J-20 versus F-35

The F-35 compared with other modern jets.
  • Author
  • Message
Offline
User avatar

ricnunes

Elite 4K

Elite 4K

  • Posts: 4300
  • Joined: 02 Mar 2017, 14:29

Unread post21 Sep 2022, 19:47

milosh wrote:
Btw,

download/file.php?id=39188&mode=view

Look the value for VHF ;)


I've seen that picture countless times! If I earned 100 bucks for everytime I saw it, I would be millionaire by now.

BTW, that's not the F-117! That's a Lockheed concept that eventually lead to the F-117. That's likely Have Blue or even some earlier mock/concept (earlier than Have Blue).

Point being that this shape:
Image
Image

is quite different from this (albeit sharing the same origin):
Image
Image


Moreover, what's below that picture is a part of some Excel type spreadsheet that was pasted below the picture. So there's a chance that the 175 MHz being a typo or simply wrong data.

BTW, that's the source of that picture??
“Active stealth” is what the ignorant nay sayers call ECM and pretend like it’s new.
Offline

jessmo112

Forum Veteran

Forum Veteran

  • Posts: 902
  • Joined: 16 Mar 2020, 02:09

Unread post21 Sep 2022, 20:22

You need HF for that , not VHF
Capture.PNG
[/quote]

I said UHF earlier.[/quote]
HF is frequency between 3 MHz - 30 MHz
VHF is frequency between 30 MHz to 300 MHz
UHF is frequency between 300 MHz to 3 GHz[/quote]

But UHF can be bounced of on the ionosphere.
I already said this. My bad, I suppose I meant to say UHF.
How does this change the fact that Russia has trouble detecting VLO platforms.
So far we have shown that VHF, UHF, And X-band are useless versus F-35.
Offline

jessmo112

Forum Veteran

Forum Veteran

  • Posts: 902
  • Joined: 16 Mar 2020, 02:09

Unread post21 Sep 2022, 20:29

jessmo112 wrote:1. I thought Big long range VHF radars bounced off of the ionosphere to get long range returns.

2. I'm simply demonstrating how extensive the Russians next work is. We have actually had this same conversation countless times. And discovered that The Russians have radar assets looking over Syria.
I'm not going to look up all of the radars now, but we have been over this to the point of exhaustion.

3. Even If I posted the wrong radar how does that change the out come? Can VHF radars be put in missile seekers?
Do they have the resolution for weapons grade track
My point still stands the U.S. will not launch ICBMs from certain vectors. So why on earth are the long range radars pointed towards Iran and Syria?


Edit* from Quora

How do VHF radars detect stealth planes?
Stealth is an overarching term. It is actually multispectral and frequency dependent. You can have acoustic, IR, visual, and radar frequencies to name a few. In the radar frequency world, you have longer wavelengths in the UHF/VHF bands and short wavelengths such as the X and K bands. The band the radar uses depends on many things. Typically fire control and missile radars use the shorter wavelengths for higher precision and also because it allows you to use smaller antennas.

Longer wavelengths require larger antennas and allow you to push more power through them. The offset is less precision. If you are just looking to find something and generally know where it is then the longer wavelengths have an advantage. If you are going to guide a missile in a high g environment to within kill range the higher frequency short wavelength is the better option.

Stealth aircraft are also frequency and aspect dependent. There are different techniques used to make an aircraft stealthy at the different frequencies including IR, acoustic, visual, and the radar bands. In general, what you do to make a radar stealth airplane doesn’t help that much in the visual or acoustic spectrum. Though the A-12 and B-2 are difficult visually because of the lack of vertical tails.

On the radar front there are similar issues. What you do for K band might be a lot different than what you do at VHF. So now you have to decide what do I need for a particular type of airplane and how much “stealth” and of what kind am I going to put on the airplane.

While I can’t get into the details, just from a physics standpoint solving the UHF/VHF issue requires more space because of the longer wavelength. And as mentioned earlier the VHF systems tend to be more powerful and designed for long range. Remember, stealth is not invisible, it is a significant reduction in ability to detect and or track the target.

