F-22 vs J-20 - aka USA-made jet fighters vs China-made jet fighters

[LKJ86]

The Su-35's Irbis-E is advertised to have 350Km range vs 3m2 target. The advertised range for the old Bars is 135Km against a 3m2 target. The new Bars is double that of the old Bars.

The RCS of Su-30MKI is about 10 m2, so how long can Su-30MKI be detected by the two radars?
I want the accurate data.

They are talking about something that's already been done.

The very next statement is: The new Chinese jets are not so invisible after all.

So it was verified physically before coming to the conclusion.

It just said it can. But can you provide some information that it had done that?
Everyone can say he can do something, but it doesn't mean that he has done it.

 

[randomradio]

The RCS of Su-30MKI is about 10 m2, so how long can Su-30MKI be detected by the two radars?
I want the accurate data.

You know very well you won't get that detail anywhere.

Anyway, the MKI's untreated RCS is 20m2. The treated RCS is obviously many times lower.

But if a Su-27 was detected at 330Km away, then Su-30MKI will be detected at a similar range.

It just said it can. But can you provide some information that it had done that?
Everyone can say he can do something, but it doesn't mean that he has done it.

You are arguing about the English word "can"? You can interpret the statement anyway you want, but the following statement says it was verified.

"The Sukhoi’s radar can see them. The new Chinese jets are not so invisible after all. No special technology is required to detect the J-20, as it can be detected by ordinary radar stations"

You can't have that second statement without verification.

 

[LKJ86]

You know very well you won't get that detail anywhere.

Anyway, the MKI's untreated RCS is 20m2. The treated RCS is obviously many times lower.

But if a Su-27 was detected at 330Km away, then Su-30MKI will be detected at a similar range.

You mean Su-30MKI can be detected by Su-30MKI at about 330km?

You are arguing about the English word "can"? You can interpret the statement anyway you want, but the following statement says it was verified.

"The Sukhoi’s radar can see them. The new Chinese jets are not so invisible after all. No special technology is required to detect the J-20, as it can be detected by ordinary radar stations"

You can't have that second statement without verification.

The question is: How can you get the conclusion "The new Chinese jets are not so invisible after all.", before you have detected J-20, instead of saying "can"?

 

[Ultima Thule]

I don't know what you mean. Are you asking for a source? It's all open source.

The Su-35's Irbis-E is advertised to have 350Km range vs 3m2 target. The advertised range for the old Bars is 135Km against a 3m2 target. The new Bars is double that of the old Bars.

https://defence.pk/pdf/threads/mini...1m-bars-hybrid-radar-system-su-30-mki.256937/
For aircraft N011M has a 350 km search range and a 200 km tracking range. The radar can track and engage 20 air targets and engage the 8 most threatening targets simultaneously. The forward hemisphere is ±90º in azimuth and ±55º in elevation. These targets can include cruise/ballistic missiles and even motionless helicopters. A MiG-21 for instance can be detected at a distance of up to 135 km. Design maximum search range for an F-16 target was 140-160km. A Bars' earlier variant, fitted with a five-kilowatt transmitter, proved to be capable of acquiring Su-27 fighters at a range of over 330 km.

YOU SAID FOR 3M2 OK ABOUT THAT BUT WHAT ABOUT F-22 CLASS JET @randomradio AND AS FOR EXTREME RANGES PULSE DROPLER/PEASA/AESA CAN'T DETECT SU-27 CLASS TARGET ACCURATELY LET ALONE 5TH GEN JET @randomradio

They are talking about something that's already been done.

The very next statement is: The new Chinese jets are not so invisible after all.

So it was verified physically before coming to the conclusion.

LO/STEALTH DOESN'T MEAN TOTAL INVISIBLE TO ALL ELECTROMAGNETIC RADIATIONS YOU FOOL @randomradio EVEN US/RUSSIA/EU NOT CLAIMING THAT THEIR JETS HAVE A TOTAL INVISIBLE TO ALL ELECTROMAGNETIC RADIATIONS @randomradio BUT A VERY LOW OBSERVABLE TO RADAR/IR/ACOUSTIC/VISBLE RCS @randomradio ONLY YOU'RE CLAIMING THAT YOUR RAFALE HAS A TOTAL INVISIBILITY @randomradio BUT NOT DASSAULT @randomradio


THEY MAIN QUESTION OF WHEN @randomradio




MAY I ASK YOU A QUESTION PLEASE DO INDIA KNOWS WHAT IS THE MATERIALS (RAM, RAS) IS USED ON THE J-20, DO INDIA KNOWS WHAT IS CAPABILITIES OF J-20'S AVIONICS ( RADAR/ETOS/ECM/EW) OF J-20, IF NOT KEEP BLABBRING WITHOUT A CLUE @randomradio

 

[randomradio]

You mean Su-30MKI can be detected by Su-30MKI at about 330km?

