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Report On Indian MMRCA IN CHINESE..

The words 'conductor' and 'conductivity' are not to be confined to electrical conductivity. Else by your argument ground penetrating radar would not work. Are electrons in atoms of dirt being transferred from one to another to effect radar detection?

EM waves are also scattered (diffuse reflection) by discontinuities of dimensions comparable to their wavelengths; in optical frequencies that would be comparable to the size of the gap between packed soil measured in the micrometers, but in RF, dirt should be as transparent as glass is at optical frequencies. This depends on depth as well, there would definitely be attenuation.

Surface plasmons is the accepted microscopic theory of reflection. Frequencies below the plasma frequency are reflected due to resonance and those above are transmitted in conductors. In dielectrics, pure substances with no discontinuities comparable to incident wave wavelength also transmit, while discontinuities produce diffuse reflection. Compared to RF wavelengths, dirt can be probably be viewed as a continuous dielectric just like glass is for optical. I'm not sure on the signal processing details but that's what I know from the basic physics.
 
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EM waves are also scattered (diffuse reflection) by discontinuities of dimensions comparable to their wavelengths; in optical frequencies that would be comparable to the size of the gap between packed soil measured in the micrometers, but in RF, dirt should be as transparent as glass is at optical frequencies. This depends on depth as well, there would definitely be attenuation.

Surface plasmons is the accepted microscopic theory of reflection. Frequencies below the plasma frequency are reflected due to resonance and those above are transmitted in conductors. In dielectrics, pure substances with no discontinuities comparable to incident wave wavelength also transmit, while discontinuities produce diffuse reflection. Compared to RF wavelengths, dirt can be probably be viewed as a continuous dielectric just like glass is for optical. I'm not sure on the signal processing details but that's what I know from the basic physics.
Just like the other guy, you have confused the contexts of words being used in specific situations to describe actions with intrinsic properties. I will use one thing to illustrate both our points:

The radome.

If YOU apply direct voltage to the radome itself, nothing would happen. The radome's material would act like an insulator. But if I reach into the cockpit and turn on the radar, we would have EM radiation emanating from inside the aircraft, THROUGHT the radome, and into space.
 
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Just like the other guy, you have confused the contexts of words being used in specific situations to describe actions with intrinsic properties. I will use one thing to illustrate both our points:

The radome.

If YOU apply direct voltage to the radome itself, nothing would happen. The radome's material would act like an insulator. But if I reach into the cockpit and turn on the radar, we would have EM radiation emanating from inside the aircraft, THROUGHT the radome, and into space.

True and that is because the radome is a dielectric - usually a plastic or a ceramic. If it was a conductor, it wouldn't be letting EM radiation through. It fits what I've said before. Radome isn't conducting, it is TRANSPARENT. There is a major difference between EM transmission and electrical conductivity which I think you got confused. Glass is EM transmitting in the visible, but it is not conductive. Its resistivity in fact is over 10^20 ohms.
 
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A sponge is an absorber and a conductor. You made the typical mistake of a scientifically ignorant who confused the application with the property (or behavior). A sponge cannot absorb liquids unless one of properties (or behaviors) is that of being conductive somehow to liquids. You confused one of the contexts of 'absorb', which is to draw in, to be a distinct behavior when the behavior is typical -- conduction.

A standard canopy is a pass-through material, which is another behavior made possible by conductivity, or little or no resistance. The result is that radar signals entered the cockpit well and with alternating destructive and constructive interferences, the cockpit become an EM resonating beacon. A treated canopy with an absorber or conductor film will not allow conductivity in one direction -- pass-through -- but conductivity on another direction -- surface traveling waves. Whether is is pass-through or surface waves, both are not possible unless there is conductivity. The issue is which direction do we want.
I find it interesting how you always divert attention away from your errors by posting tenuously related but ultimately contextually irrelevant factoids that slowly grow in message size to ridiculous dimensions. I remember the 30 page replies. LOL Read below for my response.


So what I said is contextually and technically correct, that an absorber is or rather MUST BE a conductor and a conductor can be exploited in application to be an absorber.

Further...If my usage of 'absorber' is inappropriate, then those saw-tooth patterns we see cannot be called 'geometric absorber' because that is how they are called in the industry...

Convoluted (APC) | www.siepel.com
We were talking about the treated stealth coated canopy where I said it was "conductive" and you interjected and said it is both an "absorber" and "conductive". That is the context. Now you're trying to muddy the waters with semantic nonsense as if treated stealth canopies are "absorbers" of radar in the same sense as radar absorbent materials on the rest of a LO stealth airframe.

