Do you understand what a non-sequitur is? Because you just demonstrated one. The second sentence there has nothing to do with the first. The fact that stealth aircraft have different RCS from different aspects has nothing to do with the question of size. Incidentally, it's amusing that you believe the B-2's RCS from the bottom aspect is higher than a B-52's. Anyway, you don't need to take my word for it - I quote Ben Rich's "Skunk Works": - "with [stealth surfaces] the amount of radar energy returning to the sender is independent of the target’s size. A small airplane, a bomber, an aircraft carrier, all with the same shape, will have identical radar cross sections."
The
ENTIRE and
CORRECT quote, as on page 33 of the paperback version of
Skunk Works, which sits on my bookshelf, is...
He told me later that he was surprised to learn that with flat surfaces the amount of radar energy returning to the sender is independent of the target’s size. A small airplane, a bomber, an aircraft carrier, all with the same shape, will have identical radar cross sections.
The relevant words are
'with flat surfaces' and
'all with the same shape'.
The 'he' in that passage referred to Kelly Johnson, who, as remembered by Ben Rich, talked to Denys Overholser, the engineer who dissected Pyotr Ufimtsev's math and who came up with the final
SHAPE for the F-117.
What that passage mean, in the technical sense, is that the 'small airplane, a bomber, an aircraft carrier' must be composed of flat surfaces and all must be of identical shape. Further, the position of the seeking radar must also be at identical location and distance
PER body, meaning that if the seeking radar is perpendicular to and 5 km away from the small airplane, it must also be perpendicular to and 5 km away from the aircraft carrier. It cannot be even one degree and one meter off from body to body. So in hypothesis, not theory, all bodies would have the same RCS. This hypothesis was never proven to become a theory simply because no one yet built these bodies to be of the same material and shape.
But if we take a specific body from that hypothetical list and rotate it, there will be different RCS values simply because the body will present different shapes to the seeking radar. Yes,
DIFFERENT SHAPES.
Look at it this way -- a square plate.
Assume I label the plate with 'top' and 'bottom' sides. If I rotate the plate so that 'top' is visible to you, you will see a square. But if I rotate the plate so neither 'top' nor 'bottom' is visible to you, the shape you will see is a line or an edge. Under radar bombardment, the edge will produce the least reflections while 'top' and 'bottom' will produce the most. What Ben Rich, Kelly Johnson, and Denys Overholser was talking about was 'specular reflections'. Look it up.
Specular reflection off and edge will not be the same as off a flat surface. Further, specular reflection off a leading edge will not be the same as off a trailing edge.
Let us return to our plate and assume it to be one meter area.
If the seeking radar signal is perpendicular to one edge, the highest specular reflection will be from the edge that is facing the radar, or the leading edge. Then there will be some surface traveling waves which will produce weaker specular signals and these are usually called 'leaky' or 'radiated' signals. Since our plate is finite at one meter area, eventually these surface traveling waves will meet another edge, the trailing edge. The signals that will come off this location will be called 'diffraction' signals.
So from an edge point of view, we see in order of signal strength:
- Specular reflection
- Leaky or radiated
- Diffraction
In an EM clean and isolated environment like a lab, the seeking radar will see specular, some leaky, but no diffraction, but mathematically, all three should add up to equal the original signal strength.
To compound the already complex subject of signal behaviors, the leading edge will produce diffraction signals as well, then there is the issue of signal characteristics such as amplitude, freq, and pulse, if pulses are used.
Not only did you have the incomplete passage from Ben Rich, it looks to me you have neither education and experience in the subject in discussion. I have no experience in designing 'stealth' aircrafts, but I have a combined nearly 19 yrs of aviation and avionics experience in and out of the USAF. I know what 9 gs in an F-16 felt like since I was on it for 5 yrs. Before the F-16, I was on the F-111 from RAF Upper Heyford, UK. Out of the USAF, I used to design field radar tests to detect 'low altitude non-piloted aircrafts' for a company that will remain unnamed.
So yes, I do not have to take your words for it since you have nothing relevant, especially since you could not even get the book's passage correct probably because you never read it in the first place.
