I've been working on mapping GPS jamming using ADS-B data for a couple
years, and I'll try to address questions and points brought up here
based on what I know.
(From my comment on that 2023 post: "Why haven't FlightRadar24,
FlightAware, or any of the other flight trackers done this?")
"A single observer can't really say for certain that jamming is
happening; you need a distributed sample from multiple different
sensors over a period of time to have reasonably high confidence."
There are heuristics you can use that allow you to make a pretty good
guess about whether jamming is happening based on signals from just
one or two aircraft, and have worked well on GPSJAM for the past
couple years.
With regard to localization of GPS jammers, yes you can do direction
finding of the emitted signal directly, but that's easy mode. For a
fun challenge, do it based just on observations of the ADS-B data from
affected (and unaffected aircraft). Here's one approach from
researchers at the GPS laboratory at Stanford, "GNSS Interference
Source Localization Using ADS-B data":
https://web.stanford.edu/group/scpnt/gpslab/pubs/papers/Liu_...
I have some other ideas about how to do that localization.
"Do aircraft systems really only use GPS and not the full
constellation of navigational satellite systems?"
ADS-B doesn't tell you what navigation system is, but my understanding
is that most aircraft are still using GPS. Maybe someone who works on
aircraft avionics will chime in. A few years ago I did see data that
distinguished between different GNSS, and GPS was experiencing more
jamming than the others. I assume as multi-network systems become more
and more common jammers will just target all of them, if they're not
already.
"There looks like a big hole of no data over Ukraine, where I'd most
expect GPS jamming, but I suppose there are no civilian flights
either. Maybe they could setup an GPS observation station on the
ground at a surveyed point to get data there."
That's right, no (or few) flights over Ukraine with ADS-B transponders
means no data. I actually first started mapping GPS jamming on
Feb. 14, 2022
(https://gpsjam.org/?lat=45.00000&lon=35.00000&z=3.0&date=202...),
because I thought it might give me an early warning of the expected
Russian invasion of Ukraine. It didn't work out that way--there was no
indication of interference right up until Feb 24., and then all civil
aviation stopped and there was no more data for that region
(https://gpsjam.org/?lat=49.18928&lon=33.51687&z=3.9&date=202...).
As some of you have noticed, GPS jamming is highly correlated with
conflict zones. Some conflicts are higher intensity than others--for
example, I think the airspace around Cyprus has been jammed for years
(since 2018 maybe?), and I get the feeling it's more harrassment than
anything else (maybe someone more geopolitically savvy than me knows
more).
"I see 2 red cells on the US/Mexico border right about Texas/Coahuila
region". Someone always says it's cartels, and the evidence is that
it's much more likely to be U.S. military testing and training. First,
the interference is always in the Laughlin and Randolph military
operating areas (MOAs) (https://imgur.com/vieGhgN). Second, the
interference usually runs during the week and takes weekends
off--which I doubt cartels do, but that's the typical pattern seen for
military exercises.
"am I missing any other GPS jamming mapping or data collection projects?"
From 2/24/2022 until 3/19/2024, gpsjam.org was the only site with
regularly updated GPS jamming maps. On Twitter, @auonsson
(https://twitter.com/auonsson) and @rundradion
(https://twitter.com/rundradion) have been posting geospatial and
other analysis of similar data for the past several months at least,
and @x00live (https://twitter.com/x00live) has looked at ADS-B and GPS
interference for a while too. (I'm not even going to try to catalog
academic or government efforts, though I will mention HawkEye 360's
satellite based GPS interference mapping:
https://spacenews.com/hawkeye-360-gps-ukr/)
"If line of sight to the jamming antenna is required to be jammed, why
do aircraft not have a downwards shield so that they only receive GPS
signal from the sky (satellites) and not from jammers (coming from the
bottom hemisphere)? Or is the jamming signal so many orders of
magnitudes stronger than the satellites that there's always going to
be some gain no matter how good the shield is?"
Yes, GPS signals are so weak (below the noise floor!) that it's just
super easy to overpower them with terrestrial (or airborne)
jammers. But there are special antennas and other techniques for
building jam-resistant systems, e.g. "controlled reception pattern
antennas" (CRPA):
https://www.gpsworld.com/anti-jam-technology-demystifying-th...
But I think the main reason most civilian aircraft systems aren't jam
resistant is because they didn't need to be--For the past several
decades GPS jamming has been a much smaller issue than it is now, and
I don't think there was sufficient reason to spend time and money on
what would have been an over-engineered, mostly unnecessary
system. But the situation is changing, and I expect anti-jamming to
become a more significant concern by equipment manufacturers and
aviation authorities.
[Edited to add:]
"I'm in the middle of one of the red blobs on the map and just used my
phone with google maps to drive around. It worked fine."
From the GPSJAM FAQ: ""I live in one of the red zones and my GPS was
fine?""
(https://gpsjam.org/faq/#i-live-in-one-of-the-red-zones). Yeah, the
answer is, as you mentioned, aircraft fly at higher altitudes, so they
get much longer line of sight to the jammer.
On the general idea of using ADS-B to map GPS interference, when I
thought of this idea I was pretty excited. I realized that if you had
access to worldwide ADS-B data, which ADS-B Exchange graciously gave
me as part of my Advisory Circular project
(https://news.ycombinator.com/item?id=24188661), you could also make a
worldwide map of GPS jamming, and I hadn't seen anyone do that before
(later I found some researchers who realized you could get GPS jamming
information from ADS-B, but they only looked at a couple
aircraft).
I just think it's pretty neat that even though there were multiple
companies devoted to processing, analyzing, and selling ADS-B data,
and ADS-B data is not all that complicated, none of those companies
had realized this new way of using it. Sometimes there's gold left
even in data that you think must have been completely mined out.
