Radar technologies were originally designed to identify and track airborne military targets. Today, they're more often used to detect motor vehicles, weather formations, and geological terrain. Until now, scientists believed that radar accuracy and resolution are related to the range of frequencies or radio bandwidth used by the devices. A new approach inspired by optical coherence tomography (OCT) requires little to no bandwidth to accurately create a high-resolution map of a radar's surrounding environment. The new technology has numerous applications, especially with respect to the automotive industry.
It was commonly believed that radar resolution was proportional to the bandwidth used — the broader the range of frequencies, the more accurate the detection of objects. But it has now been demonstrated that low-bandwidth radars can achieve similar performance at a lower cost and without broadband signals by exploiting the coherence property of electromagnetic waves.
Two wave sources are perfectly coherent if they have a constant phase difference, the same frequency, and the same waveform. The new “partially coherent” radar is as effective at resolving targets when compared with standard “coherent” radars in experimental situations.
The new concept offers solutions in situations that require high range resolution and accuracy but in which the available bandwidth is limited, such as self-driving cars, optical imaging, and astronomy. Not many cars on the road today use radars, so there is not much competition for allocated frequencies; however, that will change when every car is equipped with radar and every radar demands the entire bandwidth.
The technology could be applied to previously unexplored areas like rescue operations to sense if an individual is buried in a collapsed building, or street mapping to sense if a child is about to cross the street behind a bus that conceals him.