CAC J-20 vs. F-22 and other technical issues

[gambit]

Are you serious? The only real public analysis on the J-20's RCS was done by Kopp, and that was widely panned (and based on an early prototype).

And correctly panned. Think about it for a minute.

Why is Kopp's the only public attempt? Because those in the know -- knows better than to make fools out of themselves.

The graph you posted is a non-sequitur,...

I wonder if you know the proper use and context of non sequitur.

The graph I posted is an important component of the foundation of understanding how basic radar detection works and is absolutely applicable to the subject at hand, which is now your quite precise numerical values that are based on NOTHING.

...all you and Westerners have are memes like "canards unstealthy lol".

There are three rules in designing a low radar observable body...

- Control of quantity of radiators
- Control of array of radiators
- Control of modes of radiation

For all the yrs I have been saying that -- NOT ONE of you, here or in any other China friendly forums, have proven that wrong. Not even Kopp and his crew can challenge that. Not even the engineers of the J-20 can challenge that. And horror of horrors, not even the guys over at sinusdefence can challenge that.

When the J-20 have eight flight controls structures vs the F-22's six, the J-20 is less compliant to Rule One. That is all there is to it. This is not about the canards but about the QUANTITY of structures that made the J-20 suspect in comparison to the F-22 and F-35.

I've said all I'm going to say about this.

Which is not much to start.

 

[Pepsi Cola]

And correctly panned. Think about it for a minute.

Why is Kopp's the only public attempt? Because those in the know -- knows better than to make fools out of themselves.


I wonder if you know the proper use and context of non sequitur.

The graph I posted is an important component of the foundation of understanding how basic radar detection works and is absolutely applicable to the subject at hand, which is now your quite precise numerical values that are based on NOTHING.


There are three rules in designing a low radar observable body...

- Control of quantity of radiators
- Control of array of radiators
- Control of modes of radiation

For all the yrs I have been saying that -- NOT ONE of you, here or in any other China friendly forums, have proven that wrong. Not even Kopp and his crew can challenge that. Not even the engineers of the J-20 can challenge that. And horror of horrors, not even the guys over at sinusdefence can challenge that.

When the J-20 have eight flight controls structures vs the F-22's six, the J-20 is less compliant to Rule One. That is all there is to it. This is not about the canards but about the QUANTITY of structures that made the J-20 suspect in comparison to the F-22 and F-35.


Which is not much to start.

No one challenges that because it's no one really cares. Sure if the F-22 is more stealthy then so what? Stealth isn't everything, and the Chinese engineers trade stealth with more mobility. Can the Chinese design a stealth fighter without canards? Sure it can, and the J-35 is an example to that. You people keep talking about the stealth disadvantage of having canards but never the advantages. Lmao

These planes are designed for different things, I honestly don't even know why you guys are comparing them so much...

 

[SME11B]

Far more amazing is that reasoning even less rigorous than that is published by the likes of The National Interest and Business Insider and accepted by people like you as Gospel. You can throw out whatever word salad of quasi-technical terms you like, the simple fact is the legions of highly qualified engineers working on the J-20 with the benefit the most capable supercomputers in the world have designed an aircraft at least as capable as the F-22 from the 1990's, full stop. That I gave the F-22 a slight advantage is just arguing a fortiori.

How can you be so sure the new comer can match or outdo 40 years of experiments and multiple generations of stealth and other tech. China is the up and comer they have to prove themselves they don't get the benefit of the doubt that doesn't make sense. Lets see a track record first.

you're not putting any ground realities on the section but blabber and troll baseless, i have to ask one question if you knows nothing about military tech/tactics then why you always troll against J-20 and most of J-20 tech is classified, reported again for trolling @SME11B

I reported you to so what. I even said the tech was largely classified and I gave my reasoning why are you trolling me? lol

 

[Ultima Thule]

No one challenges that because it's no one really cares. Sure if the F-22 is more stealthy then so what? Stealth isn't everything, and the Chinese engineers trade stealth with more mobility. Can the Chinese design a stealth fighter without canards? Sure it can, and the J-35 is an example to that. You people keep talking about the stealth disadvantage of having canards but never the advantages. Lmao

These planes are designed for different things, I honestly don't even know why you guys are comparing them so much...

NASA said that their experimental X-36 with canards has a extremely low RCS from front and below, main concern for J-20 currently using interim engine WS-10B/AL-31FN and from rear/side it exposed more to RADAR and IR sensor bro @Chinese Commie

 

[SME11B]

Please fact-check your sources before telling others they're wrong

Show me a source that proves me wrong, like a source talking about IR suppression, heck even from ccp state media anything. All I am saying is I look this stuff up a lot and I have never seen it.

 

[Ultima Thule]

How can you be so sure the new comer can match or outdo 40 years of experiments and multiple generations of stealth and other tech. China is the up and comer they have to prove themselves they don't get the benefit of the doubt that doesn't make sense. Lets see a track record first.

