TropicalDingdong, tropicaldingdong@lemmy.world

Me on new pipe and invidious:

Stop calling it sideloading.

Its called “installing software”, on a computer, that you own.

What do you mean you arent on grub?

Ahh yes.. let me just go hunting with my beamforming radar.. I’ll be tracking the rate at which that deer is changing course at over 100khz.

No, I’m not confused whatsoever. You can not get the same kind of information using radar using the system you are describing. Period. You are confusing broad, beacon like radar systems (like a flashlight or a paint brush) with phased systems, which are fundamentally different.

Phased systems depend on nano-pico second scale precision in timing; you aren’t accomplishing that across a distributed system. And the exact structure of the beam that is going to be formed is dependent on what the receiver has detected, whatever scan pattern is being used. They are a coupled system.

Look, if I could point this thing at the ground and get soil moisture at depth, I wouldn’t be in this situation ok.

“actually cheap” and “reliable interceptor”, the US military industrial complex

This is antithetical to the US military industrial contractor complex doctrine.

If this guy thinks its a threat, its probably where you should be putting your energy.

Okay so I was overly general with my first statement.

No one is saying passive radar systems don’t exist. We’ve been using them for decades and there have been massive improvements. But the actual radar system we’re discussing here isn’t. You simply aren’t going to get the same capabilities from a purely passive system than you will from an active + passive system where you can tightly control the frequencies and directions you are transmitting on, and have the information about what frequencies you transmitted on, when you transmitted them, and how (what array configuration) you transmitted them. The point is that the transmission itself is structured to reveal certain information. So when you get a response back (also, coming back to a phased system), you can learn far more about your target than you could in a purely passive system because you that prior information about what you transmitted.

Yeah I mean, this speaks even further to the doctrinal difference I’m trying to highlight.

How are the Ukrainians pushing back on radar systems? Are they relying on anti-rad munitions? Well. No. We’re seeing them using long range drones, which, arguably, is far less complex, much more versatile, easier to produce, and cheaper to produce. The difference highlights the doctrine difference.

This is all really a debate about how one thinks about fighting a war and what one values along the way.

75%?

This doesn’t have any practical application in Ukraine.

How can you be so dismissive? Of course it has practical application in Ukraine.

I guess I’m not sure the point.

That’s just not how phased array systems work. The system we’re talking about needs to have excruciatingly tight and correct timings regarding signal transmission and reception. These are beam forming systems, so a multidimensional array of antenna are using to steer the beam, using constructive and destructive interference to “point” the energy where you want it to go. That alone requires extremely tight timing. That’s coupled with a phased array receiver system, so that you can detect very slight changes in the wavelength/ speed of the return signal to apply the doplar effect to detect things like motion. The github states that this system operates at 10.5 GHz, of which one RF cycle is about 95 ps, ~2.5cm. This puts the practical per-element beamforming granularity/error budget is very much in that sub-picosecond to picosecond-equivalent range. That would be practically impossible for anything but a coupled system.

Not completely impossible, I mean, probably US military systems exist in a decoupled system. But its technologically way, way way harder because timings need to be nano to pico second correct.

And locating radar emissions is a passive process, it doesn’t reveal your own location

That depends very much so on the radar system. In practical terms, almost all the radar systems we’re discussing here are going to be both transmitter and receiver in one design. You can’t simply rely on passive radio energy to detect moving objects in a complex environment. You would want both passive and active beam forming in one instrument; not having both is just leaving some of the most valuable developments in modern radar on the table.

And the specific radar we’re discussing, is an active, pulsed LFM phased-array radar. It does both, because, obviously it needs to do both. Its wouldn’t be useful for its intended use if it cant do both.

I think this is just the wrong intuition. Not a faulty one, but one which is mostly the same as the doctrine which is being exposed as entirely ineffective.

US military doctrine is the “towards complexity” doctrine such that your opponent also needs to follow you into complexity. This worked for the US in the post WWII era because it was coupled with an exponentially increasing economic output.

Whats being show, as doctrine, is “away from complexity” and “towards distributed” approach to warfighting ends up being far more effective.

So coming from, practically, 100 years of “more advanced more complicated technology and approaches are better” being doctrine, its understandable to want to add complexity to systems.

A quad copter with 500g of payload would be just as effective