F-35 Multirole Joint Strike Fighter

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SpudmanWP

The Bunker Group
As far as I can tell, the article I posted is not based on the earlier APA work.
My point in showing you the comparison to his earlier work is so that you can see what a lousy job Kopp does at research.

Ozzy Blizzard has some interesting counterpoints, however he too misrepresents some points.

The AIM-120D won't reach Navy IOC until at least 2010, and perhaps later if news of another slippage is true. JRDRAM's IOC is who know's when, if ever.
If the AIM-120D goes IOC in 2010 and the F-35 goes IOC in 2013, then there will be plenty of 120Ds for it when it is in squadron level service.

As for the JDRADM, it is planned for 2018-2020 IOC.

The F-35 can carry up to 10 AMRAAMs only if it forgoes its clean, stealthy configuration and uses external stores. It's debatable whether operationally this would be done.

There may someday be an internal dual-AMRAAM rack for the F-35 but there isn't one today, and there may never be one.
The F-35 will go IOC with the ability to carry 4 AIM-120Ds internally and 10 externally (if it wanted to). Dual AIM-120s on the inner 2 pylons and a single on the outer pylon.

The dual-AMRAAM internal rail is scheduled for Block 5 upgrades at approx 2017 time-frame. If another govt wants to pony up the $$$ to do it sooner, that is fine too.

When the JDRADM comes around, there is nothing to keep them from loading 12 internally.

On the whole though, I look forward to Ozzy's rebuttal to Kopp's latest work, if he chooses to make one.
How many times does a person have to be completely debunked before you dismiss him out-of-hand? Kopp hit my limit a long time ago.

But if you must, here goes the short version.

Cal Poly, San Luis Obispo Design Team, did a complete design study of a vlo 'next gen F-111' type aircraft. Warning, the PDF is 117 pages long. It was done in 2002 and included EXTENSIVE shaping RCS studies. So much for Kopp being the first.

I added an attachment (page 19 of the pdf) below that clearly shows the RCS across the entire arc of the airframe based on shaping alone, no RAM materials.

Just a note on radar bands, they covered all the bands from L to X (1-12 ghz).

You will notice that there is not a great difference in band db levels (from one band to another) as you go around the aircraft. Granted, the sides have a greater return than the front or rear, but there is little difference from the L, S, and X band returns.

What's my point??

1. Kopp's assertions that the F-35 does not follow good shaping techniques is bull. All VLO fighter aircraft, be it the F-22, F-35, etc, will follow the same pattern of max VLO to the front, medium VLO to the rear, and LO to the sides.

2. Since all the true RCS numbers for actual VLO aircraft are not public, Mr Kopp is being very bias and disingenuous is his broad assertions as to the F-35's abilities.

3. If he did actual RCS studies, where are the Ray diagrams as below? All he has are simple piechart-type of graphics.

4. He totally underplays the F-35's EW systems and RAM coatings in the detection paradigm.

5. This was a design study done in a few months by some students. I am sure that LM has done a much better job at not only shaping, but also integration of the EW and RAM coatings.
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Grand Danois

Entertainer
Can anyone spot what material the APA piece assumes the F-35 is made of in their specular analysis?

Do they assume it is metallic or just basic composite?
 

Abraham Gubler

Defense Professional
Verified Defense Pro
I’d be interested to see how Carlo made these calculations. I’ve heard unsubstantiated and admittedly derogatory motivated rumours that he has an old mainframe computer at home for number crunching. But what software is he running? The CalPoly students used Surface Optics Corporation Radbase 2 which is an American export controlled product so anyone can’t just buy it...
 

Firn

Active Member
A good discussion so far, I just wanted to add some cents

3. If the GBAD detects the SAR scan all it has s a threat bearing, it wont be able to geo locate the source without multiple bearings. Thus this information is useless to anyone without range information, including the battery being interrogated.
A couple of networked sensors within the narrow beam of the SAR capable to detect its short scan could geolocate it and its vector and speed and thus launch a datalinked fire-and-forget missile to the calculated inteception basket. However the value of this information would deteriorate very very rapidly and the various MAWS should enable the pilot to evade.

On the other hand an single aircraft with a capable radar can geolocate the static emitting source thanks to its travel through space and time very precisely and act accordingly. Even if the mobile radar detects a launched missile it most likely won't be able to scoot in time.
 