The treated stealth canopies of LO stealth aircraft like the F-22 and J-20 are thermomolded polycarbonate with conductive oxide coatings applied via deposition in between. The canopy of the F-22A iridium-tin oxide coating is so thin that it is almost completely transparent other than a tell-tale golden tint. Its thickness is said to measure in the microns. As a RAM, it absorbs next to zero radar energy. As I said, your claim that the canopy coating is an "absorber" is inappropriate and nonsense and your use of semantics is ridiculous. You might as well argue to an electrician that copper is an "absorber" rather than a conductor because it gets warm when electricity flows through it. Using your logic, almost everything in existence would then be an "absorber" since only supercooled superconductors have no resistance! LOL As I said, the canopy coating is conductive and allows the canopy to reflect radar and residual EM would travel along the conductive coating of the canopy with the same stealth shaping rules as the rest of the stealth airframe. It not that difficult to comprehend.


IEEE Xplore - Reduction of the radar cross section of a moderate cylindrical structure using central impedance loading

Notice the mention of a cylinder. Why a cylinder but not a plate? Because electrical absorber or passive cancellation works best against surface waves. This lead to the next debunking of your argument.


:lol: The phrasing 'continuous curvature' is something he made up. He is also grossly wrong about the cylinder because the source he brought on does not mention the 10 lambda rule, which comes into play whenever a radar signal encounters a curvature on a sphere or a cylinder. A cylinder does not have an 'edge on' perspective but an 'end on' perspective. At this point, we would be dealing with a plate.
I guess it wasn't that you willfully ignored the point about his use of the term "continuous curvature", it's that you didn't understand his point. It was concerning the relatively large specular reflection NOT traveling waves, even though you agree with it without realizing it and have posted volumes of minutiae supporting the point. Looking from 1 end of a cyclinder to the other end will be a straight line "edge"...what Martian2 referred to as NOT have "continuous curvature". You and others can reference those signal strength graphs from the airports that you quoted and posted several times where by far the strongest signals came from the tail and wings...which just happen to be the shapes that appear closest to straight cyclinders and thus with a large area to illuminate from the perspective of those radar towers, notwithstanding the 90 degrees respective of the tail.

Second, good luck trying to use passive cancellation against an illuminating AESA radar in LPI mode.


Incorrect:
- (Specular) or (surface waves). This is your interpretation of my position.

Correct:
- (Specular) or (specular and surface waves). This is my true position.

Get it now, liar?

I will now put it into real world examples, see if you can grasp it...
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...[innocuous contextually irrelevant factoids]...
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This is the third time that I have explained to you the differences between the mono-static and bi-static configurations and why certain behaviors are prominent at which point. I cannot dumb it down further. I am not well versed in 'Chinese physics'. So looks like it is YOU who are par for the stupidity course.
I guess things aren't registering afterall since you're now simply repeating the same innocuous factoids in different words without actually saying anything contextually relevant. Speaking of liars, what I find interesting is a certain somebody with a chip on his shoulders looking for every opportunity to pursue a certain agenda pretending to be somebody he is not, know what I mean? Somebody who has publicly stated that he hangs out at STORMFRONT and AMREN, both well known White Power racist websites and has used these websites as his sources on several occasions all while claiming to be a disgruntled Vietnamese-American. That sounds like an interesting case study for psychoanalysis don't you think? hmmmm....fascinating.

Btw, the F-117 was always vulnerable because even without multi-modal radars, as long as it was either maneuvering or there were several illuminating independent radars in the vicinity (fighters, AWACs, ground radars), it was in danger of being detected. This is the same stealth weakness that is pointed out for canards, but on a much bigger scale because it is the entire aircraft.


No, it is not secondary. At least not to US. But I sincerely do hope that the Chinese engineers do take your position. It will make shooting down Chinese not-so-stealthy fighters that much easier.
On a LO stealth aircraft, the large majority of RCS is eliminated through reduction of specular reflections and RAM. The remaining EM that can potentially return even with optimal reinforcing constructive interference will on average be a small fraction of what was already eliminated. So, yes it is definitely secondary.


How you can claim a traditional canopy is a minor stealth issue is surprising given that RCS is now measured in the fractions of a sq/m2.
*** Message Post #228 ***
On any part of an aircraft, in one moment a complex structure may produce destructive interference and reduce the overall RCS, but at the next instance, the same complex structure may produce constructive interference that increases the overall RCS. The worst offenders are cavities (wells) and tubes, that mean cockpits and engine inlets tubes or tunnels.
Let's see, first you claim that the cockpit is a minor stealth issue, then you write post #228 and say a cockpit can cause constructive interfere to increase the RCS suddenly and yet you consider a non-stealthy canopy a minor issue...Nice! LOL
 
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True and that is because the radome is a dielectric - usually a plastic or a ceramic. If it was a conductor, it wouldn't be letting EM radiation through. It fits what I've said before. Radome isn't conducting, it is TRANSPARENT. There is a major difference between EM transmission and electrical conductivity which I think you got confused. Glass is EM transmitting in the visible, but it is not conductive. Its resistivity in fact is over 10^20 ohms.
You might as well argue to an electrician that copper is an "absorber" rather than a conductor because it gets hot when electricity flows through it.
The context of the words 'conductive' or 'conductivity' here is meant to be in line of something being 'conducive', which is about...

