News Chinese scientists use Starlink signals to detect stealth aircraft and drones

[Admin]

Chinese scientists have successfully used Starlink satellite signals to detect a moving stealth target during a radar experiment in the South China Sea.

Chinese scientists use Starlink signals to detect stealth aircraft and drones : Read more

 

[Rdslw]

I dont think starlink is necessary mention here, as it should work the same with any EM wave emiter that is abundant in the wild. Issue is range and how many antenas, and how much compute you need for it.
for me it feels like it depends on very short range effects, so it would use a lot of compute 24/7 to warn you when you are already dead.

 

[bit_user]

I dont think starlink is necessary mention here, as it should work the same with any EM wave emiter that is abundant in the wild.

Like what, pulsars? Seriously, I think the idea is that it needs to be in orbit above the thing you want to detect. I doubt the spectrum of pulsar emissions would work for this.

Starlink satellites aren't just orbiting in a haphazard way, they're orchestrated to fly in orbits that space them somewhat evenly over the territories they're meant to cover.

Issue is range and how many antenas, and how much compute you need for it.
for me it feels like it depends on very short range effects, so it would use a lot of compute 24/7 to warn you when you are already dead.

Synthetic aperture radar has always relied on significant amounts of computation, so that's nothing new to the field. This was probably prototyped on a GPU or FPGA. For deployment, they could use a FPGA or even a custom ASIC, in order to achieve the necessary compute performance.

The idea is probably that they'd position these monitoring stations far enough away from targets that they would have advanced warning before the bombs started falling.

I think a key piece of information we don't know is how far off-oxis the aircraft can be, in order to be detected. I assume it doesn't have to fly directly in between the satellite and the receiver, but presumably it can't be too far off the axis between them. So, one key question is just how far?

 

[magbarn]

Let's say the Taiwan issue came to a head, couldn't the US government just force Starlink to shut down?

 

[Specter0420]

So the government just tells Musk he needs to disable the transmissions as they orbit over certain locations at certain times... That may tip China off, but there are ways around that like random outages before the attack. However, China is launching their own constellation system and it'll probably be more purpose driven for these types of uses.

 

[bit_user]

Let's say the Taiwan issue came to a head, couldn't the US government just force Starlink to shut down?

Maybe, but that seems a bit drastic. Millions depend on Star Link, including for things like emergency services.

What I was wondering about is whether the satellites can just go silent above sensitive areas. It seems this little trick depends on them continuously transmitting.

Of course, that only helps as long as other constellations of satellites can't be used. I think China is already planning (maybe even started?) launching a fleet of its own low-altitude satellites. Plus, I wonder how many other satellites can be used, or is there something fairly specific to Star Link satellites, like the RF band they use?

 

[edzieba]

RF Shadow / forward-scatter bistatic and multistatic RADAR has been known for decades, and demonstrated years ago. As long as you have a consistent background source, the technique works. Starlink is nice because its a consistent overhead source, but other sources such as weather RADAR, over-the-horizon emissions (e.g. terrestrial TV and radio), and so on. There are other satellite constellations that can act as RF sources, e.g. Oneweb, Iridium, the various and growing SAR constellations (these are nice because they are VERY high power RF sources), etc.

Let's say the Taiwan issue came to a head, couldn't the US government just force Starlink to shut down?

Given how vital it has proven to be for Ukraine's continued connectivity, and how likely China is to attempt to disrupt undersea telecomms cables to Taiwan, that would be a poor strategic move.

 

[Mattzun]

RF Shadow / forward-scatter bistatic and multistatic RADAR has been known for decades, and demonstrated years ago. As long as you have a consistent background source, the technique works. Starlink is nice because its a consistent overhead source, but other sources such as weather RADAR, over-the-horizon emissions (e.g. terrestrial TV and radio), and so on. There are other satellite constellations that can act as RF sources, e.g. Oneweb, Iridium, the various and growing SAR constellations (these are nice because they are VERY high power RF sources), etc.

