光栅衍射激光告警接收机的探测性能分析  

Detectability analysis of laser warning receiver based on grating diffraction

作　　者：王明[1] 张记龙[1] 田二明[1] 李晓[1] 王志斌[1] 张悦[1] 

机构地区：[1]中北大学仪器科学与动态测试教育部重点实验室

出　　处：《红外与激光工程》2008年第4期683-686,718,共5页Infrared and Laser Engineering

基　　金：国家自然科学基金资助项目(60572019,60378019);山西省青年科技研究基金资助项目(2007021019)

摘　　要：灵敏度和信噪比是激光告警接收机两个重要的性能指标,它们直接影响系统的探测性能和抑制噪声的能力。根据信号统计检测理论,提出了一种计算光栅衍射型激光告警接收机灵敏度和信噪比的方法。首先,对激光信号和系统的内、外噪声进行了系统分析。然后,基于阈值探测理论和奈曼-皮尔逊准则,通过引入探测概率因子和虚警概率因子,求解出以激光信号电流为变量的方程,得到了灵敏度和信噪比的一般表达式。最后,结合该方法利用自行研制的基于正弦光栅衍射型激光告警接收机的实际参数对探测灵敏度和信噪比进行了数值模拟和实验验证,得到0.532!m激光入射时的探测灵敏度计算值为1.95mW/cm2,实验值为2.55mW/cm2。不同入射波长之间的信噪比差异较小,表明该分析方法可以对激光告警接收机的信噪比进行评估。The sensitivity and signal-to-noise ratio（SNR） are very important performance parameters in laser warning system,which influence the detection performances and the ability of noise reduction directly. Based on the signal statistical detection theory,a method for calculation of the sensitivity and SNR in grating diffraction laser warning receiver（LWR） was proposed. Firstly,the laser signal and internal and external noises of the system were analyzed. The results show that the two kinds of noise both are uncorrelated Gaussian white noise by testing the probability density function,power spectral density and correlation function. Secondly,based on threshold detection theory and Neyman-Pearson criteria,the current equation of the signal was established by introducing detection probability factor and false alarm rate factor,then the general expression of SNR of laser warning receiver based on grating diffraction was deduced. Finally,the sensitivity and SNR of sinusoidal grating laser warning receiver developed by our group were calculated with the new method. The results show that the detection sensitivity of the numerical simulation and the experimental result are 1.95 mW/cm^2 and 2.55 mW/cm^2 respectively when laser wavelength of incidence is 0.532 μm. There is little difference during the SNR when laser wavelength of incidence is different.The result indicate that this analysis method is feasible which can be used in performance analysis of LWR.

关 键 词：激光告警技术 灵敏度 信噪比 探测率 虚警率 

分 类 号：TN247[电子电信—物理电子学]