A powerful VHF system would have a better chance to find a tactical target than a smaller higher band fighter radar. But that stationary VHF radar (or slow moving stable airborne UHF radar) is also very easy to detect at very long range. It is vulnerable to lots of things including getting shot at. Also, a VHF/UHF radar can not target or kill you, it is primarily used for early detection and vectoring killing system onto the target.

Now I said tactical aircraft which are already relatively small. Let’s look at the B-2 which is a strategic aircraft that is much larger with long lines and space to do things the tactical aircraft don’t have. Also, its mission is long range strategic strikes so it has a higher priority to work in those longer wavelengths and you might assume that they have better stealth capability in those bands than a smaller tactical carrier based aircraft.

Your question is how does a VHF radar detect stealth airplanes. The answer is just like every other radar system. Put out lots of power and preferably in a band that the stealth airplane is not optimized. Then hope you get lucky because the stealth aircraft know where you are and are not going to fly in a place they will likely get detected. Neither stealth nor VHF are magic, it is just physics.

Probably the best I can answer without getting classified. But feel free to ask more detailed questions and I will try to say what I can.

What is the safest investment in 2022?
With talking heads from CNBC to Fox Business crying out recession, it’s difficult for investors to cut through the noise, and discover good opportunities. Stocks are volatile, cryptocurrencies can make big swings to either side, and even gold isn’t safe from market chaos.

That’s why if you are looking for a solid investment, you should check out a real, but overlooked asset: fine art.

It may sound unconventional. Companies make profits. Rental properties collect rent. But what can fine art deliver?

Well, it can potentially provide the one thing that matters most to investors: growth.

Contemporary

The same way non-VHF radar detect stealth planes, they receive a return and determine that there is a contact.
Low-observable aircraft are optimized to have a low probability of detection primarily against Radar frequencies that are typically used for detecting aircraft. The designs are not as effective against less conventional air search or early warning radar wavelengths in either the lower VHF range or much higher millimeter wave range. These ranges have some downsides that make them less desirable for use in radar sites, but one of the upsides is the much better performance against stealth aircraft. Some of these RADAR use over the horizon technology where they bounce the pulse off of the ionosphere. This means the pulse is hitting the “stealth” aircraft at a far different angle than the aircraft is optimized against.
The downside of these radar tend to be that the antenna has to be very large and while they can detect contacts they are not great at pinpointing an exact location and are not good for targeting.


Ok now I'm confused. I just read that VHF radars can also bounce off the ionosphere to get a return.
You said earlier that they can't. Please don't shoot the messenger, I'm simply quoting from online.
I can't tell if your purposefully trying to muddy the waters to achieve a goal or what. Why not just admit that no matter if it's UHF, VHF, or X-band, non of them can stop F-35
Offline

garrya

Forum Veteran

Forum Veteran

  • Posts: 995
  • Joined: 25 Dec 2015, 12:43

Unread post22 Sep 2022, 02:54

jessmo112 wrote:
jessmo112 wrote:1. I thought Big long range VHF radars bounced off of the ionosphere to get long range returns.

2. I'm simply demonstrating how extensive the Russians next work is. We have actually had this same conversation countless times. And discovered that The Russians have radar assets looking over Syria.
I'm not going to look up all of the radars now, but we have been over this to the point of exhaustion.

3. Even If I posted the wrong radar how does that change the out come? Can VHF radars be put in missile seekers?
Do they have the resolution for weapons grade track
My point still stands the U.S. will not launch ICBMs from certain vectors. So why on earth are the long range radars pointed towards Iran and Syria?


Edit* from Quora

How do VHF radars detect stealth planes?
Stealth is an overarching term. It is actually multispectral and frequency dependent. You can have acoustic, IR, visual, and radar frequencies to name a few. In the radar frequency world, you have longer wavelengths in the UHF/VHF bands and short wavelengths such as the X and K bands. The band the radar uses depends on many things. Typically fire control and missile radars use the shorter wavelengths for higher precision and also because it allows you to use smaller antennas.

