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GPS antenna mods make Starlink terminal immune to jammers

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Re: GPS antenna mods make Starlink terminal immune to jammers

#61

Post by nradov »

lazide wrote: post #59
BHSPitMonkey wrote: post #53

Earlier quoted context omitted.

Maybe, but unless your goal was to deny service to a small, fast-moving window of the earth's surface you would need quite a lot of these.

If I was a nation state adversary, I’d put pretty high on my TODO list getting a handful of jamming satellites with a decent power supply at geostationary locations above all my adversaries. Since a single geostationary satellite has line of sight covering about 1/3 of the planets surface, I bet if they had a decent sized reactor onboard and a well thought out transmitter/antenna array, the ROI would look pretty good…

That is not feasible at a cost any current nation state could afford. Due to the inverse square law, the power output requirements to achieve any noticeable jamming from geostationary orbit would be enormous. There have been limited tests of fission reactors in space but they are too complex to operate reliably unattended for long. So, satellites are going to limited to solar or RTG power.

Re: GPS antenna mods make Starlink terminal immune to jammers

#62

Post by lazide »

nradov wrote: post #61
lazide wrote: post #59

Earlier quoted context omitted.

If I was a nation state adversary, I’d put pretty high on my TODO list getting a handful of jamming satellites with a decent power supply at geostationary locations above all my adversaries. Since a single geostationary satellite has line of sight covering about 1/3 of the planets surface, I bet if they had a decent sized reactor onboard and a well thought out transmitter/antenna array, the ROI would look pretty good…

That is not feasible at a cost any current nation state could afford. Due to the inverse square law, the power output requirements to achieve any noticeable jamming from geostationary orbit would be enormous . There have been limited tests of fission reactors in space but they are too complex to operate reliably unattended for long. So, satellites are going to limited to solar or RTG power.

Only if using old school ‘blanket the area’ monopole antennas or if the goal was to cover the entire potential area all at once -but that seems unlikely to be desirable most of the time.

Phased arrays and beam steering would allow them to pick and choose the area at will with high resolution - or even specific targets like several hundred airliners at once.

Notably, the same things that starlink needs for being able to properly track base stations and communicate at the timescale/numbers it needs, and the tech is widely used in everything from cell phone towers to military.

Starlink has it a lot easier due to LEO, but they’re also a private company with a much harder problem and on a shoestring budget compared to a nation state.

TDP would be a lot lower if they could get it focused well enough. And it wouldn’t need to be operating all the time - a ‘war’ mode vs sleep mode seems like it would work too.

When not jamming, it could be a passive signals intelligence platform.

Or build a couple dozen and put in a lower orbit. Not like it would make a dent in China or Russias military budget, or require any tech newer than 20 years old for them.

Re: GPS antenna mods make Starlink terminal immune to jammers

#63

Post by BenjiWiebe »

diebeforei485 wrote: post #60

Why does Starlink need to use GPS if it can use its own satellite constellation to make time of flight measurements?

Do StarLink satellites have the same level of clock stability and precision that GPS satellites do? IDK but I really doubt it.

Re: GPS antenna mods make Starlink terminal immune to jammers

#64

Post by nradov »

lazide wrote: post #62
nradov wrote: post #61

Earlier quoted context omitted.

That is not feasible at a cost any current nation state could afford. Due to the inverse square law, the power output requirements to achieve any noticeable jamming from geostationary orbit would be enormous . There have been limited tests of fission reactors in space but they are too complex to operate reliably unattended for long. So, satellites are going to limited to solar or RTG power.

Only if using old school ‘blanket the area’ monopole antennas or if the goal was to cover the entire potential area all at once -but that seems unlikely to be desirable most of the time. Phased arrays and beam steering would allow them to pick and choose the area at will with high resolution - or even specific targets like several hundred airliners at once. Notably, the same things that starlink needs for being able…

Given the wavelengths and distances involved there are severe physics limits to how much beams can be steered and focused. These aren't lasers. What you are proposing isn't practical at a cost any nation state can currently afford.

Re: GPS antenna mods make Starlink terminal immune to jammers

#65

Post by lazide »

nradov wrote: post #64
lazide wrote: post #62

Earlier quoted context omitted.

Only if using old school ‘blanket the area’ monopole antennas or if the goal was to cover the entire potential area all at once -but that seems unlikely to be desirable most of the time. Phased arrays and beam steering would allow them to pick and choose the area at will with high resolution - or even specific targets like several hundred airliners at once. Notably, the same things that starlink needs for being able…

Given the wavelengths and distances involved there are severe physics limits to how much beams can be steered and focused. These aren't lasers. What you are proposing isn't practical at a cost any nation state can currently afford.

You seem really invested in ‘no one could afford it’, even at lower orbits.

Which seems pretty hilarious considering how much is getting spent on all this tech, and how much of an arms race it clearly is.

Especially considering how TS programs in general are usually a decade or two ahead tech wise anyway.

[https://www.defenseone.com/threats/2022/04/dia-warns-chinas-...]

If you think there aren’t surprises hiding in the Chinese or Russian’s pockets on this front, you’re far more optimistic than I.

Maybe they’ll just shoot down all the GPS satellites though.

Re: GPS antenna mods make Starlink terminal immune to jammers

#66

Post by ambichook »

dylan604 wrote: post #48
kayodelycaon wrote: post #41

Earlier quoted context omitted.

It's even easier than that. You use a missile (or bomb) programmed to lock onto the source of the jamming.

The heat seeker would have problems unless you launched from behind it, which would be problematic if you're launching from the ground, depending on the jamming plane. A steathly plane with the heat sources minimized might not be detected by a heat seeker if launched towards an oncoming source

heat seekers havent been rear aspect only in decades, all aspect IR missiles are the norm now. the main issue is that most NATO IR missiles are very short range. much easier to instead program your radar guided missile to lock the big glowy thing and explode in its face

Re: GPS antenna mods make Starlink terminal immune to jammers

#67

Post by serf »

meindnoch wrote: post #31
nixgeek wrote: post #22

Earlier quoted context omitted.

Would you explain why?

No. The Internet is at your fingertips.

an explanation not only helps the ignorant, it reinforces the idea within your own thoughts and perhaps seeds new ideas that are derivative; it even teaches the otherwise uncaring that may happen upon the comment.

what you did wasn't that -- but I would just like to point out that simple concise explanations helps the community as a whole; it's not just the ignorant that lose out.

Yes, I know it's likely not your job to educate, and maybe it's a bother that someone acts expert on something that they're clearly not -- but those that care to educate serve everyone in the context of an online forum, not just the naive or ignorant.

Re: GPS antenna mods make Starlink terminal immune to jammers

#69

Post by yencabulator »

denton-scratch wrote: post #30

So "immune to jammers" seems to be hyperbole; perhaps "more resistant to jammers" wuld be a more accurate phrasing.

It's really a question of distance, which is not mentioned in the article. Russian style is to park jammer vehicles pretty much evenly spread out on a line behind their defensive boundary.

I'll easily believe "immune to Russian GPS jammers as typically deployed when used X kilometers behind active battles".

Re: GPS antenna mods make Starlink terminal immune to jammers

#70

Post by yencabulator »

diebeforei485 wrote: post #60

Why does Starlink need to use GPS if it can use its own satellite constellation to make time of flight measurements?

The linked-to original article says GPS works better and faster.

> Calculating position based on Starlink constellation requires more resources, and it’s not so fast. Plus, It can’t be used correctly in motion. Accumulated errors may be so significant that Starlink will not be able to work.

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