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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.
sorry but you are wrong - .....
From
http://www.bbc.co.uk/news/science-environment-29758872
"
The system works using a fleet of satellites orbiting high above the Earth, but the signal they transmit is weak and can be easily interfered with.
Other sat-nav systems - such as Galileo in Europe and Glonass in Russia - have the same vulnerabilities, says Prof David Last from the Royal Institute of Navigation.
"A little bit of power from a jammer on the frequency used by GPS close to your receiver can deafen it, and it won't be able to hear the GPS signals," he says.
"For example, jamming is a real issue in Korea. There have now been three occasions when the North Koreans have transmitted high-powered jamming in South Korea."
The Sun too can knock satellite systems offline, he adds.
"It starts to transmit radio noise during solar storms, so intense that it either makes GPS positions wobble about or causes GPS to be lost across the entire sunlit side of the Earth."
"
It's not only the US, Norway is also about to shut down the (old) LORAN-C system.
"The Department of Fisheries has desided to close down
the 4 Norwegian Loran-C stations from January 1. 2016.
Ther reason given is that there is not many users, the GPS is the
primary navigation system, and that the equipement in use
are old and need expensive uppgrade." source: home.online.no/~loran-c/
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
The GPS specification is public and known 100%. In the early days of the GPS system, there was a random error introduced deliberately that could only be filtered out with a military receiver. The Federal Government stopped including the random error in the early 90s, and made it against the law for them to turn the random error back on in 2000. Modern GPS satellites don't even have the capability of transmitting the error signal.
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.