JF-17 Thunder Multirole Fighter [Thread 4]

[Pfpilot]

Be careful with this simplistic claim.

A radar cross section (RCS) depends on these main factors:

- Freq employed
- Power
- Distance
- Target features

Radar Cross Section (RCS)

The chart in that source is that rough approximation. It is based upon ONE fixed variable: The seeking radar.

What it means is that we used the same radar with all the same main factors above to measure some objects to give the readers some scale. Without using the EXACT radar, the next best thing is to use systems that have as close approximations regarding capabilities to each other as much as possible. Then we employ statistical chicaneries from those system differences to justify our presentations.

Can a B-52 have a 1m2 RCS? Absolutely, but at several hundreds kms out. This is where distance is our fix.

The problem lies with the receiver portion of the seeking radar, or the physically distinct receiver antenna, but we will call it 'the receiver' for simplicity.

If the receiver is not as capable as its competitors, instead of the B-52 being 1m2 at 500km, this inferior receiver may have that 1m2 at 490km or even 400km, and this will make the F-22 even closer than 30km. Someday in the future, there will be really good radar that will make the F-22's RCS as 1m2 at 500km.

What about aircraft with their full external load out? Would a jf-17, which has a relatively small RCS, be suddenly comparable with a much bigger fighter with a similar load out? You had mentioned previously how 4th gen aircraft have some inherent features that raise their RCS above a certain threshold; so I had made, the ambitious and most probably erroneous, assumption that something as complex as a cluster of missiles on a wing would trump any RCS reduction measures and make most fighters carrying external munitions relatively comparable. I do realize I am trying to simplify the complex field despite your warning, but excuse it to my limited understanding of the subject.

 

[Viper0011.]

What about aircraft with their full external load out? Would a jf-17, which has a relatively small RCS, be suddenly comparable with a much bigger fighter with a similar load out? You had mentioned previously how 4th gen aircraft have some inherent features that raise their RCS above a certain threshold; so I had made, the ambitious and most probably erroneous, assumption that something as complex as a cluster of missiles on a wing would trump any RCS reduction measures and make most fighters carrying external munitions relatively comparable. I do realize I am trying to simplify the complex field despite your warning, but excuse it to my limited understanding of the subject.

This is very hard to guess. Yes, you'll have bigger RCS if there are weapons on the wings. Remember, these weapons not only increase the RCS physically, they are also connected to the radar of the plane so upon getting 'armed', tracking the target, firing...all these functions will require radiation / radio frequency to be released and thus further increasing the RCS.
So your rcs definitely increases but what are you comparing it to? A bigger jet empty or fully loaded? A bigger jet with stealthy features in the design / rcs controls with a weapon load? All these play a role. But simple non stealthy jet to jet comparison, yes, there should be some increase in the smaller plane's rcs with full weapons load. Especially the guided weapons requiring guidance from the radar.

I've explained this above and Gambit just put it above this post that in newer jets like the F-22, its a lot more there than just being able to see it through a simple radar demo or picture. These planes carry signal denial electronics, along with energy reduction features, stealthy design, etc. So the picture above may prove to be accurate (or accurate in majority of the cases like Su-30, Mig 29, F16, etc) but it won't be the case for an F-22 (the 30km scenario). There's a lot more that happens in an F-22 to avoid radar detection than just RAM and smooth / angular surface.

 

[gambit]

What about aircraft with their full external load out? Would a jf-17, which has a relatively small RCS, be suddenly comparable with a much bigger fighter with a similar load out? You had mentioned previously how 4th gen aircraft have some inherent features that raise their RCS above a certain threshold; so I had made, the ambitious and most probably erroneous, assumption that something as complex as a cluster of missiles on a wing would trump any RCS reduction measures and make most fighters carrying external munitions relatively comparable. I do realize I am trying to simplify the complex field despite your warning, but excuse it to my limited understanding of the subject.

