Quantum Radar--End of Stealth?

Discussion in 'Physics' started by BR-549, Sep 22, 2016.

  1. BR-549

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  2. nsaspook

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    I've read several technical papers on the subject. That Chinese report is at best misinformation. You need to be able to track and target the aircraft not just detect a ghost signature. For true long range radar you need microwaves. The theory is to entangle optical photons, design a optical to microwave quantum mixer that preserves optical quantum coherence in a microwave RF signal, send the optical signal to a idle module while transmitting the microwave signal, receive the reflected microwave photonic signal return from the target, remix the microwave photons return with the original optical photons in the idler to detect coherence as a radar return. To say this is tricky is an understatement.

    https://www.researchgate.net/publication/291698953_Range_detection_using_entangled_optical_photons
     
  3. Papabravo

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    Stealth is not required if you can fly higher and faster than your adversary. Nobody ever touched an SR-71 and they overflew numerous sensitive areas.
     
  4. BR-549

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    That's kinda how I understood it.......but if the emitted wave and the idle module wave are entangled..........then who cares about a reflection?
    Everything the emitted wave encounters.....will be mirrored in the keeper wave.
    No receiver needed.
    If an entangled wave gets bounced.....doesn't the mirror get bounced in an inverted manner?
     
  5. BR-549

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    If a small us destroyer can shoot down a satellite, an SR-71 hasn't a chance.
    The only reason the blackbird was successful, was missile range and speed. That is no problem now.
     
  6. nsaspook

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    The SR-71 had the 'Stealth' technology of the period. The RSC was about 10m^2 (about the same as a small light aircraft). I've seen a few fly out of Kadena Air Base (visual), top off the tanks mid-air and then streak off the northern coast of Russia on radar. This little bit of stealth combined with speed and height made a firing solution impossible for the time they spent over country once detected and tracked.

     
  7. nsaspook

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    You need the reflected signal as part of the quantum detection system. The communication of information about the target is not superluminal. You need a classical (light speed) return channel to decode the response.
     
  8. Papabravo

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    I got up close and personal with the one at the Air Force Museum in Dayton, OH. I was fascinated by the turbine starting trailer which couples a pair of big Chrysler Hemi engines to a vertical shaft that attaches to a fitting in the bottom of the turbine pods and spins those babies up.
     
  9. nsaspook

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    They had several countermeasure packages for missiles


    We have one in Oregon.
    [​IMG]

    and the CIA had their A-12 to play with.
     
  10. wayneh

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    I saw one, in Utah at Hill AFB I think. I was intrigued with the titanium skin and the fact that the wingtips were just solid titanium, not a skin over a hollow space. Every detail about this thing is amazing, like the way they leak fuel like a sieve until they heat up in flight, expanding the skin and closing the leaks. Not gonna see that on a 737.
     
  11. Papabravo

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    I just think it was one of Kelly Johnson's finest creations.

    https://en.wikipedia.org/wiki/Kelly_Johnson_(engineer)
     
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  12. BR-549

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    Problem........stealth aircraft absorb or deflects radar. The reflected signal is too weak. There is NO reflected signal.

    Solution..........Do not require reflected signal.

    Wave entanglement..................The ability of a partnered stationary wave to react in an inverted or mirrored manner...........superluminal, to the moving wave. If the reaction is not instantaneous.......entanglement is useless for this app, because of the needed time or length reference needed for c.

    And if ANY reflection is required....................the whole premise of quantum radar is useless.
     
  13. nsaspook

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    It's not useless because in 'theory' just a few returned entangled photon could detect the target. The RCS of a F-22 type aircraft is the size of a small bird. The plane is not EM cloaked, it only seems very small on radar so the return signal for classical radar is below the thermal shot-noise level even for the best cryogenic frontends at target-able distances.
    https://arxiv.org/pdf/1305.4162v3.pdf
     
  14. BR-549

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    OK let me see if I got this. Your saying that the idea is that the entangled returning wave can be detected easily in the noise because of the mirror reference?
    Is that it?
     
  15. nsaspook

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    Yes, that's about it. You have a quantum coherent signal not related to Gaussian noise or normal EM effects to process. You then find methods to destructively remove those signals while reinforcing the quantum probability signal from the return. I think the main problem will be effectually processing the quantum signal into usable targeting information without a true quantum computer in field conditions.
     
  16. WBahn

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    One thing to keep in mind is that stealth radar technology isn't so much that the radar is not reflected, it is that it is reflected somewhere other than the receiver when the receiver is located near the transmitter. If you locate the two in very different locations (so that the subtended angle between the two from the target is significant), then you have a lot more signal to work with. But such systems are unwieldy and complex (read -- unreliable and expensive).
     
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  17. WBahn

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    The only one I ever got to work on -- and I am grateful both that I got to work on one and that I only had to work on just one -- is (as of about 2004 when I was there) on display at the Pima Air Museum near Tucson, AZ. It was parked almost right next to one of the F-15's that I had also worked on. Other than those two, the only other bird that I know of that I physically worked on is the F-15 on the Terrazzo at the Air Force Academy.
     
  18. BR-549

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    As for entanglement...........when it is broken............the effect is instantaneous right?
    No matter the distance right?
    And this has been recorded, right? And can be repeated?
    This is a proven action...................is that correct?
     
  19. nsaspook

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    I never got close to a operational bird only maybe some of the Intel product as messages. We only would see the possible (Officially, the SR-71 never overflew Russian airspace) end product of a flight by the FLASH traffic of intercepts usually near the soviet border at Kamchatka Peninsula from an Asian based SR-71.

    Even today they still fly over Vietnam. :D
     
  20. nsaspook

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    That seems to be the case by the best scientific measurements.
    http://newatlas.com/quantum-entanglement-speed-10000-faster-light/26587/
    https://en.wikipedia.org/wiki/Quantum_nonlocality
    http://arxiv.org/pdf/1303.0614v1.pdf

    What this tells us about the true nature of the universe is beyond my understanding.
     
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