Kostamovaara Juha, Jahromi Sahba S, Keränen Pekka
Circuits and Systems Research Group, ITEE Faculty, University of Oulu, 90570 Oulu, Finland.
Sensors (Basel). 2020 Oct 22;20(21):5973. doi: 10.3390/s20215973.
The relation between signal and background noise strengths in single-photon avalanche diode (SPAD)-based pulsed time-of-flight 3-D range imaging is analyzed on the assumption that the SPAD detector is operating in the single photon detection mode. Several practical measurement cases using a 256-pixel solid-state pulsed time-of-flight (TOF) line profiler are presented and analyzed in the light of the resulting analysis. It is shown that in this case it is advantageous to concentrate the available optical average power in short, intensive pulses and to focus the optical energy in spatial terms. In 3-D range imaging, this could be achieved by using block-based illumination instead of the regularly used flood illumination. One modification of this approach could be a source that would illuminate the system FOV only in narrow laser stripes. It is shown that a 256-pixel SPAD-based pulsed TOF line profiler following these design principles can achieve a measurement range of 5-10 m to non-cooperative targets at a rate of ~10 lines/s under bright sunlight conditions using an average optical power of only 260 µW.
基于单光子雪崩二极管（SPAD）的脉冲飞行时间三维距离成像中，在假设SPAD探测器工作在单光子探测模式的前提下，分析了信号与背景噪声强度之间的关系。根据所得分析结果，给出并分析了使用256像素固态脉冲飞行时间（TOF）线阵探测器的几个实际测量案例。结果表明，在这种情况下，将可用光平均功率集中在短而强的脉冲中，并在空间上聚焦光能是有利的。在三维距离成像中，这可以通过使用基于块的照明而不是常规使用的泛光照明来实现。这种方法的一种改进可以是仅在窄激光条纹中照亮系统视场的光源。结果表明，遵循这些设计原则的基于256像素SPAD的脉冲TOF线阵探测器，在明亮阳光条件下，使用仅260 μW的平均光功率，能够以约10线/秒的速率实现对非合作目标5 - 10米的测量范围。