Grand Danois

Entertainer
I’d be interested to see how Carlo made these calculations. I’ve heard unsubstantiated and admittedly derogatory motivated rumours that he has an old mainframe computer at home for number crunching. But what software is he running? The CalPoly students used Surface Optics Corporation Radbase 2 which is an American export controlled product so anyone can’t just buy it...
There are absolutely nothing on the methodology on the ray-tracing analysis of the specular returns.

Any submission to a peer-reviewed journal would have to include what software was used and basic assumptions on object properties (like metallic vs composites, and no, I'm not even talking about RAM). Just for basic reproducibility of results; i.e. the CalPoly asssumed their jet was metallic.

Instead we get a humongous rehash of Russian technology with the addition of a teeny-weeny analysis based on the bulgy shaping of the F-35 underbelly and the only supporting material is some work on the propagation of radio waves in the atmosphere...

It's meant for impressing the layman, shaping opinion, particularly with the flashy-easy-to-understand-graphics.
 
A

Aussie Digger

Guest
Can anyone spot what material the APA piece assumes the F-35 is made of in their specular analysis?

Do they assume it is metallic or just basic composite?
[FONT=Times New Roman, serif][FONT=Verdana, sans-serif]Though I'm tempted to say "sh*t" - "absorbent or lossy coatings or laminates[/FONT][/FONT]" is the best you'll get I'm afraid...

Of course this:

"No classified materials needed to be used, nor were classified materials used in the preparation of this analysis."

shows the arrogance and ignorance of the man.
 

alexsa

Super Moderator
Staff member
Verified Defense Pro
There is one issue that always gets me with Kopp that does not get picked up. He runs down the F-35 with some speculative analysis yet proposes we us an updated F-111 for strike missions (even if his super Pig ever got built) would ahve an RCS the size of a bus. Lest hope the EW Raptors (bugger they don't exist) can deal with the IADS before hand.
 

Feanor

Super Moderator
Staff member
If by search radars you mean fixed site radars (like airports etc) then they will be targeted by the first wave B-2s and cruise missiles. Any portable SAM & AAA that lights up a search radar in the presence of our assets will be dealt with in either an passive, active, or lethal manner.
By search radars, I mean AEW&C assets, as well as larger mobile radars. I understand that the first wave of B-2s and cruise missiles will attempt to disable all fixed site radars, but they may or may not be succesful as those radars do enjoy SAM coverage, and our discussion of penetration problems applies to the B-2 also, with the exception that if an intercept is achieved by defending fighters, it can't fight back. Again I get the feeling that we're rehashing a situation where the IADS is that of Iraq, or weaker.

There will certainly be an attempt to deal with the SAM and AAA radars, but whether it will be successful or not is debatable. Especially if those radars are protected by other units, and especially if you go from flying over territory that has a single fixed hot radar that survived the initial strike because of heavy AD assets, to having the ground under you, in front, and behind, light up like a christmas tree, then dealing with abovementioned IADS in any manner becomes rather difficult.

JSTARS, U2s, small low-altitude UAVs, or larger high-altitude UAVs will be able to find them easier the more they move around using SAR and FLIR .
By using a combination of GPS and Millimetric Wave Radar. An inflatable decoy will not fool a MMW radar seeker.
The UAVs themselves are targets, as are the U2s.

Currently, HARMs are too big to be it be carried in the F-35. They have to be carried externally thereby increasing the RCS of the F-35. The JDRADM will combine the capability of the AMRAAM with the HARM. It will be a 7-8 inch, 12 foot long missile with folding fins. The F-35 will be able to carry 4-5 internally PER-BAY and use them against both enemy fighters and SAM & AAA sites. They will have many more missiles available for SEAD & DEAD than a comparable package of HARMs today. Also, the JDRADM will have an IIR seeker in addition to the Active and MMW radar seeker that the HARM has now making it even MORE difficult to escape or fool.
Bottom line: the F-35 will have access to better strike weaponry. Ok got it.

