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World War II Tech eLoran Deployed As GPS Backup In the UK
hypnosec (2231454) writes General Lighthouse Authorities (GLA) has announced that they have deployed a World War II technology called Long Range Navigation system, which they have named eLoran, in seven ports across Britain to serve as a backup for the existing Global Positioning System (GPS). GLA notes that modern ships have a lot of equipment that rely on Global Navigation Satellite Systems for functioning and in case of failure the consequences will be disastrous. For this reason technology that doesn't rely on the GPS was required as a backup. eLoran is a ground-based system rather than satellite-based and is designed to be used in the event of a GPS failure. The system was quite successful and post-WWII era, the system was updated and crowned a new name Loran-C. The navigation system was adopted by mariners across the globe and was used until GPS was deployed. Loran has now been renamed as eLoran because of the upgrades to the technology as well as the infrastructure. The more accurate system generates longwave radio signal, which is 1 million times more powerful than those from positioning satellites, are capable of reaching inside buildings, underground and underwater. According to GLA, eLoran and GPS are quite different from one another and hence there is no common mode of failure.
Funny how two countries can take the exact same situation and arrive at completely opposite decisions.
I remember loran from my early ham radio days (50's and 60's). It made a hell of a noise on HF. It probably would not bother anyone any more as the hf frequencies are not utilized as they once were. Sounds like an excellent idea as the gps system is very vulnerable.
The primary risk to GPS in the UK is the USA deciding to turn it off.
That risk doesn't apply for US shipping near the US, as if GPS was turned off - rather than severely degraded - so would the local LORAN locators.
GPS is not going away unless someone actually presses the button.
It's not vulnerable (theoretically) to single points of failure (ideally) as it's intended to carry on even in the event of moderate wars.
No common mode of failure? An EMP or nuke would beg to differ.
Silence is a state of mime.
In the event of a war with a major world power, GPS will be destroyed, because most of those powers have proven they can shoot satellites. If you depend too much on GPS you will be in for a rude shock when it goes away.
This is not your old 70's LORAN system. Thanks to advances in DSP processing, eLORAN gives your position with precision comparable to GPS (10m or so). It also have data channel that's used to broadcast DGPS corrections, so it complements GPS nicely.
Because of low frequency, signal penetrates buildings and ground (however with greatly reduced range). This may be one of the solutions for a car navigation in tunels. Even if it produces less precise position, it's always better than no position at all.
Great contrast between UK and USA, where LORAN transmitters were demolished in the past years. When so many things dependd on GPS signals, we really need some backup system for precise timing and positioning. Not thinking about backup only means we will learn about it the hard way - and it will not be pretty.
in case of failure the consequences will be disastrous
Yeah, because no shipping ever occurred before LORAN or GPS. What a joke! It's not like people found their way around the globe for centuries using the sun, moon and stars.
Actually, we HAVEN'T been shipping super sized cargo ships without at least LORAN. The need for near continuous, weather independent localization pretty much coincided with the development of radio. We COULD develop different back up systems - for example inertial navigation systems have progressed from refrigerator sized boxes with a price tag suitable only for military ships to a shoebox sized box priced reasonably for a multi million dollar freighter. Subsequent improvement could probably decrease the size and cost but I doubt it would get to GPS sized dimensions - if only for the fact that the frequency requires longer antennas.
And remember, a-Loran, b-Loran, c-Loran and e-Loran require multiple, expensive ground stations. We are all waiting to see what i-Loran will require, probably just some pixie dust and a persistent connection to i-cloud, but Apple hasn't weighed in with their plans just yet.
Faster! Faster! Faster would be better!
In case anyone is intersted, this slideset gives a nice overview of this "WWII tech".
http://www.ursanav.com/sites/default/files/pdfs/news/UrsaNav%20ILA-40%20eLoran%20System%20Definition%20%26%20Signal%20Specification%20Tutorial.pdf
Please understand that the technology to kill satelites has been around for a long time. Several military contractors for the US Defense Department have developed kinetic kill vehicles. They are in orbit as we speak. Their purpose is to destroy satelites by ramming into them at high velocity. They are like an anvil with a guidance system and a simple propulsion system. I know that Boeing had these back in the early 1990s. I'm sure there are hundreds or thousands of them up there by now with their targets locked in. If the US has them, you know the Russians and possibly the Chinese have them. If there is a major war between any of the major powers on Earth, the satelites will be one of the first casualties.
