星载石英漫反射板双向反射分布函数实验测量研究

石英漫反射板用于星载大气痕量气体差分吸收光谱仪测量太阳参考谱的观测系统中，太阳光谱的测量精度将会直接影响痕量气体反演的精度，为保证载荷全视场太阳光谱的测量精度，石英漫反射板需具有良好的朗伯特性，在仪器观测视场内能够提供均匀的光源。为此，在实验室利用双向反射分布函数(BRDF)测量仪，选取F4(聚四氟乙烯)粉压制板作为标准板，采用相对测量法对研制的四种石英漫反射板样品进行了朗伯特性测量，得出了四种样品在波长180～880 nm、观测角度-70°～+70°范围内的BRDF。通过对样品BRDF的分析，筛选出了两种工艺下的朗伯特性较好的石英漫反射板作为初选样品，并测量比较了石英漫反射板和F4标准板对太阳光的漫反射光谱，石英漫反射板对太阳光的反射特性较好，可以作为测量用漫反射板获取太阳参考谱。为进一步的紫外辐照、原子氧侵蚀等试验以及对比试验提供了数据支持。

Bidirectional Reflectance Distribution Function of Space-Borne Quartz Volume Diffuser

Quartz Volume Diffuser(QVD)is used in the observing system of Space-Borne differential optical absorption spec-trometer.The precision of observed solar spectrum directly influences the accuracy of the gas retrievals.Therefore the QVD is required for well Lambert feature to ensure the accuracy of full field solar spectrum,and it can provide uniformity source in the observing view of the instrument.Using bidirectional reflectance distribution function(BRDF)measurement instrument,adop-ting the powder pressboard of F4(polytetrafluoroethylene(PTFE)),QVD’s BRDF is measured by choosing the relative measure-ment method.Four kinds of QVD’s BRDF is obtained in the range of 180~880 nm,the observing view of -70°~+70°.Two kinds of QVD which has a well Lambert feature are selected by analyzing the QVD’s BRDF.The diffuse sunlight measured by QVD and F4 is compared,which show that QVD has well scattering properties with regard to solar spectrum and can be selected as the measuring diffuser.That supports for next Ultraviolet irradiation measurement,atomic oxygen erosion measurement and comparison measurement.