Not in the least. Because of the small RSC of the F-35, the targeting radar will have to stay up longer to provide data for the missile because the radar in the SAM head will not be powerful enough to detect the F-35 until it gets VERY close. This lengthened targeting time gives the F-35 even more time than legacy aircraft for a response, either passive jamming, active jamming, or launching a HARM / JDRADM / SDB at the targeting radar. Remember that HARMs are VERY fast and arrive within 10-20 seconds of launch.
This is provided that the hostile SAM isn't protected by point AD assets, radar-guided short range AAA, ManPADS, etc. that could potentially engage the HARM itself.

Where are these assets coming from? How long do they hang around? Are they always active? Where is the F-22 CAP? These and other questions will play a big role in determining whether the enemy air assets are even an issue.
We're discussing a penetration strike that attempts to capitalize on the VLO aspect of the F-35 to deliver a strike package deep into hostile territory of a largely unsuppressed IADS.

I would only engage those assets if they tried to engage me first. I would not need to go closer towards their GBAD assets.

Just because they know where I was, does not mean they know where I am going. That is all part of good route planning. Even saying than and given that JDAM and SDBs can be launched from miles away from the target, the F-35 may not even have to get with 10-15 miles of the target.
To be able to make these kinds of judgements we need a specific scenario.

Let’s not forget that the F-35 can internally carry stealthy JSOWs also.
Again please elaborate. My knowledge of American weaponry is very limited.
 

Ozzy Blizzard

New Member
It seems to me that most of the scenarios being discussed here are against an inferior opponent. I understand the contextual relevance, but it's hardly worthwhile to analyze a situation where the opponent is inherently inferior in capability. We all know the USA can bomb third world countries into sawdust. If we are trying to truly see where the limits of the F-35 vs the F-22 are in penetration, then we have to push them both to the limit, to the point where their differences in signature management, RCS, etc. become relevant. Against a Syria-level IADS either one will do just as well, fly in, drop the payload, and fly out without anyone noticing.
The simple reality is in the 2020 timframe there will be no IADS or air power on earth that can achieve parity with the USAF. That is the real world. I understand we are talking about high end IADS, but even the most advanced threat will be inferior. So unless you want to discuss "made up" systems we must assume the USAF has some level of superiority.

But the missile fired at the SAM unit, itself can be engaged and shot down, and a modern IADS will have no problems intercepting it.
Possibly, depending on the missile, the ECM environment and the actual GBAD system we're talking about. An SDB II is an awfully small weapon (tiny RCS), and since we are talking about the USAF here (the only operator of the F-22A) there is likely to be heavy and extremely sophisticated ECM support. Thus wireless communication between the battery elements and the defending Tor M1 esk elements would have likely been compromised. All this will make it extremely difficult for the battery to engage the incoming.


If it also happened to have caught the short EM burst, it can then put 2+2 together, and at least have more or less confirmed detection of inbound hostiles.
That's what I said earlier. The battery crew will have the option of abandoning their posts and running or possibly engaging the incoming, which is by no means a givin.

The other thing is that in a properly done IADS, the only permanently hot radars will be general airspace control radars, and only when a threat is detected will the SAMs actually go hot and start searching for targets. Even the Georgian SAMs (SA-11) during the recent war (which is hardly an exemplary ADS employment) operated in this manner. An S-300P battery can go from march (cold) to hot in 5 minutes. This includes time to set up the unit. It would be reasonable to assume that if it's already deployed, and just needs to flip the switch, it could go from hot to cold in notably less time. The Buk M1 proved it had the capability also. I think it's safe to assume that many of the SAMs currently being actively proliferated around the world are capable of this type of employment, which immediately changes the game for the penetrating platform. It doesn't know where the GBAD is until the GBAD is ready to open up on it, and thus can't judge threat levels.
Current Wild Weasel opps deal with this tactic every day. The point is you goad the GBAD FCR into emitting by eliminating the search radars and then engage them with a combination of hard and soft attacks. Thats the way SEAD is conducted currently.

The penetrator will only have to engage a threat if it can not proceed without entering the GBAD's engagement envelope. Thus if the GBAD FCR's remain cold then the F-22A will most likely be able to fly straight to the target by simply avoiding the search radars, the platforms tiny RCS should reduce their range so significantly that even if they are densely populated there would be wide corridors through them.

Additionally we cant view this in a vacuum, its likely that any operating ground based search radars would have been engaged by stand off means ala JASSM. There are plenty of ways to skin a cat.

