光子计数激光雷达游走误差与时间抖动的研究

Research on Range Walk Error and Timing Jitter of Photon Counting Lidar

摘要:

光子计数激光雷达具有灵敏度高、体积小等特点,是未来远距离探测激光雷达的发展方向。光子计数激光雷达在探测时会产生游走误差,从而影响系统的测距精度。文章就游走误差与探测器时间抖动之间的关系进行了理论分析与实验验证。首先,基于激光雷达方程、单光子探测器时间抖动与光子计数探测的概率统计特性,建立了激光回波信号与探测器时间抖动的数学模型；然后使用该模型进一步推导了探测器时间抖动与游走误差之间的关系,计算分析与仿真实验都表明:系统的游走误差与探测器时间抖动呈正相关关系。最后,使用拥有不同时间抖动的单光子探测器进行了实验,实验结果表明:当探测器时间抖动标准差分别为15,350和1152ps时,游走误差分别为0.88,2.55和12.56cm。

Abstract:

With the characteristics of high sensitivity and small volume, photon counting radar represents the future development trend of long-range detection radar. But photon counting radar in the detection will produce range walk error, thus affecting the ranging accuracy of the system. In this paper, the relationship between the range walk error and the detector's timing jitter is theoretically analyzed and experimentally verified. First, based on the lidar equation, timing jitter of single-photon detector and probabilistic statistical properties of photon counting detection, a mathematical model of the echo signal and detector timing jitter was established. Then the model was used to further derive the detector's timing jitter and range walk error. Computational analysis and simulation experiments show that the range walk error of the system is positively correlated with the timing jitter of the detector. Finally, experiments were conducted using single-photon detectors with different timing jitter, and the results show that when the standard deviation of the detector time jitter is 15,350 and 1152ps, the walk error is 0.88,2.55 and 12.56cm, respectively.