高精度星上定标漫射板双向反射分布函数绝对测量系统研究

星上定标漫射板双向反射分布函数（BRDF）的测量不确定度直接影响着星上绝对辐射定标的精度。现有的BRDF测量装置难以在功能和测量精度等方面满足星上定标漫射板BRDF测量的要求，在这样的背景下，建立了BRDF绝对测量系统。该测量系统以高亮度、高均匀性积分球辐射源为照明光源、高精度串联式六轴机器人和中空分度盘为BRDF转角主体、宽光谱大动态范围辐射计为光电信号探测单元，通过几何、电子等相关物理量的高精度溯源及标校，实现了星上定标漫射板BRDF小于1%的测量不确定度。

High Accuracy Gonioreflectometer for Solar Diffuser Spectral BRDF Measurement

Bidirectional reflection distribution function (BRDF) measurement uncertainty of the solar diffuser has direct impact on the on board absolute radiometric calibration accuracy. Conventional BRDF measurement apparatus is difficult to meet the requirements of on board absolute radiometric calibration in terms of measurement accuracy and function. In this context, a set of BRDF absolute measuring system was established. In the system, the high brightness, high uniformity integrating sphere radiationare used as light source, high-precision six-axis robot and indexing plate are used as BRDF gonioreflectometer, and wide spectrum of large dynamic range of the photoelectric detectoris used as signal detection unit. Through geometry, electronics and other related physical quantities of high precision calibration and traceability, BRDF measurement uncertainty of solar diffuser less than 1% is achieved.