Its Official: JXX is going to test fly in the next few days

[gpit]

It is about canards and how they are not very conducive in RCS reduction. Without explanations like mine, Chinese 'fanboys' like yourself would very likely get away with numerous violations, moving and non-moving, of the laws of physics. If you have problems following the discussion's progress, best to stay out of it...

I understand your intention very well, but you citation is just way, way off the track.

Your citation of edge diffraction in the topic of radar detection is questionable in its relevance, as ding has pointed out above, radar signals to detect flying objects are based on reflections/scattering. Are you going to put your radar detector after the object that you are detecting, or rather after some obstacles?

You first citation about randomly positioned active scattering centers in a know background has nothing to do with diffraction, and is also too remote to the topic of detecting a particular canard, causing we, the non-credulous, to question your sincerity.

 

[gambit]

I can see what you're saying, but I don't see how it relates to stealth. Diffraction is not the same thing as reflection, and the diffracted signal, by definition of diffraction, cannot travel back toward the source. If anything, I'd think that diffraction can only help with regard to stealth for the very same reason.

Let me give you another example...

Try to visualize a wave, not a laser like beam. In the example above, not only will there be a reflection from the underside, but there will be surface traveling wave on the top side. When that surface traveling wave run out of 'ground', in a manner of speaking, that wave will diffract, as in 'knife edge diffraction', and with the wave superposition principle, some of this signal will merge with some of the underside reflection and will travel back to source direction.

We know about this under controlled conditions...

RCS Pylons and Assemblies :: ORBIT/FR

There are two other scattering mechanisms. The first is the result of "creeping" waves which move around the shaded side, get diffracted by the trailing edge of the pylon, and emerge back towards the illuminated side. The second scattering mechanism is the "traveling" wave scattering which occurs at the ogival cross section for the electric field component which is perpendicular to the surface.

The 'illuminated side' is that source direction.

Surface traveling and creeping waves have been known to add as much as 1 meter square to a body's total RCS value, depending on target aspect angle. So if under controlled laboratory condition, as shown above, the 'knife edge diffraction' effect is to be avoided, the effect is even more uncertain and hazardous to the RCS reduction efforts under 'real world' conditions. As if it is not bad enough, we are talking about a canard, a MOVING body in front of another body -- wing -- so some of the diffracted energy will reflect off the wing as well. More uncertainty.

The behavior of radar waves on a body is known since the early days of radar. But it was Ufimtsev who gave the world the PREDICTIVE equations of that behavior and vital to those predictive equations are...

Petr Ufimtsev - Wikipedia, the free encyclopedia

In the 1960s he began developing a high-frequency asymptotic theory for predicting the scattering of electromagnetic waves from two-dimensional and three-dimensional objects. Among such objects were the finite size bodies of revolution (disk, finite cylinder with flat bases, finite cone, finite paraboloid, spherical segment, finite thin wire). Now this theory is well known as the Physical Theory of Diffraction (PTD).

Specifically -- Edge diffraction.

 

[gambit]

I understand your intention very well, but you citation is just way, way off the track.

Please see post 198 and see how YOU are way off the knowledge track.

Your citation of edge diffraction in the topic of radar detection is questionable in its relevance, as ding has pointed out above, radar signals to detect flying objects are based on reflections/scattering. Are you going to put your radar detector after the object that you are detecting, or rather after some obstacles?

Absolutely we could. It is called a 'bi-static' configuration and currently the US is only country that can wield a viable airborne bi-static radar system via secured data links. Looks like the laugh is on you, fanboy.

You first citation about randomly positioned active scattering centers in a know background has nothing to do with diffraction, and is also too remote to the topic of detecting a particular canard, causing we, the non-credulous, to question your sincerity.

See post 198, fanboy.

 

[desiman]

few days are over, where is the J-XX lol maybe the photoshop factory is down

 

[gpit]

Please see post 198 and see how YOU are way off the knowledge track.