This is very hard to guess. Yes, you'll have bigger RCS if there are weapons on the wings.

Yes. Essentially, external loads as currently designed will overwhelm -- or negate -- any RCS control methods, worst of all from the lateral aspects. Both the F-22 and F-35 can carry external wing load into combat but only after the determination that the low radar observable requirement is either reduced or not required at all. We knew about this back in the F-117 days when pilots were briefed that opening weapons bay doors is the EM equivalent of a lighthouse beacon.

 

[raazh]

F22 is a true tech marvel, yet it does not mean the end of hope for the rest of the world. Doing the original R&D for such tech is good long hard work .. finding a way to hack it .. comparatively speaking .. should not be that difficult .. Especially with all the spies continuously prowling to find the technical details/designs for such big projects .. Following is one example of what the US is researching for Stealthy Aircraft detection !

Help coming for AWACS in a J-20 era?
By Stephen Trimble on October 24, 2011 2:09 PM

The Boeing E-3A airborne warning and control system (AWACS) is like the binoculars of a fighter formation. By emitting a 3GHz electromagnetic pulse, the E-3A's Northrop Grumman APY-2 radar can spot an inbound fighter at 30,000ft as far as 430nm away. But what if the fighter is stealthy, which means partly that its designed to scatter radar waves in any direction except back to the source? That is the whole idea behind electromagnetic stealth -- a capability almost monopolized by US forces until very recently. The appearance of the Sukhoi PAK-FA and the Chengdu J-20 within the past 20 months is a warning. To detect the most dangerous targets, E-3A soon may need help.

A new concept for addressing precisely this problem appeared late last week. In a 19 October solicitation notice, the US Air Force Research Laboratory asked radar companies if they could develop a new electromagnetic trick. Technically, it's called bistatic target detection. It basically means one aircraft -- in this case, the E-3A -- emits the radar pulse, and the returns are detected by radar receivers operating passively on one or more other aircraft. So the stealthy target scatters the radar waves in different directions, but it still can't hide.

The AFRL wants to demonstrate a bistatic radar system for AWACS using an unmanned air vehicle with a very unique radar antenna. The E-3A operates a giant 24ft by 5ft planar array antenna installed on top of the aircraft like a flying saucer. The AFRL, however, wants the UAV radar receivers to be integrated into the load-bearing structure of the aircraft. It's a concept that's been in development for many years, and it's called Sensorcraft (see picture of AFRL wind tunnel model above). The AFRL solicitation could be a prelude to full-scale development of such a new UAV. On the other hand, it's possible the conformal antenna could be integrated into an existing UAV, such as the Northrop Grumman X-47 or the General Atomics Aeronautical Systems Inc Avenger.

link Help coming for AWACS in a J-20 era? - The DEW Line

Im sure the Chinese, with 1000's of their engineers, are definitely looking for solutions to F22 stealth also.

 

[Viper0011.]

A new concept for addressing precisely this problem appeared late last week. In a 19 October solicitation notice, the US Air Force Research Laboratory asked radar companies if they could develop a new electromagnetic trick. Technically, it's called bistatic target detection. It basically means one aircraft -- in this case, the E-3A -- emits the radar pulse, and the returns are detected by radar receivers operating passively on one or more other aircraft. So the stealthy target scatters the radar waves in different directions, but it still can't hide.

The AFRL wants to demonstrate a bistatic radar system for AWACS using an unmanned air vehicle with a very unique radar antenna. The E-3A operates a giant 24ft by 5ft planar array antenna installed on top of the aircraft like a flying saucer. The AFRL, however, wants the UAV radar receivers to be integrated into the load-bearing structure of the aircraft. It's a concept that's been in development for many years, and it's called Sensorcraft (see picture of AFRL wind tunnel model above). The AFRL solicitation could be a prelude to full-scale development of such a new UAV. On the other hand, it's possible the conformal antenna could be integrated into an existing UAV, such as the Northrop Grumman X-47 or the General Atomics Aeronautical Systems Inc Avenger.

lIm sure the Chinese, with 1000's of their engineers, are definitely looking for solutions to F22 stealth also.

