微光夜视系统光晕效应定量表征与建模方法

摘要

The relationship between the size and gray distribution of the halo in the output image of LLL(low light level) TV system and the parameters of the system was studied and a feature quantitative model of the halo was established.Firstly,the mechanism of the halo in the output image of the system was analyzed;Then,according to imaging theory,the feature quantita-tive method of the halo was realized by analyzing the number and the initial angular distribution of photoelectrons generated by photocathode,the movement of the photoelectrons between the photocathode and the MCP,and the collision law of the photoelec-trons with non-opening wall of the MCP.Finally,the digital simulation model of the halo was built on the basis of the theories mentioned above.The experimental results show that:the results of the proposed halo effect model agree well that of experiment in gray distribution and size;the halo effect will be more obvious with the stronger of the light energy,which will generate greater impact on the imaging quality.%研究了微光夜视系统输出图像中光晕尺寸和灰度分布与系统参数之间的关系，建立了系统光晕效应的定量化表征模型。首先分析了系统输出图像中光晕的产生机理；其次依据微光夜视系统成像原理，通过分析光电阴极产生的光电子数及初角度分布、光电子在光电阴极与微通道板之间的运动、光电子与微通道板非开口壁碰撞后的运动规律及微光成像系统各环节对能量的逐级传递，研究了光晕的定量化表征方法；结合上述理论研究，建立了光晕的数字仿真模型。结果表明：所提出的光晕效应表征模型能够与实验结果中光晕的灰度分布及尺寸较好地吻合；随着强光源能量增大，系统光晕效应越明显，光晕效应对系统成像质量影响越大。