GPS Jamming over most of UK 7/8 JUL
 

Just spotted this in the NOTAMs:

AC 5555
07 JUL
1100-1400 30000ft (A1063/02pt)
08 JUL
0715-1015 30000ft (A1063/02pt)
GPS Jamming Activity 5555N 00550W rad 320nm. Tel 01436 674321 X
4402/4404/4379

So thats the whole of the UK almost as far as LHR!!!

We have been warned!

Is this common? Any idea why they would be jamming them?
Not that I use one, just curious :)

Anyone know WHO is doing the jammimg & WHY ?

Where is noggin when we really need him ?

Ah well, I suppose this means that I will have to revert to a chart, & mark one eyeball, for a bit of navigation, this weekend. :D

I've only used a GPS on one previous trip (France/Spain) so not too worried. Anyway, my trip to Leicester and Wyton this weekend is on Saturday, weather permitting, so not affected.

As to who and why, well I'm pretty sure it would be the military testing their ability to deny the service to others whilst still operating effectively themselves - its a defence issue.

Yet another reason not to rely solely on GPS!

Possibly MOD testing to see just how vunerable GPS is to jamming?
Remember, our cousins across the pond are considering using GPS as the primary air navigation tool as opposed to good old NBD's and VOR's.

Uncle Tony and his band of merry men might want to find out for themselves what could possibly go wrong if we tried it.

Or am I way off course? ( if you'll pardon the pun!)

WO

WO
 

You are way out of date the US goverment is now not going for GPS as a the only navigation system because of the problems outlined above.

In fact funding for new NDB,s and replacment of old VOR equipment has been granted for the short term.

For the longer term I suspect that GA aircraft will be using dual DME to update the GPS position via the data ports that most panel mounted GPS units have.

This link shows the area affected.

http://gc.kls2.com/cgi-bin/gc?PATH=&...avy&MAP-STYLE=

Call me cynical, but I suspect that some (not all) ppls who rely on GPS as their main or only system of navigation may also be none too diligent in checking notams. If so, and if they don't also visit this bulletin board, there could be a bit of oops going on this weekend.

Same thought occured to me mate! Hey, I know, maybe PPRUNE should be referenced in the AIP as a necessary element of pre-flight briefing ;-)

GPS was designed as an "unjamable" aid, it uses spread spectrum modulation and correlation techniques which make it very difficult to jam over a wide area. It requires some very clever techniques to effectively jam signals that are inherently below the ambient noise level; MOD want to find out just how susceptable it is and conduct periodic trials. Thats not to say they will be effective but you have been warned!

Interestingly it is illegal to "interfere with other wireless telegraphy" but as GPS does not operate in a frequency band allocated to radio navigation, it is considered as fair game.

I do check the Notams before flight - I particularly don't want to get mixed up in PJEs. However, I would have missed this because it only appears in the Scottish A8 Fut notam. I would have thought something with a 320nm radius should also have been in the London A8 notam.
I have not been in the habit of looking at the Scottish notams when my flight is within the London FIR and I never thought I was doing anything wrong. What do other pilots do?
Fortunately I don't rely on gps. Thanks for bringing this to our attention on PPRUNE.

Spoke to the people at the contact number provided in the NOTAM and the details are as follows:

28 nm range from 51 52N 5 40W from a four hour period in the range 0800-1700 local daily from 5/7 to 8/7

320 nm range from 57 35N to 4 00W for a one hour period in the time ranges:
1600 - 1900 UTC on 7/7
0715 - 1015 UTC on 8/7

320 nm range from 55 55N to 5 50W for a one hour period in the time ranges:
1100 - 1400 UTC on 7/7
0715 - 1015 UTC on 8/7

The purpose it to test mobile GPS jammers.

Looks like I'll have to use that thing with the dials and needles again.....
:rolleyes: :D

I'd have missed it as well. I check the NOTAMS, but if I'm in going to be London FIR I only check the London NOTAMS. However I wonder how much it will affect us. GPS uses high frequency ratio wave (in the GHz, I believe) which are only 'line of sight', so if you're pottering around somewhere on the Southern map at 2500ft then my guess is that you won't be affected.

I recognise the telephone number - its the AirOps Room in Faslane, Scotland, been well published in NOTAMS before.

GPS is jamable! Put enough nonsense into the receiver and close enough and its gonna stop working.

It uses freqs in the 1.5 and 1.2 GHz bands - yes NORMALLY line of sight use.

Don't forget radio range vs altitude means a larger coverage area. 320NM - dunno what that equates to ?

where does the lat/long put it?

Some where in the Clyde estuary would be my guess!

regards

Lat/Long puts it on Jura. Apart from a distillery, I've no idea what's there. Good one for the UFO lot :)

Notamplot
 

For a really good way to pick up notams go to:

http://www.notamplot.flyer.co.uk

This is a program which basically downloads the notams and then displays them graphically on a map of the UK so you can see immediately which ones affect you.

Apologies if this is old hat.

QDM

S&L
If what you say is correct then presumably the GPS is not covered by the RCA "licence" fee (for licence read RIP OFF). In which case we have no ability to challenge the RCA fees. HOWEVER when the military jam other frequencies for testing then the RCA may have allowed the breaking of the terms and conditions of your licence so could be challenged for the fee. Any experts out there care to enlighten us?

JMC!
The jammer is just inside the entrance to Loch Ewe.
Please don't ask me how I know... I'd have to kill you. :D

PS The jammer is pointing out to sea, so only the Fleet should suffer. However, it would appear from the NOTAM that the effects of backscatter are an unknown quantity, so you'll just have to start navigating again. :p

QDMQDMQDM (great name btw!) - yes, Notamplot is excellent - thats how I spotted it. I strongly recommend Notamplot to everyone!

Working Hard

Quite right the aircraft radio licence does not cover the GPS. At one point the RA said they would sell GPS licences for £5 to make the use of GPS legal! Never head of anyone with one!

The radio licence fee covers administration and costs for "protection" of frequency space; believe it or not the RA actually do a good job here, if you see how many people they apprehend every year.

As regards to jamming other protected frequencies, it would be an offence however, the military can usually get away with such things in isolated areas.

Why doesn't everyone monitor their GPS and see if it really is affected on the notamed dates. Chances are you will not observe anything. If you do, respond here and we can see how effective the jamming is or isn't.