Old news. USAF and USN are already way beyond this. The F-22 and JSF can detect a missile launch out to about 800 miles and can track it. Also, they've been using Distributed Aperture System (I think DAS). This system provides 360 degree view of the world around the pilot and the situation. It can find anything around you, without limitations of the numbers of planes or UAV's or missiles. Also, it can look out to many hundred miles and scan, track and identify any airborne objects.
The AFRL is talking about a technology that existed 15 years ago through Russians and Czech. I think someone told me the name was Vera radar. It would have two transmit and receivers (two separate encoding and decoding system working together). One would transmit and the other would remain silent but analyze the output to find deflection of signals, or other patterns or disarraying the EM beam form the radar. Resulting in detecting a smallest rcs and track its motion and three d display. Sorry, pretty much all you said is old news.


ASAIK, the Chinese are working on the new tech but it'll be a while

 

[alimobin memon]

Jf17 Cannot Detect F22 because RCS of F22 is 0.0001 !!! that figure is wrong

 

[gambit]

I see a couple posts mentioning the bi-static configuration as the 'stealth' anti-dote.

True...Technically speaking, the bi-static radar is the greatest threat to 'stealth'...At the theoretical level at this time.

To understand what is this 'bi-static' thingie, one must understand how radar behaves upon contact in the first place.

When a signal impact a surface, the direction of reflection depends on the reflecting surface, as illustrated above. Basic geometry tells us the angle of deflection (reflection) equals the angle of incidence (impact). Nothing new here.

The concept applies at all levels of fineness, from the surface level...

...To the body level.

The vast majority of radars are mono-static, meaning a single antenna does both jobs of transmission and reception and when dealing with airborne targets, it is extremely rare than a mono-static radar will receive the full strength of a flat plate type reflection. The majority of the time, the majority of the reflected signal are of the angled type with only a very small percentage (specular) to return to source direction.

So what a bi-static system does is to station physically distinct receivers that are sufficiently far enough away from the transmitter (avoid interference) to catch that majority of reflected signal. The ideal configuration is the 90deg bi-static triangle but because the target is mobile, that ideal situation practically never exist.

Which lead us to the multi-static configuration with many receivers stationed at what is believed to be 'ideal' locations to catch passing target. Sooner or later, in a multi-static system, one of the many receivers will momentarily achieve this ideal geometry with the target. That mean the more receivers there are, the greater the odds of detecting and triangulating a 'stealth' target.

Which lead us to the often cited Kolchuga system and its supposedly 'cure' for the F-22.

First, there is no such beast as a 'passive radar'. Radar detection is a two-part process: Transmission and Reception. Without either, the concept of radar itself does not work.

What Kolchuga, Silent Sentry, and other similarly proposed systems are: passive opportunistic reflection detectors. They are either receivers only or a collection of receivers working under the guidance of a main transmitter. The word 'opportunistic' mean they rely on transmitters and transmissions that ARE NOT UNDER CONTROL, meaning transmitters that came from TV, cellular, music radio, and even other radars for reflections off any target.

The main problem with the typical bi-static set up is that each transmitter/receiver pairing must be fully conscious of what the other is doing. The receiver must know what the transmitter is doing in terms of freq, pulse characteristics, power, and direction. Timing and coordination is crucial. In a multi-static system, it is no different because there is still a bi-static triangle for each transmitter/receiver pairing. If there are 10 receivers, there are 10 bi-static triangles.

The problem is much greater in a passive opportunistic detector because it does not have knowledge of when the TV is going off the air or how many music radio stations are in the area or how many cellular towers are there in the defended area. The receiver does not control them, does not know how many signals are in collision, thereby contaminating each other, and so on...