There is no question that whenever there is a change, being gradual or abrupt, in permittivity and/or permeability of the medium in which electro-magnetic wave travels, there will be reflection/scattering or diffraction. This is well known fact and your pictures in 198 are all valid. But, what is the magnitude? Compared with direct reflection, those are secondary or higher order approximation.

And your (or whoever’s) statement of explanation “that wave will diffract, as in 'knife edge diffraction'” is completely wrong, as this is more of scattering by abrupt medium changes.

Note: diffraction is a phenomenon that wave goes around barriers and into the shadow areas that geometric (straight line) theory fails to predict, but wave theory can. Thus, in your case, diffraction energy (only in the wing tipping edge) will mostly go upward, above the wings. Scattering energy from teh wing body will run into half space below the wing. In the wing tipping point, scattering energy will spread in full solid angle of 4 pi (roughly). In the tipping edge, scattering energy will go up and down.

Again, in small size parameter approximation for scattering, forward scattering is the strongest. Given the glancing incidence nature of the incoming light in your picture, even with bi-staic radar, a ground station wouldn’t get much signal due to the inhomogeity of the medium. Bi-static radar is mainly meant to captch the deflected (reflected in a way that contrary to enemy's expectation) waves not going to the direction as the shining wave (or the primary source, as optics will normally so term it.)

If stealth is achieved by coating certain absorption materials, EM waves are gradually let into the medium (to avoid in maximum being reflected) and are generally dissipated into heat in the material. So called “creeping wave” (assuming that you or whoever know the words) is the part that goes around and gets into the geometric shadows, which will diminishes exponentially. There are also waves that are in the material (skin effect) which reduces themselves also exponentially. Thus, when it runs out of medium, the effect would be about in third order, or perhaps in even higher order, approximation.

Absolutely we could. It is called a 'bi-static' configuration and currently the US is only country that can wield a viable airborne bi-static radar system via secured data links. Looks like the laugh is on you, fanboy.


See post 198, fanboy.

OK, a) suppose a fundamentalist’s air plane invades a country of different believings from Ocean, as the fundamentalists can never tolerate the truth that the universe is a diverse entity, and the very existing of that country is a huge pain in their a$$. Does the defender have to place the receiving radar (of bi-static) 500 miles away in the ocean, without much protection, if it supposedly to get the “diffraction” signal in order to detect the target 500 miles off shore?

b) even based on your great edge diffraction, how can a air plane or similar object behaves like an edge? Does your object occupy the half space of the universe?

c) Suppose your object is so enormous, the diffraction signal from the edge is still fortuitous as depicted by your very own.

d) all right. Let chop off a part of the edge, and make it a double edge diffraction. That doesn’t make sense, either. As you perhaps know that if you add another branch of Cornus Spiral, it only reduces the diffraction signal in general.

e) perhaps only fundamentalist bi-static radars are the one that with one station behind the target?

Let’s not talk about an amusing configuration of an offensive that attempts to sandwich an enemy target between a pair of friendly air born radars.

BTW, I'm a fanboy of no country by only of facts and truth.

 

[gambit]

There is no question that whenever there is a change, being gradual or abrupt, in permittivity and/or permeability of the medium in which electro-magnetic wave travels, there will be reflection/scattering or diffraction. This is well known fact and your pictures in 198 are all valid. But, what is the magnitude? Compared with direct reflection, those are secondary or higher order approximation.

Are you really that shortsighted? Do you really believe that radar detection is contingent upon only one part of a body? Is it possible that depending on certain factors of a body, such as shape and materical, specular reflections, aka direct reflections, can have the same signal strength as diffracted signal? Yes it is possible...The F-22 is sparing on RAM and most absorbers are on leading edges. That mean if taken as a standalone object, the specular reflection off the leading edge, as affected by absorber, will have the same or very similar signal strength as the diffracted field from the wing's trailing edge. If the entire wing's surface is coated with absorbers, then of course the diffracted field strength will be less than specular signal strength due to wave's energy loss as it traverse the wing.