Adjective: Making a certain situation or outcome likely or possible.
Synonyms: helpful - contributory - instrumental

...Not about being electrically conductive. So if the discussion involve an electrician, he would see their context as being about exchanges of valence electrons, and so on. But if the discussion involve a radar engineer, specifically one working with RCS control measures, if <something> is found to be 'conducive' or 'conductive' towards the overall RCS, then it would be appropriate to use 'conductive' or 'conductivity'.

If the radome material is transparent, it cannot be so unless some of its properties are helpful or complimentary in some ways towards the properties of another substance, which in this case is EM radiation. Directly applying electrical current on to the material means applying a different set of behaviors other than radiation. So to a radar engineer working with RCS, things that contribute to the final RCS value have different degrees of 'conductivity' or of being helpful towards that goal.

Take the word used here -- transparent.

The radome material is 'transparent' in what regime? The visible? Of course not. The material is certainly an 'insulator' in the visual range, correct? Would the word 'transparent' be appropriate in conversation with an electrician? Either not at all or very little. When you deal in non-scientific matters, like the government for example, the context of 'transparency' changes, does it not? Do you want 'transparency' in a radome and in the government?

---------- Post added at 08:17 AM ---------- Previous post was at 08:14 AM ----------

*** Message Post #228 ***

Let's see, first you claim that the cockpit is a minor stealth issue, then you write post #228 and say a cockpit can cause constructive interfere to increase the RCS suddenly and yet you consider a non-stealthy canopy a minor issue...Nice! LOL
Post 228 is about the canopy, not about the cockpit. The canopy is a minor issue compare to the cockpit. We can treat the canopy but we cannot yet treat the cockpit. But in treating the canopy, we treated the fuselage area that includes the cockpit. Get it? :lol:
 
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Second, good luck trying to use passive cancellation against an illuminating AESA radar in LPI mode.
This is clearly an example of someone who just throw up words and hope that something will stick.

First...All radars are illuminating, and we know the proper context of the word 'illuminating' here.

Second...If passive cancellation techniques such as load matching devices works against more powerful signals, they will certainly work against the much weaker LPI signals.
 
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The treated stealth canopies of LO stealth aircraft like the F-22 and J-20 are thermomolded polycarbonate with conductive oxide coatings applied via deposition in between. The canopy of the F-22A iridium-tin oxide coating is so thin that it is almost completely transparent other than a tell-tale golden tint. Its thickness is said to measure in the microns. As a RAM, it absorbs next to zero radar energy.
Do you want to revise that claim?

Radar absorber - ISP Investments Inc.
The radar absorber is used to cover a structural part of an aircraft or to shield a part of a naval vessel. The absorber, or coating in this embodiment, includes an inner layer having an elastomeric carrier material with a carbonyl iron powder dispersed therein, or disposed therein, of a regular particle size of about 4 to 5 micron, and includes an outer layer having an elastomeric carrier material with a carbonyl iron powder dispersed therein, or disposed therein, of a fine particle size of about 0.5 to 1.5 micron.
 
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We were talking about the treated stealth coated canopy where I said it was "conductive" and you interjected and said it is both an "absorber" and "conductive". That is the context. Now you're trying to muddy the waters with semantic nonsense as if treated stealth canopies are "absorbers" of radar in the same sense as radar absorbent materials on the rest of a LO stealth airframe.
Please explain the context of 'geometric absorber'. I provided a source. What is 'absorber' here?
 
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We were talking about the treated stealth coated canopy where I said it was "conductive" and you interjected and said it is both an "absorber" and "conductive". That is the context. Now you're trying to muddy the waters with semantic nonsense as if treated stealth canopies are "absorbers" of radar in the same sense as radar absorbent materials on the rest of a LO stealth airframe.
No, it is not semantics.

Materials Research - Dielectric microwave absorbing material processed by impregnation of carbon fiber fabric with polyaniline
This study presents the effect of carbon fiber fabric impregnation with polyaniline conducting polymer aiming at the radar absorbing material processing.

Conducting polymeric materials are currently being used in RAM processing, however, they can present certain problems related to adhesion, environmental stability and adequate values of electrical conductivity.
A 'radar absorbent material' (RAM) is a composite whose constituents must have some electrical conductivity in order for an impinging radar signal to be 'ingest' or 'absorb' into the material. Just like 'semiconductor' material that straddle the fence between being a complete conductor and a complete insulator.

