Cycling UK Forum

In today's BBC news http://www.bbc.co.uk/news/uk-scotland-h ... s-36493619: (my bold)

People planning walks in Scotland's hills have been warned against relying on GPS devices and to instead navigate using a map and compass....

It has also warned that walkers in certain areas next month may even find their GPS has been jammed.

Services are to be denied in and around the Hebrides during military training.

Communications watchdog Ofcom has issued a notification about GPS jamming planned for periods of time between 1-29 July while aircraft crews train over a military range on Benbecula.

Ofcom notice:

Dates: The exercise will run over the period 1 to 29 July 2016.

Times: Between 09.00 – 11.00 and 13.00 – 15.00 daily.

Location: Jamming aircraft flying on a ground track based on the Benbecula VOR 275° radial. The aircraft track will extend from 10nm west of the BEN VOR to 60nm west of the BEN VOR.

Frequencies: 24 MHz bands centred around 1575.42 MHz and 1227.60 MHz.

"in and around the Hebrides" is a bit vague! As there aren't many roads and choices are limited, this will be less of a problem for cyclists unless they are recording a DIY Audax, but forewarned is forearmed -- it may not be your Garmin crashing after all!

Interesting! I'm going to be on Lewis during that period I wonder if the jamming will extend that far? I wonder if it will also impact GLONASS signals (my Garmin uses both GPS and GLONASS)? They use slightly different frequencies.

I bet all GPS networks will use frequencies in this range or why bother jamming just this range? They're jamming to knock out GPS so all GPS networks will likely be affected in the areas affected.

Why the jamming out of interest.

Is it to force folks on the exercise to revert to old unjammable systems?

They generally these days are making sure modern militaries are prepared for an EMP attack, so it might be to do with that.

Tin foil hats at the ready!

Them over the water are planning a similar exercise in California - at least over here its being restricted to a fairly sparsely populated area where impact will be limited

Snow wrote:They generally these days are making sure modern militaries are prepared for an EMP attack, so it might be to do with that.

Yes, that'll be it.
If WW3 breaks out, the GPS sats will be on the hit list.

They can't switch them off for a specific local area, so targeted jamming will be the only way.

AaronR wrote:Tin foil hats at the ready!

Them over the water are planning a similar exercise in California - at least over here its being restricted to a fairly sparsely populated area where impact will be limited

Scotland has a population of like 5 million, London has about 6 million, so it's as good as it really gets around here lol.

Well GLONASS uses 1602 MHz and 1246 MHz which are both outside of the bands that are being jammed
"Frequencies: 24 MHz bands centred around 1575.42 MHz and 1227.60 MHz.".
But no doubt the jamming will spill over a little!

I assume that most NATO equipped forces will be using GPS and so there is no need to jam GLONASS to simulate the loss of GPS. But who knows!

Just as well you can't really get lost cycling in the Hebrides

robing wrote:Just as well you can't really get lost cycling in the Hebrides

I suspect tho that there are a lot of people who could not find the Hebrides without a GPS

I remember on my first ship - HMS Achilles - in 1971, we were heading over the Indian Ocean en route for Singapore.
We were on our own. No supply ship and no-one in convoy with us.
We needed to get fuel of course, so were calling in at Gan in the Maldives. There was an RAF base there and a fueling barge for passing ships.

How do you find a low-lying small island in the middle of an ocean?
Obviously no GPS in those days!
Dead reckoning and sextants got us in the right area, but radar wouldn't find a flat island any more than ten miles away.

What we did, was to track the RAF aircraft on radar and triangulate the island's position.

I guess this will have the same effect as the regular Joint Warrior excercise and all GPS gets jammed.

Thackie wrote:I guess this will have the same effect as the regular Joint Warrior excercise and all GPS gets jammed.

Don't count on jamming, they could be spoofing. If you riding on a road and the gps track is 2km to the right,
you're being spoofed.