That said...On a complex body, like an aircraft, all scattering points are CONTRIBUTORY elements towards the final total RCS, and we are not talking about just the geometric cross section, which is the surface area that is facing the transmitting radar. A scattering point could be from direct reflection OR from a diffraction field. If we confine the discussion to a geometric RCS, then one scattering point that exist in one aspect angle may not exist in another aspect angle. But no matter what, the signal magnitude of a diffraction field is still a CONTRIBUTOR to the body's total RCS. Not only that...On the same complex body, a diffraction signal could create a direct reflection signal. How? When the canard is in front of the wing, the canard's trailing edge create a diffraction field, which then impact the wing's leading edge. Is the wing on a different horizontal plane than the canard? Most likely. That mean part of the diffraction signal and the radar's signal may merge. Part of the diffraction signal may impact an area of the wing, leading edge or elsewhere, that is not impacted by the radar's transmission at all. So what we have here is a good possibility that the canard actually ASSISTED the seeking radar in revealing target information.

So for you to demand that we focus only the signal strength differences between direct reflection and diffraction field is utterly absurd in your feeble attempt to salvage a failed argument that the JXX's canards cannot be a negative in RCS reduction.

And your (or whoever’s) statement of explanation “that wave will diffract, as in 'knife edge diffraction'” is completely wrong, as this is more of scattering by abrupt medium changes.

No...It is YOU who are wrong. As a surface wave travel, any disruption IS an abrupt medium change and will create a diffraction field. The term 'knife edge diffraction' is appropriate and is well used to describe such an abrupt medium change. Yours is typical of someone who has no relevant experience in the subject under discussion and is willing to impose his own flawed understandings of terminologies related to the subject. In radar detection, a 'scattering point' is a general descriptor for any disturbances in a radar signal's path, be it in open air or when there is a traveling surface wave. A flat plate directly facing the transmitter is a scattering point. A diffraction field IS a scattering point. A diffraction field CREATE a scattering point. On a wing, there are two edge diffraction fields: leading and trailing. So for a wing, we have direct reflections from the top and bottom surfaces combined with the two diffraction fields to make the wing one large scattering point.

Note: diffraction is a phenomenon that wave goes around barriers and into the shadow areas that geometric (straight line) theory fails to predict, but wave theory can. Thus, in your case, diffraction energy (only in the wing tipping edge) will mostly go upward, above the wings. Scattering energy from teh wing body will run into half space below the wing. In the wing tipping point, scattering energy will spread in full solid angle of 4 pi (roughly). In the tipping edge, scattering energy will go up and down.

If stealth is achieved by coating certain absorption materials, EM waves are gradually let into the medium (to avoid in maximum being reflected) and are generally dissipated into heat in the material. So called “creeping wave” (assuming that you or whoever know the words) is the part that goes around and gets into the geometric shadows, which will diminishes exponentially. There are also waves that are in the material (skin effect) which reduces themselves also exponentially. Thus, when it runs out of medium, the effect would be about in third order, or perhaps in even higher order, approximation.

In the case of a wing, the diffraction field strength is affected by the angle of approach of the incident wave. If the incident wave is perpendicular to the surface, meaning directly facing it, then the diffraction field strength is statistically insignificant. But your argument, sections of which I grouped together for clarity, missed two points: that there are two surfaces that an incident wave can traverse, and that an airfoil is not a sphere where a creeping wave can exist. An airfoil is conducive to surface traveling waves, which do not lose energy as it traverse the wing's surface. A surface traveling wave is continuously supported, or kept alive, by the transmission power itself. So for an airfoil, if the incident wave has a low grazing angle, we will have two surface traveling waves and when they meet at the airfoil's trailing edge, they will merge and the diffraction field created will have some backscatter. In the case of an aircraft, a highly complex body, creeping waves can be statistically insignificant, on the other hand, if we take a look at the F-15 from its frontal profile, the cylindrical nose section can create creeping waves if the aircraft is being scanned from the side. Looks like I know what a 'creeping wave' is better than you do...