Longer wavelengths require larger antennas and allow you to push more power through them. The offset is less precision. If you are just looking to find something and generally know where it is then the longer wavelengths have an advantage. If you are going to guide a missile in a high g environment to within kill range the higher frequency short wavelength is the better option.

Stealth aircraft are also frequency and aspect dependent. There are different techniques used to make an aircraft stealthy at the different frequencies including IR, acoustic, visual, and the radar bands. In general, what you do to make a radar stealth airplane doesn’t help that much in the visual or acoustic spectrum. Though the A-12 and B-2 are difficult visually because of the lack of vertical tails.

On the radar front there are similar issues. What you do for K band might be a lot different than what you do at VHF. So now you have to decide what do I need for a particular type of airplane and how much “stealth” and of what kind am I going to put on the airplane.

While I can’t get into the details, just from a physics standpoint solving the UHF/VHF issue requires more space because of the longer wavelength. And as mentioned earlier the VHF systems tend to be more powerful and designed for long range. Remember, stealth is not invisible, it is a significant reduction in ability to detect and or track the target.

A powerful VHF system would have a better chance to find a tactical target than a smaller higher band fighter radar. But that stationary VHF radar (or slow moving stable airborne UHF radar) is also very easy to detect at very long range. It is vulnerable to lots of things including getting shot at. Also, a VHF/UHF radar can not target or kill you, it is primarily used for early detection and vectoring killing system onto the target.

Now I said tactical aircraft which are already relatively small. Let’s look at the B-2 which is a strategic aircraft that is much larger with long lines and space to do things the tactical aircraft don’t have. Also, its mission is long range strategic strikes so it has a higher priority to work in those longer wavelengths and you might assume that they have better stealth capability in those bands than a smaller tactical carrier based aircraft.

Your question is how does a VHF radar detect stealth airplanes. The answer is just like every other radar system. Put out lots of power and preferably in a band that the stealth airplane is not optimized. Then hope you get lucky because the stealth aircraft know where you are and are not going to fly in a place they will likely get detected. Neither stealth nor VHF are magic, it is just physics.

Probably the best I can answer without getting classified. But feel free to ask more detailed questions and I will try to say what I can.

What is the safest investment in 2022?
With talking heads from CNBC to Fox Business crying out recession, it’s difficult for investors to cut through the noise, and discover good opportunities. Stocks are volatile, cryptocurrencies can make big swings to either side, and even gold isn’t safe from market chaos.

That’s why if you are looking for a solid investment, you should check out a real, but overlooked asset: fine art.

It may sound unconventional. Companies make profits. Rental properties collect rent. But what can fine art deliver?

Well, it can potentially provide the one thing that matters most to investors: growth.

Contemporary

The same way non-VHF radar detect stealth planes, they receive a return and determine that there is a contact.
Low-observable aircraft are optimized to have a low probability of detection primarily against Radar frequencies that are typically used for detecting aircraft. The designs are not as effective against less conventional air search or early warning radar wavelengths in either the lower VHF range or much higher millimeter wave range. These ranges have some downsides that make them less desirable for use in radar sites, but one of the upsides is the much better performance against stealth aircraft. Some of these RADAR use over the horizon technology where they bounce the pulse off of the ionosphere. This means the pulse is hitting the “stealth” aircraft at a far different angle than the aircraft is optimized against.
The downside of these radar tend to be that the antenna has to be very large and while they can detect contacts they are not great at pinpointing an exact location and are not good for targeting.


Ok now I'm confused. I just read that VHF radars can also bounce off the ionosphere to get a return.
You said earlier that they can't. Please don't shoot the messenger, I'm simply quoting from online.
I can't tell if your purposefully trying to muddy the waters to achieve a goal or what. Why not just admit that no matter if it's UHF, VHF, or X-band, non of them can stop F-35

UHF, VHF can't bounce of the ionosphere
HF can but it need very big antenna, something that make VHF /UHF radars look like toys since it is several kilometers long
Offline

milosh

Elite 1K

Elite 1K

  • Posts: 1850
  • Joined: 27 Feb 2008, 23:40
  • Location: Serbia, Belgrade

Unread post22 Sep 2022, 08:15

wrightwing wrote:
milosh wrote:
About AAGM-ER how it will find JY-27 if its seeker cant track VHF? It need to use active seeker to search for radar signature of JY-27 itself. And China isn't Arab desert at least not in part relative for Taiwan war. You have lot of hills and forests.

