F-22/F-23 Radar Cross Sections Update

[TempestII]

DB Selector

DB3K

Affected DBID(s)

691, 2201, 4972, 5952, 4858, 3821, 4875, 3319, 4107, 5852

Summary of Changes

The F-22A Raptor has a frontal Radar Cross Section (RCS) in CMO DB503 of 0.010m2 which appears to be on the higher side. Several sources estimate the F-22 RCS is the following: Radar Cross Sections cited (X-band): F-22A Front Aspect = 0.0001 m2, Side and Rear Aspect = 0.01 – 0.001 m2.

The F-23A Black Widow is/was believed to have a lower RCS than the F-22, albeit, being slightly less agile reportedly. Therefore, at the very least, it should match the above RCS.

Sources

https://militaryembedded.com/radar-ew/signal-processing/radar-cross-section-the-measure-of-stealth

https://www.ausairpower.net/APA-NOTAM-300309-1.html

https://en.wikipedia.org/wiki/Lockheed_Martin_F-22_Raptor

https://nationalinterest.org/blog/buzz/f-22-raptor-badass-fighter-was-yf-23-better-208154

https://warriormaven.com/air/why-did-the-stealthy-yf-23-fighter-jet-lose-to-f-22#:~:text=Although%20potentially%20stealthier%20than%20the,now%20sit%20in%20a%20museum.

https://theaviationgeekclub.com/yf-23a-thermal-designer-explains-why-northrop-lost-atf-competition-even-though-the-black-widow-ii-was-stealthier-than-the-yf-22a/

[LuigiP57]

Propaganda or science? Until we figure that out, it's probably useless to talk about fighter RCS data

https://militaryembedded.com/radar-ew/signal-processing/radar-cross-section-the-measure-of-stealth

To the institutional/personal blogger who created this post, I would like to know: how did he manage to make such a complex physics problem so simple? What sources did he cite when he determined the RCS level of J-20 and Su-57? What sources did he cite when he determined the RCS levels of the F-22, F-35, and B-21? When I read the whole article, I didn't get any useful information other than a litany of bragging about American technology and belittling Chinese and Russian technology.

https://www.ausairpower.net/APA-NOTAM-300309-1.html

The research done by Ausairpower is very rigorous (far from the first source you cite), its research is logical, and it provides a comprehensive introduction to the various details related to stealth technology. However, in the article you are quoting, the stealth data for the F-22, F-35 and Su-57 is only a cursory RCS estimate that is often seen on the Internet. The problem lies in this value.

Ausairpower also ran RCS simulations on the J-20 and Su-57, and their modeling data included simulations of the radar reflection performance of the aircraft in all directions, using tried-and-true modeling techniques.In the comprehensive modeling simulation, we find that J-20 and Su-57 have the same VLO characteristics in the simulation of different bands. For example, in the simulation of J-20 in the band of 8GHz and above without RAM/RAS, a large area less than -15.5dbsm appears in the front hemisphere of the J-20 model. As the band increases (starting from about 12GHz), the J-20 model will become more and more stable. There are even quite a few -40dbsm areas (equivalent to RCS 0.0001㎡). https://www.ausairpower.net/APA-2011-03.html

If we take this value, then we can also say that the J-20's stealth capability is comparable to or even exceeds that of the F-22. But for supporters of the F-22 and F-35, that sounds like something weird, doesn't it? But anyway, for both the J-20 and Su-57 (they even admit at the beginning of the article that modeling the J-20 can only present the least ideal situation due to various limitations), their conclusion is: “no fundamental obstacles exist in the shaping design of the J-20/T-50 prototype, which would preclude its development into a genuine Very Low Observable design.”

The radar reflection signal is not a balanced value in the distribution of the aircraft body. Whether it is F-22, F-35, B-21 or J-20, Su-57, when the radar is illuminated from other angles (such as the side of the body, up and down or even greater than 20-30° horizontal or vertical), its RCS value will inevitably rise sharply. There is also another modeling here (though less elaborate than ausairpower). https://basicsaboutaerodynamicsandavionics.wordpress.com/2023/01/15/f-35-vs-j-20-vs-su-57-radar-scattering-simulation-summary/

All in all, I don't think the CMO has enough detail in this aspect of radar modeling. It generally unified the forward, side, and rear hemispheres of an aircraft into one value, resulting in "optimal value" RCS data similar to the F-22 and F-35 instead of "average" filling in, thus having far more powerful stealth performance than the real world. For the J-20 or Su-57, the database takes the "average", which in my opinion is the more scientific simulation method.

