Quantum Radar


Quantum Computing is about to upend our Digital Privacy, but I only just learned Quantum Algorithms will do the same for Military Stealth too…

Currently, stealth works in a couple of basic ways:

  1. Minimising the reflected radar signal.
  2. Sending back a fake signal.
  3. Messing with the electronic brain of the radar system (but this is more electronic warfare than stealth).

For a radar system, both 1 and 2 can be circumvented if there is someway for it to focus exclusively on the echoes from its own beam by filtering all the other photons. In this way, it can concentrate on the real target and ignore innocent but confusing background noise, and deliberate spoofing with fake signals.

Radars today try to filter out these false signals by focusing on specific frequency ranges and very precise timings, but clever EM warfare packages are able to spoof these techniques.

What the radar needs is a way to securely ‘tag’ its own photons, so that it can filter and ignore anything else…

Enter the Quantum Radar…

“Only a few of the photons sent out will be reflected back if they hit a stealth aircraft. A conventional radar wouldn’t be able to distinguish these returning photons from the mass of incoming signals created by natural phenomena—or by radar-jamming devices. But a quantum radar can check for evidence that incoming photons are entangled with the ones held back. Any that are must have originated at the radar station. This enables it to detect even the faintest of return signals in a mass of background noise.

Confused signals from target, environment and spoofing.

Background noise is filtered by quantum algorithms which only allow photons through if they are entangled with clones of the transmitted photons held in the radar’s ‘quantum memory’ .

The target is revealed.
However faint the real signal, it can never be swamped because only reflections from the radar station are considered.

https://www.technologyreview.com/s/612421/us-china-quantum-arms-race/

Amazing!