And even if AAGM-ER find something which look like JY-27 is it real thing of mockup? We used mockups a lot in 1999, they work. Ukrainians use them now they work. China have factories dedicated to build realistic mockups, making something like JY-27 is nothing special I could make it if I have time and my welding skills are poor hobby level, let alone factory.


Did you read what I wrote. The AARGM-ER doesn't need to detect the emissions of a VHF radar. It's got GPS/INS, datalinks with the launch aircraft, multi-spectral guidance, MMW guidance, in addition to the ARM guidance. That means it doesn't matter whether a target is emitting, or what frequency it's emitting on. If the launch platform can detect the hostile emitter, the missile can find it through the redundant guidance systems, and provide BDA.


As you can see I already wrote what you wrote.

AARMG-ER need active seeker and it have one, so it got location of radar, then when it get in that location it use MMW radar to find SAR image of radar, problem is decoys, how will MMW seeker know which antenna is part of radar and which one is decoy?

VHF/UHF antennas like on JY-27 are something very easy to build as decoy. So you waste lot of AARMG-ER hitting decoys. This is why I tried to explain what happened in Syria doesn't mean much in case of war with China.

Also from our 1999 experience, those antennas like JY-27 have are lot easier to repair when hit then antennas of other radars.

jessmo112 wrote:Why not just admit that no matter if it's UHF, VHF, or X-band, non of them can stop F-35


It isn't just Russians or Chinese talking about efficiency of UHF/VHF radars vs stealths, Americans talk about that too:
https://news.usni.org/2014/06/09/u-s-na ... lain-sight

About your mentioning of Russian EW radars in Syria, here were their bases are:
https://gdb.voanews.com/b1a2d9cb-93aa-4 ... 8_r0_s.png

Tartus is 150km and Hmeimim is even further from Damascus and NEBO is in Hmeimim base if I remember right.
Offline

wrightwing

Elite 4K

Elite 4K

  • Posts: 4049
  • Joined: 23 Oct 2008, 15:22

Unread post22 Sep 2022, 19:12

milosh wrote:



As you can see I already wrote what you wrote.

AARMG-ER need active seeker and it have one, so it got location of radar, then when it get in that location it use MMW radar to find SAR image of radar, problem is decoys, how will MMW seeker know which antenna is part of radar and which one is decoy?

VHF/UHF antennas like on JY-27 are something very easy to build as decoy. So you waste lot of AARMG-ER hitting decoys. This is why I tried to explain what happened in Syria doesn't mean much in case of war with China.

Also from our 1999 experience, those antennas like JY-27 have are lot easier to repair when hit then antennas of other radars.


Okay, I'll type slower since there still seems to be confusion. The aircraft's sensors would be used to detect/identify (i.e. what kind of threat?/decoy?) the threat emitter. That information would be fed into the AARGM-ERs GPS/INS systems, so the missile would know where the target was, regardless of emissions/frequencies. While in flight, the missile and aircraft would be talking to each other, for guidance updates/retargeting/etc.... As the missile gets close to the target, it uses MMW and multi-spectral seekers to get a positive ID on the target (and provide the launch aircraft with that information, and the BDA from the engagement.) NCTR works against ground targets as well as aerial targets. We're way beyond 1999 level target discrimination.
Offline

milosh

Elite 1K

Elite 1K

  • Posts: 1850
  • Joined: 27 Feb 2008, 23:40
  • Location: Serbia, Belgrade

Unread post23 Sep 2022, 08:06

wrightwing wrote:Okay, I'll type slower since there still seems to be confusion. The aircraft's sensors would be used to detect/identify (i.e. what kind of threat?/decoy?) the threat emitter. That information would be fed into the AARGM-ERs GPS/INS systems, so the missile would know where the target was, regardless of emissions/frequencies. While in flight, the missile and aircraft would be talking to each other, for guidance updates/retargeting/etc.... As the missile gets close to the target, it uses MMW and multi-spectral seekers to get a positive ID on the target (and provide the launch aircraft with that information, and the BDA from the engagement.) NCTR works against ground targets as well as aerial targets. We're way beyond 1999 level target discrimination.