I also want to say a few words here about the principles of anti-stealth radar. The technology employed by this type of radar includes the use of resonance reflection principles, and even aircraft using stealth materials (including B-2 or B-21 optimized for UHF/VHF bands) will inevitably produce resonance effects and be detected from a long distance.

4090

[LuigiP57]

About the “stealth performance damaging” canard https://www.youtube.com/watch?v=lDgVpLbtQI0 https://twitter.com/Flankerchan/status/1683021282986856450

[ghost]

Propaganda or science? Until we figure that out, it's probably useless to talk about fighter RCS data

https://militaryembedded.com/radar-ew/signal-processing/radar-cross-section-the-measure-of-stealth

To the institutional/personal blogger who created this post, I would like to know: how did he manage to make such a complex physics problem so simple? What sources did he cite when he determined the RCS level of J-20 and Su-57? What sources did he cite when he determined the RCS levels of the F-22, F-35, and B-21? When I read the whole article, I didn't get any useful information other than a litany of bragging about American technology and belittling Chinese and Russian technology.

https://www.ausairpower.net/APA-NOTAM-300309-1.html

The research done by Ausairpower is very rigorous (far from the first source you cite), its research is logical, and it provides a comprehensive introduction to the various details related to stealth technology. However, in the article you are quoting, the stealth data for the F-22, F-35 and Su-57 is only a cursory RCS estimate that is often seen on the Internet. The problem lies in this value.

Ausairpower also ran RCS simulations on the J-20 and Su-57, and their modeling data included simulations of the radar reflection performance of the aircraft in all directions, using tried-and-true modeling techniques.In the comprehensive modeling simulation, we find that J-20 and Su-57 have the same VLO characteristics in the simulation of different bands. For example, in the simulation of J-20 in the band of 8GHz and above without RAM/RAS, a large area less than -15.5dbsm appears in the front hemisphere of the J-20 model. As the band increases (starting from about 12GHz), the J-20 model will become more and more stable. There are even quite a few -40dbsm areas (equivalent to RCS 0.0001㎡). https://www.ausairpower.net/APA-2011-03.html

If we take this value, then we can also say that the J-20's stealth capability is comparable to or even exceeds that of the F-22. But for supporters of the F-22 and F-35, that sounds like something weird, doesn't it? But anyway, for both the J-20 and Su-57 (they even admit at the beginning of the article that modeling the J-20 can only present the least ideal situation due to various limitations), their conclusion is: “no fundamental obstacles exist in the shaping design of the J-20/T-50 prototype, which would preclude its development into a genuine Very Low Observable design.”

The radar reflection signal is not a balanced value in the distribution of the aircraft body. Whether it is F-22, F-35, B-21 or J-20, Su-57, when the radar is illuminated from other angles (such as the side of the body, up and down or even greater than 20-30° horizontal or vertical), its RCS value will inevitably rise sharply. There is also another modeling here (though less elaborate than ausairpower). https://basicsaboutaerodynamicsandavionics.wordpress.com/2023/01/15/f-35-vs-j-20-vs-su-57-radar-scattering-simulation-summary/

All in all, I don't think the CMO has enough detail in this aspect of radar modeling. It generally unified the forward, side, and rear hemispheres of an aircraft into one value, resulting in "optimal value" RCS data similar to the F-22 and F-35 instead of "average" filling in, thus having far more powerful stealth performance than the real world. For the J-20 or Su-57, the database takes the "average", which in my opinion is the more scientific simulation method.

I also want to say a few words here about the principles of anti-stealth radar. The technology employed by this type of radar includes the use of resonance reflection principles, and even aircraft using stealth materials (including B-2 or B-21 optimized for UHF/VHF bands) will inevitably produce resonance effects and be detected from a long distance.

