变阈值检测对无扫描距离选通激光雷达探测概率的影响  

Effects of Changing Threshold on Detection Probability of Scannerless Range-Gated Lidar

作　　者：吴龙[1] 赵远[1] 靳辰飞[1] 张宇[1] 孙秀冬[1] 

机构地区：[1]哈尔滨工业大学物理系,黑龙江哈尔滨150001

出　　处：《光学学报》2010年第11期3117-3123,共7页Acta Optica Sinica

基　　金：武器装备预研基金(9140A01040307HT0125)资助课题

摘　　要：根据无扫描成像激光雷达光电阴极输出光电子计数分布满足泊松统计的特点,由极大似然估计方法,给出判定是否接收到回波的似然比判据阈值的计算方法。并针对典型无扫描距离选通成像激光雷达情况,给出了系统探测概率、虚警概率和漏警概率的近似计算方法,并采用蒙特-卡罗模拟方法进行验证。分析了系统阈值对探测概率的影响,并提出变阈值的方法提高探测系统探测概率。而受系统硬件的限制,在满足探测要求的情况下,尽量缩短探测距离和减少探测器像素数,增加接收目标的有用信号光子数,并同时根据极大似然估计法来确定阈值,达到提高探测概率的目的。The converted number of photoelectrons after the photocathode of scannerless imaging lidar meet the Poisson statistical distribution.The calculation for judging threshold of lidar system is proposed according to maximum likelihood estimation.Taking a typical scannerless range-gated imaging lidar as the case,an approach to approximately calculate detection probability,false-alarm probability and dropouts probability is presented which is proved by Monte-Carlo simulation.The effect of system threshold on detection probability is analyzed.A proposal that increases the detection probabilities when threshold changes with signal and noise is raised.Under the hardware limitation of lidar system,as the detection requests are satisfied,reducing the detection range and number of detector pixels mostly,increasing arrived signal photons from the target,determining the threshold by maximum likelihood estimotion,the detection probability of the system is improved.

关 键 词：成像系统 距离选通激光雷达 探测概率 虚警概率 变阈值检测 蒙特卡罗法验证 

分 类 号：TN958.98[电子电信—信号与信息处理] TN959.6[电子电信—信息与通信工程]