Slashdot Mirror
Chinese Researchers Reveal Active Stealthy Material (popsci.com)
hackingbear writes: Even after billions and billions of dollars spent on the stealthy skin used on F-22, F-35 and B-2, the material has weaknesses, and one of those is ultra-high-frequency (UHF) radar, which can pick up traces of the plane that other radar misses. Chinese researchers came to the rescue and created a material just 5/16 of an inch thick that can safeguard stealth planes against UHF detection. The material tunes itself to a range of detection frequencies, protecting against a large swath of radar scans. What's even more amazing? They published this seemingly top secret invention wide open in the Journal of Applied Physics .
If this thing works, how did anyone notice it?
-=This sig has nothing to do with my comment. Move along now=-
Are they publishing it because (1) they have something better, (2) they have figured out a way to beat it and hope we will use it, or (3) they were simply incompetent?
Although it was hard to see from where we stood, I think that the exhaust structure had been removed. Compared to some of the pictures I have seen, I also think that they removed features like the bomb bay doors.
Even so, it was a fantastic experience to see one up close. If you ever git the chance to visit the museum, take it. There is a long waiting list, you can't just go there and get in. Planning is required.
Why is Snark Required?
No matter how fast your plane is, there will always be a missile that is faster.
Translation: 5/16 Inch = 8mm
It's still better than nothing. A passive broadband radar will take milliseconds to adapt the coating to any single radar frequency. With more than one it will run into trouble, but again, multiple blips at predictable intervals are quite easy to program, so the airplane would be able to hide from multiple radars.
This can be thwarted relatively easily with a radar that constantly shift frequencies randomly, but... you need to build one. The old infrastructure becomes obsolete, necessitating costly upgrades. It may provide exactly zero battlefield advantage in the long run but if it forces the opponent to suffer costs of performing upgrades of their infrastructure which would be otherwise not needed, it's already a win. And by publishing the paper (instead of costly building air force exploiting the new tech, which *might* leak through the opponent spies (and become obsolete fast), or might remain secret and become obsolete much slower) they are simply running the costs up for the USA.
"Upgrade all your radars to frequency-hopping right now, before anyone builds a plane that will be invisible to them". And the plane *will* be built somewhere, because there are many countries that just can't afford upgrading their radar infrastructure, and their opponents would benefit greatly from planes invisible against them - even if they are useless against the (upgraded) USA radars. And the USA will definitely dislike the option of having 3rd party airplanes in the air which they can't see, even if they don't mean a direct threat currently.
Economical warfare: at relatively low cost for yourself force the enemy to spend a bunch of money on defenses they will probably never need. (but will never need them only if they build them... if they don't, they'll regret they didn't.)
45 5F E1 04 22 CA 29 C4 93 3F 95 05 2B 79 2A B2
The future of air warfare (neglecting space) is pilotless aircraft. They can pull much higher Gs and no pilot means you don't have to put up with propaganda showing captured pilots. Just about all of the U.S. military knows this except a few spaghetti splattered uniformed Air Force generals.
Dodging in the form of guerrilla warfare where you move around all the time seems to work still. It's why it was so hard to find Bin Laden and that there's still ongoing work trying to locate IS leaders.
Bunkers are outdated when it comes to serious assault stuff, but such weapons are expensive and limited in supply so if you can trick your opponent into wasting bunker busters and missiles by fake bunkers and similar then you can at least let things play in your favor.
During WWI it was not unusual to have the "disappearing guns" in fixed artillery fortress locations protecting harbors. They became obsolete with the advent of the bomber aircraft, which resulted in a ceiling on the fortresses to protect against incoming bombs, which was pretty common during WWII. When the battleships got gyro-stabilized guns with high precision and aircraft able to do precision attacks on bunkers they became obsolete too since they now were essentially death traps.
That's why most artillery units (both coastal and land) today are highly mobile. They can be operated by 1-2 men, stop and fire several rounds in under a minute and then be on their way again. (Bofors Archer)
When you look at aircraft today it's a lot of stealth, but the downside with that technology is that it limits the punch it can carry. The A10 is non-stealth, and carries over 1000 30mm rounds, carries rockets externally to the level that it looks like a porcupine while the F-35 has a few hundred 20mm rounds and have to hide every rocket inside the hull. The stealth capabilities are also constraining the aerodynamics so that maneuverability suffers.
However the advantage with stealth is that the first strike may appear with little warning, but after that the advantage is lower - and since the carried payload is lower it takes more missions to get the job done. A war zone is also highly fluid - the weapons you brought with you at the beginning of the mission may not be the right weapons when you arrive in the strike zone.
If builders built buildings the way programmers wrote programs, then the first woodpecker would destroy civilization.
first, UHF does not detect American stealth. China just claims it in hopes that fools will buy their radar.
China is giving up nothing. They have a compound that will absorb UHF, but all others are reflected. IOW, it is worthless.
So, why not publish it?
I prefer the "u" in honour as it seems to be missing these days.
I've applied this new technology to my 1975 Toyota pickup. Here's a photo of me standing next to it:
http://www.nrcs.usda.gov/Inter...
You are welcome on my lawn.
Radars have been wideband (wider than the absorption peak of this new material) for at least 30 years, and probably longer. Pulse compression with multi-hundred MHz bandwidth is a standard thing, and has been for a very long time. The SPY-1 on Aegis cruisers is a good example.. It's L-band (where this material seems to be designed) and the bandwidth is very wide. (hundreds of MHz). And the frequency on modern radars is agile. The air traffic radars at 5GHz that have the interference problem with WiFi are another example.
We've come a long way since the old magnetron based systems.
The other problem is that this material shows good absorption for normal incidence. As soon as the signal comes in from an angle, it doesn't work as well, because it's relying on the wavelength and the classic 1/4 wavelength thick absorber (but not actually 1/4 wavelength, just simulating it). If the signal comes in from 45 degrees, now you need an absorber that's 1.4 times thicker.
Kind of a neat idea, but it's not going to change stealth airplanes.