Except that an IADS does not consist solely of GBAD. It also includes airborne components. So the EO-DAS still has significance in that regard.
Sure but the point i was making was in regard to another point raised by another poster on the F-22A's inability to engage GBAD effectively, and then a rebuttal to that point on the F-35A's superiority with EO DAS as evidence of said superiority.

Anyway a strike asset is FAR more likely to encounter GBAD than tac air. Airborne threats should be dealt with by dedicated escort assets which in this case would no doubt be A2A equipped F-22A's. Thus in real terms the EO DAS's relevance vs GBAD is far more apt within the context of this discussion.


The true objection here should be that once you're down to fighting the enemy, instead of a stealthy penetration, you've already defeated the whole point of a VLO platform.
Do you think the only objective of VLO platforms is to conduct a whole strike mission without ever betraying their presence, and anything less negates VLO's worth?

A major advantage VLO gives the user (one of the primary reasons it was included in the JSF concept originally) is the survivability bonus it grants the platform. Even if the penetrator has to give away its presence briefly to negate a GBAD installation, so what? The F-35/F-22A's precise position, track or intent will not be known and the IADS's elements will still have a very hard time engaging the platform. Just because the striker may not behave like an F-117 doesn't mean you would be equally well off with a 4.5th gen platform.



The SAMs will be cold, and their locations not known if the IADS is operating on wartime footing. Being mobile they can change locations every 3-6 hours if need be to avoid sattelites spotting them. The corridors may exist, but you don't know where they are. You also have air-space control radars, and AEW&C which may not be able to provide targetting data on a VLO target, but is likely to provide detection info at least, which would then enable all the SAMs around the area where hostiles were detected to go hot in unexpected places. They could go hot for no more then a minute, to make sure they don't have targetting data (or take a shot off if they do) and then go cold again and relocate immediately. This would also enable AD fighters to vector in at least an approximate intercept, if the VLO targets are detected. If the AD fighters are datalinked to the SAMs, then we have a situation where the pentrating platforms are in for a very messy penetration.
That scenario is basically uber IADS vs a single F-22A, and thus has no bearing on the real world.

That IADS would face 500km ranged, LO standoff weapons. Extremely heavy and precise ECM including EA at the platform level, several packages of VLO, SEAD/DEAD "weasels" hitting search radars and GBAD FCR's as they illuminate, F-22A flights conducting offensive counter-air missions (which could likely get into an AIM-120D launch position on an AWACS without being defected, in addition to EA), special forces raids, TACTOM all directed by Rivet-Joint et al. And of course our penetrators.

Against that level of ISTAR, EW, precision strike and the ability to disrupt communications, any IADS will rupture at the seems. Once C4I installations are struck the IADS soon devolves into an ADS and everyone can go dirty.

Remember this isn't platform vs integrated force, its integrated force vs integrated force, and the choice of a specific platform for a specific mission.

The Iraqi IADS was not operated competently. Nor was it's airborne component worth the cost of gas in their fuel tanks. ;) Again bombing third world countries into sawdust, with complete capability overmatch, is not true test of capability.
Iraqi IADS was no joke. It was the most capable IADS deployed outside the Eastern Block in 91' even if it wasn't as lethal as any IADS could possibly be. The IADS was dense, integrated and enjoyed reasonably capable GBAD systems. It was the most lethal threat western air forces have ever actually engaged. Dismissing its capability derides the achievements of those who overcame it.
 

Ozzy Blizzard

New Member
There is one issue that always gets me with Kopp that does not get picked up. He runs down the F-35 with some speculative analysis yet proposes we us an updated F-111 for strike missions (even if his super Pig ever got built) would ahve an RCS the size of a bus. Lest hope the EW Raptors (bugger they don't exist) can deal with the IADS before hand.
This is what i hate about including Kopp in a discussion (i know i am one of the worst former offenders), people make emotive and derogatory comments on platforms that don't add much to the discussion.
 

Ozzy Blizzard

New Member
There are absolutely nothing on the methodology on the ray-tracing analysis of the specular returns.

Any submission to a peer-reviewed journal would have to include what software was used and basic assumptions on object properties (like metallic vs composites, and no, I'm not even talking about RAM). Just for basic reproducibility of results; i.e. the CalPoly asssumed their jet was metallic.

