- State of the art jamming technology sends back ‘spoof’ signals that fool radar operators into believing their target is harmless or elsewhere
- New technology can detect these kinds of ruses by reading the quantum signature of photons transmitted to ensure the signal is genuine
- Any attempt to measure a photon always changes its quantum properties
By DAMIEN GAYLE
U.S. researchers have employed the quantum properties of photons to create an unjammable radar signal.
Conventional radar is vulnerable to a range of technologies, ranging from dropping chaff to create false reflections to drowning the radar frequency with noise.
More sophisticated radar can deal with such ploys, but the most sophisticated radar jammers are able to intercept the the signals and send back false information.
However, a team from the University of Rochester, New York have shown how the quantum properties of photons can be used to outsmart this advanced stealth technology.
The new radar concept relies on the fact that any attempt to measure a photon always destroys its quantum properties, MIT’s Technology Review explains.
To exploit this curious property, the Rochester team suggest using polarised photons to detect and image objects.
If a stealth aircraft attempts to intercept these photons and resend them in a way that disguises its position, it would inevitably change the photons’ quantum properties – revealing any interference.
‘In order to jam our imaging system, the object must disturb the delicate quantum state of the imaging photons, thus introducing statistical errors that reveal its activity,’ the researchers say in a paper published in the journal Applied Physics Letters.
‘A sophisticated jammer may use quantum teleportation to teleport the polarisation state of our querying photons onto photons carrying false position or time information’