Also, of course, the Chinese proved they could destroy satelites from the earth by their launch of a missile at one of their own several years ago. (Thanks for the space debris, China.)
Nice to know the grown-ups are in charge of strategic planning in the UK. Contrast the no-intellect kiddies and political scum in the USA. Congress passed an appropriation in 2008 to implement eLORAN, but some puffed-up asshat in the executive branch zeroed out the funding and nobody ever followed through.
I think YOU are confused, how much energy does it take to build these satellites and put them into their orbits? THAT's what I'm talking about!
If a long-wave LORAN transmitter with mere 1 MW of RF output power (usually, it's more) could replace a microwave sat with 25 W of output RF power, then the equivalent energy needed for running that LORAN transmitter for the projected GPS sat lifespan of 7.5 years is equivalent to burning almost 6000 tons of kerosene, without taking the electricity generation efficiency into consideration. Quite optimistically, the corrected figure would be somewhere around 12000 tons. And the 7.5 figure is for the old sats, the new ones have a projected lifespan of 15 years, so that's more like 25000 tons of kerosene. In comparison, a suitable rocket for those GPS sats could have something like 200 tons of fuel at most (it tends to be a Delta II, or an Atlas V, these days). Now what is it you were saying about "high-energy approaches"? (Also, I should imagine that those larger receivers mean more energy and materials consumed when manufacturing them.)
Ezekiel 23:20
I read the title as "World War II Tech DeLorean Deployed As GPS Backup In the UK".
Followed by "They had time travel in WW2?"
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How come slashdotters always write it as HAM? It's ham radio, not HAM. Despite rumors, it does not stand for Highly Antique Morse.
I saw a documentary on a US Navy Aircraft Carrier, it had a relevant incident. The carrier has GPS, LORAN, inertial navigation, etc. Yet every day a sailor steps outside the bridge with a sextant and takes readings on the horizon and sun. (does another sailor do so at night with the stars?). He then goes inside and using a WW2 manufactured mechanical chronometer calculates the position of the ship. When asked why the Navy still uses such ancient mechanical technology the sailor replied that this ship is a warship and is expected to be where it needs to be regardless of whether the fancy electronics is working or not.
LORAN-C would probably be rather resistant to EMP. Like just about everything military, the transmitting equipment would be designed to be EMP-resistant, and receiving equipment on vehicles would not be particularly susceptible. It's stuff with long cables that picks up EMP. LORAN-C is certainly much more jam-resistant than GPS. The transmitter power levels are/were enormously higher, some in the megawatt range, to overcome natural background noise and antenna inefficiency. Even the large towers used are only a small fraction of a wavelength (3 km). Also, LORAN-C operates by groundwave propagation (that's why the frequency is so low) so it's not very sensitive to solar activity.
GPS L1C signal have 60W (a few times more on newer GPS sats) of power being irradiated by the antenna. By the same that signal travels 18000Km to the ground its down to miliwatts, in fact so weak that a one watt transmitter one Km away can still overpower the original signal. A 1 watt jammer can fit in your pocket. A 100 Watt jammer (no more than the size of a suitcase) can jam GPS for a hundred Kms easily.
GPS works great as long as its not jammed. And the dangers are far worst when there's a signal being spoofed (artificially sending a signal that looks genuine, but has the wrong parameters, potentially leading to aircraft crashes, banking transactions recorded with the wrong timestamp, shutting down celullar towers, leading people to the wrong locationto name just one of the dozens of life threatening scenarios).
eLoran is the only solution that can actually compliment GPS, providing it with a signal of similar accuracy to GPS L1C that can be received without line of sight to the antenna transmitting the signal 1000 Km away from the antenna.
In my opinion destroying the Loran-C towers was the single worst decision the Obama administration made. The Loran-C signal was worthless, but the towers and adjacent building could have been shutdown and then repurposed to transmit eLoran.