Even specifically looking at ADS-B data as it relates to GPS
interference, there's still lots to be done! FR24 is mapping jamming,
but I don't think anyone else has made worldwide maps of spoofing
(yet!): https://twitter.com/lemonodor/status/1770515361739493488
[Edited to add more:]
With respect to safety issues, yes, aircraft have redundant navigation
systems. But GPS is one of the important layers that add safety to
aviation, and it is not at all normal for entire countries or even
larger regions to lsoe GPS while still maintaining passenger
flights. This Eurocontrol presentation, "GNSS Interference and Civil
Aviation", has lots of details:
https://rntfnd.org/wp-content/uploads/Aviation-GNSS-interfer...
From the presentation:
Aviation Safety is built on two main principles:
• Trust your instruments
• Follow standard operating procedure
GNSS RFI causes pilots to have to question both principles!
There have been close calls due to lack of GPS. It increases workload
for both pilots and controllers, which is a safety issue by
itself. Despite a lot of airlines and government aviation agencies
saying everything is fine, they're not really prepared for a world
with frequent GPS denial, and everything is not fine. Industry and
government are organizing emergency meetings about how to handle this
in a less ad hoc way than they have been so far (commercial aviation
is kind of the opposite of ad hoc).
I'm not a NATO strategist or anything, so I'm adding this as a child comment, but I think the big story in the GPS/aviation world these days is probably Russia's n̵e̵a̵r̵-̵c̵o̵n̵s̵t̵a̵n̵t̵ frequent jamming of GPS over Poland, Finland, Sweden, Estonia, and Lithuania. Degrading and even neutralizing strategic infrastructure in EU and NATO countries, significantly affecting commercial aviation at the least, is a big deal. There's some reluctance to say it's Russia doing the jamming, though that seems to be the consensus among experts. I assume governments know with 100% confidence who it is.
It should be a big story, as should be the fact that Russia invaded a peaceful neighboring country and keeps murdering, raping and torturing its residents.
But somehow much of the world pretends not to notice and only does whatever is convenient at the moment (buy Russian oil/gas, do business in Russia, stay "neutral", etc). I find it incredibly depressing, I thought that surely in the 2020s our civilization would have progressed further.
Russia will play the slowly boiled frog game to their advantage — GPS jamming is just the beginning. We will likely soon see further small incursions, each one ever so slightly larger than the previous one. And we'll hear Mr Scholz say something about doing something, but we won't see him actually do anything. Mr Macron will use grand words and do nothing as well. Austria will "declare neutrality" (easy to do when you have other countries as buffers from the aggressor).
As someone currently living in the EU close to Ukraine, I find all this very sad.
John, I've been following your work for years (including back in the old lemonodor years). I just wanted to say thank you here, for sharing your expertise for all on this topic, and for all the other tremendous work you've done. What an inspiration.
I know older long-range planes from the 70s and 80s had excellent inertial navigation systems.
Not quite as good as GPS, but good enough to know the location of the plane within a few nautical miles. The main problem is that inertial navigation systems drifted over time and required constant recalibration from the crew whenever they had a fix from real navigation beacons and errors could be catastrophic (especially when skirting the edge of Soviet airspace).
I've always wondered if modern avionics suites kept the older style inertial navigation systems as a backup to GPS, or if the systems were deleted when everyone switched to GPS.
I think it would be smart for larger planes to have a modern inertial navigation system that constantly recalibrated off GPS, ready to take over in the case of GPS jamming or spoofing.
They do that! Unfortunately, they don't always know when they're being spoofed, so oops, your inertial reference system has just been infected by the spoofed location and now both nav systems are hosed.
Based on discussions of some accidents, pilots often ignore inertial navigation systems at which they rarely look today, and sometimes forget to set the known good location before flights (which does not depend on GPS, as airports don't move).
I have lived in Kiev and I have seen how GPS jamming works on the ground. As soon as russian missiles or drones approached Kiev, our air defense typically turned on the GPS jamming. I could immediately see on my phone that I'm steadily moving in a straight line directly northeast at a high speed in a very different part of the city - all while sitting on the couch in my home not very high above the ground. A few times like that.
I was curious how powerful should a jammer be to completely actively substitute GPS coordinates in a city so large.
Who is jamming around Tallinn area? Also is GPSIII just as susceptible to jamming?
Hawkeye + SAR data would be pretty interesting for ship tracking. I think I've seen some papers here before, but nothing interactive like your site. I think open SAR data is not quite realtime yet, but hope soon is.
If you look at that for a few seconds, you'll see that it's almost entirely civilian passenger aircraft that are not making erratic movements, and that are near conflict zones.
Detecting GPS jamming with planes actually works a lot better than from a fixed terrestrial object, because 1. They have greater sensor range, 2. There are lots of them, 3. They move and cover lots of area, 4. they cover e.g. parts of the Black Sea where it would be more difficult to put a ground-based sensor.
> but my understanding is that most aircraft are still using GPS.
GNSS, GPS plus other constellations depends on the receiver. Even drones or consumer ones support that these days, some bigger drones even support L5 bands.
Consumer GNSS devices are developed a lot quicker than aviation GPS receivers due to high cost and strict certification requirements.
So your 100 dollar drone very likely has a receiver with more features than a 100 million dollar airliner. And that drone is probably made recently, but airliners fly for 30 years.
> As part of the ADS-B messages we receive from each aircraft, the Navigation integrity category (NIC) encodes the quality and consistency of navigational data received by the aircraft. The NIC value informs how certain the aircraft is of its position by providing a radius of uncertainty.
