超大口径均匀光源辐射性能设计与测试

Design and Measurement of Radiometric Performance of Ultra-Large Aperture Uniform Light Source

目前光学遥感器向着大口径、宽视场的趋势发展,随着遥感器口径和视场的不断增大,需要与之对应的定标设备来满足其全口径全视场的定标要求。为此,研制了一套超大口径(3.2m)均匀光源系统。首先基于积分球理论和黑体普朗克理论设计出口光谱辐射亮度,并利用LightTools软件对出口均匀性和朗伯特性进行内置光源分布仿真设计。然后针对超大口径均匀光源辐射性能测试存在的问题,研制了一套基于阵列探测器的辐射性能测试装置,并应用校正算法进行一致性校正。最后利用新研制的设备对超大口径均匀光源进行测试实验,并对测试不确定度进行分析。结果显示:0.8m口径光源的光谱辐射亮度大于600 W·m^(-2)·sr^(-1),3.2m口径光源的均匀性优于98.362%,中心点±45°范围内朗伯特性优于98.810%,数据表明新研制的超大口径均匀光源满足设计要求。

At present, optical remote sensors are developing in the direction of large aperture and wide field of view. With the increase of the remote sensor＇s diameter and field of view, corresponding calibration devices need to be developed to meet the radiometric calibration requirements of full aperture and full field of view. Therefore, a ultralarge aperture （3.2 m） uniform light source system is developed. Firstly, the spectral radiance of exit aperture is designed based on the integrating sphere theory and Plank theory, and the LightTools software is used for the simulation design of the exit uniformity and Lambert properties of the built-in light source distribution. Then, a set of radiometric performance measuring devices based on multi-detectors is developed to solve the problem of ultra- large aperture uniform light source measurement. The calibration algorithm is applied to make multi-detectors consistent. Finally, the new device is applied in the testing experiment of ultra-large aperture uniform light source, and its test uncertainty is analyzed. The results show that the integrated spectral radiance of 0.8 m exit aperture is more than 600 W·m-2 ·st-1 , the spatial uniformity of 3.2 m exit aperture is more than 98. 362M, and the Lambert uniformity in central point of ±45° is more than 98. 810%. The newly developed ultra-large aperture uniform light source meets the design requirements.