扩展目标光子测距回波特性及误差研究  

Echo Characteristics and Error of Extended Target for Photon Ranging

作　　者：侯阿慧 胡以华 赵楠翔 方佳节 张鑫源 Hou Ahui;Hu Yihua;Zhao Nanxiang;Fang Jiajie;Zhang Xinyuan(State Key Laboratory of Pulsed Power Laser(National University of Defense Technology),Hefei Anhui 230037 China;Anhui Key Laboratory of Electronic Restriction(National University of Defense Technology),Hefei Anhui 230037 China)

机构地区：[1]国防科技大学脉冲功率激光技术国家重点实验室,安徽合肥230037 [2]国防科技大学电子制约技术安徽省重点实验室,安徽合肥230037

出　　处：《中国激光》2021年第4期256-263,共8页Chinese Journal of Lasers

基　　金：国家自然科学基金(61871389);国防科技大学科研计划项目(ZK18-01-02)。

摘　　要：光子测距具有灵敏度高,探测距离远的特点,目标形状和姿态对光子测距的影响不可忽略。针对扩展平面、球面和非球面三种典型目标,建立了扩展目标光子探测回波概率分布模型,推导出不同倾斜角下混有时空分布的光子回波概率分布一般方程。实验表明,扩展平面的光子回波概率分布与数值计算结果一致。理论仿真分析了扩展目标的光子回波概率分布特性,讨论了光子测距误差与扩展目标类型和倾斜角间的变化规律。结果表明:平均回波光子数为3.9,目标处激光光斑半径为0.2m,倾斜角小于20°时不同扩展目标间的光子测距误差小于1.23mm;光子测距误差随着目标倾斜角的增大逐渐增大,且扩展平面目标测距误差受倾斜角影响最大。Objective Photon ranging exhibits the advantages of high sensitivity and long-distance detection.Compared with laser ranging in the linear mode,the photon detection exhibits the first photon bias effect owing to the dead-time of the single-photon detector,which results in greater distortion of the probability distribution of photon echo.This distortion is closely related to the intensity and distribution of the laser echo.There is a close relationship between the target shape and posture and the probability distribution of photon echo.As a result,the range errors in photon ranging caused by the target shape and posture cannot be ignored.Most researchers have focused on analyzing the modulation effect of target characteristics on the laser pulse echo.However,there is a lack of research on the range errors of extended targets in the photon-detection mode.Therefore,we discuss the relationship between the target shape and inclination and photon ranging for three typical extended targets.Methods Based on the Poisson probability response model and the traditional laser radar equation,the probability distribution model for the photon detection of an extended target is established herein.Combining this with the coordinate-rotation transformation formula,the general probability distribution equation mixed with spatial and temporal distribution at different inclinations is derived for the three typical extended targets:aplane,a sphere,and an aspheric.Experimental results reveal that the probability distribution of this photon echo is consistent with the numerical results.We then simulate and analyze the differences in the photon echo probability distribution and laser pulse echo characteristics of the three typical extended targets.Finally,the variation between the range errors in photon detection and the types and inclinations of the extended targets is discussed theoretically.Results and Discussions Compared with the laser pulse echo,the probability distribution of the photon echo moves forward as the inclination increas

关 键 词：激光光学 光子测距 测距误差 扩展目标 概率分布 回波特性 

分 类 号：O439[机械工程—光学工程]