Yes and no. A 2002 delivered Su-30MKI can be detected by a 2002 delivered Su-30MKI at 330Km.

Modern Su-30MKIs have significantly reduced RCS and better radars. We don't have modern numbers.

The question is: How can you get the conclusion "The new Chinese jets are not so invisible after all.", before you have detected J-20, instead of saying "can"?

You are basing your argument on how you are interpreting the English here.

Considering the sources are named, ACM and another IAF officer, their words carry enough weight for it to be real assessments.

Assume that the officers informed the general public after having seen it with their own eyes. Normally, they wouldn't say anything at all.

 

[LKJ86]

You are basing your argument on how you are interpreting the English here.

Considering the sources are named, ACM and another IAF officer, their words carry enough weight for it to be real assessments.

Assume that the officers informed the general public after having seen it with their own eyes. Normally, they wouldn't say anything at all.

There needs solid evidence to prove what you said.
And until now, no other evidences have proved that India has detected J-20.

Yes and no. A 2002 delivered Su-30MKI can be detected by a 2002 delivered Su-30MKI at 330Km.

Modern Su-30MKIs have significantly reduced RCS and better radars. We don't have modern numbers.

Which Su-30MKI is said to have detected J-20?
You say "Modern Su-30MKIs have significantly reduced RCS and better radars", so is it more or less than 330km?

 

[Pepsi Cola]

First of all, radar contact is not that "Smart" their process start with sending Microwave and end with receiving the Microwave. This is not transponder we are talking about, where it report Speed, Heading and Squawk code, any radar system will not know the target they are tracking is flying at 1963km/h. It will just show up on your radar as a dot, you can tag information in it, but the radar itself will not know anything other than this is a radar contact, and the size of Radar Contact.

Secondly, you are still assuming Stealth can be hidden from radar. It does not, any radar can pick up any signal, how to process these signal is another business. And the most important question of any Radar Operator is you know what is that signal. Stealth Aircraft made their leading edge reflection similar to something else but not the fighter itself, which mean the F-22 can be looking like anything but a F-22.

While the principal of stealth is the same, the EXECUTION of stealth is not, which mean the signal return vary between different stealth platform. And no, if you don't know what the signature looks like, how do your AA know what are they shooting at? It maybe a F-22, it maybe a Boeing 727, or it may even be a Cessna which return similar radar signature.



That is because you still don't understand the point.

Comparing i7 to i5 is to demonstrate how starting point is different and the outcome is different even with moore's law progress, which is my point.

And if you think US stealth is still linger in the F-117 era, then you are dead wrong, also you cannot study a wreckage to determine how stealth work, because the structure is compromised. Stealth work as a whole, form engine noise, engine heat signature, leading edge shaping and Electro-Magnetic emission. It does not work if you just have a piece from a wreckage, you may know what kind of Radar Absorption Paint F-117 use back then but I can guarantee you, this is not the same paint currently on F-22, F-35 and B-2.

[/QUOTE][/QUOTE]

Wow, you need to work on your technical knowledge.

"Secondary radar is similar but uses a different pulse and return signal. On board the aircraft, a transponder will reply to a radar pulse with encoded pulse of its own that is specific to that aircraft. This encoded pulse is then received by the radar antenna on the ground. The pulse is designed to relay not only position of the aircraft but also the aircraft identity, altitude, speed, etc. This technology is based on the identification friend or foe (IFF) developed during World War II. It is the main system used by civilian air traffic control around the world."


I was the one who previously said any radar can detect stealth aircrafts but the range is the variable factor. Please stop spinning.

You're funny. This is why all civilian aircrafts have to report or have transponders to identify themselves. If an unidentified aircraft gets close to a restricted airspace, you go look at them. However, in times of war, you just shoot them down.

