利用自行设计的CMETS005型检测与光谱测试系统对微光瞄准镜进行测试,完成了像增强器光阴极在热冲击环境下的噪声频谱特性测试。试验与分析结果表明:像增强器经过温度冲击后的噪声功率谱在0-1kHz范围内随频率增加而变化较大,呈1/f噪声特性。当环境温度升高时,光电阴极中的热致电流密度增大,从而导致微光瞄准镜观察景物图像时的对比度与鉴别率降低,最后引起夜视系统探测目标性能的下降。
The noise spectrum characteristics testing of the image intensifier photocathode in thermal shock environment is implemented by means of CMETS005 detection and spectrum testing system,which are self-designed for testing low-level-light(LLL)sight.The experimental results and analysis show that the noise power spectrum of the image intensifier fluctuates widely after the temperature shock within 0~1kHz with a larger increase in the frequency change,noise characteristics are 1/f.When the environment temperatures rise,the heat current density of photocathode increases.This causes decrease of LLL aiming sight image contrast ratio and differential rates and induces the decline of the target detecting performance of night-vision system.