RCS = 3 is too low BUG

[GumidekCZ]

I have been long time suspitious that JF-17 RCS is to small when compared with other fighters. So I take a frontal pictures (DCS compares the frontal RCS, not any other aspect) from DCS model viewer of JF-17 and F-16C with same scale and draw a lines and areas of major reflection sources ( intake area, cockpit, leading edges, probes and sensors, wall behind radome). Than I added guessed reflectivity index in % to some special areas like GoldenF-16 cannopy with Faraday cage effect which reduces RCS, or JF-17 special intakes with same reduced RCS effect). Since DCS model viewer JF-17 is without pylons, I didnt count them. After that I took Zoner Photo studio, selected the pixels from both planes and count them.

Result is little surprise to me, I thought that both planes would be very simillar, but this quick simple analysis showed, that JF-17 with all that stuff reflecting radar energy like the airframe wall behind the pilot head (no such thing behind F-16 pilot, just seat with golden plexy glass), the Jeffs RCS is even bigger than Falcons. So with this result in mind, the RCS of Jeff in DCS must have RCS = 4 NOT 3 as it is now.

Both pictures are in scale!

Once again EDGE pixels include not only any edges visible from front, but also Radome area. Canopy includes its airframe and cockpit back wall surface.

Edited December 5, 2021 by GumidekCZ
Grammar correction

[Mike_Romeo]

I just want to say that this isnt a very scintific way to messure RCS. You could make the nose area smaller or bigger as you want and I dont see why you why you marked the whole canopy area of the JF-17 but not of the F-16 or why you marked the top of the JF-17 tail bigger than the one of the F-16. Beside that there are much more factors like material which influence the RCS.

I would say you see what you just want to see

Edited December 5, 2021 by Mike_Romeo

[GumidekCZ]

36 minutes ago, Mike_Romeo said:

I just want to say that this isnt a very scintific way to messure RCS. You could make the nose area smaller or bigger as you want and I dont see why you why you marked the whole canopy area of the JF-17 but not of the F-16 or why you marked the top of the JF-17 tail bigger than the one of the F-16. Beside that there are much more factors like material which influence the RCS.

I would say you see what you just want to see

 

Nobody before me has introduced here more scientific method to compare RCS of two airframes, at least what I know. If you know about better one, you can show it to us.

Didn't you read about the F-16 canopy Faraday cage RCS effect? Please try to Google it. Beside that, thick or thin line is a factor of sharp or round lead edge. F-16 has sharp to of tail avoinics compartment and JF-17 have round shade, more reflective. I really tried to be not biased to one airframe. I known that if I would be, this post would became just one big laugh to everyone. Materials used are same or very similar for both airframes.

Nice to see & learn:

 

Edited December 5, 2021 by GumidekCZ

[Mike_Romeo]

7 minutes ago, GumidekCZ said:

Didn't you read about the F-16 canopy Faraday cage RCS effect?

The whole airframe is a Faraday cage. Beside that, could you send me please your sources to that topic so that we are one the same level ?

[GumidekCZ]

without F-16 HAVE GLASS, it would be just huge hole in airframe with so many reflective things inside/behind it.
May be some day, Pakistani will also make one for its JF-17 fighter, if the technology used to made it, will be known to them.

https://www.key.aero/article/have-glass-making-f-16-less-observable

Another interesting cannopy and RCS info found here starting at page 16 (year 1979):

https://aircraftdesignguide.com/wp-content/uploads/2020/03/10-Guidelines-for-the-Design-of-Aircraft-Windshield-Canopy-Systems-Chapter-Eight.pdf

Please, if any of you want to write down here that JF-17 have to be smaller RCS just because its newer, more modern. Keep this in your mind for yourselves. Heards this many times before with none scientific support of such claim.

Edited December 5, 2021 by GumidekCZ

[bies]

RCS, just like missile parameters, has to be set and control directly by ED themselfes for unification, because right now its implemented in very rudimentary and arbitrary way.

Right now if three different 3rd parties would make identical i.e. "F-16A Block 1" each of them would have different RCS value. Not even a malice - just every 3rd party would estimate and measure it in a different way, because there is no one standarized way.

 

 

BTW: According to real life F-22 pilot interview F-16 is notoriously hard to detect from the front even by advanced F-22 radar due to its blended shape and very small frontal section.

Edited December 6, 2021 by bies

[MiG21bisFishbedL]

I'd be curious to see if the RCS in DCS also factors in the Jeff's AAR probe.

[Ignition]

3 hours ago, MiG21bisFishbedL said:

I'd be curious to see if the RCS in DCS also factors in the Jeff's AAR probe.

I was thinking the same.

 

[AnarchyZG]

Many things in DCS are simplified, like RCS and IR signature, but that's OK as long as the relative ratio between planes is OK, like Su-27/F-15 having large radar and IR signatures compared to smaller single engine fighters. Calculating RCS by counting frontal area projection is plain silly. Take a look at frontal area projection of F-22, should have huge radar return if you count the pixels .