Instead we get a humongous rehash of Russian technology with the addition of a teeny-weeny analysis based on the bulgy shaping of the F-35 underbelly and the only supporting material is some work on the propagation of radio waves in the atmosphere...

It's meant for impressing the layman, shaping opinion, particularly with the flashy-easy-to-understand-graphics.
Check out the RADAR comparisons.

Makes damming conclusions based on speculative power/aperture comparisons alone. Typical over simplification.
 

Feanor

Super Moderator
Staff member
The simple reality is in the 2020 timframe there will be no IADS or air power on earth that can achieve parity with the USAF. That is the real world. I understand we are talking about high end IADS, but even the most advanced threat will be inferior. So unless you want to discuss "made up" systems we must assume the USAF has some level of superiority.
Yes it's a "made up" system. Like I mentioned earlier, if we are trying to compare the F-22A and F-35 in terms of penetration performance, then (given the vast superiority of both platforms) it becomes necessary to devise an artificial scenario that would allow us to push both platforms to their limits.

Or if you must contextualize, it's an assasination strike on Moscow, with a time sensetive moving target (cortege of the Russian president for example). If the timeframe is 2020, then the IADS consists of A-50U AEW&C, heavily upgraded S-400 spin-offs, Tor M2 and Pantsyr-1 for points ADS, and Buk-M2, for GBAD, late gen Flankers, and most likely early variant T-50. Density is high, fighters are present in 2-4 regiment strength. It's not parity in the strategic sense, but for arguments sake, given the limited strike window, out of theater assets are not an option.

Possibly, depending on the missile, the ECM environment and the actual GBAD system we're talking about. An SDB II is an awfully small weapon (tiny RCS), and since we are talking about the USAF here (the only operator of the F-22A) there is likely to be heavy and extremely sophisticated ECM support. Thus wireless communication between the battery elements and the defending Tor M1 esk elements would have likely been compromised. All this will make it extremely difficult for the battery to engage the incoming.
Once again I'm not trying to propose an uber-IADS to face off against a USAF strike package. We're trying to evaluate the potential of the F-35 vs the F-22 for high-end penetration strikes.

Current Wild Weasel opps deal with this tactic every day. The point is you goad the GBAD FCR into emitting by eliminating the search radars and then engage them with a combination of hard and soft attacks. Thats the way SEAD is conducted currently.
We're not talking about SEAD. I know this conversation got very far off track in the debate about modern IADS employment, but I'd like to bring it back to the original discussion of penetration potentials of the F-22 and the F-35.

The penetrator will only have to engage a threat if it can not proceed without entering the GBAD's engagement envelope. Thus if the GBAD FCR's remain cold then the F-22A will most likely be able to fly straight to the target by simply avoiding the search radars, the platforms tiny RCS should reduce their range so significantly that even if they are densely populated there would be wide corridors through them.
Are you saying that the F-22 or F-35 would remain entirely undetected by any search radars? I don't mean tracked, or targetted, I mean detected? And afterall at least acoustic confirmation would be possible, which would then enable all of the GBAD to go hot. And if you don't know where their engagement envelopes are until they go hot, you can't avoid them.

Anyway a strike asset is FAR more likely to encounter GBAD than tac air. Airborne threats should be dealt with by dedicated escort assets which in this case would no doubt be A2A equipped F-22A's. Thus in real terms the EO DAS's relevance vs GBAD is far more apt within the context of this discussion.
So a penetration strike would be accompanied by escorts?

Do you think the only objective of VLO platforms is to conduct a whole strike mission without ever betraying their presence, and anything less negates VLO's worth?
No. But if the IADS effectively engages you, additional airborne assets can be directed to intercept, and GBAD assets around the location will be ready to deal with you.

That scenario is basically uber IADS vs a single F-22A, and thus has no bearing on the real world.
The scenario is to compare the F-22A and F-35 in the same situation and see which one comes out as a superior penetration strike platform against high-end IADS. The IADS is the measuring stick. Not a real opponent whose capabilities we are attempting to analyze.

