摘要
目标成像特征和信噪比是天基激光告警系统优化设计、目标检测及攻击事件判定的重要依据。在介绍告警系统结构的基础上,分析计算了攻击激光成像光斑的情况,并进行了实验验证,讨论了系统的背景光噪声环境,计算了入瞳处的背景光辐照度,推导了系统成像信噪比公式,并得到了攻击激光成像信噪比。结果表明:攻击激光在正入射情况下的理论光斑直径约26.5μm,光斑形状随着入射角的增大由圆形向椭圆形变化,光斑面积随入射激光强度的增加而变大;系统最主要的背景光辐射是地球反射太阳光,反射太阳光辐照探测器像面产生均匀背景噪声;系统信噪比决定于太阳天顶角、入射激光功率密度及滤光片的透射率函数,对致盲性激光和毁伤性激光成像的最小信噪比分别为40dB、60dB。
Features of target image and signal to noise ratio（SNR） are important performance parameters for system design,threaten laser detection and attack event determination of space-based laser warning system.Based on the introduction of the warning system architecture,the imaging spots of threaten laser by near infrared detector of system are analyzed and verified by experiments.The background light radiation environment of system is discussed and the solar irradiance at the pupil of camera in system operating waveband is obtained.The calculation formula of SNR is derived and the SNR of system for threaten laser is given.The results show that the spot size of threaten laser is about 26.5 μm for normal incidence.The profile of imaging spot is changing from circle to ellipse with the incident angle increasing,and the spot area are becoming larger due to the blooming effects for the high energy intensity of laser.The main background light radiation of the warning system is the sunlight reflected by earth in the short wave infrared spectral range.Solar light of the system optical pass band exposure the detector focal plane,and generate uniform image background.The SNR of system depends on the solar zenith angle,the power density of threaten laser and the filter transmission function.The minimum of SNR are 40 dB and 60 dB for blinding laser and damage laser separately.
出处
《光学技术》
CAS
CSCD
北大核心
2011年第3期376-380,共5页
Optical Technique
关键词
光电对抗
卫星防护
激光告警技术
光斑
信噪比
electro-optic countermeasure
satellite protection
laser warning technology
spot
signal to noise ratio