Gumi, did you get your ass kicked by someone in a Jeff? Just asking

[GumidekCZ]

@Mike_Romeo @AnarchyZG Seems you are very happy with RCS of JF like it is now, you making everything to stay it like it is by just trying to disproof any try to correct it. Good job guys, but first before you throw salt next time, try to gather evidence of your disprooval claim. Find better method if you can, or just leave the topic unresponded. Many thanks guys.

@Mike_Romeo Not whole airframe is acting as Faradays cage. Every material other than metal (like ordinary plexy glass or composite nose cone) is just open hole to allow radar energy to go through and reflect from anythink behind it.

@AnarchyZG Nobody is calculating just frontal area projection, really dont know where you get that. Why the hack you are waving here with F-22 RCS? This plane is absolute different class with astronomic price.

Edited December 6, 2021 by GumidekCZ
Grammar

[okopanja]

I believe you are referring to the gold tinted canopies of F-16. 

Couple of things:

• not all F-16s have them
• the usage of gold tinted canopies is not secret for at least 20 years => by know everyone know this
• what makes you think China or Pakistan are not capable of producing such canopies, this is widespread technology nowdays. Just to give you a hint on where these technologies are used:
  • glass buildings (they all contain metallic coatings today)
  • optical glass, virtually all  of the lenses today contain a coating that gets applied to reduce the reflections, while waste majority of telescopes (even expensive ones) are made in China.
  • sun glasses.

Therefore you can assume that these canopies did receive at least some treatment (likely not gold, but there are other possibilities).

On top of it: once you load your F-16 with fuel tanks and hang all those bombs/rockets you RCS increases. The RCS changes might be needed, but would likely apply to all of the modules, and still not bring large difference compared to the current state (unless F-22/F-35/J-20/Su-57 appear officially in the game).

[Mike_Romeo]

1 hour ago, GumidekCZ said:

Seems you are very happy with RCS of JF like it is now

According to Deka, the RCS should even be smaller.



Topic was already discusced here:

 

[GumidekCZ]

@Mike_Romeo this is not any proof of 3 sqm RCS for JF-17, this is just even less proof backed nice wish of to guys I didn't see anything from them  , what might give us a hint, that they tell us the truth.

@okopanjaI know that not all F-16 use the gold, the modern ones use other materials instead of gold. But we have the option in DCS to have the gold tint - so? On the other hand JF-17 is designed as a cheap fighter (when compared with its competitors) and from pictures present all the internet, not even Block 3 have black or gold tint of canopy glass - giving us clue of such feature used. If somebody want to have 3 sqm RCS, than they need for example post here any trustful document declaring use of such technology for Block 1, but according to photos, I still would be very sceptic.

Edited December 6, 2021 by GumidekCZ

[GumidekCZ]

What ED and all 3rdparties should aim for is a best estimate RCS values across whole DCS sim. Problem is, that there is nothing anywhere written by ED, how did they come to these values. Did they tried co calculate its 3D models from frontal view with static RCS simulation analysis? I guess that not. Is it just base on guess made by some fighter pilot or the module developer guess? I don't know.

What I know that if there is something suspicious about RCS difference, we can make simple analysis to back such claim. If my proof is not enough, than this can be done by someone from ED team, more educated (with good knowledge of composite properties, canopy material, coating), equipped with may be static RCS analysis software tool can make much more accurate result.

Edited December 6, 2021 by GumidekCZ

[Mike_Romeo]

3 hours ago, GumidekCZ said:

@Mike_Romeo this is not any proof of 3 sqm RCS for JF-17

Thats true

3 hours ago, GumidekCZ said:

What ED and all 3rdparties should aim for is a best estimate RCS values across whole DCS sim.

Deka is already going in that direction and has developed a new radar model that consider the RCS of various aircrafts and the aspect to the Jeffs radar. I would say they are the radar experts in DCS

 

3 hours ago, GumidekCZ said:

What I know that if there is something suspitious about RCS difference, we can make simple analysis to back such claim.

You should have done this before you claim that the RCS of the JF-17 is to low
 

3 hours ago, GumidekCZ said:

If my proof is not enough

You didnt proofed anything. I used your methode to "compare the RCS" of the JF-17 and the F-117


Edges, canopy and intakes are 100% refelctive. The JF-17 has a RCS 2.5 times greater than the F-117. The F-117 has a front RCS of lets say 0.1^2m which means the JF-17 should have a RCS of 0.25^2m

[GGTharos]

If you really want to estimate the RCS, there's software out in the public domain to do it with.  I doubt it's easy to use and you'd have to find appropriately detailed 3D models to run it against.

[GumidekCZ]

3 hours ago, Mike_Romeo said:

You didnt proofed anything. I used your methode to "compare the RCS" of the JF-17 and the F-117

That's a really not good idea, to take absolute different plane RCS class and do the same pixel technique. Somebody told you to do that, or you figured it out yourself?
Next time don't forget also to color the radome.
(Some new radomes have FSS (frequency selective surface) composite design, which actually absorb outer radar energy, but never by 100%. - I don't know if JF-17BL1 or F-16C-BL50 have it, I just red that JF has dielectric radome. So to be fair to both airframes, I colored both radomes.)
I know this pixel technique is not accurate, and did that only to point out the very similar RCS F-16 vs JF-17.... nothing more, nothing less. This not a method for every airframe in DCS, but can lead te better estimations rather than just arguing around.