Given how vital it has proven to be for Ukraine's continued connectivity, and how likely China is to attempt to disrupt undersea telecomms cables to Taiwan, that would be a poor strategic move.

China already has an over the horizon radar which should have a similar ability to detect stealth aircraft.

It is possible that using Starlink provides better coverage of the approaches to Taiwan, but this seems more like a cheap proof of concept than a military system. China would probably launch its own cheap satellites with a consistent rf source if it depended on the capability. They would probably get better results if the satellite wasn’t providing internet.

 

[pixelpusher220]

Another thing that blankets many modern battlefields is cellphone coverage. You can do the same thing with those signals and is I think the posited reason the F117 was downed in Bosnia years ago.

We target comms infrastructure first for multiple reasons. Spot on comments about US 'turning off' Starlink as well as the fact that China's home grown 'Starlink' system will be built for such uses.

 

[bit_user]

Given how vital it has proven to be for Ukraine's continued connectivity, and how likely China is to attempt to disrupt undersea telecomms cables to Taiwan, that would be a poor strategic move.

That occurred to me, as well. However, do you think Taiwan is really putting all its eggs in the Starlink basket, for this? Did they not invest in their own comms satellites, as a fallback for their undersea connections getting severed?

 

[edzieba]

That occurred to me, as well. However, do you think Taiwan is really putting all its eggs in the Starlink basket, for this? Did they not invest in their own comms satellites, as a fallback for their undersea connections getting severed?

They have cohosted payloads on GSO satellites (ST-2), slots on other GSO satellites (INTELSAT, ASIASAT) and OneWeb coverage. The GSO links are relatively low bandwidth compared to national needs (and not suitable for mobile applications), and Onwewebn are still in the process of building out their initial constellation, and has not been tested in an actively hostile environment. More diversity and bandwidth is preferable to less.

 

[DS426]

Why would China reveal this important military capability (edit: assuming it's an enhancement for their existing targeting capability)? As a deterrence?

 

[wbfox]

It's funny because there is nothing new here and that low frequency radar can already detect stealth aircraft. It's about having a system that can get you a targeting solution, not a vague, "they're somewhere over there," response. China is like a zoomer: they just invented walking without a phone, or as it used to be called: walking.

 

[The Historical Fidelity]

It's funny because there is nothing new here and that low frequency radar can already detect stealth aircraft. It's about having a system that can get you a targeting solution, not a vague, "they're somewhere over there," response. China is like a zoomer: they just invented walking without a phone, or as it used to be called: walking.

+1, was about to comment but you beat me to it. You can’t guide a missile to intercept an F-22 if the only reliable detection methods provide results like “It’s somewhere over there”.
There is a reason stealth coatings are designed to absorb Ka/Ku, X, V, W, and E-band radiation, because those are the only bands with short enough wavelengths to accurately and precisely lock-on objects in 3-d space to the point where interception is possible.
Interestingly, starlink only uses Ka/Ku, X, V, W, and E- bands, so these “students” have created an entire study based on faulty premise and the fallacy of equivalence. Saying an off the shelf drone with no optimizations to reflect or absorb targeting radar bands and is dimensionally 10,000x bigger than the demonstrated radar cross section (RCS) of an F-22 (F-22 has an RCS of 0.0001 inches^3).
And here is the last straw, and I am surprised that the students published this because it disproves this entire theory, the instant I read that “they were able to detect the moving rotors of the drone” I knew this detection method was being artificially boosted. Why? Because moving rotors are so efficient at reflecting radar waves back to the tracking radar that the drone’s RCS would be bigger than the physical dimensions of the drone. This same principle applies to the compressor blades of turbojet and turbofan engines which is why stealth design relies upon sigmoidal shaped air intakes to hide the face of the engines from radar waves. The air intakes of the F-22 start 15-feet in front of the engine face and the 15-foot intake tunnel curves so that you cannot physically see the engine face from the air intake opening.

 

[ex_bubblehead]

Once again another conversation has been ruined by those that can't take the politics elsewhere. Thanks to those that followed the rules (you know who you are).