Yes you have the experience but they have latest tech also, why don't you understand intelligence is not only USA property @SME11B

I reported you to so what. I even said the tech was largely classified and I gave my reasoning why are you trolling me? lol

I am not trolling but you always troll in this thread and you're not looking in the weakness of F-22 tech it have a 80s stealth @SME11B

Show me a source that proves me wrong, like a source talking about IR suppression, heck even from ccp state media anything. All I am saying is I look this stuff up a lot and I have never seen it.

And IR tech is massively improved since @SME11B

 

[Figaro]

Show me a source that proves me wrong, like a source talking about IR suppression, heck even from ccp state media anything. All I am saying is I look this stuff up a lot and I have never seen it.

Where did "CCP state media" state that the J-20 had perfect stealth?

 

[SME11B]

Yes you have the experience but they have latest tech also, why don't you understand intelligence is not only USA property @SME11B

I am not trolling but you always troll in this thread and you're not looking in the weakness of F-22 tech it have a 80s stealth @SME11B


And IR tech is massively improved since @SME11B

Ok but you made a statement seemingly implying that j-20 not only has IR suppression but that since it's newer it has this new improved version so where did you read that? I never said ccp media claimed perfect stealth that's sort of my point, I said even they have not claimed this feature is included to my knowledge. Sure China knows how to make things but I won't just assume they have mastered something that only one country has been building for decades and this is their first go and they obviously took design ideas in more ways than one to try to compete. So why would I assume anything let alone that they have mastered it on the first try? To put it even simpler yes china has capabilities they also have large obstacles.

I don't assume even the US has mastered a tech until it's all been checked out and has a track record of working. Look at how much scrutiny the f-35 got all those years even kopp was very bias against it but now the conventional wisdom is it is operational and more or less works. J-20 is not being put through that level of scrutiny and is just assumed to work and more and I don't get why. Now f-35c is said to be operational but I won't assume it's completely ready until a deployment has been done and we get the word from our much more free press.

 

[gambit]

No one challenges that because it's no one really cares.

And that is why no one from the Chinese camp are taken seriously. You guys are treading into a subject that requires at least a B.S. just to start as a junior engineer and works in that position, or something similar, for several yrs. But none of you have any aviation experience other than being a passenger in an airliner.

 

[Ultima Thule]

Ok but you made a statement seemingly implying that j-20 not only has IR suppression but that since it's newer it has this new improved version so where did you read that? I never said ccp media claimed perfect stealth that's sort of my point, I said even they have not claimed this feature is included to my knowledge. Sure China knows how to make things but I won't just assume they have mastered something that only one country has been building for decades and this is their first go and they obviously took design ideas in more ways than one to try to compete. So why would I assume anything let alone that they have mastered it on the first try? To put it even simpler yes china has capabilities they also have large obstacles.

I don't assume even the US has mastered a tech until it's all been checked out and has a track record of working. Look at how much scrutiny the f-35 got all those years even kopp was very bias against it but now the conventional wisdom is it is operational and more or less works. J-20 is not being put through that level of scrutiny and is just assumed to work and more and I don't get why. Now f-35c is said to be operational but I won't assume it's completely ready until a deployment has been done and we get the word from our much more free press.

so you saying that China can't innovate, No system is perfect Even F-22/F-35 have weakness, F-22 short range jet, whereas F-35 has slightly higher RCS but i admit F-35 is one of the most electronically advance jet, Behind the J-20 philosophy is to rely in BVR fight nor close air combat (shoot and scoot) @SME11B

 

[rcrmj]

J-20, F-22 and F-35 they are all at the same level of RCS (front)````X.X% varies on RCS wont affect radar detection in big deal``````the only problem for F-22 is that the latest stealth fighter J-20 and F-35 has optical sensors, that can detect stealth objects for more than 150KM (conservative estimation), very useful means when radar signal is highly suppressed````````

J-20 is our first try on 5th gen fighter, to be realistic, its far from perfection```not only the ideal engine, but due to its absence, J-20 has to make many compensations on its areodynamic designs and such. But it doesn have its own advantage, as the potentional for improvement is much better than F-22 and F-35``````

 

[gambit]

the only problem for F-22 is that the latest stealth fighter J-20 and F-35 has optical sensors, that can detect stealth objects for more than 150KM (conservative estimation), very useful means when radar signal is highly suppressed````````

Here is the TACTICAL flaw in that argument...

The reason why the radar is STILL the sensor of choice is because the radar is INTERACTIVE. It means you control a medium -- electromagnetic radiation -- and that medium provides constant real time information about the target. The radar gives you information when you did not have any. In contrast, the optical sensor is passive, meaning it depends on the target to provides information. It means you have to turn your attention to an area that you suspect a target maybe and hope your optical sensor will see something.

The issue is not technical but TACTICAL, meaning how to use what you have to its maximum capabilities under the best and worst situations.

The F-22's LPI AESA is already problematic for all opponents. The F-22 pilot may know that you have an optical sensor or you may not have, but if he 'sees' you are moving away from him, he has the INITIAL tactical advantage.

 

[rcrmj]

Here is the TACTICAL flaw in that argument...

The reason why the radar is STILL the sensor of choice is because the radar is INTERACTIVE. It means you control a medium -- electromagnetic radiation -- and that medium provides constant real time information about the target. The radar gives you information when you did not have any. In contrast, the optical sensor is passive, meaning it depends on the target to provides information. It means you have to turn your attention to an area that you suspect a target maybe and hope your optical sensor will see something.

