MPDI Special Issue Depth Sensors and 3D Vision publishes University of Siegen, Germany, paper "Pulse Based Time-of-Flight Range Sensing" by Hamed Sarbolandi, Markus Plack, and Andreas Kolb.
"Pulse-based Time-of-Flight (PB-ToF) cameras are an attractive alternative range imaging approach, compared to the widely commercialized Amplitude Modulated Continuous-Wave Time-of-Flight (AMCW-ToF) approach. This paper presents an in-depth evaluation of a PB-ToF camera prototype based on the Hamamatsu area sensor S11963-01CR. We evaluate different ToF-related effects, i.e., temperature drift, systematic error, depth inhomogeneity, multi-path effects, and motion artefacts. Furthermore, we evaluate the systematic error of the system in more detail, and introduce novel concepts to improve the quality of range measurements by modifying the mode of operation of the PB-ToF camera. Finally, we describe the means of measuring the gate response of the PB-ToF sensor and using this information for PB-ToF sensor simulation."
So, as far as I understand, the PB-ToF emits short pulses repeatedly rather uniformly(?), while AMCW emits pulses in bunch of bursts. The distance detection principle seems quite similar (from my knowledge of AMCW).
ReplyDeleteI don't see much explanation on how these seemingly minor differences are causing the changes in the modes (or something) to the sorts of errors described ...