基于太空风化作用对月壤中不同矿物影响差异的Hapke模型改进及应用

Hapke’s radiative transfer model is widely used to determine mineral abundance on the lunar surface. However, recent studies have indicated that the derived mineral abundance using this model shows a large deviation from measured data because of inaccurate description of space weathering effects in the model. This study first focuses on improving the description of space weathering effect in Hapke’s model. Variation of space weathering effects on different mineral in lunar soils is added to the Hapke’s model by considering varying abundance of nanophase iron (npFe0) in different mineral. Then, we will use this improved Hapke’s model to derive mineral and npFe0 abundance of lunar soil samples from Lunar Soil Characterization Consortium （LSCC）dataset through fitting the measured reflectance. Results will be compared with measured data to test the efficiency of this improved model. Finally, this improved Hapke’s model will be used to the reflectance data of sensor to estimate global mineral and npFe0 abundance on the lunar surface. Results will help to determine the maturity of lunar soils, explain the formation of lunar swirl, and understand the formation and distribution of lunar surface OH-/H2O.

Hapke 辐射传输模型被广泛的应用于定量反演月表矿物含量。然而，最近的研究表明，该模型不能准确的描述太空风化作用，导致反演矿物含量与实测值存在较大误差。本次研究首先侧重对Hapke模型中太空风化作用的描述进行改进。通过考虑月壤中不同矿物的纳米相金属铁（npFe0）含量的差异，在模型中加入太空风化对矿物差异性影响的描述。然后，将利用此改进的Hapke模型对Lunar Soil Characterization Consortium（LSCC）的光谱数据进行矿物和npFe0含量反演，并与实测值进行对比，验证此改进模型的有效性。最后，将此改进的Hapke模型运用到卫星传感器数据，对月表矿物和npFe0含量进行填图。其结果有助于指示月壤成熟度，解释月球漩涡的形成及了解月表水的成因及分布。

长期以来，月表太空风化作用的重要产物纳米铁（npFe0）含量的估算一直是困扰研究人员的问题。本项目中通过对Hapke辐射传输的模型进行简化，并基于Lunar Soil Characterization Consortium对月壤样品实测的数据结果，建立起一套利用高光谱数据快速准确反演月壤中纳米铁（npFe0）含量的方法。验证结果表明，该方法受月壤中不同矿物太空风化差异性作用影响较小，反演值与实测值有很好的相关性。同时，本项目将该模型直接应用于卫星传感器数据，对月球旋涡区域的纳米铁（npFe0）进行了填图，证明了旋涡确由太阳风粒子偏转形成，且太空风化的主要机制为太阳风离子注入。此外，本项目的研究成果直接服务于我国嫦娥四号探测任务着陆区光谱数据的矿物组成分析和雷达数据的解译，为提高嫦娥四号探测任务的科研产出提供了重要的数据支撑