Coincidence in SPAD-based time-of-flight sensors

High ambient illumination reduces the range and target detection reliability in light-based 3D sensors. Raising the optical power of the artificial illumination source to overcome the influence of high ambient light is often not possible for systems with flash illumination due to eye safety constraints. The high timing resolution of single-photon avalanche diodes enables the search for photon concurrences in incident photon streams. In this paper a theoretical analysis of coincidence and its benefits for 3D sensors with single-photon avalanche diodes is presented.