[jjwiseman]

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 notices to pilots about potential GPS outages in those areas.

Around Syria, C4ADS did some research a few years back identifying Russia as the main culprit; I think the conclusion was that Russia is jamming GPS to defend their bases from drone attack. https://www.c4reports.org/aboveusonlystars

At least some of the jamming around Moscow is thought to be an anti-drone measure (to stop nosy photographers? assassins?): https://www.gpsworld.com/jammers-at-dachas-add-to-russias-ab...

In the Baltic, the assumption seems to be that it's usually Russian military.

I wish someone more knowledgeable about what's going on in other regions with interference would write about them! I just don't have the time and expertise do dig into all of them.

[n4r9]

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/...

[fmajid]

In the US there were incidents with truckers using illegal jammers to defeat their employers’ GPS trackers:

https://www.cnet.com/culture/truck-driver-has-gps-jammer-acc...

[yencabulator]

It's not immediately obvious to me that a jammer employed on the surface will affect planes going overhead at 30,000 feet. Such consumer GPS jammer products will probably have better customer satisfaction if their range is less than several miles.

[galangalalgol]

I read about the same thing affecting flights at Heathrow.

[martinmunk]

I zoomed in on a red spot in the US and was surprised to see the city name "Uvalde" pop up. Not quite in the center of the spot, but any thoughts on if it might be related to the reason that a European like me knows that name?

[reaperducer]

From what I've read in the newspapers, Uvalde is the home of a big Customs and Border Peotection headquarters, which is a federal sorta-military operation. That's why so many CBP officers responded to the school shooting.

Speculation on my part, but it coincides with the fact that most jamming in the U.S. is near military facilities.

[the_biot]

> Around Syria, C4ADS did some research a few years back identifying Russia as the main culprit

The amazing thing is that there's ADS-B data from Syria at all. Who in their right mind would fly over Syria? With ADS-B enabled, no less.

[gdy]

You forgot massive jamming in Iraq.