GPS jamming around Cyprus gives our air traffic controllers a headache, says Eurocontrol
- Reference: 1614944714
- News link: https://www.theregister.co.uk/2021/03/05/gps_jamming_eurocontrol/
- Source link:
Jamming of the essential navigational satellite signal has caused enough headaches for the EU air traffic control organisation to prompt an investigation, complete with an instrumented aircraft designed to detect signs of GPS jamming.
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Airliners rely on GPS to a great extent, and air traffic management (the science of making sure airliners don’t come dangerously close to each other) is almost solely focused nowadays on building approach paths and airways that are defined by GPS waypoints.
Regulators invented the term GNSS (Global Navigational Satellite Service) to cover GPS-style systems like the EU’s [2]Galileo , Russia’s [3]nobody-else-uses-this equivalent GLONASS and China’s nascent Beidou GPS-a-like system. In reality the original US GPS is what all modern airliners use for independent position fixes. And when warring nations start jamming or distorting the GPS signal, everything turns into a massive headache for civilian aviators.
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Eurocontrol “started collecting GNSS outage reports by pilots in 2014, following up significant numbers of outage reports in a given area to determine cause and impact, and to support the [air traffic control company] and operators in question,” said the organisation in its report
[5]PDF
, adding that between 2017 and 2018, reported outages increased by 2,000 percentage points, rising from 154 in 2017 to a whopping 4,364 the following year.Most of this jamming is focused on the Eastern Mediterranean and specifically affects Cyprus, Eurocontrol said. During a three-hour period in February 2020, a fifth of all flights passing through Cypriot airspace were affected, said the air traffic control org, extrapolating from a research flight it operated with an instrumented Airbus A320 that flew south of Cyprus itself.
The eastern Med, especially around Syria and Lebanon, has long been a conflict zone – and air forces from West and East alike have long been jamming GPS as part of their military operations there.
“Larnaca could become an absolute shitshow when the Americans jammed it,” an airline pilot told The Register . Describing one incident, where a radar* contact that was “going at least 50 per cent faster than us” passed below his aircraft, the pilot said it seemed to be on course for Sicily shortly before his own aircraft had a GPS failure.
“Luckily at that point, because at high altitude, it's irritating, but not a major issue. Because for short term, you've got your eyes and your internal navigation system,” said the pilot.
It has deeper effects, however. “The main issue is when it happens in Larnaca (eastern Cyprus), because you're right next to mountains and [you’re following a] GNSS approach. And if you get jammed, it causes the map to shift and the plane then decides that it's currently inside a mountain. Sets off all of your terrain warnings.”
A GNSS approach is where the airliner follows a series of GPS-defined waypoints to a safe landing. Jamming or interfering with GPS means that following a safely plotted (and published) course may no longer be safe.
Triggering a terrain warning means immediately having to perform a [6]prescribed escape manoeuvre that can mean breaking off an otherwise safe approach to land, said the pilot, who spoke on condition of anonymity because he is not an official spokesman for his airline. This causes delays and potentially extra costs to the airline and its passengers.
Military GPS jammers have long been [7]in service around the world because many missiles and military location-finding technologies depend on GPS – which, after all, was developed for that exact purpose by the US. Its later civilian use only came about because the signal was publicly accessible worldwide.
As for Eurocontrol, the body plaintively concluded: “At national level, local RFI [radio frequency interference] mitigation measures need to be taken, ideally including the ability to conduct in-flight RFI measurements.
"While the majority of RFI hotspots appear to originate in conflict zones, they affect commercial aviation at large distances from these zones, reflecting a disproportionate use of jamming that appears to go well beyond simple military mission effectiveness."
So far the problem’s been formally identified: but, other than flying around jamming zones, what else can pilots do? ®
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* TCAS, for aviation-minded readers. Not really radar at all but works in a very similar way as far as the flight deck crew are concerned.
