J-20 5th Generation Fighter VII

Tam said:

Which is correct, but missed an important reason. AEW uses long wave, long wavelength radars, like S-band and L-band. Array size requirements for these radars makes it next to impossible for use with a fighter jet, and even if you use a linear array L-band like on the Su-35, it still not as good in terms of overall power and coverage than having it on an AEW.

Long range, long wavelength radar can pick up stealthy objects much better than X-band radar, but is unable to provide a high quality track on them, and provide sufficient resolution on the target to distinguish it. Could be a bird? Could be a plane? This is where the AEW sends message to its network, and routes other fighters to the suspected area to find, ID or deal with the threat. Fighters will have to share sensor information with the AEW in a CEC network.

Special EW J-20 may try to incorporate a L-band array but this has to be done through a linear conformal array. Another way is through a HALE drone that has to be modified with a conformal array.

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The theory is that multi-static somehow disables the refractive disadvantages of millimeter wave AESA that render it nigh-useless vs stealth. That's the theory, Brumpy is calling bunk on it, but it'd be tautological than multi-static would have some level of advantage over single-location receival. Whether it's enough to beat AEW&C UHF-band advantages is another question.

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The overall issue is that there's a lot of new technologies and new directions air combat can develop in. Even people with access to their country's respective classified doctrines don't know exactly when these technologies will mature and when these directions will come to life.

For the J-20, everything suggested in this thread is possible, but ultimately you have to stick to the abilities that are most mature. That's not drones, micromissiles, multi-static radar, lasers, etc.

That's just to say, the twin-seater will be a twin-seater. All of the other technologies are possible future upgrades, but it's best to just assume there's going to be a J-20 twin-seater version. A bit more aggressively, we can assume it'll function as an escort in 4th generation regiments so that it can protect older fighter aircraft as well as train prospective J-20 pilots in older regiments. If you want to be even more aggressive, you could expect 1 twin-seater J-20 per flight squadron (中队) or flight group (大队). Even if these twin-seaters don't add to J-20 capability in flight group, they'd still be essential as trainers for new pilots.

Bltizo said:

This is the exact kind of "does J-20 have AESA" debate I'm not going to entertain with my time.

Similar to how the null hypothesis for that question to disprove is "is there any evidence to suggest J-20 does not have an AESA," the null hypothesis for this question is "is there any evidence to suggest J-20 is not equipped with a stealthy datalink".

The fact that you are even willing to include "it has no data link" as a "conceivable possibility" just demonstrates how fruitless it has having these kinds of discussions with you when we are universes away from each other in terms of what constitutes a "reasonable assumption" or "reasonable question".

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In other words you have no evidence beyond your own assumption.

The bulk of the F-18C/Ds in the USMC inventory do not have datalinks. Why is the default assumption of the J-20 have stealthy data link a reasonable assumption? In fact the whole US inventory of fighters (except F-35/F-22) do not have stealthy datalinks.

vesicles said:

OK, let me see if I can use your logic and ask you another question... Do you think a Tesla has a radio? It's an electric car and one of the most advanced vehicle in the world. but people have doubts about whether it has a radio?!

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I assume you actually understand that you are making a fallacious argument unless you actually want me to explain it to you.

Brumby said:

In other words you have no evidence beyond your own assumption.

The bulk of the F-18C/Ds in the USMC inventory do not have datalinks. Why is the default assumption of the J-20 have stealthy data link a reasonable assumption? In fact the whole US inventory of fighters (except F-35/F-22) do not have stealthy datalinks.

I assume you actually understand that you are making a fallacious argument unless you actually want me to explain it to you.

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Why? Just about every air to surface and air to air missile, other than heaters, would require a datalink to operate.

Inst said:

The theory is that multi-static somehow disables the refractive disadvantages of millimeter wave AESA that render it nigh-useless vs stealth. That's the theory, Brumpy is calling bunk on it, but it'd be tautological than multi-static would have some level of advantage over single-location receival. Whether it's enough to beat AEW&C UHF-band advantages is another question.

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Millimeter wave? That's really like too short a wave.

Meter wave radar is different. Anything it detects, the minimum RCS would be rounded off to the length of the frequency. In this case, one meter, nothing looks smaller than one meter if your wavelength is one meter.

The overall issue is that there's a lot of new technologies and new directions air combat can develop in. Even people with access to their country's respective classified doctrines don't know exactly when these technologies will mature and when these directions will come to life.

For the J-20, everything suggested in this thread is possible, but ultimately you have to stick to the abilities that are most mature. That's not drones, micromissiles, multi-static radar, lasers, etc.

That's just to say, the twin-seater will be a twin-seater. All of the other technologies are possible future upgrades, but it's best to just assume there's going to be a J-20 twin-seater version. A bit more aggressively, we can assume it'll function as an escort in 4th generation regiments so that it can protect older fighter aircraft as well as train prospective J-20 pilots in older regiments. If you want to be even more aggressive, you could expect 1 twin-seater J-20 per flight squadron (中队) or flight group (大队). Even if these twin-seaters don't add to J-20 capability in flight group, they'd still be essential as trainers for new pilots.

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Everything at one point is untried technologies however. And now suddenly you wake one morning, and these are your new normal.

Brumby said:

In other words you have no evidence beyond your own assumption.

The bulk of the F-18C/Ds in the USMC inventory do not have datalinks. Why is the default assumption of the J-20 have stealthy data link a reasonable assumption? In fact the whole US inventory of fighters (except F-35/F-22) do not have stealthy datalinks.

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Again, the question you ask and the way you ask it reflects how widely our opinions differ for what assumptions are considered reasonable, and I'm not going to waste additional posts and pages debating this with you.

Bltizo please just ignore empty questions that argue against null hypothesis, and just focus your finite energy keeping up the good work, man you singlehandley gives this forum value sometimes I thought you work for the defense intelligence

There's a logical lapse here because the null hypothesis is that the J-20 doesn't have an AESA. There's enough evidence to suggest it does; i.e, it's intended to be AESA, and there's no evidence of pulse doppler or PESA electronics.

You can't claim, however, that the J-20 not having an AESA is not a null hypothesis; that's a misinterpretation of the scientific method. The negative or the status quo is always the null hypothesis.

The functional question, though, is what level of maturity is the J-20's AESA at? Does it have an LPI mode? How reliable is it?

@Brumby

Tam said:

Millimeter wave? That's really like too short a wave.

Meter wave radar is different. Anything it detects, the minimum RCS would be rounded off to the length of the frequency. In this case, one meter, nothing looks smaller than one meter if your wavelength is one meter.



Everything at one point is untried technologies however. And now suddenly you wake one morning, and these are your new normal.

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Going by your argument, tomorrow the Chinese will have Romulan Birds of Prey in orbit in the Sol System.

As for millimeter wave, sorry, the correct answer is centimeter wave and I misspoke.

But functionally, stealth shaping works by scattering the radar waves pointed at the target so that it doesn't return to its receiver. Multi-static has the promise of picking up these scattered waves.

In theory, it should degrade the effects of shaping on RCS, but by what degree is still unknown.

Something interesting...