> Poor NIC values alone might indicate a problem with an aircraft’s equipment or unfavorable positioning. However, when observed in multiple aircraft in close proximity during the same time frame, it suggests the presence of a radio signal interfering with normal GNSS operation.
A single observer can't really say for certain that jamming is happening; you need a distributed sample from multiple different sensors over a period of time to have reasonably high confidence.
> A single observer can't really say for certain that jamming is happening; you need a distributed sample from multiple different sensors over a period of time to have reasonably high confidence.
Could you use RTLSDR triangulation to hone in on granular lat long of jamming sources?
With synchronized receivers you could do some rudimentary direction finding. Note that synchronizing SDRs is much more achievable if they're physically nearby (e.g. can run a cable between them for a common clock) vs if they're physically distant observers (can't exactly use GPS time for synchronization if you're measuring GPS interference)
You can get rough areas with a GPS and a RTLSDR and a bunch of samples (either over time OR with lots of people with the same device)
But to get fine granular data, you need a timestamping SDR. (each parcel of signal data for a quantum of data needs an exact time down to 6-8 significant figures, basically GPS timebase).
Most your cheaper SDRs cant do that.
Stuff like the BladeRF and higher do provide timestamped data.
KrakenSDR would do a good job of this, they combine five RTLSDR into a coherent array. The top end of their tuning range is 1766 MHz which would include the 1575 MHz of the GPS L1 signal.
The little five antenna array can even attach on the roof of a car for a handy ground plane. Prob not a good idea to drive with it out there tho.
You could also use a single receiver with a small antenna array (GPS wavelength is around 20 cm) to estimate the angle of arrival of the incoming signals.
This is really cool since ASDBExchange was bought out by a private equity firm and has since stopped giving out data to cool projects. I see they are being sued for IP theft and a couple other items. Link to Lawsuit in CA is below because I was reading it tonight.
Do aircraft systems really only use GPS and not the full constellation of navigational satellite systems?
Besides GPS, the GNSS currently includes other satellite navigation systems, such as the Russian GLONASS, and may soon include others such as the European Union’s Galileo and China’s Beidou.
The linked page already says that it reports on the constellation, not just GPS:
"The map uses are color coded overlay to indicate low (green) to high (red) levels of interference with global navigation satellite systems (GNSS). Often just referred to as GPS, there are actually multiple systems beside the US GPS constellation, such as Russia’s GLONASS, Europe’s Galileo, China’s BeiDou, and others."
Like the article states, many people use GPS as a shorthand for GNSS generally. In any case, they're all at similar frequencies, so typically they'll all go out together if there's significant interference.
It doesn't matter too much, aircraft don't rely solely on any GNSS for navigation, because they're all susceptible to similar availability issues. Magnetic, inertial, barometric, and land-based radio systems are also used. One or more of those other systems are used as a fallback when GNSS fails.
Modern phones use all the available navigation constellations, and have done so for years.
But aviation is much more conservative due to its safety-critical nature. Galileo was only just recently (2023) certified for use in aircraft systems by ICAO:
Just for the record, this must have been written ages ago. Today you would rather look up to NavIC joining them as a global system and QZSS operating independently from GPS soon.
So how should I interpret this? The map lacks geopolitical boundaries, so it's hard to interpret.
There looks like a big hole of no data over Ukraine, where I'd most expect GPS jamming, but I suppose there are no civilian flights either. Maybe they could setup an GPS observation station on the ground at a surveyed point to get data there.
There's a big red blob over Turkey, is that maybe the southern edge of the reach of Russian jammers in the Black sea?
There's also a big red blob over the eastern Mediterranean. Is that Israel? I'm not so sure though, because it's not centered on Israel and parts of Israel proper are green on the map. I also assume they're heavy users of GPS, so wouldn't want to jam it.
There's a red blob in Southeast Asia, and that looks like Myanmar, where there's a civil war right now.
There's a little red blob over what looks like Kashmir.
The hole over Ukraine is definitely the lack of civilian flights.
Another notable spot is Kaliningrad, the Russian exclave. It looks relatively normal on some days, like today, but on others like yesterday it's covered by solid red stretching far into Poland, Sweden and even Germany.
> Another notable spot is Kaliningrad, the Russian exclave. It looks relatively normal on some days, like today, but on others like yesterday it's solid red.
Oh yeah, I totally forgot that was a thing, and that explains that spur of red in the Baltic. I'd (probably incorrectly) assumed it was some kind of spillover from jamming in Ukraine.
I didn't realize you could look at it over multiple days. One interesting thing about that blob is the outline of red seems to always be there, in the same shape, but the middle is often green. Maybe that's some artifact of their agreement algorithm? More overflights around the edges than through?
It also looks like there's some jamming in Estonia? Or maybe that's just the edge of jamming around St Petersburg?
I was curious too. Did some sleuthing, it looks more like Punjab. I think that’s to block drone infiltration from Pakistan [1]. It does change going back to 14th March there is no jamming in the region, US and Europe blobs also reduced, so I think this stuff is event driven, wonder what goes on, fascinating stuff.
Their data comes from commercial flights. If there are no flights, there's no data. There aren't many commercial flights over Ukraine or Belarus right now, so that whole area's empty.
The Eastern Mediterranean might be the (significant, underreported, under-remembered) Russian military presence in Syria. They have airbases, a naval base, they rotate and train their officers there, they constantly ship military equipment back and forth from the Black Sea ports via the Bosphorus to Syria, they train the Syrian army, they build human shield observation posts overlooking Israel.
What's unfathomable to me is how Israel (or Netanyahu?) keeps treating them as a frenemy.