Again, in small size parameter approximation for scattering, forward scattering is the strongest. Given the glancing incidence nature of the incoming light in your picture, even with bi-staic radar, a ground station wouldn’t get much signal due to the inhomogeity of the medium. Bi-static radar is mainly meant to captch the deflected (reflected in a way that contrary to enemy's expectation) waves not going to the direction as the shining wave (or the primary source, as optics will normally so term it.)

If there is a god of radar physics, he must be laughing his guts out when he read the nonsense about bi-static radar operation from you. Anyway...What the hell does this...'inhomogeity of the medium'...mean? The 'medium' here is air, or rather relatively 'empty space'. A bi-static configuration exploits the greater forward scatter signals. So by your argument here...the inhomogeity of the medium...whatever the hell that mean...make a bi-static configuration inefficient, then that would make the mono-static configuration completely worthless. And yet mono-static radars are prevalent. As I have pointed out before and will repeat, in theory, a bi-static configuration is low observable aircrafts' best detector precisely because of those forward scatter signals. So in trying to prove me wrong about canards, you just ended up calling bi-static radars worthless against 'stealth'. Am beginning to suspect that these are not your words but someone else's that you are trying to pass off as your own. There seems to be no technical consistency.

Does the defender have to place the receiving radar (of bi-static) 500 miles away in the ocean, without much protection, if it supposedly to get the “diffraction” signal in order to detect the target 500 miles off shore?

That is why bi-static radars are no panacea to 'stealth' despite what some chinese fanboys would like believe whenever they tried to downplay the F-22. This is not because bi-static sensor systems, like the Kolchuga or Silent Sentry, do not work but because a bi-static configuration is inherently structurally intensive, requiring physically distinct transmitter and receiver stations.

OK, a) suppose a fundamentalist’s air plane invades a country of different believings from Ocean, as the fundamentalists can never tolerate the truth that the universe is a diverse entity, and the very existing of that country is a huge pain in their a$$.

b) even based on your great edge diffraction, how can a air plane or similar object behaves like an edge? Does your object occupy the half space of the universe?

c) Suppose your object is so enormous, the diffraction signal from the edge is still fortuitous as depicted by your very own.

d) all right. Let chop off a part of the edge, and make it a double edge diffraction. That doesn’t make sense, either. As you perhaps know that if you add another branch of Cornus Spiral, it only reduces the diffraction signal in general.

e) perhaps only fundamentalist bi-static radars are the one that with one station behind the target?

Meaningless drivel. The point I am making is that diffraction energy in a contributor to a body's total RCS. So far you have yet to show the readers a source that says otherwise.

Let’s not talk about an amusing configuration of an offensive that attempts to sandwich an enemy target between a pair of friendly air born radars.

Sandwich? When a fighter launches a semi-active radar guided missile, we have an airborne bi-static configuration.

The parent aircraft illuminated the target, the missile is the receiver and its position is an offset from the parent's position, thereby creating a 'bi-static triangle'...

Bistatic radar noncooperative illumination synchronization techniques

Synchronization techniques used in the Bistatic Alerting and Cueing (BAC) program are examined. Particular attention is given to illuminator search, target search synchronization, RF synchronization, PRF (pulse repetition frequency) synchronization, range gate synchronization, and solution of the bistatic triangle.

When we have data link capability, the transmitter aircraft is one leg of that triangle, the target is another leg, and the receiver aircraft is the final leg. It does not matter if there is one or ten receiver aircrafts, for each receiver there is only one bi-static triangle. That mean we can have ten bi-static triangles from one transmitter. The receivers do not have to be directly opposite of the transmitter. Forward scatter does not mean literally straight forward but can be angular as the signal is deflected off the target. If anything, the ideal bi-static position is when the transmitter-target-receiver triangle is like below...

...But since airborne targets are in motion we know this is not possible. A bi-static configuration can exploit diffraction or deflection or both. So once again your ignorance and pretense is exposed.

