不同粒径的月球橄榄石二向性反射特征研究

Bidirectional reflectance of lunar olivine with the consideration of grain size

研究月表矿物组成和分布,对于探测月表地质构造以及月球的起源和演化具有重要的意义。因此,物质成分探测一直是月球研究的重点课题之一。尽管人类已经能够从月球采集样品进行实验室分析,但遥感技术仍然是研究月球的主要手段。文中主要目的是模拟不同粒径下橄榄石的二向性反射特征。为此,首先提出模拟不同粒径下反射特征的方法,然后利用Hapke模型和Mie散射理论对不同粒径下富铁和富镁橄榄石的二向性反射特征进行了模拟。模拟结果显示,富镁橄榄石的二向性反射率较富铁橄榄石的反射率高。最后,分析了反射率差值和等效粒径的相关性。该结论为选择探月传感器的波段组合、识别橄榄石镁铁含量提供了理论依据,也为应用遥感数据的橄榄石的判别奠定了基础。

The distribution of mineral abundances on lunar surface is one of the significant kinds of information which contains important data such as the geological formation,origin and evolution of the Moon.Although lunar mineral samples were brought back and analyzed in laboratory,remote sensing technology still plays important role in lunar study.This paper briefly introduces the bidirectional reflectance feature of olivine based on grain size.In order to distinguish the olivine＇s composition,a method is proposed to simulate reflectance with the consideration of grain size.We discussed the spectral characteristics of Mg-rich olivine and Fe-rich olivine based on the reflectance which calculated by Mie theory and Hapke＇s radiative transfer model in this study.The simulated results showed that the spectral reflectance of Mg-rich olivine was higher than the reflectance of Fe-rich olivine.Finally,the linear relationships between reflectance difference and mean size weighted by cross sectional area were analyzed.The results provide the basis of identifying the olivine using absorptive positions and depths of the olivine,which can also be applied to future remote sensing data processing.