微脉冲激光雷达中的光子计数死区时间瞬态效应

建立了光子计数器的模型,对光子计数器的死区时间效应进行了理论分析和实际测量,并提出了校正光子计数效应对微脉冲雷达信号影响的方法。利用马尔科夫链对微脉冲雷达的探测过程进行理论分析,并利用MATLAB对死区时间对光子计数产生的影响进行了计算和分析,描述了计数死区对探测结果产生的瞬态形态变化。在此基础上,搭建了微脉冲激光雷达光子计数的测量平台,实验验证了死区时间对于光子计数采集的影响。最后,测量了不同光强下死区时间对探测结果的抑制情况,给出了微脉冲激光雷达信号的校正方法。基于提出的方法对真实微脉冲激光雷达信号进行了校正实验。实验结果表明:在峰值功率为100mW的405nm激光照射下,光子计数在采集频率100 MHz时的散射光计数效应减少了50%。文中的方法较好地解释了小尺寸目标的探测信号形态,实现了对光子计数探测结果的校正。

Transient effect of dead time of photon-counting in micro-pulse lidar

A photon counter model was established to analyze theoretically and measure actually the effect of dead time of the photon counter in a micro-pulse lidar. A correct method for the influence of photon-counting on micro-pulse lidar signals was proposed. The Markov chain was used to theoretically describe the detection process of the photon counter in the micro-pulse lidar theoretically. Then, the influence of dead time on photon counting was calculated based on MATLAB, and the transient morphological changes of the results due to the dead time of photon counting were described. After the theoretical analysis and computer simulation, a photon counting platform based on micro- pulse lidar was performed to illustrate the effect of the dead time on counting photons. Finally, the effect of the dead time was measured under different light intensities, and the correction method of the micro-pulse lidar signal was given. A correction experiment was carried out based on the proposed method. The results show that the effect of photon counting on the scattering light has been reduced by 50%. It concludes that the proposed method has well explained the signal shapes of small targets and achieves the correction of the detection results of photon counts.