How China's J-20 Stealth Fighter Would Shoot Down an F-22 or F-35

[Mithridates]

@gambit
your post was very informative and in some cases confusing. so if i understand it correctly, we can't achieve burn-through against stealth planes??
an other point, why a su-24 can lock an anti radiation missile on vhf band radar so why we can't use the bip on radar screen to lock similar missile (with additional IIR seeker for terminal phase, considering that that bip do not give the exact location of target) on an stealth plane??

So by all means, Iran can use those long wavelengths, high energy, and long range radars. See how effectively they will be, but by then, it will be too late for Iranian air defense.

iran does not use the OTH radars to target planes, they are early warning and they are placed deep inside the country so i don't think you can hit them.

also are you sure you didn't confused the radar ampilitude with the duty cycle of radar??

 

[Surya 1]

I'm not sure about the past, but I know you got your asses kicked this time. Peace.

All who are kicked by our forces make such stories whether it is Balakot or it is Doklam.

 

[ARMalik]

the challenge for china is to detect f22 or f35 at bvr distance. near close combat f35,f22 are difficult to lock on due to super maneuverability

And this is the key question which a lot of people just do not comprehend. Unless jets like J-20, F-35s, etc have stealth detection radars, they won't be able to find each other, so how are they going to shoot each other?

Until a credible stealth detection radar is not developed, J-20, F-35s are more of offensive/strike fighter jets. And if a stealth detection radar has been developed, then even a 4th Gen fighter in a Netcentric, AWACS environment can shoot down these 5th Gen jets with missiles like PL-15.

 

[Surya 1]

And this is the key question which a lot of people just do not comprehend. Unless jets like J-20, F-35s, etc have stealth detection radars, they won't be able to find each other, so how are they going to shoot each other?

Plane like J 20 are not stealth and detectable by ordinary PESA radar from a long distance. F 35 will find and shoot it even before J 20 knows what happened to them.

 

[Ultima Thule]

Plane like J 20 are not stealth and detectable by ordinary PESA radar from a long distance. F 35 will find and shoot it even before J 20 knows what happened to them.

even USA is concern about capability of J-20 and countering them with 6th gen, is Your HYPER POWER OF THE UNIVERSE has better tech and Sensor then USA What a proof that your ACM claims that J-20 detected at long ranges ( Might be just a MORAL BOOSTER), ok if you do Your MKI detected J-20 than J-20 detected MKI further MKI can detect J-20 because your MKI is Not a reduced cross section or Stealth jet and destroyed your MKI at extreme ranges (150+ KM ) @Surya 1

 

[gambit]

@gambit
your post was very informative and in some cases confusing. so if i understand it correctly, we can't achieve burn-through against stealth planes??
an other point, why a su-24 can lock an anti radiation missile on vhf band radar so why we can't use the bip on radar screen to lock similar missile (with additional IIR seeker for terminal phase, considering that that bip do not give the exact location of target) on an stealth plane??

iran does not use the OTH radars to target planes, they are early warning and they are placed deep inside the country so i don't think you can hit them.

also are you sure you didn't confused the radar ampilitude with the duty cycle of radar??

No, I am not confused between amplitude and duty cycle.

I used the MIG-25's radar as an extreme. Extremes are needed to establish boundaries. So here we go...

In radar detection, there are four main target resolutions...

- Altitude
- Speed
- Heading
- Aspect angle

Some people may not be clear on 'Heading' vs 'Aspect angle' so for their benefits, I will post a non-US explanation to avoid charges of biases.

https://openi.nlm.nih.gov/detailedresult?img=PMC3231005_sensors-10-10181f1&req=4

I do not think Tsinghua University is in the US, but I could be wrong...

Anyway...As long as these four resolutions are available, air traffic control or any other types of responses can be formulated. How they are made available and their granularity depends on the technology of the seeking radar.

There are three main ways to affect those resolutions...

- By the seeking radar itself
- Environmental contamination
- Target caused

I will begin in reverse order.