Edited December 6, 2021 by GumidekCZ

[Blinky.ben]

On 12/6/2021 at 8:32 PM, GumidekCZ said:

JF-17 is designed as a cheap fighter

I see this statement all the time and is a poor excuse for an argument. They didn’t go down to the nearest scrap yard and beat an aircraft out of scrap on the ground. They didn’t have a over the top development project by trying to invent new stealth materials or shapes, they didn’t spend millions/billions over decades trying to develop a new engine. They developed a aircraft by inventing nothing new with lessons already learnt by other state of the art fighter programmes and they brought mostly everything that’s is already in use and PROVEN and put it all together to make what they got. a big difference between cheap crap and a cheap project.

Edited December 8, 2021 by Blinky.ben

[okopanja]

On 12/6/2021 at 11:32 AM, GumidekCZ said:

On the other hand JF-17 is designed as a cheap fighter

Affordable != Cheap. Be aware that Pakistan is a bit of odd Bird just like Iran or Turkey once was. Iran did not receive the F-14 only because of the money but rather due to the long border with the second super power.

Similarly Pakistan (and China) did receive significant technology transfers from USA in the past. Furthermore Pakistan did receive help from China and Russia. Therefore such claims that the technology is not there, is likely misguided. I will just remind you that Pakistan is a nuclear power. It can be assumed that JF-17 might be even nuclear capable (official Mirage III has this role, but it is clear it will not fly much longer!).

Not to forget geostrategic positions: Pakistan competes with India (frozen conflict), China competes with India (frozen) conflict. Both USA and Russia have their own stakes. A country like Pakistan is in much better position (large size, position, huge population) to negotiate technology transfers than even some NATO members (e.g. ex-eastern block).

The population of western countries and their newest satellites (ex-eastern block) often incorrectly make the assumption of superiority over others without actually being aware of the development made or being made. Obviously this is flawed way of thinking and future it can backfire if the historic lessons are not learned on time.

[GumidekCZ]

@Blinky.ben@okopanjaNothing what should change mine or anyone alse mind about reported RCS. Also this not something I want to discuss. I could use word "Affordable", but its just a game with words, nothing else.

[AeriaGloria]

On 12/8/2021 at 4:04 AM, GumidekCZ said:

@Blinky.ben@okopanjaNothing what should change mine or anyone alse mind about reported RCS. Also this not something I want to discuss. I could use word "Affordable", but its just a game with words, nothing else.

I am surprised you give equal weight to F-16 and JF-17 intakes when one has DSI the other does not and has splitter plates. One has a fan close enough to intake that it can be seen from any aspect under the nose, the other has an engine so buried far behind the split intakes that the fan can only be seen from two very specific aspects that could not be maintained in air to air combat, with a lot of the blockage due to the DSI bumps, 

 

how you can give these two intakes equal weight is surprising to me

Edited January 3, 2022 by AeriaGloria

[L0op8ack]

RCS is not just simple number, like what it is in DCS.

<<INTRODUCTION TO RADAR SYSTEMS>> by Merrill Skolnik, chapter 2, sention 2.7

[BIGNEWY]

thread cleaned, 

sarcasm does not always work on forums, and please remember to treat each other with respect. 

thank you

[Dragon1-1]

If anything, it's the Viper's RCS that's too high. It's a dinky little thing with a very small frontal profile, and it's well known to be hard to detect (and see, it can "hit the disappear switch" just like the Tiger II). The engine is a little exposed, but it doesn't do all that much.

[Tiger-II]

In a museum near me are RCS models of the Canberra and the F-35 (yes, you read that correctly). How we have an RCS model of the F-35 I don't know, but it's there.

You might find this interesting:

 

It's not only about "sharp edges" or "frontal area", but how RADAR energy is returned to the transmitter. A small mirror the size of your little finger can reflect bright sunlight that can be seen for miles, but a sheet of A3 paper will not.

The OP's attempt at calculating RCS is laughable to say the least.

The fact the F-35 has a large frame inside the canopy shows that it is not nearly as critical to RCS as previously assumed. Just because a few Vipers had golden canopies doesn't mean it was effective. We also don't know why some of them were fitted with it, and others not. Maybe there was a specific threat or theatre of operations that required it. We will never know.

The canopy design of the F-35 is also plain weird. Why it has that solid frame when they are capable of making bubble canopies defies logic (and I don't care about "sensor fusion" and ability to see through the cockpit - it is still a visual obstruction).

As for the Jeff being "cheap [junk]", it isn't. If you look at how it is built, it is actually very well designed.

The F-16 had an export model for about 3 weeks. They scrapped the program and started selling the "full fat" model instead. The original plan was to include engines that deliberately overheated so they couldn't match the performance of the US versions, but I guess someone realized that was just a dumb idea.

Edited January 6, 2023 by Tiger-II