为了考察星上定标漫射板的光学特性及其在航天环境下的稳定性,对其进行了方向半球反射比(DHR)、双向反射比因子(BRF)、双向反射分布函数(BRDF)等反射特性的测量;同时,进行了系列环境模拟试验。结果显示:星上定标漫射板反射率在可见近红外波段可达0.99,光谱差异＜0.01,在短波红外波段达0.95以上;10~60°BRF变化低于0.1,0~60°BRDF变化＜0.045,其方向特性与光谱、紫外辐照关系不大;漫射板350 nm反射率在120 h等效紫外辐照下的衰变＜3％,其光学特性受原子氧、质子轰击影响甚微,并通过了航天级力学环境试验。试验研究表明:漫射板具备高反射率、光谱平坦性、朗伯性及其在航天环境下的稳定性,能够满足航天应用要求。

In order to investigate the optical properties and the stability of a diffuser panel used for on-board calibration for satellite optical sensors under space environments,some reflective properties including the Directional/Hemisphere Reflectance (DHR),Bidirectional Reflectance Factor (BRF)and the Bidirectional Reflectance Distribution Function(BRDF) were measured,and a series of environment simulation tests were performed.Experimental results show that the reflectances achieve 0.99 at VNIR,0.95 at SWIR;and the differences of the reflectances at VNIR are within 0.01;The variations of BRF(10-60°) and BRDF (0-60°) are less than 0.1 and 0.045,respectively,and the Lambertian property of the diffuser panel is independence on the spectral band and UV radiation.Moreover,the degradation of reflectance at 350 nm is within 3% after 120 h equivalent solar UV radiation and the atomic oxygen exposure or proton bombardment has little effect on the optical properties of the diffuser panel.As characterized by above,the diffuser panel has gotten through on-orbit level mechanical environment tests.For its high reflectance,spectral flatness,Lambertian characteristics and stability in orbit, the diffuser panel can satisfy the requirements for space applications.