The issue is not technical but TACTICAL, meaning how to use what you have to its maximum capabilities under the best and worst situations.

The F-22's LPI AESA is already problematic for all opponents. The F-22 pilot may know that you have an optical sensor or you may not have, but if he 'sees' you are moving away from him, he has the INITIAL tactical advantage.

LPI is not that exclusive to the U.S, as far as I kow J-10C and J-16 already has that, and again LPI is not the answer to everything, like many functions that new AESA radar system has, that is to detect enemy without being noticed````as you say a tactical matter based on technical avilability

optical sensor does have narrow field niew, that is the reason that PLAAF and USAF put huge resources on 5th gen information centric warfare system, that is to rely on the system, not one radar or one optical sensor to fight the war``````varies types of radar and sensors across the theatre to provide awarness, single platform can use that information to work out a sutable tactic, optical sensor can play a very significent supplementary means to the point when the environment is not ideal to electronic means

however Russia, unlike China and U.S, takes a different approach in dealing with such matter, they incorporate multipul bandwith system on their jets

 

[gambit]

optical sensor does have narrow field niew,...

You are missing the point, which is that the optical sensor do not give you target information as detailed as radar can. It is not about the narrow view but about how quickly can target resolution be determined.

These are vital target resolutions...

- Heading
- Speed
- Altitude
- Aspect angle

With the camera, it is up to you to determine if the target is moving away or towards you. The radar can give you that almost instantly. That does not mean the optical sensor is useless. The F-35 have six of them.

This...

...Is how a radar 'sees' an aircraft.

This...

...Is how YOU sees an aircraft, in this case, it is an F-15 silhouette.

Combine the two sensor outputs, aka 'sensor fusion', you will have a more complete view of the target, in this case, it is an F-15 in both radar and visual information.

The F-22 does not have the optical target data does not make it an 'inferior' combat platform because its primary mission does not require the optical sensor. When the F-22 enters disputed airspace, all targets are assumed 'enemy' until proven otherwise. Its mission is to established air supremacy in as short a time as possible.

 

[rcrmj]

You are missing the point, which is that the optical sensor do not give you target information as detailed as radar can. It is not about the narrow view but about how quickly can target resolution be determined.

These are vital target resolutions...

- Heading
- Speed
- Altitude
- Aspect angle

Well I beg to differ, optical sensors like EOTS and EODAS can work out target's speed, heading, altitude and angle```

since you cant read Chinese, I can only try to explain in English
EOTS and EODAS all has the ability to work out speed and aspect angle...these two sensors sending continuous target data to the fire-control system, and the fire-control system combines its won platform data, like its speed, heading, altitude and angle, so the fire-control system will calculate these data, to get a synchronous data of the target.

EOTS starts scan mode to overview the area, find any target, combined with its own platform's flying posture (飞行姿态), it fuses and translates those info into an unified target coordination to lable each individual target after each scan, and between two scans, there is a time difference + changes of target's flying posture, so the speed can be worked out```

each EODAS lense uses gazing mode, overview the area, gaze up on any target, combined with its own platform's flying posture (飞行姿态), it fuses and translates those info into an unified target coordination to lable each individual target too, and the target coordination labling is continous, so there is the track

and then the fire-control system fuses all of those info from EODAS and EOTS, to find out angle of relativity to each sensors, sellecting the lables with closest time difference, hence the target's speed, aspect angle, altitude and heading can be worked out```````

I paste the Chinese part, just in case anyone has better English`````

4代机上面的光电系统，都必须能够对探测到的信号进行角度跟踪，无论是EOTS，或者是EODAS。它们只需要向火控系统连续提供所探测到的目标角度跟踪数据，火控系统会根据载体的飞行姿态数据给出的同步的数据，计算出对应的目标测距和航迹····

机载光电系统探测数据融合的过程：EOTS采用扫描模式，全景探测飞机四周范围内的所有目标。并且结合飞机姿态和导航信息，将探测到的所有目标信息转化为统一坐标标定，并且给每个目标标注本次扫描探测到的时间；EODAS各个镜头采用凝视模式，全景探测飞机四周范围内所有目标，并且结合飞机导航和姿态信息，将探测到的所有目标转化为统一坐标标定，并且将探测到的目标时间连续标定。

最后火控系统读取这两个传感器系统标定的目标数据，早出两类光电系统对应测角目标，选去相差时间最短的时间标注数据，完成各个目标的跟踪距离计算。

以上的系统工作是循环的。在几十到几百微秒以内完成一轮计算和融合过程，然后进入下一个探测、数据读取、计算周期，如此循环往复。所以光电探测的敏感度、精度是雷达无法企及的·······

radar as the primary target info acquiring method, it also becomes the primiary target for any modern electronic warfare platforms```as a counter measure to EW means, fighter jet needs supplementary means to gain air superiority. optical sensor is one of them for the future`````

PLAAF's new air-to-air BV missle uses dual sensor head````active radar and optical sensor``````