I think there are probably many parties contributing to the interference in the Eastern Mediterrarnean. Russia and Israel are two of the big ones right now (and both have admitted doing it).
I see 2 red cells on the US/Mexico border right about Texas/Coahuila region. Navigating that dessert region without GPS or with GPS for that matter can be deadly.
Organized crime in Mexico would probably do it to prevent other people from using migration routes they control and reduce police efficacy. Of course, slightly rogue Mexican police or even US vigilantes also have an incentive.
Yea, oddly, if you go back to like august, there's still a bunch of red over the Mediterranean, parts of Israel, Jordan, Lebanon, etc. so it's not totally clear what that is. I've heard anecdotally that gps has gotten unusable in Israel in recent weeks but it's not clear why that's changed based on the mapping information we're seeing here.
If anyone found the above interesting, I wrote a short article mapping plane activity on FlightRadar's 'blocked' list (i.e FlightRadar had agreed to remove the ADBS data from their dataset following probable legal pressure).
The article was interesting alone, simply for the Google Dork technique explanation. Have not heard the "unusual, yet specifically frequent" search technique described that way previously. Very similar to what's necessary for searching StackExchange and similar, such as "site:https://aviation.stackexchange.com/ tracking private planes"
Known Conversions: GlobalEye, Project Dolphin, Raytheon Sentinel, Saab Swordfish, PAL Aerospace P-6, E-11A, HALOE, PEGASUS, Hava SOJ, CAEW, HADES.
Actually has a tie-in with the article, since the Hava SOJ is an air stand-off jammer configuration for the Turkish region.
Otherwise, if I still worked for the government contracting, I'd probably offer you a job, although you're apparently British, so there might have been citizenship issues.
Apparently people now call using Google's advanced search operators Dorking, neat! I guess I've been dorking for a while.
Most of us know about "site:" since it's extremely handy, but there are a lot more. For some reason I had it in my head that many of the documented operators didn't work properly -- or at least I couldn't get them to work properly the last time I tried to experiment. I'll have to try again.
That's LADD (Limited Aircraft Data Displayed), which requires that aircraft marked as such in the FAA's database to be removed from the official data feeds used by the commercial flight radar sites.
Crowdsourced data isn't subject to LADD, so adsbexchange and other such sites can and do display such aircraft.
For flights within the US, there's also a private address program that allows an ADS-B equipped plane to broadcast an alternate address.
Thanks for linking gpsjam -- flightradar24's map is total trash by comparison (colours, lack of borders).
Does anyone know if a similar service covers things like GLONASS, Galileo or BeiDou?
EDIT: nevermind, these services can't distinguish. From the FAQ:
> The ADS-B data used by this map includes information on the accuracy of the navigation system used by each aircraft, but doesn't specify the type of navigation system. It could be GPS, another global navigation satellite system (GNSS) like GLONASS, or it could be an inertial navigation system (INS). My understanding is that most aircraft are using GPS, so that's probably mostly what the map shows.
Flightradar24's visual representation definitely sucks, but comparing the two, gpsjam has a lot of unexpected missing areas across Africa, South America, and SE Asia that at least have some data on FR24.
I'm not sure if that means FR24 has a better dataset, or they're processing it differently or if they're just extrapolating from few data points when they maybe shouldn't be.
If line of sight to the jamming antenna is required to be jammed, why do aircraft not have a downwards shield so that they only receive GPS signal from the sky (satellites) and not from jammers (coming from the bottom hemisphere)? Or is the jamming signal so many orders of magnitudes stronger than the satellites that there's always going to be some gain no matter how good the shield is?
- GPS positioning is more accurate if the satellites it sees come from a variety of angles (GDOP), so the satellites near the horizon are valuable.
- Aircraft pitch and roll, so a fixed antenna like this would lose precision as it turns to make an approach - just about the worst possible time.
It's difficult to make an antenna with a sharp cutoff to limit the ground vs. above-ground. So, most anti-jammers will use beamforming to cancel out interference in one or more specific directions. So, the null in the antenna moves to follow the interference.
I thought GPS signals from space were incredibly weak. Limited power budget + 100km in the sky. Seems trivial for a ground based system to crank up the watts to whatever arbitrary limit they desire.
True, signal per satellite is only around 150-160dBW on earth despite them radiating at 25W. Satellites are ~20000km away. If a jammer is 100 times closer (200km), they need to use only 1/10,000 (1/100^2) the power, so it's very easy to jam sadly.
The data is taken from aircraft [EDIT: not airlines; see traceroute66's comment], so it doesn't give full coverage of the world, but it does include other satellite navigation systems aside from just GPS. Looks like the jammed/interfered areas are:
* A large part of Eastern Europe around Ukraine is missing data, and there are many jammed/interfered areas around it, including the southern coast of the Black Sea and parts of Poland and the Baltic. Part of the Baltic Sea off the coast of Kaliningrad are also jammed/interfered.
* Part of Germany near Berlin, possibly part of the Ukraine-related jamming/interference?
* A large part of the eastern Mediterranean and some of the Middle East around Gaza.
* A small area on the India-Pakistan border near Punjab and Lahore.
* Two medium-sized areas in western Myanmar.
* Two small areas in New Guinea with a gap in the data between them, spanning the Indonesia-Papua New Guinea border.
* Two small areas in western Australia.
* A small area on the US-Mexico border.
* A dot in southern China with some gaps in the data around it near the border with Vietnam.
Ukraine, Gaza, and Myanmar all have major conflicts going on. Other comments have suggested that the US-Mexico interference might be related to drug cartels. The India-Pakistan border is a longstanding point of tension. Not sure what (if anything) is going on in New Guinea and Australia.
