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GPSJam: Daily Maps of GPS Interference

gpsjam.org

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Re: GPSJam: Daily Maps of GPS Interference

#31

Post by thriftwy »

jjwiseman wrote: post #3

I made this site. Copying a comment I made on HN a few weeks ago: The ADS-B signals that many aircraft broadcast include not just the aircraft's GPS positions, but also a measure of GPS accuracy (strictly speaking, ADS-B doesn't talk about GPS specifically and can handle any sort of navigation technology; I'm sure there are some planes out there reporting positions based on inertial navigation systems, with correspon…

Most of the red zone around Moscow is situated on east and northeast, whereas "oligarch dachas" are mostly located directly west of Moscow (that hexagon is also red).

I think it's mostly aerospace installations apparent on that map, such as https://ru.wikipedia.org/wiki/Медвежьи_Озёра_(центр_космичес...

Not sure what's going on in Pereslavl-Zalessky.

Having said that, of course GPS/GLONASS in the form of consumer phone-based navigation works just OK in Moscow. There is sometimes visible interference near the Kremlin though (your phone might suddently think it's in VKO).

Re: GPSJam: Daily Maps of GPS Interference

#32

Post by fjfaase »

jjwiseman wrote: post #3

I made this site. Copying a comment I made on HN a few weeks ago: The ADS-B signals that many aircraft broadcast include not just the aircraft's GPS positions, but also a measure of GPS accuracy (strictly speaking, ADS-B doesn't talk about GPS specifically and can handle any sort of navigation technology; I'm sure there are some planes out there reporting positions based on inertial navigation systems, with correspon…

Maybe you want to connect with Bert Hubert. https://berthub.eu/ He gave an interesting talk about GPS, and other global positioning systems on MCH2022: https://media.ccc.de/v/mch2022-17-how-do-gps-galileo-really-...

Re: GPSJam: Daily Maps of GPS Interference

#33

Post by gdy »

fmajid wrote: post #22
vincnetas wrote: post #20

Why is Moscow almost constantly red?

Perhaps they are jamming GPS and Galileo in favor of Glonass. They are certainly concerned about US GPS-powered artillery like the HIMARS given to Ukraine. They’d need fairly precise jammers because the frequencies are only 50MHz apart (GLONASS uses a frequency of 1.602 GHz, whereas GPS uses 1.57542 GHz).

You are underestimating how vast Russia (and Ukraine) are.

Moscow is out of reach even for the longest range (300km) HIMARS missiles which are not supplied to the Ukraine.

GPS jamming protects Russia's command and control structures from American intermediate range cruise missiles that can be launched from Mk41 launchers in Romania and Poland as well as from American ships.

Re: GPSJam: Daily Maps of GPS Interference

#34

Post by dpq »

jjwiseman wrote: post #3

I made this site. Copying a comment I made on HN a few weeks ago: The ADS-B signals that many aircraft broadcast include not just the aircraft's GPS positions, but also a measure of GPS accuracy (strictly speaking, ADS-B doesn't talk about GPS specifically and can handle any sort of navigation technology; I'm sure there are some planes out there reporting positions based on inertial navigation systems, with correspon…

Virtually all of the oligarch dachas are actually to the west of Moscow; Wikimapia shows though that there are some military areas such as firing ranges and artillery ammo dumps to the east.

Re: GPSJam: Daily Maps of GPS Interference

#36

Post by n4r9 »

jjwiseman wrote: post #19
graderjs wrote: post #9

This is fascinating. Really cool to see a map of GPS signals on Earth and the site looks really good, too. Love the colors and interface! Awesome :) Can anyone narrate any of the jammed signals? Like for instance what would be jamming in the ocean between Tripoli and Benghazi? Or what would be jamming around San Antonio, TX?