#4090

The database should also reflect the RCS of the f22/35 similarly to how it does with the su57 and j20. A one size fits all figure for A-D and E-M bands is too simplified, not as scientific like you said. AusAirPower and Flankerchan are two of the best sources available. I've seen many RCS simulations and some hit -40 dBsm, but most do not (most fluctuate between 0.015-0.005m^2, yet 0.0001m^2 is automatically the accepted figure for the whole frequency range of E-M bands. Too simplistic and not as detailed. Especially how the side RCS is just a small amount larger, when the simulations show a 5-10% rcs gain, and similar with rear but even more (15-25% rcs gain)

[LuigiP57]

Especially how the side RCS is just a small amount larger, when the simulations show a 5-10% rcs gain, and similar with rear but even more (15-25% rcs gain)

I would like to add:

First of all, the RAM/RAS effect of reducing the radar echo signal is not for all bands. Secondly, RAM/RAS does not radically improve the stealth performance of an aircraft (no more than 10dbsm, according to one of the Wikipedia quotes), otherwise there is no need for a stealthy aircraft at all. https://en.wikipedia.org/wiki/Radiation-absorbent_material

In fact, in addition to stealth flying wing fighters such as B-2, all conventional layout of stealth tactical aircraft can only ensure that the front has excellent stealth performance. Because the side of the aircraft has too many non-parallel planes, angles and tips, the side radar wave reflection is too severe, even with RAM/RAS can not avoid. https://www.researchgate.net/figure/RCS-polar-plot-for-the-F-35-model-seen-from-10-below-at-a-carrier-frequency-of-10-GHz_fig3_317642781

But even an aircraft of the B-2's shape, in the case of early reliable research and modeling, still has a large radar echo at a certain angle.

Once I was officially rejected as unreliable folk simulation data, but if we think logically: propaganda is subjective, it serves a certain purpose, may exaggerate some facts. Science is objective, and the scientific simulation carried out according to certain laws can reflect the roughly correct appearance of a thing. The principle of invisibility is not a well-kept secret, and when almost all reliable unofficial simulation data points to an outcome, the outcome itself is more credible than the claims.

A belief in authority is not a value that a democratic and free world should aspire to.

[LuigiP57]

Another point is that the CMO database arbitrarily divides the frequency band, resulting in the anti-stealth effect of HF/VHF band can not be reflected, so that F-22/F-35 can hardly be effectively dealt with in the game. This simulation shows the performance of the stealth fighter at VHF (150MHz) band (including simulation with RAM). https://basicsaboutaerodynamicsandavionics.wordpress.com/2022/09/23/f-35a-radar-scattering-simulation/

[LuigiP57]

I sincerely hope that the DB manager will think about the above issues carefully, and if necessary, discuss it with the development team or consult a trusted professional.

[ghost]

I sincerely hope that the DB manager will think about the above issues carefully, and if necessary, discuss it with the development team or consult a trusted professional.

This is extremely important, very well put in your comments above. Always people claiming "sources say" but they take it out of context completely when it comes to the "golf ball" or "steel marble" rcs estimate, that is from one or multiple angles only and yet they take that estimate and apply it to an a viewing area of 120 degrees or even 360 degrees and for all radar bands, which makes zero sense whatsoever, especially to those who have a basic background or understanding in this area - which some do and have ran various RCS simulations factoring in RAM/no-RAM against different frequencies (VHF,meter,decimeter,centimeter) and their results are much more in-depth and realistic than what misled users on Quora and Youtube or AviationGeek have to say.

Stealth and RAM technologies cannot evade Raleigh scattering just like radars cannot evade the 4th inverse root law of range. Based on many simulations of RCS, stealth planes would need so much RAM to have an all around RCS of -40 dBsm against E-M band (3-12GHz) that they wouldn't even be able to fly in the first place... it would weigh down the craft tremendously. Of course newer technologies will continue to absorb high frequency radars, but VHF/UHF will still be the Ace card against stealth

As AESA technology evolves and quantum computing progresses, it would not surprise me to see a small enough uhf or l-band fire control radar one day able to be fitted onto a fighter plane. Maybe 20-50 years from now? Who knows. Before then, it's much more likely UHF/L-band fire control radars for ground based air defense systems will be accurate enough to provide SARH guidance (allowed by future evolutions in quantum computing) , even then of course the missiles of such an air defense system would most likely have terminal radar/infrared guidance.

I do appreciate an objective, scientific view on this issue especially concerning RAM and RCS estimates for this game. I've seen some of these RCS simulations graphs/pictures before and was always intrigued. Thank you! Hopefully the devs can pay more attention to this area.