The jamming/interference in India-Pakistan, US-Mexico, and China all went away in the last 6 hours -- they're only visible in the 24-hour data.
The data is ADS-B data which is broadcast by aircraft.
FR24 (and other similar services) obtain the data via a community[1], you can take part too[2].
For certain parts of the world, they may have the option to augment the data via commercial services, but that is highly unlikely to be on a global basis.
Conclusion: Missing coverage means no community coverage in that area and no commercial augmentation.
FR24 is a bit of farce as their blocking and removal of 1000's of aircraft makes the data picture incomplete. Plus it's kinda of a money hungry commercial enterprise. Same reason that Raytheon bought FlightAware and Silversmith Capital Partners via JETNET bought ADSBexchange -DATA = CASH - the later buyout is going to court because they apparently stole IP from the company that built the infrastructure. https://www.documentcloud.org/documents/23963235-golden-hamm... - wild stuff in there!
> Part of Germany near Berlin, possibly part of the Ukraine-related jamming/interference?
Of the four tiles in that area (for March 19th at least), one is entirely in Poland, one is covering the Polish-German border, one is a bit of the German coast around Rügen but mostly the Baltic Sea, and the other is Bornholm (island in the Baltic Sea) and a bit of the Swedish coast.
My guess is, this is part of a larger system to limit Russian military use of the Baltic, and possibly also a single layer of defence against Russian aircraft and missiles targeting Berlin and Copenhagen. Likewise, I would guess that the strip of interference from St Petersburg in the direction of Moscow is a similar single-layer of defence by Russia.
At this resolution, it also looks like the west is interfering with access to St Petersburg and someone (could reasonably be either side) is worried about Kaliningrad, but that image is also also making me think "WTF?" about the Gulf of Riga.
The single tile near Kandalaksha (Russia) suggests something interesting is going on there, but I have no idea what that might be, and there's a non-zero possibility that it's a deliberate red-herring to make western analysts waste time — as an analogy, imagine a troll releasing three greased pigs with the numbers "1", "2", and "4" painted on the side.
I crosschecked with google Maps and I belive the Jindalee Operational Radar Network in Laverton is stationed there. Maybe that has something to with the interference. A 560kw transmitter is no joke.
I guess south-west Texas is most likely also military. E.g. the Naval Air Station Kingsville is not far away.
That spot in western Australia is interesting, I was looking at that earlier. My map doesn't show any indication of interference there, in fact from what I can tell there's plenty of evidence of _no_ interference. Eh, there are sometimes analysis or other artifacts, and it can be tricky to try to infer too much from one hex.
Readit News
Relevant previous posts on HN:
2022: https://news.ycombinator.com/item?id=32245346
2023: https://news.ycombinator.com/item?id=37868106
(From my comment on that 2023 post: "Why haven't FlightRadar24, FlightAware, or any of the other flight trackers done this?")
"A single observer can't really say for certain that jamming is happening; you need a distributed sample from multiple different sensors over a period of time to have reasonably high confidence."
There are heuristics you can use that allow you to make a pretty good guess about whether jamming is happening based on signals from just one or two aircraft, and have worked well on GPSJAM for the past couple years.
With regard to localization of GPS jammers, yes you can do direction finding of the emitted signal directly, but that's easy mode. For a fun challenge, do it based just on observations of the ADS-B data from affected (and unaffected aircraft). Here's one approach from researchers at the GPS laboratory at Stanford, "GNSS Interference Source Localization Using ADS-B data": https://web.stanford.edu/group/scpnt/gpslab/pubs/papers/Liu_...
I have some other ideas about how to do that localization.
https://twitter.com/lemonodor/status/1764054377982308484
"Do aircraft systems really only use GPS and not the full constellation of navigational satellite systems?"
ADS-B doesn't tell you what navigation system is, but my understanding is that most aircraft are still using GPS. Maybe someone who works on aircraft avionics will chime in. A few years ago I did see data that distinguished between different GNSS, and GPS was experiencing more jamming than the others. I assume as multi-network systems become more and more common jammers will just target all of them, if they're not already.
"There looks like a big hole of no data over Ukraine, where I'd most expect GPS jamming, but I suppose there are no civilian flights either. Maybe they could setup an GPS observation station on the ground at a surveyed point to get data there."
That's right, no (or few) flights over Ukraine with ADS-B transponders means no data. I actually first started mapping GPS jamming on Feb. 14, 2022 (https://gpsjam.org/?lat=45.00000&lon=35.00000&z=3.0&date=202...), because I thought it might give me an early warning of the expected Russian invasion of Ukraine. It didn't work out that way--there was no indication of interference right up until Feb 24., and then all civil aviation stopped and there was no more data for that region (https://gpsjam.org/?lat=49.18928&lon=33.51687&z=3.9&date=202...).
As some of you have noticed, GPS jamming is highly correlated with conflict zones. Some conflicts are higher intensity than others--for example, I think the airspace around Cyprus has been jammed for years (since 2018 maybe?), and I get the feeling it's more harrassment than anything else (maybe someone more geopolitically savvy than me knows more).
"I see 2 red cells on the US/Mexico border right about Texas/Coahuila region". Someone always says it's cartels, and the evidence is that it's much more likely to be U.S. military testing and training. First, the interference is always in the Laughlin and Randolph military operating areas (MOAs) (https://imgur.com/vieGhgN). Second, the interference usually runs during the week and takes weekends off--which I doubt cartels do, but that's the typical pattern seen for military exercises.
"am I missing any other GPS jamming mapping or data collection projects?"