I understand that that is what I wrote, missile will be able to came near location of radar that isn't problem, problem is if Chinese lower real antenna and left fake one missile will go for fake one because it is same as real one, btw it don't even need to be fake it just need to be non operational one, because those are antennas with lot of jagi antennas so cost of antenna isn't big at all.

When I mentioned 1999, it isn't you can fool antirad missile today as back them, but it is example this type of antennas is easy to repair.

This is why I mentioned one radar don't mean much like in Syria. USAF would deal with lot more radars which are lot better hidden (coastal China is hilly forest country).

Also we need to remember Chinese AF have more then 100 J-20 so planes which are carrying antirad missiles could be intercepted without big problems which could happen if you send non stealths.

And that is now, in future they will have even more J-20.

Btw Taiwan would also be smart to develop advanced network of VHF/UHF radars if they didn't already and they could use APY-9 as base for something like that.
Offline

hornetfinn

Elite 4K

Elite 4K

  • Posts: 4167
  • Joined: 13 Mar 2013, 08:31
  • Location: Finland

Unread post23 Sep 2022, 12:50

I think there is also big difference between HARM and AARGM-ER with MMW seeker as to what kind of damage they inflict on target. HARM would go for the antenna as that was the main targeting method and damage would be mostly the antenna. However AARGM-ER with MMW seeker would destroy the whole vehicle as it would likely target the vehicle/container itself and not just the antenna. However I bet the preferred method for dispatching low-frequency radars would be cruise missiles or bombs with significantly larger destructive power than HARM/AARGM. Those radars are less mobile and less numerous and less of a direct threat than high frequency radars, so such slow weapons could be used.
Offline

sprstdlyscottsmn

Elite 5K

Elite 5K

  • Posts: 5433
  • Joined: 10 Mar 2006, 01:24
  • Location: Nashua NH USA

Unread post23 Sep 2022, 12:56

you can't lower one of those antennas in the time it takes an AARGM-ER to get there. F-35 SAR mapping would be able to spot all the antennas, real or otherwise. Then the Barracuda would be able to tell which ones are radiating, i.e. which ones are real. So missile is given precise GPS/INS coordinates and two minutes later the warhead goes off. Funny thing about those antennas... they wont stop the frag from the warhead. much of it will go right through and destroy the actual radar box behind it, the onboard MMW radar will see to that. So being able to rebuild the antenna is useless and the decoys were just a waste of time. This is how the modern kill chain with F-35s in the loop works.
"Spurts"

-Pilot
-Aerospace Engineer
-Army Medic
-FMS Systems Engineer
-PFD Systems Engineer
-PATRIOT Systems Engineer
Offline

milosh

Elite 1K

Elite 1K

  • Posts: 1850
  • Joined: 27 Feb 2008, 23:40
  • Location: Serbia, Belgrade

Unread post23 Sep 2022, 13:23

sprstdlyscottsmn wrote:you can't lower one of those antennas in the time it takes an AARGM-ER to get there. F-35 SAR mapping would be able to spot all the antennas, real or otherwise. Then the Barracuda would be able to tell which ones are radiating, i.e. which ones are real. So missile is given precise GPS/INS coordinates and two minutes later the warhead goes off. Funny thing about those antennas... they wont stop the frag from the warhead. much of it will go right through and destroy the actual radar box behind it, the onboard MMW radar will see to that. So being able to rebuild the antenna is useless and the decoys were just a waste of time. This is how the modern kill chain with F-35s in the loop works.


