Object Detection System Separates Range Resolution from Bandwidth Limitations

A new Tel Aviv University (TAU) study investigates an approach to object detection, inspired by OCT, that requires little to no bandwidth to accurately create a high-resolution map of the environment that is within range of a radar system.

The new system contests the belief that radar resolution must be proportional to the bandwidth used. The TAU researchers demonstrated that low-bandwidth radars can achieve similar performance to radars with high bandwidth, at a lower cost and without broadband signals, by exploiting the coherence property of electromagnetic waves. The new “partially coherent” radar was shown to be as effective as a standard radar in experimental situations. In a trade-off between bandwidth and longer sweep time, the TAU system separates the quality of range resolution from the transmitted signal bandwidth.

Partially coherent radar operation schematics. The coherence length (or time) of the radar is swept from shortest to longest, scanning the location of targets along the line of sight. Note: The width of the beam is drawn differently for each wave solely for clarity of illustration. Inset: Schematic representation of the radar system. Courtesy of Nature Communications.

The system could be utilized to make bandwidth-efficient, low-power, physically compact systems for ranging purposes, integrated into existing beamforming and scanning systems. Autonomous cars, airborne radar systems, and aerospace imagers could use this system to improve their ability to detect targets and identify objects that are situated close together in densely populated frequency spectrum areas.

“Our concept offers solutions in situations that require high-range resolution and accuracy but in which the available bandwidth is limited, such as the self-driving car industry, optical imaging, and astronomy,” said researcher Vitali Kozlov. “Not many cars on the road today use radars, so there’s almost no competition for allocated frequencies. But what will happen in the future ... Our solution permits drivers to share the available bandwidth without any conflict.”

Professor Pavel Ginzburg said that the team intends to apply its technology to other areas, such as sensing whether an individual is buried under a collapsed building, or whether an individual who is concealed from oncoming traffic is about to cross the street. “It’s worth noting that existing facilities support our new approach, which means that it can be launched almost immediately,” Ginzburg said.

The research was published in Nature Communications (https://doi.org/10.1038/s41467-019-09380-x).