From 2/24/2022 until 3/19/2024, gpsjam.org was the only site with regularly updated GPS jamming maps. On Twitter, @auonsson (https://twitter.com/auonsson) and @rundradion (https://twitter.com/rundradion) have been posting geospatial and other analysis of similar data for the past several months at least, and @x00live (https://twitter.com/x00live) has looked at ADS-B and GPS interference for a while too. (I'm not even going to try to catalog academic or government efforts, though I will mention HawkEye 360's satellite based GPS interference mapping: https://spacenews.com/hawkeye-360-gps-ukr/)
"If line of sight to the jamming antenna is required to be jammed, why do aircraft not have a downwards shield so that they only receive GPS signal from the sky (satellites) and not from jammers (coming from the bottom hemisphere)? Or is the jamming signal so many orders of magnitudes stronger than the satellites that there's always going to be some gain no matter how good the shield is?"
Yes, GPS signals are so weak (below the noise floor!) that it's just super easy to overpower them with terrestrial (or airborne) jammers. But there are special antennas and other techniques for building jam-resistant systems, e.g. "controlled reception pattern antennas" (CRPA): https://www.gpsworld.com/anti-jam-technology-demystifying-th... But I think the main reason most civilian aircraft systems aren't jam resistant is because they didn't need to be--For the past several decades GPS jamming has been a much smaller issue than it is now, and I don't think there was sufficient reason to spend time and money on what would have been an over-engineered, mostly unnecessary system. But the situation is changing, and I expect anti-jamming to become a more significant concern by equipment manufacturers and aviation authorities.
[Edited to add:]
"I'm in the middle of one of the red blobs on the map and just used my phone with google maps to drive around. It worked fine."
From the GPSJAM FAQ: ""I live in one of the red zones and my GPS was fine?"" (https://gpsjam.org/faq/#i-live-in-one-of-the-red-zones). Yeah, the answer is, as you mentioned, aircraft fly at higher altitudes, so they get much longer line of sight to the jammer.
On the general idea of using ADS-B to map GPS interference, when I thought of this idea I was pretty excited. I realized that if you had access to worldwide ADS-B data, which ADS-B Exchange graciously gave me as part of my Advisory Circular project (https://news.ycombinator.com/item?id=24188661), you could also make a worldwide map of GPS jamming, and I hadn't seen anyone do that before (later I found some researchers who realized you could get GPS jamming information from ADS-B, but they only looked at a couple aircraft).
I just think it's pretty neat that even though there were multiple companies devoted to processing, analyzing, and selling ADS-B data, and ADS-B data is not all that complicated, none of those companies had realized this new way of using it. Sometimes there's gold left even in data that you think must have been completely mined out.
Even specifically looking at ADS-B data as it relates to GPS interference, there's still lots to be done! FR24 is mapping jamming, but I don't think anyone else has made worldwide maps of spoofing (yet!): https://twitter.com/lemonodor/status/1770515361739493488
[Edited to add more:]
With respect to safety issues, yes, aircraft have redundant navigation systems. But GPS is one of the important layers that add safety to aviation, and it is not at all normal for entire countries or even larger regions to lsoe GPS while still maintaining passenger flights. This Eurocontrol presentation, "GNSS Interference and Civil Aviation", has lots of details: https://rntfnd.org/wp-content/uploads/Aviation-GNSS-interfer...
From the presentation:
There have been close calls due to lack of GPS. It increases workload for both pilots and controllers, which is a safety issue by itself. Despite a lot of airlines and government aviation agencies saying everything is fine, they're not really prepared for a world with frequent GPS denial, and everything is not fine. Industry and government are organizing emergency meetings about how to handle this in a less ad hoc way than they have been so far (commercial aviation is kind of the opposite of ad hoc).But somehow much of the world pretends not to notice and only does whatever is convenient at the moment (buy Russian oil/gas, do business in Russia, stay "neutral", etc). I find it incredibly depressing, I thought that surely in the 2020s our civilization would have progressed further.
Russia will play the slowly boiled frog game to their advantage — GPS jamming is just the beginning. We will likely soon see further small incursions, each one ever so slightly larger than the previous one. And we'll hear Mr Scholz say something about doing something, but we won't see him actually do anything. Mr Macron will use grand words and do nothing as well. Austria will "declare neutrality" (easy to do when you have other countries as buffers from the aggressor).
As someone currently living in the EU close to Ukraine, I find all this very sad.
Why the reluctance? I do not think there is much love lost in regards to Russia.
I know older long-range planes from the 70s and 80s had excellent inertial navigation systems.
Not quite as good as GPS, but good enough to know the location of the plane within a few nautical miles. The main problem is that inertial navigation systems drifted over time and required constant recalibration from the crew whenever they had a fix from real navigation beacons and errors could be catastrophic (especially when skirting the edge of Soviet airspace).
I've always wondered if modern avionics suites kept the older style inertial navigation systems as a backup to GPS, or if the systems were deleted when everyone switched to GPS.
I think it would be smart for larger planes to have a modern inertial navigation system that constantly recalibrated off GPS, ready to take over in the case of GPS jamming or spoofing.
https://ops.group/blog/gps-spoof-attacks-irs/
https://aerospace.honeywell.com/us/en/about-us/blogs/spoofin...
I was curious how powerful should a jammer be to completely actively substitute GPS coordinates in a city so large.
Hawkeye + SAR data would be pretty interesting for ship tracking. I think I've seen some papers here before, but nothing interactive like your site. I think open SAR data is not quite realtime yet, but hope soon is.
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It might be sampling bias. More military aviation with erratic movement and also planes turning off and on their transmitters.
To measure GPS jamming, you should measure from a fixed object. Trying to do that with planes is unnecessary hard.
