Arbitrary? In your ignorance, not mine.
Here we go again...There are three rules in designing a low radar observable body...
- Control of
QUANTITY of radiators
- Control of
ARRAY of radiators
- Control of
MODES of radiation
If the rules are 'arbitrary', then how do you explain the Lincoln Calibration Sphere in orbit and the B-2? The fact that Lincoln Sphere exists is proof enough. But wait...There is more...
https://www.centurymetalspinning.com/radar-calibration-spheres/
Why is the sphere -- but not the cube or the pyramid or the trapezoid or the cone or whatever -- the ideal calibration body for any radar design?
Because the sphere is the most obedient to Rule One: Control of
QUANTITY of radiators.
Look at these...
https://www.popularmechanics.com/mi...-stealth-drone-has-no-moving-surfaces-at-all/
BAE Systems has unveiled a new aircraft design that could be a major advance in stealth technology.
...uses blown air to change direction instead of complex mechanical controls.
https://www.thedrive.com/the-war-zo...hing-wing-technology-will-the-b-21-feature-it
Joints are not good for low observability, and flapping around control surfaces exposing those joints are especially bad. Large, seamless, continuously rounded structures that are edge-aligned to the general aircraft design are best for broadband low observability.
What is the common theme for both attempts to reduce RCS?
Rule Two: Control of
ARRAY of radiators
Moving structures affects how EM waves exits a finite body like a wing.
In post 11865 page 791, I asked
YOU: In theory, what is the first thing a radar engineer is taught about surfaces?
In theory, the first thing an aspiring radar engineer is taught about surfaces is that it is infinite, whether that surface is on a plane or an edge. Of course, we know such a thing does not exist. All bodies are finite in shape and dimensions. But the reason an EE is trained to calculate on an infinite surface is to eliminate all other influences.
In real life, any body is a finite body and somehow some time an EM wave must leave that body as in Rule Three: Control of
MODES of radiation
So now with the two above sources, we have rules two and three in play. A moving structure like an aileron changes its physical relationships -- array -- to other structures. As the EM wave exits the aileron, how or the mode it radiate into free space is important. Rules Two and Three affects each other.
If we can eliminate aileron like how BAE is exploring or by introducing curvatures like how the USAF is experimenting, we becomes more and more obedient to all three rules.
Still think I do not know what I am talking about? Then look at this...
Why is the radome on the Su-27 a rounded conic but the radomes on the F-22, J-20, and PAK-FA have ridges on the sides?
Because of Rule Three: Control of
MODES of radiation
In radar detection, there is something called the '10-lambda rule'. To sum it up, lambda ( λ ) is the symbol for wavelength and if the diameter is less than 10-lambda, there will be an effect called the 'creeping wave'...
A radome is not a cylinder but mostly a conic, so that mean eventually, a radar signal will travel around the decreasing diameter of the radome and this is not what we want in a low radar observable design, hence the ridges or chines on the radomes of the F-22, J-20, and the PAK-FA. As the creeping wave travels around the radome, the ridges provided an exit point that will not be detected by the seeking radar on the other side. In this instance, we exploited Rules One and Three to our advantage: we increased the
QUANTITY of radiators and altered the
MODES of radiation.
And just in case you think I made up this 10-lambda rule, think again...
Look at the names of the authors and city where they came from. You can be quite sure they are non US, eh? Look at the yr of the conference. Look at the intro: >10 λ
Like it or not, the J-20 is less obedient than the F-22 and the F-35 to the three rules. You can take everything I posted so far to any EE professor and I will be proven correct. You are treading into a domain you know nothing about but too arrogant to admit it.
I schooled you, pal.