"Korean Air Lines Flight 902 (KAL902, KE902) was a civilian Boeing 707 airlinershot down by Soviet Sukhoi Su-15 fighters on April 20, 1978, near Murmansk, Russia, after it violated Soviet airspace and failed to respond to Soviet interceptors."

No, the question is: why are you even comparing purposely inferior products made for different consumer needs?

Big part of stealth is metallurgy, you can study them under microscopes. And only stupid people would think F-117's stealth characteristics are exactly the same as F-22. The point is, the Chinese at least know how some of them work, have physical evidence of it, and way better than having nothing at all. That's why even the US bought and study Sukhoi jets. Nothing out of ordinary.

I once thought you as a respected member, but with this amount of technical knowledge, I'm doubtful.

 

[HariPrasad]

And your Sukhoi would detect and tracked 200 KM by J-20 AESA @HariPrasad

Sukhoi never claims stealth and jf 17 has no aes

 

[randomradio]

There needs solid evidence to prove what you said.
And until now, no other evidences have proved that India has detected J-20.

As far as we are concerned, the words of our military chiefs are good enough.

If the J-20 was a real threat, then the IAF would have raised the alarm and forced the govt to go for the F-35 or PAK FA at short notice, and we would have seen something happening by now. But if the air chief says the J-20 does not signify an asymmetrical threat to the IAF (his words), then that's a massive plus point for us.

This year, the govt came under massive criticism from the armed forces publicly for not giving enough hike in the budget. The J-20 threat would have been a good chance to increase the budget.

https://www.indiatoday.in/mail-toda...n-defence-dashed-our-hopes-1188693-2018-03-14

The point I'm making is our military leaders are not liars. If there is a problem, they will be open about it. If the J-20 was a significant threat, the air chief would have kept quiet about it or used diplomatic answers that does not actually answer the question.

Which Su-30MKI is said to have detected J-20?
You say "Modern Su-30MKIs have significantly reduced RCS and better radars", so is it more or less than 330km?

Nobody knows. Only the squadron involved would be able to say because the MKI fleet is not homogeneous. Different squadrons have received different upgrades.

 

[Pepsi Cola]

And you are partially wrong.

An airframe CONFIGURATION produces a unique radar signature. See the illustration above.

Airliners do not have wing sweep like jet fighters do -- that is one major contributor to a configuration.

Airliners have engines below the wings which produces a unique radar signature as shown in Fig 2 above. Jet fighters may or may not fly with external stores under their wings, therefore, an F-16's radar signature can radically differ from day to day, base upon what it carries -- or do not -- under the wings.

The B-52 bomber is comparable to the airliner in many major structures, which produces a similar radar signature to that of the airliner's radar signature.

You are partially wrong in that it helps immensely if the radar system have a library of known COMMON CONFIGURATIONS of major airframes in the world. That way when it 'sees' a target WITHOUT a cluster of voltage spikes like the examples above, it can immediately raise the priority level of that target. The target could be an F-15 or an F-16, but at least you can rule out an civilian airliner or a B-52 bomber. Do you understand?


You mean using the Doppler component of a radar return to track a 'stealth' fighter flying at 1900 km/h? That would be the 'Moving Target Indicator' (MTI) radar as an option.

You joined this forum May 2016. I posted a rebuttal to the MTI argument yrs ago...

https://defence.pk/pdf/threads/chinas-blitzkrieg-on-u-s-carrier.54955/page-29#post-3309403

That was in Aug 2012. If it was that easy to exploit the Doppler component (MTI) as a 'counter-stealth' method, that would have been proven after the F-117, and the F-22, F-35, and the B-2 would have never came to be. The MTI counter-stealth argument was nothing more than a fantasy cooked up by various anti-US Internet trolls ignorant of basic radar detection principles, and used more to attract attention to themselves than to enlighten the readers.

The MTI method does not work.


Then why are Russia and China still trying to deploy their 'stealth' fighters?

If it is that easy to defeat 'stealth', especially with the AESA technology, that mean ANYONE can defeat 'stealth' on the cheap. So why are Russia and China struggling to deploy their 'stealth' fighters?

But I will say this about US -- that we have effectively defeated 'stealth'. Forty+ yrs of flying various publicly known and unknown 'stealth' aircrafts provided US with plenty of data on how a certain structural layout will produce a certain RCS signature. Your China is still trying.