If you look at that for a few seconds, you'll see that it's almost entirely civilian passenger aircraft that are not making erratic movements, and that are near conflict zones.
Detecting GPS jamming with planes actually works a lot better than from a fixed terrestrial object, because 1. They have greater sensor range, 2. There are lots of them, 3. They move and cover lots of area, 4. they cover e.g. parts of the Black Sea where it would be more difficult to put a ground-based sensor.
GNSS, GPS plus other constellations depends on the receiver. Even drones or consumer ones support that these days, some bigger drones even support L5 bands.
So your 100 dollar drone very likely has a receiver with more features than a 100 million dollar airliner. And that drone is probably made recently, but airliners fly for 30 years.
> As part of the ADS-B messages we receive from each aircraft, the Navigation integrity category (NIC) encodes the quality and consistency of navigational data received by the aircraft. The NIC value informs how certain the aircraft is of its position by providing a radius of uncertainty.
> Poor NIC values alone might indicate a problem with an aircraft’s equipment or unfavorable positioning. However, when observed in multiple aircraft in close proximity during the same time frame, it suggests the presence of a radio signal interfering with normal GNSS operation.
A single observer can't really say for certain that jamming is happening; you need a distributed sample from multiple different sensors over a period of time to have reasonably high confidence.
Could you use RTLSDR triangulation to hone in on granular lat long of jamming sources?
https://www.rtl-sdr.com/detecting-gps-jammers-in-augmented-r...
https://www.rtl-sdr.com/kiwisdr-tdoa-direction-finding-now-f...
But to get fine granular data, you need a timestamping SDR. (each parcel of signal data for a quantum of data needs an exact time down to 6-8 significant figures, basically GPS timebase).
Most your cheaper SDRs cant do that.
Stuff like the BladeRF and higher do provide timestamped data.
The little five antenna array can even attach on the roof of a car for a handy ground plane. Prob not a good idea to drive with it out there tho.
Pretty neat! I starting sending data from my ASD-B feeder as well. https://airplanes.live/get-started/
This is really cool since ASDBExchange was bought out by a private equity firm and has since stopped giving out data to cool projects. I see they are being sued for IP theft and a couple other items. Link to Lawsuit in CA is below because I was reading it tonight.
https://www.documentcloud.org/documents/23963235-golden-hamm...
https://www.lacourt.org/casesummary/ui/index.aspx?casetype=c... 23CHCV02662
Besides GPS, the GNSS currently includes other satellite navigation systems, such as the Russian GLONASS, and may soon include others such as the European Union’s Galileo and China’s Beidou.
https://www.terrisgps.com/gnss-gps-differences-explained/
"The map uses are color coded overlay to indicate low (green) to high (red) levels of interference with global navigation satellite systems (GNSS). Often just referred to as GPS, there are actually multiple systems beside the US GPS constellation, such as Russia’s GLONASS, Europe’s Galileo, China’s BeiDou, and others."
But aviation is much more conservative due to its safety-critical nature. Galileo was only just recently (2023) certified for use in aircraft systems by ICAO:
https://www.esa.int/Applications/Navigation/Galileo/Galileo_...
Just for the record, this must have been written ages ago. Today you would rather look up to NavIC joining them as a global system and QZSS operating independently from GPS soon.
There looks like a big hole of no data over Ukraine, where I'd most expect GPS jamming, but I suppose there are no civilian flights either. Maybe they could setup an GPS observation station on the ground at a surveyed point to get data there.
There's a big red blob over Turkey, is that maybe the southern edge of the reach of Russian jammers in the Black sea?
There's also a big red blob over the eastern Mediterranean. Is that Israel? I'm not so sure though, because it's not centered on Israel and parts of Israel proper are green on the map. I also assume they're heavy users of GPS, so wouldn't want to jam it.
There's a red blob in Southeast Asia, and that looks like Myanmar, where there's a civil war right now.
There's a little red blob over what looks like Kashmir.
Another notable spot is Kaliningrad, the Russian exclave. It looks relatively normal on some days, like today, but on others like yesterday it's covered by solid red stretching far into Poland, Sweden and even Germany.
Oh yeah, I totally forgot that was a thing, and that explains that spur of red in the Baltic. I'd (probably incorrectly) assumed it was some kind of spillover from jamming in Ukraine.
I didn't realize you could look at it over multiple days. One interesting thing about that blob is the outline of red seems to always be there, in the same shape, but the middle is often green. Maybe that's some artifact of their agreement algorithm? More overflights around the edges than through?
It also looks like there's some jamming in Estonia? Or maybe that's just the edge of jamming around St Petersburg?
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[1]https://www.thehindu.com/news/national/other-states/over-100...
What's unfathomable to me is how Israel (or Netanyahu?) keeps treating them as a frenemy.
See this report by C4ADS from 2019, about Russian jamming: https://c4ads.org/reports/above-us-only-stars/
Map of Israeli GPS spoofing (which is distinct from jamming, and we haven't talked much about in this discussion): https://twitter.com/lemonodor/status/1717987479255720076
https://www.google.com/maps/@29.3385589,-100.8055747,12.72z?...
https://dfworks.xyz/blog/hnwi-osint-private-jet/
Slightly tangential so feel free to remove if irrelevant
The Bombardier Global Express 6000 GLT6 result is interesting, as it's a plane with a known large number of military conversions. https://en.wikipedia.org/wiki/Bombardier_Global_Express#Mili...
Known Conversions: GlobalEye, Project Dolphin, Raytheon Sentinel, Saab Swordfish, PAL Aerospace P-6, E-11A, HALOE, PEGASUS, Hava SOJ, CAEW, HADES.