I know the stories behind some of the regions, or at least some hypotheses. Interference in the U.S. is almost always the result of military testing or training. If you check against another map (Google maps, or skyvector.com/globe.adsbexchange.com to see sectional charts) you'll see that the interference region is usually centered on or close to a military base or Military Operations Area. There are often FAA notice…

There's currently a red area around Mexico City. I googled "gps jamming mexico city" and found a couple of interesting links. There are reports from pilots about GPS issues at the airport going back years [0], and a recent news article claiming that car thieves are using jammers to prevent detection [1].

[0] https://www.aviationtoday.com/2017/01/31/are-gps-jamming-inc...

[1] https://www.economist.com/science-and-technology/2021/05/06/...

Re: GPSJam: Daily Maps of GPS Interference

#37

Post by londons_explore »

coddle-hark wrote: post #35

Since nobody’s asked: How does GPS jamming work?

Basic jamming:

Transmit a strong signal on the main GPS frequency (1575.42 MHz). Receivers get saturated and can't hear the real signal.

Medium Jamming:

Transmit the signal that a receiver would receive at a specific location loudly. GPS receivers will lock onto that signal, and report they are at the location you choose, rather than the real location they're at.

Advanced Jamming:

Pick a target, such as a VIP plane. Calculate the aggregate GPS signal that that plane is receiving right now from all the GPS satellites. Now start transmitting that same signal towards your target (you'll have to transmit ahead of time due to the speed of light delay, but that isn't an issue because GPS signals are fully predictable). Now gradually modify the signal to make the target think they're moving off their desired course, and to make them make corrections. Watch them in realtime, and adjust the signal so they correct in the direction you choose.

This is how Iran stole a drone[1].

Military GPS is encrypted (ie. XORed with a crypto-stream), which makes the signal not predictable ahead of time, which makes the advanced attack impossible. The basic and medium attacks are still possible though.

[1]: https://en.wikipedia.org/wiki/Iran%E2%80%93U.S._RQ-170_incid...

Re: GPSJam: Daily Maps of GPS Interference

#38

Post by arthur2e5 »

coddle-hark wrote: post #35

Since nobody’s asked: How does GPS jamming work?

The format of GPS civilian signal is public and you could just spoof it with any transmitter like a HackRF SDR box. There’s no cryptographic signature to verify or anything. The military code has had cryptographic anti-spoofing from the earliest days.

Or you could just send any super strong signal on the frequency to cover the satellite signal up. That can also work.

Re: GPSJam: Daily Maps of GPS Interference

#39

Post by dzhiurgis »

jjwiseman wrote: post #3

I made this site. Copying a comment I made on HN a few weeks ago: The ADS-B signals that many aircraft broadcast include not just the aircraft's GPS positions, but also a measure of GPS accuracy (strictly speaking, ADS-B doesn't talk about GPS specifically and can handle any sort of navigation technology; I'm sure there are some planes out there reporting positions based on inertial navigation systems, with correspon…

> Kaliningrad in March 2022

I'm around there and my boat plotter (~2005 device) was going berserk in June! Will have to ask other boaters if they had similar experience?

Also, how does ADS-B exchange get coverage around antarctic (i.e. Durban to Australia flights)? I thought they rely on RTL-SDR's sprinkled around the land? I know Iridium monitors ADS-B and AIS from space, but at this point they can also monitor jammed signals itself?

Re: GPSJam: Daily Maps of GPS Interference

#40

Post by tomonl »

londons_explore wrote: post #37
coddle-hark wrote: post #35

Since nobody’s asked: How does GPS jamming work?

Basic jamming: Transmit a strong signal on the main GPS frequency (1575.42 MHz). Receivers get saturated and can't hear the real signal. Medium Jamming: Transmit the signal that a receiver would receive at a specific location loudly. GPS receivers will lock onto that signal, and report they are at the location you choose, rather than the real location they're at. Advanced Jamming: Pick a target, such as a VIP plane.…

Was the drone not using the encrypted variant of GPS?
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