That's really incredible and if this is essentially the way resonance works against stealthy aircraft, does it basically mean that all the shaping and RAM and IR reduction and all the American stealth innovation and application in the F-22 and the F-35 is moot at this point?
To a degree yes, but Russia hasn't been doing nothing... these long wave and anti stealth radars didn't just fall from the sky... Russia has spent money and time and energy developing radars in different frequency ranges that can work together to help detect not just stealthy targets but also very small targets too.
It is no accident that Soviet and Russia radar space tracking equipment could track chips of paint in orbit...
It's all for nothing or makes detection and tracking just a little bit more difficult than it would ordinarily be, if say, the objective was tracking an F-15 or MiG-29, for example?
Detection is critical... it doesn't matter what missiles and guns or decoys and EW equipment you have if you don't see the attack coming then it doesn't matter because it wont be used.
Tracking is important to determine potential targets and what defence resources need to be alerted to deal with the problem.
Even if you have radar sites that can detect stealth targets you need to get systems close to it to deal with it.... obviously even the dumbest 3rd gen fighter can be directed via ground based long wave radar to cannon range of a B-2 or F-117 to shoot them down.
Directing that old fighter to an F-35 or F-22 would be more problematic for your old fighter...
Conversely, why would Russia put all the effort into the Su-57 and the eventual PAK-DA and basically stealth aircraft then? Seems counterintuitive, so to speak.
Think of it in terms of camouflage... right now the west has a few long wave radar stations that could track stealthy aircraft... if you take down such targets then they would struggle against stealthy targets because their general in service systems are not really optimised to deal with their own stealthy aircraft let alone Russian ones.
US stealth is going for near invisible and so it is enormously expensive to buy and to maintain.
Russian stealth is not to be invisible but be harder to see and engage... a much lower bar that is much cheaper but still effective enough to be tricky to deal with and they are not going for an all stealth fighter fleet... the new MiG light 5th gen fighter and Su-57 are not going to replace all their existing types... they are going to have a mix of options.
With bombers the PAK DA is going to be flying wing stealthy, but likely not as super stealthy as the B-2 because its primary role is not bomber... it is stand off cruise missile carrier... odds are it will never fly anywhere near US territory and its hypersonic 10,000km range missiles will penetrate western air defences... they just wont see where it came from... with new nuclear powered cruise missiles with unlimited range the PAK DA might take off and fly 5,000km away from its target before launching its missiles...
The Su-57 will be stealthy so it is not interrupted as it hunts down F-35s and F-22s... its wing mounted long wave AESA radars used to triangulate the location of stealthy targets...
Making such a claim just seems to need some effective validation/explanation and understanding because it's basically saying that all this $200 billion investment and development in stealth technology has essentially gone down the toilet with this radar technology!
If only it was that cheap... the F-35 programme alone is 1.5 trillion... plus F-117 and F-22 and B-2 and B-21... and the secret programmes and Commanche and the stealthy weapons and drones...
It does make those ground radars one of the most important targets so how long they would last in a war must be problematic.
Most of them are mobile and in service in large numbers... and the issue of finding them... very long wave signals are very hard to locate or jam.
Conversely very short wavelengths are hard to jam too... for instance radar guided hellfire missiles, or the MMW radar systems used by APS systems on tanks are hard to detect at distance and also hard to target with missiles too.