From combat actions to equipment failures to human errors, these could deprive a good portion of the city of electricity, thereby denying this network of passive receivers their transmitters and create coverage gaps that the enemy could pass through.

If the multi-static system have its own transmitters and power supply, the data links and synchronization of data transfer are still technical challenges. If Receiver A and B picks up reflected signals, a central authority must be available and able to correlate and verify if these signals are from true targets or a part of the EM background.

In short, the bi-static radar sounds good on paper to defeat 'stealth' but for now it is highly problematic and tactically questionable because it is not as mobile as its mono-static cousin and have too many dependencies. Forget 'Kolchuga' and 'Silent Sentry'. They are nothing more than marketing labels no different than what automobile makers give to their creations. Too many people latches onto marketing labels and give themselves and each other false understanding. The real keyword searches are 'bi-static' and 'multi-static' or variants thereof.

 

[IceCold]

I see a couple posts mentioning the bi-static configuration as the 'stealth' anti-dote.

True...Technically speaking, the bi-static radar is the greatest threat to 'stealth'...At the theoretical level at this time.
In short, the bi-static radar sounds good on paper to defeat 'stealth' but for now it is highly problematic and tactically questionable because it is not as mobile as its mono-static cousin and have too many dependencies. Forget 'Kolchuga' and 'Silent Sentry'. They are nothing more than marketing labels no different than what automobile makers give to their creations. Too many people latches onto marketing labels and give themselves and each other false understanding. The real keyword searches are 'bi-static' and 'multi-static' or variants thereof.

But you did say its technically true meaning it is plausible? What you have mentioned above are the areas of problem one could face in achieving so.
I have a question here for large areas, the problem would increase manifolds in containing all the dependencies over a large area, but lets say what about small area and by small area i mean a small country for e.g Pakistan where there might not be too many entry routes?

 

[Thorough Pro]

Where is the third squadron?
How long does it take to train pilots from one plateform to the other?
Any hope we will see the induction announced on Aug 14?

 

[Donatello]

I see a couple posts mentioning the bi-static configuration as the 'stealth' anti-dote.

True...Technically speaking, the bi-static radar is the greatest threat to 'stealth'...At the theoretical level at this time.

To understand what is this 'bi-static' thingie, one must understand how radar behaves upon contact in the first place.

When a signal impact a surface, the direction of reflection depends on the reflecting surface, as illustrated above. Basic geometry tells us the angle of deflection (reflection) equals the angle of incidence (impact). Nothing new here.

The concept applies at all levels of fineness, from the surface level...

...To the body level.

The vast majority of radars are mono-static, meaning a single antenna does both jobs of transmission and reception and when dealing with airborne targets, it is extremely rare than a mono-static radar will receive the full strength of a flat plate type reflection. The majority of the time, the majority of the reflected signal are of the angled type with only a very small percentage (specular) to return to source direction.

So what a bi-static system does is to station physically distinct receivers that are sufficiently far enough away from the transmitter (avoid interference) to catch that majority of reflected signal. The ideal configuration is the 90deg bi-static triangle but because the target is mobile, that ideal situation practically never exist.

Which lead us to the multi-static configuration with many receivers stationed at what is believed to be 'ideal' locations to catch passing target. Sooner or later, in a multi-static system, one of the many receivers will momentarily achieve this ideal geometry with the target. That mean the more receivers there are, the greater the odds of detecting and triangulating a 'stealth' target.

Which lead us to the often cited Kolchuga system and its supposedly 'cure' for the F-22.

First, there is no such beast as a 'passive radar'. Radar detection is a two-part process: Transmission and Reception. Without either, the concept of radar itself does not work.

What Kolchuga, Silent Sentry, and other similarly proposed systems are: passive opportunistic reflection detectors. They are either receivers only or a collection of receivers working under the guidance of a main transmitter. The word 'opportunistic' mean they rely on transmitters and transmissions that ARE NOT UNDER CONTROL, meaning transmitters that came from TV, cellular, music radio, and even other radars for reflections off any target.

