GPS jamming

Author
Discussion

Iamnotkloot

Original Poster:

1,587 posts

154 months

Sunday 30th June
quotequote all
Seems to be pretty commonplace by Russia (and Israel) - the RAF seem relaxed enough about it but it is undeniably reckless behaviour.

https://www.telegraph.co.uk/world-news/2024/06/29/...

OutInTheShed

9,299 posts

33 months

Sunday 30th June
quotequote all
The RAF can get by without GPS.
Some civilians rely on it too much.

I'm off in my boat when I've had my coffee, hopefully no fog this time.
Last week we found GPS pretty handy when visibility got down to about 100 feet.

LimaDelta

6,949 posts

225 months

Sunday 30th June
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It's not uncommon where I fly, though obviously NOTAM'd and comes with a panic helpline.


IanH755

1,998 posts

127 months

Sunday 30th June
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Just for clarity - The jets themselves aren't being directly targetted with "jamming" which is how the article (and most media reporting) implies. Instead its large geographical locations which have various GPS interference signals applied and the RAF, alongside other militaries and lots of civilians aircraft, are just flying through those areas.

As to the term "jamming", thats a bit of a misnomer too as that implies a "blocking" of the GPS signal so there's no GPS available, whereas whats actually happening is closer to "spoofing" or "meaconing" which is used to overpower the quite weak GPS signal coming from the various satellites with a stronger one from the ground, which acts as a way to alter the accuracy of the GPS data being fed into an aircraft's navigation system*, not only making it far less accurate but also potentially altering the actual route being flown vs the one the navigation system "thinks" its flying.

At this point its so well known about that, whilst its a pain in a bum, its not an actual "threat" to aviation at the moment.

.* - GPS is generally used to update the primary navigation sensor which is an INS (fitted with Gyros and Accelerometers to measure position in 3D space) as these will drift over time if they are not updated with accurate externally provided position info (GPS, radar fix, visual fix etc). Modern aircraft systems tend to be more reliant (and therefore more trusting) of those GPS updates to the point where the GPS is automatically assumed to always be correct and therefore it becomes the primary navigation source - "I am here" - with the INS providing "this is my position in 3D space" and as another source of "where I think I am" whereas slightly older aircraft systems still keep the INS as the primary Nav source "this is my position in 3D space and I think I am here" with only occasional updates via GPS etc just to correct the drift.

There's always going to be some differences so this not exactly a "this is all 100% accurate for every single situation" type post which is made more for the average person to have a slightly better understanding, so bare that in mind before pilots start to rip into me with "thats not how mine works" etc" please smile

Mr Pointy

11,818 posts

166 months

Sunday 30th June
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Another issue is that GPS isn't just used for navigation - it's used as a timing reference for many systems in telecommunications, IT, broadcasting, finance & more. Many IT systems that rely on NTP use a GPS reference for the NTP generators. In Moscow you can't use GPS as a reference for broadcast systems.

shakindog

496 posts

157 months

Sunday 30th June
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Ringway Manchester on YouTube has some interesting and more in depth videos on such things and radio comma in general if you’re in to that sort of thing.
Also very good at explaining things

MB140

4,353 posts

110 months

Sunday 30th June
quotequote all
Iamnotkloot said:
Seems to be pretty commonplace by Russia (and Israel) - the RAF seem relaxed enough about it but it is undeniably reckless behaviour.

https://www.telegraph.co.uk/world-news/2024/06/29/...
Doesn’t really matter to commercial aviation and military aviation. We can utilise radio nav aids VOR / TACAN, ADF beacons as a last resort. We have multiple LINS (Laser Inertial Navigation Systems) on board. Yes it will cause all sorts of spurious errors / warnings on the flight deck. Maybe trigger things likes TAWS warnings, TCAS warnings (less likely as everybody sees the same error)

Military aircraft also use a system called JTIDS (This is my area of expertise), you can navigate utilising the JTIDS network in a rudimentary way as well. JTIDS, is encrypted and frequency agile and has other means of overcoming spoofing and jamming.

Military Navy vessels have multiple ways of ensuring they can navigate without GPS. One way the Russians like to try and spoof the system is adding a small error in over time hoping you don’t notice the slight change over time. Now any system worth its salt will cross match GPS with other systems onboard and flag a warning that something needs to be checked.

It’s more of an issue for small aircraft, small boats that don’t have multiple redundant systems to rely on.

Mabbs9

1,245 posts

225 months

Sunday 30th June
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Getting "Pull Up" terrain warnings in the cruise is a bit of a pain and our systems sometimes remain downgraded for landing. It's not great and it can be a distraction too.