I’ve never heard of quantum radar before, and I fear this simple explanation in NewScientist (17 November 2018, paywall) may still be too far above my head:
In theory, a quantum radar can overcome this by using two streams of entangled photons. These are pairs of photons that have a weird connection so a change to one affects the other, even if they are miles apart.
The first photon stream is sent out, like a standard radar beam, and bounces off objects in the sky. The second stream remains inside the system.
Because the photons are entangled, the returning photons can be matched with those in the stay-at-home stream, so all background noise can be filtered out. This includes deliberate interference, such as radar jamming or spoofing signals put out to confuse radar. What is left is a clear image of the target, with no extraneous signal.
Maybe if I was a physicist, or an electrical engineer. And, yes, a Chinese defense firm claims to have developed just such a thing.
