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I have a hard time beleiving that a stealth aircraft would have a circular intake; rather than a two dementional intake. Could this just be the JF-17?
Also can anyone translate the text in the caption?
Lastly is the J-XX going to use canards? and if so, can someone explain why? The way i understand it is, canards emit a large rcs, canards also create drag.
Sukhoi got rid of the canards on the SU-35. Consiquently, the rcs improved dramatically. However, the use of composites probably helped too.
1st of all, no one is sure whether the J-XX will have canards or not.
2nd, why would it have a larger RCS? why can't you just treat the canard as any other wing on the plane?
Because an aircraft is a complex body and its RCS is the result of many surface radar signal behaviors at any time.1st of all, no one is sure whether the J-XX will have canards or not.
2nd, why would it have a larger RCS? why can't you just treat the canard as any other wing on the plane?
So as we can see that a corner reflector not much larger than hand span can create an RCS of 12 square meters in the bands that most military radars uses, including the missiles themselves.These 12 1/2" dia. reflectors are very common on many cruising boats. All models can be stored flat and assemble in minutes. Plates are held together by tough, injection molded corner latches. Assembled reflectors include a 1 1/4" (32mm) windage hole for reduced aerodynamic drag, which also allows for backstay mounting. Standard Echomaster: 13.2 square yards (12 square meters) of radar cross section in the 9-9.6 GHz X or 3cm radar band.
The 'shift' is the movements of the canards as they maintain flight stability, steady or in maneuvers. Other types of radar scintillations, or 'shifts of reflective' points, are main and tail helo rotors. Ballistic missile warheads descending through the atmosphere spins to maintain stability and because the warhead body is not uniform with fins and nozzles and whatever else, those surface imperfections also create radar scintillations.This effect can be caused by a shift of the effective reflection point on the target, but has other causes as well.
Because an aircraft is a complex body and its RCS is the result of many surface radar signal behaviors at any time.
The two illustrations above are basic radar behaviors upon planar surfaces.
Corner reflectors are like beacons and they are useful in coastal marine safety as they amplify small boats on a radar scope.
Safety Reflector
So as we can see that a corner reflector not much larger than hand span can create an RCS of 12 square meters in the bands that most military radars uses, including the missiles themselves.
And that is how the aircraft itself can become a corner reflector, a huge 'no-no' in RCS reduction.
That is the XB-70. Its design exploit the 'compression lift' principle to Mach cruise. Essentially, the body sort of 'surf' the Mach wave the aircraft produces. You can read up on the principle here...
Aerospaceweb.org | Hypersonic Waveriders - Vehicle Characteristics
But in order to exploit compression lift, the design ended up with many corner reflectors as shown with the wing tips and CANARDS. The aggressor radar from below illuminating the bomber will have its radar signals returned to it from the canard corner reflectors and the bent wings. It is bad enough that the wings themselves can reflect radar signals if the approach angle is 'just right' so why compound the problem with canards?
That is not to say that canards 'cannot' be on a body. It simply means that canards present extraordinary RCS issues to overcome. If they are control flight surfaces, their movements will create 'radar scintillations'...
Scintillation (radar) - Wikipedia, the free encyclopedia
The 'shift' is the movements of the canards as they maintain flight stability, steady or in maneuvers. Other types of radar scintillations, or 'shifts of reflective' points, are main and tail helo rotors. Ballistic missile warheads descending through the atmosphere spins to maintain stability and because the warhead body is not uniform with fins and nozzles and whatever else, those surface imperfections also create radar scintillations.
Those are scatter points on an aircraft. That is how a radar sees a target -- collections of scatter points. A statistic algorithm, and there are levels of complexity for these algorithms, will determine if these scatter points are persistent enough over time, distance and cluster and will display a target. A pair of scintillating scatter points ANYWHERE in that cluster is a giveaway and improperly designed flight control canards will negate any RCS reduction on the rest of the body. This is why I chuckled every time I read some Russian and Chinese junk fanboy's comment -- Oooohhh...Aaahhh...Canards...Coool....
The USAF heartily encourages potential adversaries to install canards on their fighters.
Clear as mud?