The main problem with the typical bi-static set up is that each transmitter/receiver pairing must be fully conscious of what the other is doing. The receiver must know what the transmitter is doing in terms of freq, pulse characteristics, power, and direction. Timing and coordination is crucial. In a multi-static system, it is no different because there is still a bi-static triangle for each transmitter/receiver pairing. If there are 10 receivers, there are 10 bi-static triangles.

The problem is much greater in a passive opportunistic detector because it does not have knowledge of when the TV is going off the air or how many music radio stations are in the area or how many cellular towers are there in the defended area. The receiver does not control them, does not know how many signals are in collision, thereby contaminating each other, and so on...

From combat actions to equipment failures to human errors, these could deprive a good portion of the city of electricity, thereby denying this network of passive receivers their transmitters and create coverage gaps that the enemy could pass through.

If the multi-static system have its own transmitters and power supply, the data links and synchronization of data transfer are still technical challenges. If Receiver A and B picks up reflected signals, a central authority must be available and able to correlate and verify if these signals are from true targets or a part of the EM background.

In short, the bi-static radar sounds good on paper to defeat 'stealth' but for now it is highly problematic and tactically questionable because it is not as mobile as its mono-static cousin and have too many dependencies. Forget 'Kolchuga' and 'Silent Sentry'. They are nothing more than marketing labels no different than what automobile makers give to their creations. Too many people latches onto marketing labels and give themselves and each other false understanding. The real keyword searches are 'bi-static' and 'multi-static' or variants thereof.

So is the infamous Czech 'Vera' system similar to what you described?

 

[DARKY]

I am aware of BARS. Not trying to deviate the topic but BARS is F-14's radar with PESA technology. Frankly speaking, it's just not the radar here. The Eagle and EF2K carry PLENTY of other electronics that play a role in detection. These are 'sensitive' electronics and in some cases, they are not sold to ANYONE outside of the US. I can agree with your statement as Red Flag was a pre-set format where certain features of the American aircraft are not utilized to put them under adverse conditions. That's how USAF or USN trains!

Let's PLEASE get back to JFT here. The thread's going off topic now. Please open up a different thread and I won't mind discussing more about this with you.

One one hand you say BARS is F-14's radar and conclude that its PESA technology.... I don't know how much are into this but don't repeat that thing again.

BARS is Electronically steered and is much more advanced and better than any fighter borne Mechanically steered radar... you cannot change the physics here.

Plenty of OTHER electronics are also carried on Su30MKI... and thats the particular reason it avoids detection inspite of its huge powerful radar and large size.... If it were only for radar It would make a red hot target even for Mig21.

Off course they train accordingly and so does other airforces.... USAF in US sees that it happens their way same with all the other airforces in their respective countries.

 

[gambit]

So is the infamous Czech 'Vera' system similar to what you described?

So is the American 'Silent Sentry' system.

 

[gambit]

But you did say its technically true meaning it is plausible?

The ground version is not only plausible but is deployable. It is the airborne version of that is still being problematic, for others, of course.

What you have mentioned above are the areas of problem one could face in achieving so.
I have a question here for large areas, the problem would increase manifolds in containing all the dependencies over a large area, but lets say what about small area and by small area i mean a small country for e.g Pakistan where there might not be too many entry routes?

The current working versions are more for city-size monitor and defense, not even for as 'small' a country like Pakistan. You should understand that radar is line-of-sight so for now, topo must be taken into consideration because natural blockages such as hills, sharp and gradual, and mountains will create coverage gaps in these multi-static set ups. Distances matter because the data synchronization must be in the milliseconds capability between stations in order to have effective triangulations between receivers and transmitters. Just hit up your local EE for degradation over distances problems. Oxygen free copper? Fiber optics? Lasers? Take your pick.

 

[Viper0011.]

One one hand you say BARS is F-14's radar and conclude that its PESA technology.... I don't know how much are into this but don't repeat that thing again.

