High precision 3D imaging with timing corrected single photon LiDAR

Abstract

Single photon light detection and ranging (LiDAR) is an important technique for high precision long distance three-dimensional (3D) imaging. However, due to the effects and native limitations of system components, there exists ranging errors when using LiDAR system. For the LiDAR system that requires trigger detector to provide synchronization signals, the fluctuation of laser pulse energy causes the change of the initial time of the constant threshold triggered timing module, and subsequently leads to the ranging error. In this paper, we build a dual SPADs LiDAR system to avoid the ranging error caused by the fluctuation of laser pulse energy. By adding a reference optical path, the flight time of signal photons is corrected by reference photons, so as to realize the correction of ranging. A series of experiments demonstrate that the proposed LiDAR system has the capability of high precision ranging and 3D imaging. The system achieves range of error of 0.15 mm and range resolution of 0.3 mm at a distance of 29 m.