BTW, I'm a fanboy of no country by only of facts and truth.

More like made up 'facts' and 'truths'. But hey...Since when is a communist an honest person?

The JXX is supposedly equipped with canards. Naturally the question would be if canards are detrimental to its RCS reduction. I presented arguments and sources that say leading and trailing edges produces diffraction fields that are detrimental to RCS reduction.

RCS Pylons | Antenna Measurement Solutions

The product guide state...

The diffraction from the leading edge is dominant, if the incident rays are perpendicular to the edge.

There are two other scattering mechanisms. The first is the result of "creeping" waves which move around the shaded side, get diffracted by the trailing edge of the pylon, and emerge back towards the illuminated side. The second scattering mechanism is the "traveling" wave scattering which occurs at the ogival cross section for the electric field component which is perpendicular to the surface.

Nowhere have I asserted with absolute certainty that canards are detrimental to RCS reduction, only that conventional technical wisdom from decades of laboratory and field experience showed that edge diffraction fields are detrimental to RCS reduction if the aircraft design does not take them into consideration. There is no shortage of those literature...

Marietta Scientific, Inc. - RCS Reduction Short Course

RADAR REFLECTIVITY MECHANISMS:

SCATTERING MECHANISMS (1 hour): Scattering from complex targets; aircraft scattering mechanism overview; general aircraft model example; everything you ever wanted to know about specular scattering: specular point definition, planar surfaces, singly curved surfaces, doubly curved surfaces, leading and trailing edges, rims, and multiple bounce; frequency characteristics of various scattering mechanisms; and hierarchy of scattering mechanisms. Suitability: DE, LOT

SURFACE WAVE MECHANISM (1 hour): Surface wave definition and requirements for existence; types of surface waves: traveling, creeping, and edge; where surface waves cause scattering; surface wave reduction approaches. Suitability: DE, LOT

Got that? There are different types of traveling waves and that a leading edge does produce a diffraction field.

But here you are trying in vain to dismiss decades worth of technical experience and literature in trying to support the JXX. You are a fanboy of lies and deceit.

 

[Cityboy]

Thread is worth reading when gambit is on interdiction mission against chinese fanboy. .thanx gambit for bursting propanganda and giving dose of reality

 

[chinapakistan]

Thread is worth reading when gambit is on interdiction mission against chinese fanboy. .thanx gambit for bursting propanganda and giving dose of reality

So, why not make him indian PM? He would never be mad to say "let the world forget shanghai only remember mombai in 5 years.

 

[Cityboy]

Are you really that shortsighted? Do you really believe that radar detection is contingent upon only one part of a body? Is it possible that depending on certain factors of a body, such as shape and materical, specular reflections, aka direct reflections, can have the same signal strength as diffracted signal? Yes it is possible...The F-22 is sparing on RAM and most absorbers are on leading edges. That mean if taken as a standalone object, the specular reflection off the leading edge, as affected by absorber, will have the same or very similar signal strength as the diffracted field from the wing's trailing edge. If the entire wing's surface is coated with absorbers, then of course the diffracted field strength will be less than specular signal strength due to wave's energy loss as it traverse the wing.

That said...On a complex body, like an aircraft, all scattering points are CONTRIBUTORY elements towards the final total RCS, and we are not talking about just the geometric cross section, which is the surface area that is facing the transmitting radar. A scattering point could be from direct reflection OR from a diffraction field. If we confine the discussion to a geometric RCS, then one scattering point that exist in one aspect angle may not exist in another aspect angle. But no matter what, the signal magnitude of a diffraction field is still a CONTRIBUTOR to the body's total RCS. Not only that...On the same complex body, a diffraction signal could create a direct reflection signal. How? When the canard is in front of the wing, the canard's trailing edge create a diffraction field, which then impact the wing's leading edge. Is the wing on a different horizontal plane than the canard? Most likely. That mean part of the diffraction signal and the radar's signal may merge. Part of the diffraction signal may impact an area of the wing, leading edge or elsewhere, that is not impacted by the radar's transmission at all. So what we have here is a good possibility that the canard actually ASSISTED the seeking radar in revealing target information.

