Planes are having their GPS hacked. Could new clocks keep them safe?

Thank you! I haven't updated that page in a long time, and there are a few things I should add. Some possibilities:

* Does this map show spoofing? No.

* How come sometimes I see aircraft flying over Ukraine? That's GPS spoofing.

* [Add Myanmar & Kashmir to the list of conflict zones.]

There are multiple sites that try to infer whether jamming is happening.

https://gpsjam.org/

https://spoofing.skai-data-services.com/

https://www.flightradar24.com/data/gps-jamming

Ukraine is of course a huge hotbed of jamming, but every time I've looked, there's been jamming on the US/Mexico border and a bit north of Texas around an airbase.

There's also a lot of info available here: https://www.nstb.tc.faa.gov/

I'm thinking about adding that. (Donations help, see the About page.)

Should you brief the NOTAMs? Yes. Is it common to miss one? Also yes. Go look at the ATC YouTube channels and you will find lots of people being intercepted by fighter jets even though they use Foreflight.

Another problem is NOTAM spam; it seems like, in some areas, there are a bunch of NOTAMs that aren't very important but that you still have to read through to see if they're relevant. "We're testing GPS jamming" or "we will send a fighter jet if you fly into this rectangle" look a lot like the more common "taxiway T at Middle Of Nowhere Municipal Airport is out of service until 1/1/2038".

NOTAMS are a bunch of garbage that no one pays any attention to. That’s not my opinion, that’s the opinion of former NTSB chairman Robert Sumwalt. I’m sure the GPS NOTAM was buried somewhere in the 27 page NOTAM list and it probably said something like this actual current GPS NOTAM: !GPS 03/022 GPS NAV PRN 08 U/S 2503061847-2506050001

https://www.ainonline.com/aviation-news/business-aviation/20...

I was flying in and out of a private airport in uncontrolled airspace, so I didn't check. If was my first test flight so I was pretty much just circling around my airstrip.

If I'm flying cross country, in to controlled airspace, or an airport I'm not familiar with, I will. But this particular notam didn't show up when I looked at nearby airports.

Russia has been jamming GPS over Finland, Estonia, and Poland on and off for a couple years, and it's been at its peak now for several months. Sometimes flights have to be canceled. Tartu airport in Estonia was closed for a while[1] because the only instrument approaches it has were GPS-based.

Even worse than jamming is spoofing, which Russia also does. With jamming, you and the aircraft's systems both know what's happening. Spoofing isn't as easy to detect, as the GPS system can report the wrong location but think it's highly accurate. Spoofing (and to some extent jamming) can have a persistent effect on aircraft systems even after they move out of range of the jammer/spoofer, which can lead to degraded navigation accuracy for the rest of the flight.

It's a whole deal. Russia is messing with strategically important systems of many European countries, and decreasing civilian aviation safety, and they rarely get called on it. For a long time there was reluctance to even name Russia as the culprit.

1. https://www.heise.de/en/news/GPS-jamming-no-more-flights-to-...

It’s because they’re next to Kaliningrad, that weird Russian exclave

Another way to see that geography is as approaches into Russia. Gdansk borders Kaliningrad, Helsinki and Tallinn straddle St Petersburg.

It's the default OpensStreetMap style, which was never intended as a cartographic basemap for visualizations. Its purpose is to facilitate editing of the underlying data... but it's also one of the "free" options out there and integrated into most map library examples. ("free" because it's community-supported and heavy usage is discouraged, https://operations.osmfoundation.org/policies/tiles/)

Myanmar, alias Burma. They're having a hot civil war since 2021. (They've had tensions and insurgencies for as long as they've been an independent state.)

Myanmar. Unstable autocracy, recent coup, ongoing uprising. A huge mess, and exactly where you'd expect the ruling party to be trying to eliminate navigation aids.

Myanmar, which is currently a conflict zone.

> to the right

*East

They don't lose signal when the receiver tips (which would make it useless for planes). They use antenna arrays to filter signals coming from directions they don't expect, too strong, etc.

