Geeezzz...
First, the oxide canopy coatings are not for absorption, they are conductive.
An absorber is a conductor. An absorber is a composite that literally attempt to conduct -- and largely succeed -- in drawing surface impinging signals
INTO the composite...
In addition, you are constantly harping about traveling waves as if they are the primary problem with stealth when specular reflections actually are. So, at least you got something right here about reflections and shaping.
Further, when absorbers are installed on a curvature, surface traveling waves can be affected as well, depending on the sophistication of the composite design. The cost is weight penalty because different composite materials must be employed to affect different signal behaviors, mainly refraction. And where did I 'harp' on that surface traveling waves is the primary concern? Still, here is where you are misinformed: The mono-static configuration.
A mono-static radar is where the same antenna is used for transmit and receive. Either it is the same antenna or when two antennas are so physically close to each other that depending on the distances involved, they might as well be one virtual antenna besides being two physically distinct antennas.
This is what a bi-static configuration look like...
Receiver B would receive the greatest amount of re-directed reflections from aircraft. As the aircraft move across the field-of-view of
ALL receivers, eventually it would be Receiver A that is the recipient of the greatest amount of re-directed reflected signals off the aircraft.
If all stations as illustrated above are mono-static radars, then we are still with a mono-static configuration, albeit the aircraft would be under multiple mono-static radar bombardment from different directions at once. If all stations communicate with each other, and am not talking about voice communications, as to who is transmitting what at what time and so on, then we would have a bi-static assault, or as some would call it' multi-static'. This is still experimental at this time.
The F-117's focus was primarily on the mono-static configuration due to the technology level at that time. The B-2, F-22, and F-35 focuses on both mono-static and bi-static configurations. Their curvatures were predicted, precisely modeled, tested, and the whole process recycled until the surface traveling waves, which became dominant after specular and equally important on a curvature, are controlled as much as possible. That is why absorber on the second generation of US 'stealth' aircrafts are not as prominent as on the F-117.
So here is the flow:
- Against a mono-static configuration using only angled faceting techniques, initial specular reflections dominate and surface wave behaviors can be safely ignored. But the bi-static configuration will have the advantage.
- Against both mono-static and bi-static configurations using curvature and angled faceting techniques with curvatures being primary, initial specular reflections are still of the highest response but once there are surface traveling waves, there is nothing else as important
IF the desire is to counter against the bi-static configuration.
The problem I see with most people who are more willing to place their nationalistic zeal over objectivity is that they refuse to consider anything more complex than what they are capable of understanding, and that refusal led them -- read the Chinese boys -- to make ridiculous claims that often bordered on defying the laws of physics.
They seems to be incapable of being curious as to why there is such a radical departure from the F-117's visually stunning design to the more ordinary shaping of the F-22 and yet the F-22 is actually more radar defying in all-around perspective. They -- like
YOU -- refuse the consider that there can be a secondary effect that are
AS IMPORTANT as the first effect but that secondary effect is important only if there is an attempt to counter another radar configuration.
So I will sum it up again:
- The F-117's design was primarily against the mono-static configuration using only one technique: angled facetings. In this situation, specular reflections is of primary importance.
- The F-22's and others' designs are against both mono-static and bi-static configurations using both angled facetings and curvatures. In this situation, we have two effects: specular reflections and surface waves, one after the other, and both are of primary importance when they occur. So if I 'harp' on the surface traveling effects, I am well within technical justifications based upon customer demands: To work against both mono-static and bi-static configurations.
For both the J-20 and the T-50, or PAK-FA or whatever anyone want to call it, we have no credible data, despite the Chinese boys' harping on that APA's crap of an 'analysis' for the J-20, if the J-20's shaping have been attempted to go against the bi-static configuration. We can only speculate from looks alone and it is entertaining at best.
I will say this and I do not care if no one here believe me: That the US with the B-2, F-22, and F-35, preempted very well most bi-static attacks, even though there has yet to be an effective bi-static military radar deployed.
Since when did I say or suggest the F-117 did not have a stealthy canopy? You brought that up all by yourself when the message you responded to was about the unstealthy T-50 canopy which has no oxide coating and a metallic frame (with rivets).
- bubble canopies have no frame, which means no frame to disrupt and reflect EM back to source
- J-20 has a conductive oxide canopy which means EM will not reflect back to source
I brought it up to illustrate the falsity of your argument. If we can install a far less radar reflective canopy on the F-16, who is saying that the Russians cannot do the same for the T-50? The reality is that the canopy is of minor importance.