Against that level of ISTAR, EW, precision strike and the ability to disrupt communications, any IADS will rupture at the seems. Once C4I installations are struck the IADS soon devolves into an ADS and everyone can go dirty.
When you say any, you are almost always wrong. The question is also whether the necessary assets can be assembled quickly enough to achieve what you are talking about. After all the enemy isn't all defensive, they can launch counter-air missions of their own to take out your stand-off jamming capabilities, insert special forces teams to disable your C4I, etc. etc. and if the opponent is Russia, tactical nuclear weapons, including nuclear SAMs, are always a possibility.

Iraqi IADS was no joke. It was the most capable IADS deployed outside the Eastern Block in 91' even if it wasn't as lethal as any IADS could possibly be. The IADS was dense, integrated and enjoyed reasonably capable GBAD systems. It was the most lethal threat western air forces have ever actually engaged. Dismissing its capability derides the achievements of those who overcame it.
None the less it was severaly lacking. I am quite aware that it was overcome by quite an effort, and that allied air power had to achieve vast numerical superiority in addition to technological superiority. None the less the dismemberment of the Iraqi IADS is a perfect example of how an IADS should NOT be employed. Truth is there were only two armies in the world during the Cold War. The WarPac and NATO. Everyone else was a downscaled imitation of one or the other.
 

alexsa

Super Moderator
Staff member
Verified Defense Pro
This is what i hate about including Kopp in a discussion (i know i am one of the worst former offenders), people make emotive and derogatory comments on platforms that don't add much to the discussion.
I did not see it as emotive, sarcastic yes. The fact is this is how he proposes to use the platfoms and I find the hypocracy of it asrounding given his case against the F-35.

It may not add much to the debate but then neither does rehashing APA propaganda on a regular basis and then having endless discussions about how we should buy the F-22 (and what it may be able to do with upgrades that are not currently programmed), and around the circle goes again. You know exactly what I mean by that given your time on the site.

Until some hard facts come out this is just frustrating. Sorry if you found it offensive.
 

Ozzy Blizzard

New Member
I did not see it as emotive, sarcastic yes. The fact is this is how he proposes to use the platfoms and I find the hypocracy of it asrounding given his case against the F-35.

It may not add much to the debate but then neither does rehashing APA propaganda on a regular basis and then having endless discussions about how we should buy the F-22 (and what it may be able to do with upgrades that are not currently programmed), and around the circle goes again. You know exactly what I mean by that given your time on the site.

Until some hard facts come out this is just frustrating. Sorry if you found it offensive.
Mate look, i had my time, i fell for his s*%t, I've admitted that on over a dozen occasions, including on other forums. I've done the best i can to right my wrongs. That was 2 years ago, get over it. If you cant engage me in the discussion with regards to what I'm saying now and just refer to episodes in the ancient past then please crawl back down your hole, STFU and let the rest of us get on with it. If you want to engage in this discussion (rather than one in 2007) in a constructive manner then by all means.

In case you haven't noticed this is a discussion that was so god damn far from the RAAF or Carlo Kopp it may as well have been taking place on the far side of the moon. Then someone brings Kopp up and people like you wade in and throw sarcastic one liners around that have NOTHING to do, even indirectly, with what was being said. It pollutes the thread and turns something informative and enjoyable into this right here. Guess what bud, the world moved on, and now the only people who make discussions on a platform called the F-22A about Carlo Kopp are people like you. So if you really want Kopp's idea's to die then don't bring it up.

If you want to continue this PM me.

Mod edit: Unapproved post following Moderator discussion and pending PM discussion amongst the involved parties.
-Preceptor
 
Last edited by a moderator:

Vivendi

Well-Known Member
Humour: another Kopp article!

To cheer you all up a bit and give you a good laugh, you may want to visit defpro:

http://www.defpro.com/daily/details/212/

It is really amazing how Kopp manages to get his stuff "published".

Anyway, I think that some of you people are worried about Kopp for absolutely no reason. The un-informed layman will of course be confused after reading one of his pieces however the important thing is that his silly "articles" will never have any real influence -- not a single partner has left, Norway even wants more than the originally stipulated 48 a/c, and most countries that will get access to F-35 in the future will no doubt buy it. The reason is of course that in real life, fiction never beats facts. And the facts are so overwhelming that nobody in charge can ignore them.