Well......you want me to lie to you or to others? It is what it is. I'd love to you give you proof but at the same time, can't do it.

BARS is Electronically steered and is much more advanced and better than any fighter borne Mechanically steered radar... you cannot change the physics here.

There's no Physics in comparing radars. It's features and technology. If you think so, you should move on with your life instead or arguing like a silly child. SU-30 isn't the world's best fighter. It's a large plane based on old-revived and some new Israeli tech. That's the truth. You don't need to further argue as it won't change the reality. Let's agree to disagree and life moves on.

Plenty of OTHER electronics are also carried on Su30MKI... and thats the particular reason it avoids detection inspite of its huge powerful radar and large size.... If it were only for radar It would make a red hot target even for Mig21.

And what makes you think SU-30 isn't detectable? The thing shines like a light house on a radar screen man. You're talking and arguing to the wrong people here. I won't expect F-14 to be Stealty or hard to detect. It's a massive plane. It's BOUND to be detected. Similarly, versions of F-15 and F-18 that haven't been upgraded recently with certain things, are also light houses for radar waves.

For real my man? You comparing USAF training to 'other' airforces? There is no 'other' airforce with training and combat experience even remotely compared to the United States Airforce or the US Navy. This is a fact, not a myth or fake ego.

 

[MastanKhan]

F22 is a true tech marvel, yet it does not mean the end of hope for the rest of the world. Doing the original R&D for such tech is good long hard work .. finding a way to hack it .. comparatively speaking .. should not be that difficult .. Especially with all the spies continuously prowling to find the technical details/designs for such big projects .. Following is one example of what the US is researching for Stealthy Aircraft detection !

Help coming for AWACS in a J-20 era?

Hi,
By Stephen Trimble on October 24, 2011 2:09 PM

The Boeing E-3A airborne warning and control system (AWACS) is like the binoculars of a fighter formation. By emitting a 3GHz electromagnetic pulse, the E-3A's Northrop Grumman APY-2 radar can spot an inbound fighter at 30,000ft as far as 430nm away. But what if the fighter is stealthy, which means partly that its designed to scatter radar waves in any direction except back to the source? That is the whole idea behind electromagnetic stealth -- a capability almost monopolized by US forces until very recently. The appearance of the Sukhoi PAK-FA and the Chengdu J-20 within the past 20 months is a warning. To detect the most dangerous targets, E-3A soon may need help.

A new concept for addressing precisely this problem appeared late last week. In a 19 October solicitation notice, the US Air Force Research Laboratory asked radar companies if they could develop a new electromagnetic trick. Technically, it's called bistatic target detection. It basically means one aircraft -- in this case, the E-3A -- emits the radar pulse, and the returns are detected by radar receivers operating passively on one or more other aircraft. So the stealthy target scatters the radar waves in different directions, but it still can't hide.

The AFRL wants to demonstrate a bistatic radar system for AWACS using an unmanned air vehicle with a very unique radar antenna. The E-3A operates a giant 24ft by 5ft planar array antenna installed on top of the aircraft like a flying saucer. The AFRL, however, wants the UAV radar receivers to be integrated into the load-bearing structure of the aircraft. It's a concept that's been in development for many years, and it's called Sensorcraft (see picture of AFRL wind tunnel model above). The AFRL solicitation could be a prelude to full-scale development of such a new UAV. On the other hand, it's possible the conformal antenna could be integrated into an existing UAV, such as the Northrop Grumman X-47 or the General Atomics Aeronautical Systems Inc Avenger.

link Help coming for AWACS in a J-20 era? - The DEW Line

Im sure the Chinese, with 1000's of their engineers, are definitely looking for solutions to F22 stealth also.

Hi,

Is it like the hole in the ocean for submarines----which means the ocean has certain sounds in it----so if you detect no sounds in a certain area of the ocean---or if the sounds are abnormal---it would mean that there is a submarine over there---or something of concern!