[TrackerFF]

Russians will place out jammers close to anything of importance. For example, in the Kola peninsula - which is close / bordering both Norway and Finland, they're jamming and spoofing. To such a degree that it affects civil air traffic in the area.

But why? Because they have a bunch of major strategic airfields there.

In (and close) to Ukraine it could be anything. Airfields, base, ammo storage, radio towers, etc.

[nicce]

Hmm, do they really jam 24/7 in the Kola peninsula? I thought that mostly happens when there is some sort of military exercise.

[TrackerFF]

Before 2022 they'd mostly conduct jamming operations as part of their military exercises, but after they've started jamming and spoofing much more - as a security measure against drone operations. Ukrainian drone operations have taken place as long north as Murmansk, which is roughly 90 miles / 145 km from the closest Norwegian airport (Kirkenes).

EDIT: 5 days ago they shot down Ukrainian drones there

https://www.thebarentsobserver.com/security/russian-war-mini...

[cenamus]

Do we know how effective GPS jamming is against the military bands? (Ukraine probably doesn't have access to those but still)

[mandevil]

Both military and civil GPS signals are L-band. Any jamming that runs across the L-band will hit both of them. And since the frequencies are publicly available (and it is possible to confirm that they are correct with your own detecting equipment) it is not any harder to jam the purely military frequency versus the civil and military frequency. The only thing is having more frequencies to jam should mean less power on any given frequency for a given amount of power, especially since you would probably want to jam BeiDou and Galileo signals as well (all also on the L-band). I mean, since Ukraine and Russia can buy things on the open market, they could buy BeiDou receivers just like GPS, so I would expect them to target all of those frequencies.

Block III GPS satellites added a new feature, designed to help the military signals defeat jamming. They added a "spot beam" - a high gain directional antenna capable of covering an area about 200km wide with 20db extra power, to try and burn through jamming. This spot beam is only used for military signals, and it requires extra processing on the receiver to use (since the satellite still has the earth-wide antenna broadcasting the military signals, a military receiver inside the spot-beam area would see two different signals from the same satellite, absent jamming).

During the Biden administration, at least, USAF ISR assets spent a lot of time running race-tracks just at the edge of Ukrainian airspace, monitoring events in the country, and I would expect that would be something that would be a good use case for the spot beams, though I don't know about Ukraine ever getting any of those receivers, and I would not expect coordination with the USSF on pointing the high gain antenna to support UAF operations even under Biden, but all of that is my speculation, I haven't seen anything on where these high gains are pointing.

[nicce]

Oh yeah, that explains the shift.

[bobmcnamara]

Heck, they used to jam some frequencies 24/7 worldwide!

[nicce]

I think that prior 2022 they still had to consider the political impact, at least on some level.

[bobmcnamara]

They shut down the western steel work radar because of power cost increases after Chernobyl blew, combined with the improved value provided by surveillance satellites.