Planetary Science Institute, School of Earth Sciences, China University of Geosciences, Wuhan, China.
State Key Laboratory of Space Weather, National Space Science Center, Chinese Academy of Sciences, Beijing, China.
Rev Sci Instrum. 2022 Feb 1;93(2):024504. doi: 10.1063/5.0071621.
Reflectance spectroscopy is a powerful tool for remotely identifying the compositional and physical properties of surface materials. Due to the anisotropic scattering nature of most surfaces, the spectral features, including the absolute reflectance value, spectral slope, and band depth, are influenced by illumination and viewing configurations. Therefore, it is important to understand how spectral features vary with illumination and observation geometries for various particulate surfaces through laboratory measurements. Here, we describe a non-motorized spectro-goniometric system capable of measuring the bi-directional reflectance of particulate surfaces in the upper hemisphere in the wavelength range from 350 to 2150 nm. The incident and the viewing zenith angles can be varied from 0° to 55° and from 0° to 70°, respectively. The relative viewing azimuth angle can be varied from 0° to 360°. Measurements on Labsphere Spectralon agree well with measurements done with other instruments. We also present measurement results on two typical planetary analog materials, the JSC-1A Martian soil simulant and the JSC-1A lunar regolith simulant.
反射光谱学是一种强大的工具，可用于远程识别表面材料的组成和物理特性。由于大多数表面的各向异性散射性质，光谱特征，包括绝对反射率值、光谱斜率和带宽深度，都会受到照明和观察配置的影响。因此，通过实验室测量，了解各种颗粒状表面的光谱特征如何随照明和观察几何形状而变化是很重要的。在这里，我们描述了一种非机动分光测角系统，该系统能够在波长范围从 350 到 2150nm 的上半球测量颗粒状表面的双向反射率。入射和视场仰角可以分别从 0°变化到 55°和从 0°变化到 70°。相对视场方位角可以从 0°变化到 360°。在 Labsphere Spectralon 上的测量结果与其他仪器的测量结果吻合良好。我们还展示了对两种典型行星模拟材料的测量结果，即 JSC-1A 火星土壤模拟物和 JSC-1A 月球风化层模拟物。