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[1] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_onprem/networks&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=2&c=2YEJjqeYuo01tOEAUK0J22wAAAIw&t=ct%3Dns%26unitnum%3D2%26raptor%3Dcondor%26pos%3Dtop%26test%3D0
[2] https://www.theregister.com/2020/01/29/galileo_satellite_outage/
[3] https://www.theregister.com/2020/06/23/china_beidou_gps/
[4] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_onprem/networks&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=3&c=33YEJjqeYuo01tOEAUK0J22wAAAIw&t=ct%3Dns%26unitnum%3D3%26raptor%3Deagle%26pos%3Dmid%26test%3D0
[5] https://www.eurocontrol.int/sites/default/files/2021-03/eurocontrol-think-paper-9-rf-intereference-satellite-navigation.pdf
[6] https://www.skybrary.aero/index.php/Response_to_a_%22PULL_UP%22_Warning
[7] https://www.theregister.com/2016/06/07/us_military_testing_gps_jamming/
[8] https://pubads.g.doubleclick.net/gampad/jump?co=1&iu=/6978/reg_onprem/networks&sz=300x50%7C300x100%7C300x250%7C300x251%7C300x252%7C300x600%7C300x601&tile=4&c=44YEJjqeYuo01tOEAUK0J22wAAAIw&t=ct%3Dns%26unitnum%3D4%26raptor%3Dfalcon%26pos%3Dmid%26test%3D0
[9] https://whitepapers.theregister.com/
Anti-Jam
"..other than flying around jamming zones, what else can pilots do?"
There are military null-steering antenna systems for GPS, which can block multiple jammers but still see satellites, but they are probably quite expensive.
Re: Anti-Jam
What they can do, as a body, is to refuse to fly in or out of any country found to be responsible for the blocking. Once a few countries find themselves without any air service for a few days the message will get through - act like a pillock and you become a pariah.
Re: Anti-Jam
How many flights to Syria are there?
Re: Anti-Jam
Depends on how you count them, too damned many Russian military flights, not enough carrying bombs with the name of Bashar al-Assad on them.
Re: Anti-Jam
> fly in or out of any country found to be responsible for the blocking
Problem is the blocking doesn't originate in the affected country. In this case, I very much doubt Cyprus is blocking GPS in its own airspace.
Re: Anti-Jam
Cyprus should be either Greece to annoy the turkish occupation forces in Cyprus or the Turks to do the very same to Greek forces.
Re: Anti-Jam
> either Greece to annoy the turkish occupation forces in Cyprus or the Turks to do the very same to Greek forces
In both cases it would be a very stupid and counterproductive move, because the only one really affected is the Cypriot civilian population both sides want to keep happy.
As for Greeks and Turkish butting heads, they have a way easier and more immediate playing field, the Aegean Sea and its dozens of Greek islands...
Re: Anti-Jam
As for Greeks and Turkish butting heads, they have a way easier and more immediate playing field, the Aegean Sea and its dozens of Greek islands...
With lots of them (and about all of the more well known) within easy shooting range from the Turkish coast (and vice versa).
Re: Anti-Jam
"Problem is the blocking doesn't originate in the affected country."
Read it again and not the words "responsible for".
Re: Anti-Jam
See this quote from the article - "air forces from West and East alike have long been jamming GPS as part of their military operations there.". It's everyone from all sides doing it. You can't threaten to boycott anyone involved when your own military and all their allies are just as much responsible as anyone you might dislike.
Re: Anti-Jam
"The question was "What can the pilots do?". That's the civil aviation pilots as I read it. If it's their own military is endangering them why should that stop them going on strike?
Re: Anti-Jam
That'll m,ake flying into Heathrow difficult (lots of jammers moving on the M25 for various reasons)
ILS?
Could this be partially solved by Larnaca airport upgrading its Instrument Landing System (ILS) so aircraft can lock into a glide path early enough to be less dependent on GPS? At the moment you can probably find more planes out there that are ILS CAT III capable than ones that are Galileo capable.
Re: ILS?