Absorber design is a sophisticated discipline under radar engineering and there are distinctions between specular RAM and surface wave RAM...

Radar Cross Section Reduction | Defense Technology Course | Georgia Tech Professional Education
WHAT IS COVERED
Radar Fundamentals
Electromagnetics and Scattering Basics
Radar Cross Section Data Examples and Presentation Formats
Surface Wave Mechanisms
Design Concepts
Radar-Absorbing Material Design
Nonspecular RAM
High-Frequency Scattering Mechanisms
Inlet and Exhaust Cavities
Radar Cross Section of Antennas
Radar Cross Section of Holes and Slots
Radar Cross Section Estimation
Low-Frequency Radar Cross Section Radar
Radar Cross Section Computer Models
Radar Cross Section Diagnostics
Radar Cross Section Measurement Ranges
The fact that nonspecular RAM merit its own study should tell you that surface wave behaviors are no less important than specular reflections.

Further, here is a Chinese source...

Microwave Absorbing Materials_Shenzhen FRD Science & Technology Co., Ltd.
Coating Microwave Absorbing Materials include absorption, interference and resonance type, the electromagnetic wave absorption medium is conductive powders, when the external electromagnetic waves incident upon the surface of materials, dielectric materials under electromagnetic field generated in the conduction current or displacement current by finite conductivity, allowing access to the coating of the electromagnetic energy is converted to heat loss out, or through magnetic dipole moving in the electromagnetic field by the limited role of permeability can be converted into the electromagnetic energy loss out.
Got that?

An absorber MUST be a conductor, meaning the material itself must exhibit some measures of electrical conductivity in order to function as a signal 'denial' mechanism for the seeking radar. Another appropriate phrasing is 'loss mechanism', meaning the absorber material is creating a loss of radiation off the body, thereby denying the seeking radar vital clues about the body.

Feeling foolish now?
 
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you mean japan copies at different level than China?? kid read the context please!
they have been ahead in engineering more than you can imagine and for your sake let me tell you their technology is copied rather than the other way round..
 
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you mean japan copies at different level than China?? kid read the context please!
. Can you please be so kind to post the copies by reverse engineering? They have jointly developed their fighters with US as far as I can remember... And are developing their own 5th gen fighter which is also not a copy since they wanted F-22 and were denied... Whereas Internet is abound with theories of your j-20 :chilli: :chilli:
 
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. Can you please be so kind to post the copies by reverse engineering? They have jointly developed their fighters with US as far as I can remember... And are developing their own 5th gen fighter which is also not a copy since they wanted F-22 and were denied... Whereas Internet is abound with theories of your j-20 :chilli: :chilli:


Mitsubishi ATD-X Shinshin Resembles like Stealthy F15 To Me.
 
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Mitsubishi ATD-X Shinshin Resembles like Stealthy F15 To Me.
to point you out on this, ATD-X is inspired by F15... Many aircrafts inspired by an older design does not mean they are copies... And also you canot change the aerodynamics the old designs are still being modified and adapted to build modern jets... however we were talking about reverse engineering and copies if you get my drift...
 
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they have been ahead in engineering more than you can imagine and for your sake let me tell you their technology is copied rather than the other way round..
never expecting less educated and insecure indians to argue accordingly, it is the undeniable fact that Japan started of by copying western stuffs as solid as the fact of british funded a country called India

---------- Post added at 02:50 PM ---------- Previous post was at 02:47 PM ----------

. Can you please be so kind to post the copies by reverse engineering? They have jointly developed their fighters with US as far as I can remember... And are developing their own 5th gen fighter which is also not a copy since they wanted F-22 and were denied... Whereas Internet is abound with theories of your j-20 :chilli: :chilli:

mitsubishi f-2 of F-16 on top of my head, and T-90 of Germany Leopard and so on

---------- Post added at 02:51 PM ---------- Previous post was at 02:50 PM ----------

to point you out on this, ATD-X is inspired by F15... Many aircrafts inspired by an older design does not mean they are copies... And also you canot change the aerodynamics the old designs are still being modified and adapted to build modern jets... however we were talking about reverse engineering and copies if you get my drift...
more funny uneducated Indian theory, when others have similar weapons you say its 'inspired', and when China has similar and its copied even without a shred of reliable sources to back up rather than Indian ignorance

and lastly kid let me tell you what is shame and no class, it is your pony 2nd gen LCA, the french designed the aerodynamics, the Israelis provided the avionics, the Russian daddy gave you the weapon, and your adopted daddy america gives you the engine and FBW system, and India just put on the paint job, and most likely even the paint could be Made in China
 
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