[ghost]

Another point is that the CMO database arbitrarily divides the frequency band, resulting in the anti-stealth effect of HF/VHF band can not be reflected, so that F-22/F-35 can hardly be effectively dealt with in the game. This simulation shows the performance of the stealth fighter at VHF (150MHz) band (including simulation with RAM). https://basicsaboutaerodynamicsandavionics.wordpress.com/2022/09/23/f-35a-radar-scattering-simulation/

I'll be opening a ticket, requesting an overhaul and modification to the database's current RCS implementation model which segments into HF/VHF, UHF/L-band, S/C band, X/Ku/Ka band (4 RCS segments instead of the current 2), I'd prefer to segment it more in depth such as having 9 segments for each band (HF.VHF,UHF,L-band,S,C,X,Ku,Ka) but I'm not sure if Devs/Admins would implement that, so hoping they'd at least consider segmenting it into 4 parts at least.

I'm also going to show them some of the RCS modeling pictures you've shared. Hopefully they can tweak their RCS model and values systems. Thanks for sharing this information!

[caelunshun]

There are several A-band radars in the current DB that are able to detect even the B-21 at ranges of >100nm. It seems like whatever equation is used internally for radar detection does account for frequency to some degree, in addition to the subdivision of RCS values across bands.

As AESA technology evolves and quantum computing progresses, it would not surprise me to see a small enough uhf or l-band fire control radar one day able to be fitted onto a fighter plane. Maybe 20-50 years from now? Who knows. Before then, it's much more likely UHF/L-band fire control radars for ground based air defense systems will be accurate enough to provide SARH guidance (allowed by future evolutions in quantum computing) , even then of course the missiles of such an air defense system would most likely have terminal radar/infrared guidance.

What developments exactly are you referring to with "quantum computing"? Unless there is some specific quantum algorithm relevant to radar signal processing that I'm not aware of, I don't see the connection. Quantum computers don't magically make everything possible.

In this case, since the size of an antenna needs to be proportional to the wavelength of the emitted signal (with antenna arrays spaced typically by 1/2 the wavelength), a scanned array antenna that emits on the UHF band would need to be huge. You can't fit that on a fighter no matter what processing technology you have.

Also, FCR based on low-frequency radar seems dubious as the resolution of the radar return is just too low. I don't see how adding more processing power alleviates that.

[ghost]

There are several A-band radars in the current DB that are able to detect even the B-21 at ranges of >100nm. It seems like whatever equation is used internally for radar detection does account for frequency to some degree, in addition to the subdivision of RCS values across bands.

As AESA technology evolves and quantum computing progresses, it would not surprise me to see a small enough uhf or l-band fire control radar one day able to be fitted onto a fighter plane. Maybe 20-50 years from now? Who knows. Before then, it's much more likely UHF/L-band fire control radars for ground based air defense systems will be accurate enough to provide SARH guidance (allowed by future evolutions in quantum computing) , even then of course the missiles of such an air defense system would most likely have terminal radar/infrared guidance.

What developments exactly are you referring to with "quantum computing"? Unless there is some specific quantum algorithm relevant to radar signal processing that I'm not aware of, I don't see the connection. Quantum computers don't magically make everything possible.

In this case, since the size of an antenna needs to be proportional to the wavelength of the emitted signal (with antenna arrays spaced typically by 1/2 the wavelength), a scanned array antenna that emits on the UHF band would need to be huge. You can't fit that on a fighter no matter what processing technology you have.

Also, FCR based on low-frequency radar seems dubious as the resolution of the radar return is just too low. I don't see how adding more processing power alleviates that.

Quantum computing would allow even the faintest echoes that would otherwise be undetected by a traditional radar, be received and processed. Even high band radars still reflect off stealth surfaces, the echoes just aren't able to be processed since they are way too faint, so not until the object is much closer, which is part of the basis for how stealth reduces detection range. Quantum radar algorithms would form a radar picture from these faint echoes at much larger distances, especially more so if the antenna is C or S band, instead of a traditional X-band FCR.

UHF or L-band would indeed need to be large in antenna size, but a C or S band airborne FCR antenna is very feasible with future improvements in semi-conductor technology. S band for example with very advanced AESA tech and especially quantum computing processes would have very good resolution. Keep in mind the resolution of UHF might not be adequate for SARH in FCR, but accurate enough to provide mid-course/trajectory update (similar to how A50 reportedly has remote datalink with S-400 for the ARH 40N6 missile which it can guide through the main FCR datalinks). This is most likely pertains more to ground based radars. Still, as you also said, it's not likely a SARH would be feasible with an UHF or L-band design given the poorer resolution as compared to an X-band.