So for you to demand that we focus only the signal strength differences between direct reflection and diffraction field is utterly absurd in your feeble attempt to salvage a failed argument that the JXX's canards cannot be a negative in RCS reduction.


No...It is YOU who are wrong. As a surface wave travel, any disruption IS an abrupt medium change and will create a diffraction field. The term 'knife edge diffraction' is appropriate and is well used to describe such an abrupt medium change. Yours is typical of someone who has no relevant experience in the subject under discussion and is willing to impose his own flawed understandings of terminologies related to the subject. In radar detection, a 'scattering point' is a general descriptor for any disturbances in a radar signal's path, be it in open air or when there is a traveling surface wave. A flat plate directly facing the transmitter is a scattering point. A diffraction field IS a scattering point. A diffraction field CREATE a scattering point. On a wing, there are two edge diffraction fields: leading and trailing. So for a wing, we have direct reflections from the top and bottom surfaces combined with the two diffraction fields to make the wing one large scattering point.


In the case of a wing, the diffraction field strength is affected by the angle of approach of the incident wave. If the incident wave is perpendicular to the surface, meaning directly facing it, then the diffraction field strength is statistically insignificant. But your argument, sections of which I grouped together for clarity, missed two points: that there are two surfaces that an incident wave can traverse, and that an airfoil is not a sphere where a creeping wave can exist. An airfoil is conducive to surface traveling waves, which do not lose energy as it traverse the wing's surface. A surface traveling wave is continuously supported, or kept alive, by the transmission power itself. So for an airfoil, if the incident wave has a low grazing angle, we will have two surface traveling waves and when they meet at the airfoil's trailing edge, they will merge and the diffraction field created will have some backscatter. In the case of an aircraft, a highly complex body, creeping waves can be statistically insignificant, on the other hand, if we take a look at the F-15 from its frontal profile, the cylindrical nose section can create creeping waves if the aircraft is being scanned from the side. Looks like I know what a 'creeping wave' is better than you do...


If there is a god of radar physics, he must be laughing his guts out when he read the nonsense about bi-static radar operation from you. Anyway...What the hell does this...'inhomogeity of the medium'...mean? The 'medium' here is air, or rather relatively 'empty space'. A bi-static configuration exploits the greater forward scatter signals. So by your argument here...the inhomogeity of the medium...whatever the hell that mean...make a bi-static configuration inefficient, then that would make the mono-static configuration completely worthless. And yet mono-static radars are prevalent. As I have pointed out before and will repeat, in theory, a bi-static configuration is low observable aircrafts' best detector precisely because of those forward scatter signals. So in trying to prove me wrong about canards, you just ended up calling bi-static radars worthless against 'stealth'. Am beginning to suspect that these are not your words but someone else's that you are trying to pass off as your own. There seems to be no technical consistency.


That is why bi-static radars are no panacea to 'stealth' despite what some chinese fanboys would like believe whenever they tried to downplay the F-22. This is not because bi-static sensor systems, like the Kolchuga or Silent Sentry, do not work but because a bi-static configuration is inherently structurally intensive, requiring physically distinct transmitter and receiver stations.


Meaningless drivel. The point I am making is that diffraction energy in a contributor to a body's total RCS. So far you have yet to show the readers a source that says otherwise.


Sandwich? When a fighter launches a semi-active radar guided missile, we have an airborne bi-static configuration.

The parent aircraft illuminated the target, the missile is the receiver and its position is an offset from the parent's position, thereby creating a 'bi-static triangle'...

Bistatic radar noncooperative illumination synchronization techniques

When we have data link capability, the transmitter aircraft is one leg of that triangle, the target is another leg, and the receiver aircraft is the final leg. It does not matter if there is one or ten receiver aircrafts, for each receiver there is only one bi-static triangle. That mean we can have ten bi-static triangles from one transmitter. The receivers do not have to be directly opposite of the transmitter. Forward scatter does not mean literally straight forward but can be angular as the signal is deflected off the target. If anything, the ideal bi-static position is when the transmitter-target-receiver triangle is like below...

