Innovative programmable periscope developed to enhance drone detection in urban areas

The City University of Hong Kong, in collaboration with the Nanjing University of Science and Technology, has unveiled a groundbreaking programmable periscope designed to detect drones operating out of sight, even when blocked by towering buildings.

This development aligns with Chief Executive John Lee Ka-chiu's proposal to foster a low-altitude economy in Hong Kong, as outlined in his policy address last October.

Chair Professor Guo Yongxin from the Department of Electrical Engineering at CityUHK described the periscope as a significant advancement toward safer drone operations in Hong Kong's densely populated urban environment.

"In bustling urban landscapes, ensuring safety from drones has taken a remarkable leap forward with this innovative programmable metasurface periscope," Guo said.

Equipped with a low-cost, ultra-thin metasurface, the periscope can modulate the amplitude, phase, and polarization of surrounding light, allowing for more accurate detection of obscured drones.

The research team has also lowered the periscope’s sensitivity to wave angles by introducing a full-resonant-structure-based metasurface cell, which effectively eliminates errors in radar wave direction estimation.

Guo said that the angle sensitivity issues of existing metasurfaces had previously hindered the transition from theoretical models to practical radar systems.

"Our new technology is significantly more insensitive to wave angles, paving the way for the practical design of metasurface-aided radar systems," he said.

Also, the programmable metasurface periscope is not only cost-effective to produce but also easy to deploy, making it an ideal solution for integration into conventional radar systems to expand coverage areas.

(Ayra Wang)