The in-depth analysis done by the Norwegian evaluation team was very convincing. F-35 passed all the scenarios, some of which included a2a with a future PAK FA, another operating in the vicinity of double-digit SAMs without using ECM. No 4.5 gen a/c could do that. And why go for an F-22 when the F-35 can do the job much cheaper (and in some cases better...), why consider F-22 if F-35 can beat PAK-FA? Their analysis was done with access to all the classified info Kopp does not have (and if he had he would probably have ignored it somehow...)

Kopp is not a threat or an issue, he is a clown. Sit back and relax, and enjoy the show :)


V
 

B.Smitty

Defense Professional
Verified Defense Pro
There are absolutely nothing on the methodology on the ray-tracing analysis of the specular returns.

Any submission to a peer-reviewed journal would have to include what software was used and basic assumptions on object properties (like metallic vs composites, and no, I'm not even talking about RAM). Just for basic reproducibility of results; i.e. the CalPoly asssumed their jet was metallic.

Instead we get a humongous rehash of Russian technology with the addition of a teeny-weeny analysis based on the bulgy shaping of the F-35 underbelly and the only supporting material is some work on the propagation of radio waves in the atmosphere...

It's meant for impressing the layman, shaping opinion, particularly with the flashy-easy-to-understand-graphics.
He used software called POFacets.

What he does describe about his methodology is included in an appendix here,

http://www.ausairpower.net/APA-2009-01-Annex.html#mozTocId787784

He mentions his analysis includes an assumption of a blanket -10 dBSM reduction due to RAM coatings.

He does not mention what skin or structural materials were used.

I wonder if he would be willing to make his models, custom software and configuration assumptions public for peer review?
 

Grand Danois

Entertainer
He used software called POFacets.

What he does describe about his methodology is included in an appendix here,

http://www.ausairpower.net/APA-2009-01-Annex.html#mozTocId787784

He mentions his analysis includes an assumption of a blanket -10 dBSM reduction due to RAM coatings.

He does not mention what skin or structural materials were used.

I wonder if he would be willing to make his models, custom software and configuration assumptions public for peer review?
Thanks. Absolutely brainfart on my behalf that I missed this section. It was this kind of description and tables I was looking for.

As he writes himself:

Wireframe rendering of the solid model for JSF lower fuselage geometry employed for RCS modelling. This model accurately represents the complex singly curved section of the lower centre fuselage, but does not represent the longitudinal taper or the problematic doubly curved shapes at the weapon bay and ventral blister transitions. The model was produced by digitising a section from a photograph and after scaling, extending the section into a solid using a custom C language program (Author).

See the attachment to get an idea between one type of doubly curved surface (sphere) vs single curved (cylinder). A difference of about, what, 17-18 dB...

I'm not condemning his work, but it illustrates how difficult it is to model and how far his estimates are potentially off. This should be commented on and caveated in the text.

This is what I mean by knowing the model parameters.
 

B.Smitty

Defense Professional
Verified Defense Pro
Thanks. Absolutely brainfart on my behalf that I missed this section. It was this kind of description and tables I was looking for.

As he writes himself:

Wireframe rendering of the solid model for JSF lower fuselage geometry employed for RCS modelling. This model accurately represents the complex singly curved section of the lower centre fuselage, but does not represent the longitudinal taper or the problematic doubly curved shapes at the weapon bay and ventral blister transitions. The model was produced by digitising a section from a photograph and after scaling, extending the section into a solid using a custom C language program (Author).

See the attachment to get an idea between one type of doubly curved surface (sphere) vs single curved (cylinder). A difference of about, what, 17-18 dB...

I'm not condemning his work, but it illustrates how difficult it is to model and how far his estimates are potentially off. This should be commented on and caveated in the text.

This is what I mean by knowing the model parameters.
By including this section, it appears that he is acknowledging problematic aspects of his modeling. However if he excluded the contribution of the doubly curved surfaces from his model, wouldn't he be taking a more optimistic view of the F-35's RCS? So it could actually be worse?

He certainly does not have a completely accurate model of shape or materials, but if, in his methodology, he always errs on the optimistic side, wouldn't this analysis produce what amounts to a "best case" RCS?

Note: I have no idea if he has always taken an optimistic view when making a simplifying assumption. I am just asking if the forum thinks one can produce a model this way with enough fidelity to be useful for analysis of vulnerability and tactics.
 
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