These systems have been used used in military aircraft for a long time.

> triangulation

*Trilateration

One measures the time of flight of the satellites signal, not the angle it arrives from!

https://en.wikipedia.org/wiki/Trilateration

There is a YC startup doing this right now: https://www.ycombinator.com/companies/theseus

https://youtu.be/i1QRqu3Cocw

> Galileo et al also have publicly available cryptographic signatures so you can't actually spoof them, only jam them.

Replay attacks still work allowing one to spoof location.

So the role that magnetometers play in sensor fusion w/ IMU data is for yaw/heading/magnetic north estimation. In short, it aids your orientation (RPY estimate). However, with MagNav, they play a large role in supplying information that allows you to decrease your drift rate.

https://www.sagemotion.com/blog/how-does-imu-sensor-fusion-w...

We're working on making MagNav a one stop shop backup for GPS. I think to cover ALL cases however, you'll need other technologies. TERCOM, visual, and celestial all have their niche use cases.

But for most cases, MagNav should do the job. Happy to answer more

Currently 20-40 pounds right now, but we're working to reduce the SWaP. MagNav does rely on having accurate magnetic anomaly maps, which the government and certain private companies have access to.

It's the Air Force's higher ed institution. They offer masters and PhDs. They have their own labs doing R&D.

The article is deeply confused.

It’s true that optical clocks will improve the accuracy of our measurement of time, and it’s true that GPS depends on time, but there are several steps between primary frequency standards (ie, optical clocks) and GPS, and several more steps between GPS and navigation applications.

So optical clocks cannot, in fact, have any effect on the end-user perceived reliability of GPS.

For that, the best solution is to revive LORAN which is much less susceptible to jamming. (And would also benefit from better atomic clocks.)

You can do about 5x worse (in accuracy terms) than a Cesium clock in a smaller package using a rubidium atomic clock. Average ~4 of these and you get to the same accuracy as a cesium clock. They aren't export controlled because they aren't that special in terms of what you get.

They’re probably talking about this for quantum navigation

https://www.theguardian.com/science/article/2024/jun/15/lond...

Even further, you can loose your super accurate special crystal and simply fall back to “normal” GPS.

Not all types of approaches are available at all runways (or airports), and sometimes they are down for maintenance. Specific runways may be required due to wind, aircraft weight and runway condition and length. Most airlines ban "circling approaches" (using an approach to one runway end and then circling visually to land at a other) for safety reasons. ILS, which is probably the "close range guidance" you are thinking of, must be installed, maintained and calibrated individually per runway end. Visual aids cannot be used for approach if there is low cloud.

It is usual to be able to abort an approach and try again at the same airport using a different approach technology. But if the journalist wanted to find the most extreme example, it's not surprising that it happened at least once that an alternative wasn't available. This is probably "sampling bias"!

Note that final operational decisions are made by the aircraft commander. Aircraft do not "get diverted", except by decision of the "captain".

My understanding is it depends on the amount of visibility, plus what type of approach they were on. One type of approach, an ILS, has big radio transmitters pointing from the runway into the air and allows the plane (either pilots or autopilot) to get close enough to the runway without visibility, and with enough precision, to land. In many circumstances ILS isn't available and an alternative is Required Navigation Performance (RNP) which uses GPS plus a ton of other inputs to give some amount of precision to the same end. If they're on an RNP approach but suffer a reduction in navigation accuracy then I imagine it's a policy 'go-around'. Even if there's enough visibility it allows the pilots to brief a 'visual' approach before attempting it.

Considering it's below 1000 feet, losing GPS could indicate an "unstablized" approach and require a go-around, as opposed to losing it at a higher altitude where the pilot could have more time to safely switch to alternatives (other navigating aids or go to visual?).

Source: my guess after watching a lot of aviation YouTube videos......

Commercial air travel is very risk-averse. Best practice is that if something unexpected occurs, and you have plenty of fuel to spare, you go and and find someplace else to land.

> They think most devices talk back to the satellites somehow.

