低温镜头能量集中度测试及其误差分析

低温镜头多用于深空低温环境下对暗弱点目标的探测，能量集中度是评价该类镜头性能的重要指标。以采用热卸载设计的某红外低温镜头为实验目标，设计了低温镜头能量集中度测试方案，并对测试误差进行了分析。该方案采用星点靶标成像，利用低温精密调焦技术实现对像点的精确采集，通过高斯曲面拟合计算质心和两次反卷积数据处理，实现了200 K低温下红外镜头的能量集中度测试。分析了测试系统的误差源并标定了各项误差值，通过误差和不确定度分析得到了精确的测试结果。实验结果表明，所述的低温镜头能量集中度测试精度优于7.5%，具有工程应用价值。

Measurement and error analysis of encircled energy of cryogenic lens

Cryogenic lens is usually used to detect faint point targets in deep space and low temperature environment. Encircled energy is an important index for evaluating such lens. An infrared cryogenic lens with thermal unloading structure was used as the test object. A test and error analysis scheme of encircled energy of cryogenic lens was designed. A point target was received after imaging by the lens and a cryogenic precision focusing technology was used to acquire data. Centroid extraction and Gaussian curve fitting and deconvolution had been applied to data processing. Encircled energy test was implemented of infrared lens at 200 K, and errors of the test system were analyzed and calibrated. Uncertainly analysis was also evaluated to improve the test accuracy. The experimental results show the test accuracy is better than 7.5%. The method can be used in engineering application.