Not Loran but eLoran
 

BBC report

A very good idea. It is often forgotten that the satellites running GPS are all controlled by the US military. There is no back up - in safety terms a 'single point failure.

welllllllllll - the Russians have a system in use and the Europeans are putting one in place as well so it's not all US controlled

However they are dependent on satellites and there are a number of scenarios (some natural so man made) that would see the network seriously degraded.

GPS has quite a few issues from a survey point of view that the average guy has no idea about as well

Having a back-up in place is a really good idea

I guess that it is less vulnerable to jamming.

And Chinese:
BeiDou Navigation Satellite System - Wikipedia, the free encyclopedia

Chinese only available to China and neighbours. Europe not yet operational. Russian only available if you ask Putin.

At least Galileo is said to be 10x more accurate than the Chinese one.

I see also that new GPS satellites do not have a SA capability (they say)'
.

Glonass
 

You do realise we have all been using Glonass since 2011? :cool:

GPS Test app on Android differentiates between Glonass satellites and GPS satellites if you want to see what you are locked into.

PN, they turned SA off best part of 15 years ago, although not much publicized ahead of time. They haven't even been building the facility into the birds for five years or more. Mind you, my car still can't find its way home.

There was something called Loran available over the North Atlantic Whwn I was serving in the early 1950.

Exnomad , I used it to fix a position in a frigate on the way to Halifax Nova Scotia.

Loran? We dreamt of Loran! Slaving over an 'ot sextant half way across the pond!

Loran? Luxury!

4Greens, or did you mean a weather ship? Marvellous job is you liked the ocean life and had a strong stomach. IIRC the kipper fleet did a Christmas mail drop.

It was definitely a frigate. Very bad weather and ice froze all the aerials including Loran. Got a sun position line four days later. We found our way in at last.

A Radar fitter remembers.
 

LORAN was an American version of the UK Gee system.

It worked at a lower frequency, this gave it a longer range and was used over the Atlantic and by ships, whereas Gee was 'Eurocentric' and built as a bombing aid aimed at the continent.

For bombing use, Gee evolved into Gee-H and the existing Gee transmitters were retained became a general navaid.

In the 50's and 60's most RAF 'navigator equipped' a/c had a 'Gee box' of one sort or another. An odd version in the Valiant was Gee-H with the 'H' parts not fitted.

To my knowledge, Gee II was fitted to Hastings and Gee III to Beverley's, some Hastings at Dishforth in 1959 also had LORAN.

I was never involved with Coastal Command, but I would have expected that the Shackleton's of the time would have used LORAN.

Problem was that coverage was not worldwide IIRC - if you wanted something in teh middle of no-where you had to set up your own system

We had Loran C fitted into 27 Sqn Vulcans in the MRR role, which apparently gave rise to the designation B2(MRR), a though sometimes without the brackets. It worked pretty much world-wide, with some areas that were a bit flaky, but suited our needs over the Pacific in the other sqn role. Still a lot of swing from the sextants, though to validate signal integrity (or was it the other way round...)

Mister B

Twas also used in commercial aviation.

As a VC10 pilot /nav with BOAC, I remember it well.

We used consol too and of course a sextant.

The weather ships also had radar and would give one a range and bearing.

Oh the "good old days".

What I find disconcerting is the bit in the article where he pulls the plug and everything goes dark. OK, the plot goes, but radar (raw data anyone?), steering, comms and even the clock. Too much reliance on a single point. In my last aircraft (737NG) loss of GPS was not a major failure. VOR, DME, ADF, the good old E2B compass would still get you home.

HH

This will always be so with any 'secondary' radar. The definition of secondary radar means that it is dependent upon a second piece of kit. In some cases on the ground, in others in the a/c.

Look at the MH370 thread, many people have been educated as to how the civil authorities are almost totally dependent upon the a/c side of these systems being serviceable and used correctly. No 'squawk' and the a/c was invisible!

Just about all of the primary ground based radars are in the hands of the military.