...But since airborne targets are in motion we know this is not possible. A bi-static configuration can exploit diffraction or deflection or both. So once again your ignorance and pretense is exposed.


More like made up 'facts' and 'truths'. But hey...Since when is a communist an honest person?

The JXX is supposedly equipped with canards. Naturally the question would be if canards are detrimental to its RCS reduction. I presented arguments and sources that say leading and trailing edges produces diffraction fields that are detrimental to RCS reduction.

RCS Pylons | Antenna Measurement Solutions

The product guide state...


Nowhere have I asserted with absolute certainty that canards are detrimental to RCS reduction, only that conventional technical wisdom from decades of laboratory and field experience showed that edge diffraction fields are detrimental to RCS reduction if the aircraft design does not take them into consideration. There is no shortage of those literature...

Marietta Scientific, Inc. - RCS Reduction Short Course

Got that? There are different types of traveling waves and that a leading edge does produce a diffraction field.

But here you are trying in vain to dismiss decades worth of technical experience and literature in trying to support the JXX. You are a fanboy of lies and deceit.

great post. . Thanx for the technicalities. . Jxx propaganda busted.

 

[new wave]

Thread is worth reading when gambit is on interdiction mission against chinese fanboy. .thanx gambit for bursting propanganda and giving dose of reality

Hmmm, to my humble opinion, this thread getting real hot after someone performing "Lip Service" to an so-called American, exciting i must say.

 

[gambit]

I would like the readers to take a look at this experiment conducted, not by US, but by India...

http://www.atmsindia.org/tp/2010/se...g wave effect in RADAR images ofTurntable.pdf

When the angle of incidence is a small grazing angle off the surface, and there is a component of the incident electric field tangential to the surface and in the plane of incidence, surface traveling waves can be induced. The surface wave travels toward the rear of the body and is backscattered by any discontinuity that it encounters along its journey (Figure 11). Reflected traveling waves radiate back very strongly in the monostatic backscatter direction when the incident angle is in the neighbourhood of the so-called Peter’s angle, calculated from end-fire antenna theory, typically about 15 to 20 degrees [2]. At these angles, traveling wave echoes at low grazing angles are reportedly nearly as significant as specular echoes at normal incidence.

Please look carefully at figure 11 as it give the readers a visual example of how surface traveling waves behave when confronted with a 'disruption' in the travel path. This is not a new experiment but a confirmation of many previous one, from field to laboratory. As the highlighted summarized -- That if the radar signal's angle of approach is below 90 deg, or closer to parallel, as in grazing angle, then the diffraction field created by the trailing edge would create a scattering point whose signal strength could be equal to that which came from a flat surface. If this diffraction field came from a canard's trailing edge, which situated in front of a wing, then we could have constructive interference where the diffraction field's signal merged with the radar signal that impact the wing's leading edge to create a stronger return of that leading edge. Or depending on the canard's attitude in flight we may have destructive interference where the diffraction field's signal partially canceling out the same radar signal. We do not know. But the argument presented so far in favor of the JXX's canards as an RCS non-factor does not stand up to technical literature.

 

[Speeder 2]

... But the argument presented so far in favor of the JXX's canards as an RCS non-factor does not stand up to technical literature.

Unless, of course, you take preliminary technical literatures as technical bibles.

 

[AZADPAKISTAN2009]

Its been like month where is the flight pictures

 

[SinoIndusFriendship]

Its been like month where is the flight pictures

Buddy! Knowing the PLA, it will be year(s) before the photos are leaked. But rest assured it's coming along nicely.

 

[desiman]

Buddy! Knowing the PLA, it will be year(s) before the photos are leaked. But rest assured it's coming along nicely.

ya the photoshop guys are working hard, we shall see the jet soon