The J-20 is Dead-On-Arrival (DOA).


Which was %99 useless to China.

The current low radar observable technique is shaping. If you do not have the FINAL shape, then you are gambling, and when that F-117 crashed, its final shape with that low RCS value was essentially lost to China. The curvature method on the B-2, F-22, and F-35 are superior to the angled faceting method used on the F-117.

You want me to be wrong so much, you put it as "partially wrong"? haha. Thank you for your long paragraphs though.

Well, I said you don't "need", not saying it's not good to have it at all. Of course anyone would want it, but that's top secret. Am I right?


You seems obsessed with one mode of radar tracking. Do me a favor and read about Pulse-Doppler radar.

"
Let’s say that a stealth aircraft reduces its RCS down to a square centimeter or something ridiculous like that. Getting enough power off of this target to detect it above the clutter level (without special Doppler processing) will be very challenging, especially if the target is flying low elevation. But if you separate out the clutter because it has a different Doppler spectrum and you do detection solely against noise, this is now a tractable problem. The stealth aircraft won’t be detected out at 100 miles, but a high performance search/track radar will likely still be able to detect this aircraft in time to initiate some kind of self-defense response.

So is a stealth aircraft still hard to detect? Yes. Definitely. Stealth technology yields very low RCS characteristics.

Does the speed help? Yes it can, most certainly, particularly if the radar employs MTI or the more advanced Pulse Doppler processing. Detection and track will certainly be more reliable with Pulse Doppler than without.
" (William Keim, 10 years working defense sector with integrated air and missile defense.)

Oh yes, I'm not your average PDF member. I know how to google.

Why China and Russia still fielding stealth fighters? Simple. They're hard to detect. Not impossible, but harder. 6th gen though, no longer make a big deal out of stealth. 6th gen is going for speed.

How was the stealth coating on F-117 useless to China? Shaping and angling can be simply studied using models in wind tunnels and computer simulations, especially with widely available photographs of the stealth aircrafts. That's the easy part. The stealth coatings on the F-117 wreckage sure gave the Chinese a way better idea on how stealth works.

 

[Globenim]

Considering the sources are named, ACM and another IAF officer, their words carry enough weight for it to be real assessments

Serioulsy? The sources named discredit the claims if anything. They cant be taken serious and given any weight in any real assement.

I mean come on lets be honest, this is the IAF, not the most professional airforce that comes to mind, talking about Indias sworn enemy. Any common sense tells you its more likely they may have just "detected" a lunenberg lense or some pilot noticed some blip when the J20 made some rolls and the IAF later figured out a J20 was making a testflight nearby. If it was even a J20 they detected. The fact an IAF officer is gloating over something like that in public puts themself more into question than the J20.

 

[HariPrasad]

Can you prove it?
What radar?
How long?

There is an article on this Please check

 

[Akasa]

RE: India's claim that it is capable of detecting the J-20

Air Chief Dhanoa did not explicitly say that Indian radars have detected the J-20. Instead, his words were something to the effect of "the J-20 isn't that stealthy, we can detect it from some kilometers away". This means nothing, since (1) any VLO fighter can be detected from "some kilometers away" (even the KLJ-7 can detect the F-22 from "some kilometers away" in theory) and (2) the J-20 uses Luneburg lens to mask its true RCS.

Moreover, due to a litany of uncredible claims made by Indian officials in the past (such as the ridiculous claims that India defeated the RAF 12:0 during Indradhanush 2015), it is also wise to take such statements with a massive truckload of salt.

Moreover, the J-20 has never been operationally deployed to Tibet.

In summary, even if we are to believe Dhanoa's words (which we should not without further insight into the surrounding context), they mean nothing unless given additional military & circumstantial context (such as range, radars involved, etc.).

 

[jhungary]

Wow, you need to work on your technical knowledge.

"Secondary radar is similar but uses a different pulse and return signal. On board the aircraft, a transponder will reply to a radar pulse with encoded pulse of its own that is specific to that aircraft. This encoded pulse is then received by the radar antenna on the ground. The pulse is designed to relay not only position of the aircraft but also the aircraft identity, altitude, speed, etc. This technology is based on the identification friend or foe (IFF) developed during World War II. It is the main system used by civilian air traffic control around the world."