Larnaca already has VOR-DME, which will let you determine the heading and range to the airport. ILS is far too directional to be of use beyond flying the approach. These older technologies are being phased out in favour of GNSS procedures as they are expensive to install and maintain, plus systems like ADSB/TCAS (which are required for most commercial flight these days) will still be reporting the aircraft’s position to ATC/other aircraft based of what GPS says.
Re: ILS?
Mostly probably not. The GNSS approaches bring them onto the final ascent and into the ILS range. ILS points straight up the runway, whereas the approaches are way off centre line.
Have a look at the following approach into Queenstown. Admittedly, it's difficult to see when they might have got on ILS, but it should give you an idea of how much they rely on GPS.
https://www.youtube.com/watch?v=Rhkbia1dMcI
Re: ILS?
>At the moment you can probably find more planes out there that are ILS CAT III capable than ones that are Galileo capable.
Is that really the case? Every smartphone under the sun has supported simultaneous GPS, Galileo, GLONASS and BeiDou for donkeys years now, because the chips they use support all the systems together. Are avionics versions of the same tech that far behind?
Re: ILS?
They could well be that far behind. Smartphones don't have to go through a highly regulated sign off procedure with multiple countries' authorities before being allowed to be used. Remember aircraft have a lifespan of decades and some of those solutions are relatively new. While replacement/upgrade of the GNSS system in a plane is technically fairly simple (I'd assume), the red tape surrounding it would be much harder.
Re: ILS?
" While replacement/upgrade of the GNSS system in a plane is technically fairly simple"
Except that a Boing aircraft relying on russian/european/chinese navigation satellites won't happen, for political reasons unless regulators tell them they have to do it for airworthiness certification
The scary part is that aircraft are using _only_ the trivially hjammable L1/E1/G1 signals for this stuff at all rather than using using multiband receivers to pick up the L2/L5/G2/G3E5/E6, etc transmissions which are less susceptable to jamming
Re: ILS?
Boing?
No they do not bounce
TITSUP
Terrible Interference To Suddenly Upset Pilots
How?
Assuming the GPS "jammers" are on the ground then it is difficult to see how this is happening.The plane's GPS antenna will have it's lobes pointing above the plane ideally, with a hemispherical coverage. If the GPS jammer is below the plane then the only way it could prevent normal GPS reception is by overloading the plane's GPS receiver. As GPS signals are almost in the noise (we need correlation detectors to capture them) then that is easily possible. The solution would be install better GPS antennae or, even better, electrically steerable antennae, which could move the focus away from jamming signals. The military already know how to do this so sharing the technology should be possible. Alternatively, as Kenny Everett would say, just "bomb the bastards"!
Re: How?
If the GPS antenna is on the top of the aircraft with hemispherical coverage then what happens when the plane is climbing, descending and banking? It needs more than hemispherical coverage and hence is susceptible to jamming.
Although the GPS signals are below the noise, it's a spread spectrum system with 43dB processing gain, so the jammers still need a fair bit of power and ought to be pretty easy to find by anyone who was interested enough.
The military do use GPS anti-jam antenna systems. They don't focus away from jammers, they put nulls in the directions of jamming signals.
Surely it would be relatively easy to issue a NOTAM and say GPS is unavailable so fly on inertia and NAVAIDs.
And surely Larnaca has published RNAV approaches that dispense GPS entirely?
Why is it an issue?
It might affect light aircraft, but I thought modern airliners are equipped with an integrated navigation system that contains a triple-redundant GNSS-updated solid state inertial reference platform that can be augmented by terrestrial radio beacons.
So the GNSS failing or suddenly deviating from the inertial reference systems, whilst those all stay aligned, should just cause the GNSS data to be ignored.
GPS signals are indeed way below the noise floor and extracted by correlation. Which means you only need a low-powered jammer to block them by raising the receiver noise floor, you don't need to overload it. I remember our GPS chipset test receiver being driven round to test accuracy, and in one particular area it sometimes went haywire -- but not all the time. Speculation was that there was some machinery chucking out RF noise but only when it was turned on. Never did track down what it was...
The blocker needs a present
of a cruise missle