auonsson Profile picture
Apr 29, 2024 13 tweets 5 min read Read on X
The GPS-jammer affecting aircrafts around Estonia is located in Russia, about halfway to St Petersburg from Narva, Estonia.

This is shown by plotting the highest density of intersecting radio horizons of jammed aircrafts on a map.

Further, a drone-based method supports it.🧵 Image
The GPS-jammer affecting aircrafts around Estonia is located in Russia, about halfway to St Petersburg from Narva, Estonia.

This can be shown by plotting the highest density of intersecting radio horizons of jammed aircrafts on a map.

Further, a drone-based method supports it. Image
This is a more zoomed in view of the likeliest position of the GPS-jammer operating around Estonia and recently famous for causing the brand new Helsinki - Tartu flight line to cease operating.

See this and linked posts for methodology. Image
This took some time to make so I will continue the thread tomorrow with drones, more radio horizons and closer explanations.

Data available if interest is shown. Stay tuned. Image
I should add. The jammer over Estonia is very different in scope and temporal profile. A higher proportion of aircrafts are affected around Estonia and the jammer is almost always on. See plots. Image
Proportion measure (%) is a bit skewed during nights though, because there are so few planes in the air. And this effect is even stronger around Estonia. Plots show last months total number of observations for respective area. Image
Estonia jammer is south-west of St Petersburg, part 2: drone proof!

Drone photographer @kristjanlust made this beautiful flight in Narva, pointing east. At altitude 60 meter all GPS is gone. This gives us a new radio horizon.

The horizon intersects* with location shown by me.
This drone method is very exciting since it is a direct observation, not mediated by translation through ADSb-layers.

It just shows: at this exact position the jammer jams from 60 meter and up.

Very useful!
Map of drone flight position, its radio horizon and previously found jammer position.

*As you can see, they dont match perfectly. We are ~20 km off.

Given unknown margins of errors of mine and horizon method and jam height I assume they actually overlap. Open to protests! Image
If we move our center to to the most likely position, use to find the highest peak within 15 miles and assume an antenna height of 50 meter we get these jam-radio horizons.

Almost all jammed positions are within the reach of a transmitter at that point. heywhatsthat.comImage
So, we have two ways of saying that the jammer is SW of St Petersburg.

If we test that hypothesis we get a radio horizon that contains most actually jammed aircrafts. So, we predict what actually happens.
None of this would have been possible without this excellent code by @PajalaJussi Thank you and sorry for no initial credit.

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More from @auonsson

Jun 30
Today Russian Navy corvette Soobrazitelny 531 intervened to make German media, politicians and possibly coast guard stay away from a shadow tanker in waters between Denmark and Germany. Image
Details from Swedish politician: a Greenpeace protest was under way, Russian corvette closed in at high speed, initially not replying to radio from German Coast Guard. German CG then escorted activists/politicians/media away.

Ie, Russia interrupted western democratic activities.
Full video in this article aftonbladet.se/nyheter/a/bOqx…
Read 5 tweets
Jun 13
Russia is jamming Baltic Sea - 6th proof, 4th method.

Pskov, Kaliningrad and Kingisepp stand out as highly likely spots for the jammers, found by analyzing NISAR satellite imagery.

Method is copied from work by @SeanGorman and verified by identifying a known jammer, +/- 2.5km🧵 Image
Method is best described by @SeanGorman in this article, my inspiration.

Short version, jammers produce interference seen by the radar, bearings are taken and combining several such it is possible to compute a center position and its uncertainty.
gpsworld.com/converging-on-…
Uncluttered view of my detection. NB, there are only a few passes per jammer. Some likely false positive detections and jammers around Ukraine.

The files are 14GB each and in beta, coverage is limited and unfortunately there are no perpendiculars passes (much better detection). Image
Read 10 tweets
May 11
One of the Russian GPS spoofers around St Petersburg sports what looks like an aim function.

There is a realistic possibility this has been used to drive Ukrainian attack drones into NATO territory.

So far, I only have two anecdotes to show for it, data collection ongoing.

🧵 Image
Last months have seen some drones stray into eg Finland, Estonia and latest Latvia.

While it is an obvious expected function of a military spoofer to send a drone astray, to my knowledge it has not been shown to happen.

I am not showing that, yet. But there are circumstances.
Read 7 tweets
May 9
The hypothesis that last summers telecom sabotage campaign in south Sweden was in fact aimed at dual use military installations is strengthened.

Masts facing southeastern Baltic and Kaliningrad were hit.

Finland is now implementing the tech. It is not public whether SE uses it. Image
Read 5 tweets
Mar 17
Baltic Sea is about to welcome false flagged tanker GRIF 9332028 heading for Russia

She is 19 years old and was last inspected by Russia in 2024 with deficiencies in life boats, doors and "dangerous areas"

Sanctioned by EU, UK and Switzerland. Passed inside DK without a hiccup Image
GRIF claims to be flagged in Madagascar. Madagascar on the other hand denies having a international ship registry =)

splash247.com/madagascar-exp…
Read 4 tweets
Mar 14
NATO has started broadcasting a regular request for the reporting of suspicious observations from mariners in Baltic Sea.

Not sure when it started, but a while ago. Thanks anon follower for the recording! =)
Full text:

... in the Baltic Sea region in coordination with NATO Baltic nations to safeguard safety and security, freedom of navigation and the security of undersea infrastructure.....1/2
To assist in this maritime security effort please report immediately any observations of unusual maritime activity or behavior over VHF channel 16. This is Lyngby Radio monitoring VHF chan.....2/2
Read 4 tweets

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