I was the one who previously said any radar can detect stealth aircrafts but the range is the variable factor. Please stop spinning.

You're funny. This is why all civilian aircrafts have to report or have transponders to identify themselves. If an unidentified aircraft gets close to a restricted airspace, you go look at them. However, in times of war, you just shoot them down.

"Korean Air Lines Flight 902 (KAL902, KE902) was a civilian Boeing 707 airlinershot down by Soviet Sukhoi Su-15 fighters on April 20, 1978, near Murmansk, Russia, after it violated Soviet airspace and failed to respond to Soviet interceptors."

LOL....

You are quite funny.

First of all, the question is this, how can you shoot down something when you do not know what kind of signature you are looking at.

You assume you know what you are looking for. But you don't. Hence how do you know what you are shooting down something, you don't know whether or not that is a F-22 or F35 or A Civilian Flight, you just indiscriminately shooting down EVERY radar contact you have. You know you shot down something but what?

On the other hand, F-22 or F-35 or any other Stealth Plane may or may not be shot down or even picked up by the radar. And the US wont tell you when and where they cross the border in China if US and China is at war.

So, just because your AA gun or SAM can shoot down anything that appear on your Radar, that does not mean it can shoot down Stealth Aircraft, because the main issue is, You Don't Know what you shot down. You assume that is a Stealth Fighter, but in reality, it can be anything, yes, it could be a Stealth Fighter, but it could as well be a passing jet or conventional fighter.

And in your example, along with IranAir 655 and MH-17, all those are the military of respective country ASSUME the target they are shooting down is a fighter/reconnaissance aircraft, that show you radar contact alone cannot distinguish between target.

No, the question is: why are you even comparing purposely inferior products made for different consumer needs?

Big part of stealth is metallurgy, you can study them under microscopes. And only stupid people would think F-117's stealth characteristics are exactly the same as F-22. The point is, the Chinese at least know how some of them work, have physical evidence of it, and way better than having nothing at all. That's why even the US bought and study Sukhoi jets. Nothing out of ordinary.

I once thought you as a respected member, but with this amount of technical knowledge, I'm doubtful.

The point is the "Design Reference" I am talking about, just because you are making transistor in a more advance method, that DOES not equal to that transistor is going to be superior than the one made with older method.

I7 is designed for high end gaming, i5 is designed on average usage, that is the design point. And if you don't like or don't get the i7 and i5 comparsion, how about Radeon Vx Vegas and GeForce 1080? Radeon Vx Vegas uses the latter moore's law, yet it still behind GeForce 1080, which is two generation ago.

And lol...….Your argument is "something better than nothing"?? That something is 1980 technology (yes F-117 was developed in 1980s) and even if you completely master that technology, that does not mean you know the characteristic of F-35 or even F-22 which is designed in mid-1990s.

And no, US bought Su-27 as a whole, not buying a wrecked Su-27, you cannot compare both situation.

 

[randomradio]

Serioulsy? The sources named discredit the claims if anything. They cant be taken serious and given any weight in any real assement.

I mean come on lets be honest, this is the IAF, not the most professional airforce that comes to mind, talking about Indias sworn enemy. Any common sense tells you its more likely they may have just "detected" a lunenberg lense or some pilot noticed some blip when the J20 made some rolls and the IAF later figured out a J20 was making a testflight nearby. If it was even a J20 they detected. The fact an IAF officer is gloating over something like that in public puts themself more into question than the J20.

The IAF is one of the most professional air forces around. And they are not known to lie to the public. China isn't anywhere near being India's sworn enemy, look elsewhere for that. In fact, it's the IAF that's at a disadvantage by claiming the J-20 is not stealthy enough.

As for Luneburg lens:

I am sure the Flanker pilots know what you are talking about.

Some of those Tibetan airfields are really close to the border. PLAAF was likely showing off to the IAF. Even if the J-20 was detected by a Su-30, the J-20 should still have demonstrated significant superiority to the IAF when it comes to detection ranges over the MKI.

"the J-20 isn't that stealthy, we can detect it from some kilometers away". This means nothing, since (1) any VLO fighter can be detected from "some kilometers away" (even the KLJ-7 can detect the F-22 from "some kilometers away" in theory)

The translation with the apparent body language was anything but "some". You can see it for yourself in the previous page. He simply dismisses the fact that the J-20 is a stealth aircraft itself.