Actually has a tie-in with the article, since the Hava SOJ is an air stand-off jammer configuration for the Turkish region.
Otherwise, if I still worked for the government contracting, I'd probably offer you a job, although you're apparently British, so there might have been citizenship issues.
Most of us know about "site:" since it's extremely handy, but there are a lot more. For some reason I had it in my head that many of the documented operators didn't work properly -- or at least I couldn't get them to work properly the last time I tried to experiment. I'll have to try again.
Crowdsourced data isn't subject to LADD, so adsbexchange and other such sites can and do display such aircraft.
For flights within the US, there's also a private address program that allows an ADS-B equipped plane to broadcast an alternate address.
https://www.faa.gov/air_traffic/technology/equipadsb/privacy
Also: https://gpsjam.org/ | https://hn.algolia.com/?q=gpsjam
(am I missing any other GPS jamming mapping or data collection projects?)
Does anyone know if a similar service covers things like GLONASS, Galileo or BeiDou?
EDIT: nevermind, these services can't distinguish. From the FAQ:
> The ADS-B data used by this map includes information on the accuracy of the navigation system used by each aircraft, but doesn't specify the type of navigation system. It could be GPS, another global navigation satellite system (GNSS) like GLONASS, or it could be an inertial navigation system (INS). My understanding is that most aircraft are using GPS, so that's probably mostly what the map shows.
I'm not sure if that means FR24 has a better dataset, or they're processing it differently or if they're just extrapolating from few data points when they maybe shouldn't be.
https://sapt.faa.gov/outages.php?outageType=129001450&outage...
Ok it exists, but shielding is (only) about 20dB looking downwards, which may not be enough: https://safran-navigation-timing.com/product/8230aj-gps-gnss...
- GPS positioning is more accurate if the satellites it sees come from a variety of angles (GDOP), so the satellites near the horizon are valuable.
- Aircraft pitch and roll, so a fixed antenna like this would lose precision as it turns to make an approach - just about the worst possible time.
It's difficult to make an antenna with a sharp cutoff to limit the ground vs. above-ground. So, most anti-jammers will use beamforming to cancel out interference in one or more specific directions. So, the null in the antenna moves to follow the interference.
GDOP: https://en.wikipedia.org/wiki/Dilution_of_precision_(navigat...
* A large part of Eastern Europe around Ukraine is missing data, and there are many jammed/interfered areas around it, including the southern coast of the Black Sea and parts of Poland and the Baltic. Part of the Baltic Sea off the coast of Kaliningrad are also jammed/interfered.
* Part of Germany near Berlin, possibly part of the Ukraine-related jamming/interference?
* A large part of the eastern Mediterranean and some of the Middle East around Gaza.
* A small area on the India-Pakistan border near Punjab and Lahore.
* Two medium-sized areas in western Myanmar.
* Two small areas in New Guinea with a gap in the data between them, spanning the Indonesia-Papua New Guinea border.
* Two small areas in western Australia.
* A small area on the US-Mexico border.
* A dot in southern China with some gaps in the data around it near the border with Vietnam.
Ukraine, Gaza, and Myanmar all have major conflicts going on. Other comments have suggested that the US-Mexico interference might be related to drug cartels. The India-Pakistan border is a longstanding point of tension. Not sure what (if anything) is going on in New Guinea and Australia.
The jamming/interference in India-Pakistan, US-Mexico, and China all went away in the last 6 hours -- they're only visible in the 24-hour data.
No. It is not.
The data is ADS-B data which is broadcast by aircraft.
FR24 (and other similar services) obtain the data via a community[1], you can take part too[2].
For certain parts of the world, they may have the option to augment the data via commercial services, but that is highly unlikely to be on a global basis.
Conclusion: Missing coverage means no community coverage in that area and no commercial augmentation.
[1] https://www.flightradar24.com/blog/how-we-track-flights-with... [2] https://www.flightradar24.com/apply-for-receiver/
FR24 is a bit of farce as their blocking and removal of 1000's of aircraft makes the data picture incomplete. Plus it's kinda of a money hungry commercial enterprise. Same reason that Raytheon bought FlightAware and Silversmith Capital Partners via JETNET bought ADSBexchange -DATA = CASH - the later buyout is going to court because they apparently stole IP from the company that built the infrastructure. https://www.documentcloud.org/documents/23963235-golden-hamm... - wild stuff in there!
Of the four tiles in that area (for March 19th at least), one is entirely in Poland, one is covering the Polish-German border, one is a bit of the German coast around Rügen but mostly the Baltic Sea, and the other is Bornholm (island in the Baltic Sea) and a bit of the Swedish coast.
My guess is, this is part of a larger system to limit Russian military use of the Baltic, and possibly also a single layer of defence against Russian aircraft and missiles targeting Berlin and Copenhagen. Likewise, I would guess that the strip of interference from St Petersburg in the direction of Moscow is a similar single-layer of defence by Russia.
At this resolution, it also looks like the west is interfering with access to St Petersburg and someone (could reasonably be either side) is worried about Kaliningrad, but that image is also also making me think "WTF?" about the Gulf of Riga.
The single tile near Kandalaksha (Russia) suggests something interesting is going on there, but I have no idea what that might be, and there's a non-zero possibility that it's a deliberate red-herring to make western analysts waste time — as an analogy, imagine a troll releasing three greased pigs with the numbers "1", "2", and "4" painted on the side.
But what's going on in Western Australia? And South-west Texas?
My guess is that the spots in Western Australia are the same thing, given the nearby RAAF training bases.
I guess south-west Texas is most likely also military. E.g. the Naval Air Station Kingsville is not far away.
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