Chinese don't have radar box behind or below antenna:
https://www.radartutorial.eu/19.kartei/ ... 027-03.jpg
https://tiananmenstremendousachievement ... -radar.jpg

It isn't like soviet/russian NEBO system which do have radar box behind:
http://www.ausairpower.net/PVO-SV/1L13- ... RLS-8S.jpg

and Russians also start making VHF/UHF mobile radars without radar box behind, like Vostok and some newer NEBO variants.

Also our folks used diy armor for S-125 system:
https://www.mycity-military.com/slika.p ... 20Neva.jpg

It saved lives when HARM would hit antenna. So something similar or purposely armored trailers can be done if you want to protect them, also Chinese do have lot of woods they can put generator trailer, command post in wood and only antenna plus decoy antenna have exposed. Something like this Iraq nor Syria could do. Not even we if you look photo I posted, most important part of Serbia is quite flat and with lack of forests.

Now about F-35 and 2minutes, that mean F-35 is something like 60km from radar? That is already quite inside Chinese air and sam space how realistic that would be? What J-20 pilots are doing? Sleeping? What SAM crews are doing?

I doubt Chinese are nonchalant as Arabs or Russians are, I expect they are on similar level as our guys or maybe better.
Offline

sprstdlyscottsmn

Elite 5K

Elite 5K

  • Posts: 5433
  • Joined: 10 Mar 2006, 01:24
  • Location: Nashua NH USA

Unread post23 Sep 2022, 16:04

milosh wrote:
Now about F-35 and 2minutes, that mean F-35 is something like 60km from radar? That is already quite inside Chinese air and sam space how realistic that would be? What J-20 pilots are doing? Sleeping? What SAM crews are doing?

I doubt Chinese are nonchalant as Arabs or Russians are, I expect they are on similar level as our guys or maybe better.

AARGM-ER is a very fast missile, but you are quite right that 2 min was an excessive exaggeration and I apologize as I prefer to deal with facts and not hyperbole.

With a max range of 300km, AARGM-ER time of flight would be closer to 7 minutes. It has internal carry so there could be no warning until it itself is detected. J-20s are busy trying to evade AIM-120D3s launched from F-22s or SM-3s from Aegis ships all being guided by the F-35 web of detection. Again, this isn't the 90s. The F-35 is a flying sensor node/network that has attack and EW systems built in. These things are all part of a battle plan.

And your pictures still clearly show boxes with vulnerable electronics under them.
"Spurts"

-Pilot
-Aerospace Engineer
-Army Medic
-FMS Systems Engineer
-PFD Systems Engineer
-PATRIOT Systems Engineer
Offline

jessmo112

Forum Veteran

Forum Veteran

  • Posts: 902
  • Joined: 16 Mar 2020, 02:09

Unread post23 Sep 2022, 17:28

Why even bother with Harms or anti-Rad missile. The F-35 can geo-locate the emmiter on its on.
In fact the F-35 can use its SAR map to find the TEL.
Why even bother with 2 clumsy anti-rad weapons when 2 SDB will do the trick.

https://youtu.be/wIwAOupjMeM
Offline

jessmo112

Forum Veteran

Forum Veteran

  • Posts: 902
  • Joined: 16 Mar 2020, 02:09

Unread post23 Sep 2022, 17:45

On another note does anyone know if the Chinese still use GCI? Do they allow officers flying advanced fighters to make tactical decisions on there own?
This would play a huge factor versus the F-35.
Offline

garrya

Forum Veteran

Forum Veteran

  • Posts: 995
  • Joined: 25 Dec 2015, 12:43

Unread post23 Sep 2022, 21:06

Finally finished the writing
F-35 RCS simulation
https://basicsaboutaerodynamicsandavion ... imulation/
Offline

nn8734

Newbie

Newbie

  • Posts: 13
  • Joined: 28 Nov 2017, 22:49

Unread post23 Sep 2022, 23:31

Air Force not losing sleep over the J20
https://www.thedrive.com/the-war-zone/a ... th-fighter
PreviousNext

Return to F-35 versus XYZ

Who is online

Users browsing this forum: No registered users and 3 guests