Target causes. What are those? Before 'stealth' or shaping, the target can make those resolutions 'fuzzy' by way of ACTIVE countermeasures or what is commonly called electronics warfare (EW). With 'stealth' or shaping, the target takes that 'fuzziness' to a deeper level -- at the body itself.

Environmental contamination. What are those? Weather is a major contributor and cannot be controlled. Terrain is also a major contributor but while cannot be controlled, terrain can be utilized by the target, aka 'terrain masking' combat flight tactics.

Important -- if any target resolution is affected, so will be the others.

So how can the seeking radar affects those target resolutions? To put it bluntly -- by being a technologically shitty system. As how the MIG-25's radar was -- shitty in design and execution. Our assessment of the MIG-25 as an overall shitty jet is for a different debate.

Burn through is when a target creates active countermeasures but the seeking signal is so strong in amplitude (energy) that the countermeasures signals are essentially ineffective. The seeking signals simply overwhelms the weaker countermeasure signals and make physical contact with the target anyway.

But with shaping, the other option for the target, no countermeasure signals are created. Shaping make 'fuzzy' those target resolutions regardless of energy levels. There is nothing to burn through and overwhelms because there is no resistance.

As far as energy levels goes, there are two ways to concentrate energy on a body: Amplitude and duty cycles. For the latter, it is loooooooooooooooooooooooong duty cycles. Either peak or average. The seeking radar can have high peak energy but short duty cycles for missile acquisition or lower average energy but long duty cycle for long range and volume search.

Shaping make 'fuzzy' target resolutions for BOTH designs and does it at the body level. This is why after all these decades, long wavelengths which equals to higher energy have not made serious dents on countering 'stealth' based upon shaping. It is true that with higher energy in transmit, there will be higher energy in echoes when in contact with the target, but the coarseness of those target resolutions are still there and if the target employs terrain masking or is accompanied by standoff active countermeasure like the EF-18 platform, the seeking radar will still be at a disadvantage.

This is why I said your post 31 page 3 is just wrong. It is correct if the F-22 or F-35 is in steady state flight. But then again, you could achieve the same thing by pointing a radar -- of any energy level -- at an F-35 ground static display.

People denigrates US 'stealth' as if we do not know basic radar detection principles. Everything I said above cannot be proven by anyone outside the US military, as in proven true or false in peace time. Who wants to be the first victim -- I mean volunteer -- to try to prove it in combat?

 

[Mithridates]

Either peak or average. The seeking radar can have high peak energy but short duty cycles for missile acquisition or lower average energy but long duty cycle for long range and volume search.

is this a reason air defences can't track a trajectory with really high speed??

 

[gambit]

is this a reason air defences can't track a trajectory with really high speed??

Not true. If we can track the Space Shuttle during descent, we can certainly track a missile -- ANY missile -- at any speed.

The issue is the granularity of that track.

Each pulse have an leading edge (LE) and a trailing edge (TE). Each LE and TE have a timestamp. A series of pulses is called a 'pulse train'.

https://ieeexplore.ieee.org/document/1167733

Abstract:

The stepped-frequency radar signal is revisited. The delay-Doppler response of pulse-trains with different interpulse frequency codings is investigated, including linear, nonlinear, up-down and Costas codings. Different approaches to sidelobe reduction are considered. Both matched filter and stretch processing are discussed.

The more time markers you have, the more accurate and precision the track. It is akin to tracking a target in increments of meter instead of tens of meters or hundreds of meters.

Or you can try this analogy: Open and close your eyes.

If you open/close your eyes at one second intervals, you would have a more accurate tracking of a target than if you open/close your eyes at five seconds intervals.

But the issue remains with energy levels. Each pulse is a finite packet of energy. Longer pulses have greater energy but longer timestamps between LE and TE, which is equivalent to keeping your eyes closed longer.

This is why long wavelengths frequencies do not provide the high accuracy compares to shorter wavelengths bands.