Sensing in NLOS: a Stroboscopic Approach

Sensing in non-line-of-sight (NLOS) is a well-known issue that limits the range of radar-like sensors. Existing approaches rely on either metallic mirrors, that only work under specular reflection, or dynamically-reconfigurable metasurfaces that steer the signal to cover a desired area in NLOS, with the drawback of cost and control signaling. This paper proposes a novel vehicular sensing method, here referred as Stroboscopic Sensing, where a moving source images a desired region of interest (ROI) in NLOS leveraging on source beam sweeping over a sufficiently large portion of a reflection plane, passively pre-configured as a periodic angular deflecting function to illuminate the ROI. Consequently, the source is able to cover the ROI and enhance the spatial resolution of the image, thanks to multiple diverse observation angles of ROI. In the context of vehicular sensing systems, our method allows a moving vehicle to perceive its surroundings beyond obstacles, improving situational awareness. Remarkably, the proposed method achieves near-field imaging with a sequence of far-field acquisitions, thus limiting the implementation complexity. We detail the system design criteria and trade-offs, demonstrating the remarkable benefits of such sensing method, where a possibly moving source can observe a ROI through multiple points of view as if it were static.