大气湍流对盖革光子探测测距精度影响的研究

摘要

回波光子到达时间的随机性限制了盖革光子测距系统的测距精度,大气湍流加剧了这种随机性,降低系统测距精度.根据回波光子探测的调制泊松概率模型,分析了距离门内各探测时隙的概率分布,利用回波光子可识别区域内探测时隙的归一化概率,建立了存在大气湍流影响时测距精度的理论模型,研究了大气湍流对测距精度的影响.理论分析结果表明,大气湍流降低系统探测概率和测距精度,当回波强度为1,湍流参数为2.5时,与无大气湍流影响情况相比,系统距离精度和准确度下降达4.2 cm和14 cm,且湍流越强,目标探测概率越低,虚警率越高,距离精度和准确度越低.%The range accuracy of the Gm-APD laser ranging system is limited by the random arrival time of the echo photons,while the turbulence effect aggravates this randomness,which will reduce range accuracy of the system. Based on the modulated Poisson model of the echo photons in the Gm -APD,the detection probability distribution of each time bin in the range gate was analyzed.Utilizing the normalized probability distribution in the recognizable re-gion of echo photons,the theoretical model of the range accuracy was established,and the influence of the turbulence effects on the range accuracy was investigated.The results show that the turbulence effects decrease the detection probability and the range accuracy,when the turbulence parameter is selected as 2.5 and the echo intensity is 1,com-pared to the case without turbulence effects,the range accuracy and precision decrease by 4.2 cm and 14 cm,respec-tively,and stronger turbulence degree will lead to lower target detection probability,higher false alarm rate,worse ac-curacy and precision.