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

Jul 2
Swedish maritime authority just posted maybe their most extensive interference warning to date.

Even radar is now seeing interference, besides more familiar GNSS, AIS and DGPS.

Radar is the single most important navigational aid on ships, particularly in cases of lost GPS/GNSS. Image
Source:

And on the NAVTEX terminals. navvarn.sjofartsverket.se/Navigationsvar…Image
Read 5 tweets
Jun 29
South Baltic sea is experiencing a newish type of GNSS-jamming. It is affecting units at sea level far and wide, much further than one ground based jammer can reach.

The most intense attack so far took place as the political elite of Denmark and 100k visitors met at Bornholm.
Data for animation above is the signal levels that RINEX stations receive from various GNSS-constellations.
Last year a limited span of frequencies were affected. 2025 all frequencies/bands are affected. BeiDou, not illustrated (noisy).

The Bornholm station is used as example. Image
Image
Looking per station we can see the geographic and temporal reach.

South-east corner of Baltic is affected (but not all stations!) and with an intensified period right now.

It is also evident that the ongoing 2025 attacks result in a much more degraded signal to noise ratio. Image
Image
Read 12 tweets
Feb 15
There is an estimated 1 in 10k-100k years chance that all 8 of the Nov 2024 - Jan 2025 Baltic Sea cable breaks are coincidental.
Data is hard to get by but no matter which real data or reasonable assumption one picks it is very unlikely all 8 of them are explained by chance.
🧵 Image
Illustration of a 1 in 108 908 years chance that all 8 of the Nov 2024 - Jan 2025 Baltic Sea cable breaks happens with present background levels. Above is 1 in 10 609 years illustrated. Image
Two alternative ways of illustrating the extremely low probability of the Baltic Cable breaks being normal. Red dots in each, promise! Image
Image
Read 15 tweets
Jan 19
Washington Post has again managed to find anon sources saying Russia is not doing bad things in the Baltic Sea.

They got the infographic quite wrong, so I fixed it.

They also have a named source, within mil intel, completely contradicting their headline.

Nice one WaPo! Image
Image
Washington Post today presented a wholly incomplete infographics on Baltic Sea infrastructure incidents.

Actually damaged structures: 13, presented by WaPo as 4-5.

Actual # incidents: 4, WaPo found 3.

Here is the fix. Image
According to WaPo and their anons "there is an emerging consensus that it is all accidents"

Yet officials in actual positions are ordering very expensive and resource intensive mission as we speak.

Article archived: archive.is/7JcKG
Read 9 tweets
Jan 14
'If something were to happen Denmark might have to answer to why JAZZ was not boarded and inspected'

Experts agree: Denmark should inspect broken tanker JAZZ. No one thinks they will

Naval officer, maritime law scholar + analyst says 'Do it'

DK authorities: no reply. URL👇 Image
Original link: danwatch.dk/skyggeskib-bro…
Archive-link: archive.is/0nGfY
"Of course three propulsion breakdowns should lead to a port state control" says professor of maritime law Cossen in the article.

JAZZ is loaded with 50k ton oil and has serious issues with her machinery. Broke down thrice last 14 days and needed tug assistance once.
Read 5 tweets
Nov 4, 2024
Excited intel bots project:

Leading online authorities on shipping, @johnkonrad & @mercoglianos, are popular targets in the network of intel bots I am looking into.

Bots are mainly agreeing and praising, but sometimes seemingly nudging them in other direction. Hard to say from limited material.Image
Some example posts:
1 Snarky
2 Strong agree
3 Poor bot cant sleep

In total the bots I found have posted or quoted John and Sal 69 times, but that is likely just a fraction of the total. Image
Image
Image
Full text of all replies and quotes with datetimes and urls from excited intel bots to @johnkonrad and @mercoglianos in this csv.

Not complete, there is likely much more. Eventually I will release all posts I have found and the metadata/relation data.

pastequest.com/?767a9ebaf875c…
Read 7 tweets

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