Tracking hidden objects with a single-photon camera

TL;DR

This paper presents a novel non-line-of-sight laser ranging system using a single-photon camera, capable of detecting and tracking hidden objects around corners with centimetre precision at human scales.

Contribution

The work introduces a compact, efficient method for tracking hidden objects using a SPAD camera and scattered light, overcoming previous limitations of size, surface requirements, and data acquisition time.

Findings

Successfully tracks hidden objects around corners with centimetre accuracy.

Operates effectively at human length scales.

Demonstrates real-time tracking of moving objects.

Abstract

The ability to know what is hidden around a corner or behind a wall provides a crucial advantage when physically going around the obstacle is impossible or dangerous. Previous solutions to this challenge were constrained e.g. by their physical size, the requirement of reflective surfaces or long data acquisition times. These impede both the deployment of the technology outside the laboratory and the development of significant advances, such as tracking the movement of large-scale hidden objects. We demonstrate a non-line-of-sight laser ranging technology that relies upon the ability, using only a floor surface, to send and detect light that is scattered around an obstacle. A single-photon avalanche diode (SPAD) camera detects light back-scattered from a hidden object that can then be located with centimetre precision, simultaneously tracking its movement. This non-line-of-sight laser ranging system is also shown to work at human length scales, paving the way for a variety of real-life situations.