that your jammer has to be equally massive.
It is MUCH more difficult to jam Loran, even in theory.
> Why is a new version needed?
The accuracy is not high enough to avoid collisions in busy areas. eLORAN adds:
1) QOS signals so you know if a station is bad
2) dLORAN (a-la dGPS) which greatly improves accuracy
3) globally synced signals (a-la Omega) so you can use any signal as the basis for measurements against any other
4) easy identification of ground vs. skywaves
The possibility of advances is limited. The wavelength the signal is transmitted on (to gain the above benefits of being long range and hard to jam) has various problems with the fundamental transmission that mean high data-rate or 'modern' services have real problems.
In principle, you might add a really low bandwidth data channel that would over the course of a few hours inform a receiver where the new transmitters are, but they will normally be created at such a rate that stored in firmware, rarely updated is fine.
There is little to 'improve' very much.
This article discusses the improvements that eLoran offers: http://gpsworld.com/innovation-enhanced-loran/ The article lists the following key differences between Loran-C and eLoran:
All transmissions are synchronized to UTC (like GPS)
Time-of-transmission control
The ability to use differential corrections (similar to DGPS)
Receivers use “all-in-view” signals
Includes one or more Loran data channels that provide: Low-rate data messaging, added integrity, differential corrections (dLoran and/or DGPS) and other communications including navigation messages.
Until we develop a way to block, or spoof, the sun and the stars there is a reliable and accurate backup for navigation. You need a precise time piece, sextant, nautical almanac, and charts along with a mariner who knows how to shoot the stars. The Nav on a frigate I was on did a daily celestial fix to double check our position with the radio fix. he could get a set of readings very quickly so the line of position produced a very tiny box for our fix. I'd bet my life on his fix before the radio fix.
The downside is you need to be trained and practice to keep sharp. I used to be good at it but couldn't get a fix to save my life now. With computers you could input the readings and get it to give you lat/long so there is no need to draw LOP on a paper chart. In a pinch you could send that out as you position.
Automation has caused mariners to lose skills that served our forebears well. One favorite drill a friend ran was to tell the crew GPS was down - now navigate for the next few hours the old way. Lots of head scratching and moaning when he did that. There's a lot to be said for keeping proven, if time consuming, skills sharp for when all the latest stuff goes south.
I'm a consultant - I convert gibberish into cash-flow.