To be honest, I don't think most people realize GPS is coming from satellites in the first place. Most people simply don't think about how/why at all when using things.

Spoofing is different from jamming. Spoofing is when you trick the receiver into thinking the position is one you fed it vs jamming is you preventing it from acquiring a signal at all. Jamming is much easier while spoofing can be more difficult if there’s encryption on the signal. Unfortunately I think commercial signals aren’t signed with a private key to completely prevent spoofing but I’m not 100% sure.

lol, good point. I wouldn't doubt this as a cause.

And you can even update your clock info from the GPS signal. So the only dependency is GPS or similar.

But would Iranian missiles even use GPS? Isn't accuracy limited for civilian use for precisely this reason?

> GPS signals are relatively low power (American GPS broadcasts at 25 watts and are ~10-15W at sea level)

Did you lose 16 orders of magnitude for the sea level values? GPS signal strength on the ground is usually below -135dBm per square meter. That gives you a couple of femtowatts with commonly used antenna, if you're lucky.

Easy to jam doesn't begin to describe it.

GPS (as well as most satellite) signals are weak because it's strong enough for line of sight even from so far away. They only transmit at 25W. Comparatively, an FM/TV signal will often broadcast at tens of thousands of watts and up.

> if the airspeed indicator is accurate, and you know you're heading, all you need is an accurate clock to determine absolute position

Airspeed gives speed relative to the air, not the ground. To compute ground speed, you also need winds aloft, which can be huge if the aircraft is operating in the jet stream.

Getting good data for winds aloft is difficult because there are a relatively small number of actual measurements, and everything else is model output with all the usual caveats.

But quartz is accurate enough for that, let alone a properly calibrated oscillator. So why is the article focused on giving planes atomic clocks?

Technically both techniques can be used for gps hacking. It also seems you can fake a gps signal altogether, because the public signal is not cryptographically signed, which surprises me (the only thing that makes sense to me is that the gps protocol doesn't have room for adding a signature, so it'd be a breaking change to the protocol).

The article is seriously confused. What you are talking about is easy - chip scale atomic clocks are easy to get. I can have one shipped to me today. Hell, i have one on a time card in my basement.

Assume you want it even super accurate.

Great, 3k for an SA65 https://www.microchip.com/en-us/products/clock-and-timing/co...

Holdover would be fine for even a very long flight.

Hell, even a good rubidium oscillator doing 1PPS will stay within 200 nanoseconds over 12 hours.

If you are trying to do navigation while jammed, none of these help you.

You still need good reckoning, which is the hard part

We done solved the clock problem enough already :)

Ahhhhh, that makes sense. Treating this as security mechanism rather than an anti-jamming one.

To be more concrete, space rockets nearly all fly with inertial navigation, but they are extreme case, because most use only inertial navigation just few minutes (so all those classic gyros/accelerometers integrated errors are small enough to successful enter stable orbit, and then using some sort of radio or optical fine measurements and making corrections with fine engines).

Planes flights are much more lengthy than rockets - I think, typical ~40 minutes or more (most long I hear 20 hours), so INS could integrate huge mistake.

> most sensitive achieve so fine accuracy, they detect daily Earth rotation and even yearly Earth rotation

Daily rotation is 360°/23.934h, so 0,25°/min, which is acutally quite a lot if you want to use a device to track your orientation.

> daily Earth rotation and even yearly Earth rotation.

Minor FYI: the earth rotates daily, but it revolves around the sun yearly.

    revolve /rĭ-vŏlv′/
    intransitive verb
    To orbit a central point.
    "The planets revolve around the sun."

> they detect daily Earth rotation

This is the principle gyrocompasses work on; when left running for a while they align themselves with true north; the axis of Earths rotation.

From my (very basic) understanding of GPS you need at minimum four satellites to calculate the time. If you had a local atomic clock in sync with the GPS satellites, you'd only need three satellites to get a position fix. It would (probably, maybe?) also speed up the time to first fix / time to a precise position fix.