The Moon Mineralogy Mapper (M3) is a NASA-supported guest instrument on ISRO's remote sensing mission to Moon, Chandrayaan-1. The M3 is an imaging spectrometer that operates from the visible into the near-infrared (0.42-3.0 ??m) where highly diagnostic mineral absorption bands occur. Over the course of the mission M3 will provide low resolution spectroscopic data for the entire lunar surface at 140 m/pixel (86 spectral channels) to be used as a base-map and high spectral resolution science data (80 m/pixel; 260 spectral channels) for 25-50% of the surface. The detailed mineral assessment of different lunar terrains provided by M3 is principal information needed for understanding the geologic evolution of the lunar crust and lays the foundation for focused future in-depth exploration of the Moon.

A simple semiempirical method is presented for determination of the spectral reflectance of a powdered binary mineral mixture. This technique uses a two-stream radiative transfer model (a modified Kubelka-Munk model) on a particulate medium of isotropic scatterers. The particles are assumed to be much larger than the wavelength of light under consideration. This same method can be used to determine the relative proportion of components in a mixture for which the spectral reflectance is known. Binary mixtures of olivine, two pyroxenes, and magnetite are used to test this model. The theoretical and empirical results agree approximately within experimental errors.

Hapke's model for bidirectional reflectance is used to calculate the mass fractional abundance of components in intimately mixed, particulate surfaces from laboratory reflectance spectra. Application of this model, simplified by the assumptions that all surfaces scatter light with the same constant phase function and the opposition surge is negligible, to binary mineral mixtures are summarized and compared with new results for ternary mixtures of olivine, enstatite, and anorthite. These experimental tests indicate that the simple model is accurate to within 7% for mixtures not containing low albedo components (<10% reflectance). However, several observed systematic deviations of the calculated mass fractions from the actual mass fractions suggest that the simple model may be improved by allowing for variable scattering between the minerals used. An empirical scattering function, based on the physically plausible scattering behavior that low albedo materials are backward scattering and high albedo, transparent materials are forward scattering, reduces the magnitude of the systematic deviations in mass fractions observed with the constant scattering model. To determine if the empirical scattering function is representative of the actual scattering behavior of particulate mineral surfaces, specific photometric parameters (single-scattering albedo, single-particle phase function) of five different mineral components (olivine, enstatite, anorthite, magnetite, hematite) and two mineral mixtures (90% olivine 10% magnetite, 25% olivine 75% magnetite) are derived from bidirectional reflectance spectra measured at 17 different viewing geometries between 0.5 and 1.6 0204m. Mineral components were crushed and wet sieved with ethanol to a 45 to 75 0204m particle size. All reflectance data are corrected for the non-Lambertian scattering properties of halon. Analysis of the parameters of the single-particle phase function indicate that each mineral defines a relatively unique suite of scattering parameters as a function of albedo. In particular, the silicates are forward scattering where the degree of forward scattering increases with albedo, magnetite is forward scattering but the degree of forward scattering decreases with albedo, and hematite is entirely backward scattering where the degree of backward scattering increases with albedo. It is apparent that the physical properties of the particles (roughness, transparency, shape) rather than albedo or chemical composition determine the gross scattering properties of the particulate surfaces studied here. The scattering parameters of the mixtures are similar to the parameters of the more abundant mineral in the mixture. The experimentally determined single-scattering albedos are used to calculate the mass fractions of olivine and magnetite in these mixtures. These new fractions are much improved over the previous analyses and indicate that more detailed information regarding the geometric dependence of reflectance overcomes the systematic deficiencies of the simplified methods. In general, the simplified method is appropriate for mixtures not containing low albedo material using bidirectional reflectance measured at intermediate phase angles (2000°0900094000°) and small emergence angles (near 000°). Abundance estimates using this approach are accurate to within 509000910% when information regarding the particle size of the surface components is available, and in a relative sense for surfaces of unknown particle size distributions. More precise abundance estimates can be derived if the scattering properties of the surface are well characterized and incorporated into the analysis.

月表主要矿物的空间分布是研究 月球起源演化等科学问题的重要基础信息之一。基于Hapke模型与光谱线性分解的矿物提取方法,利用Clementine UV/VIS/NIR数据提取月表单斜辉石、斜方辉石、橄榄石、斜长石及钛铁矿等5类主要矿物的体积百分含量分布,并基于阿波罗(Apollo)月岩 (壤)矿物分析数据对提取结果进行评价,对方法和提取结果中存在的问题进行分析,提出了进一步改进的措施。

[1] The main objective of this work is to quantify lunar surface minerals (agglutinate, clinopyroxene, orthopyroxene, plagioclase, olivine, ilmenite, and volcanic glass), particle sizes, and the abundance of submicroscopic metallic Fe (SMFe) from the Lunar Soil Characterization Consortium (LSCC) data set with Hapke's radiative transfer theory. The mode is implemented for both forward and inverse modeling. We implement Hapke's radiative transfer theory in the inverse mode in which, instead of commonly used look-up tables, Newton's method and least squares are jointly used to solve nonlinear questions. Although the effects of temperature and surface roughness are incorporated into the implementation to improve the model performance for application of lunar spacecraft data, these effects cannot be extensively addressed in the current work because of the use of lab-measured reflectance data. Our forward radiative transfer model results show that the correlation coefficients between modeled and measured spectra are over 0.99. For the inverse model, the distribution of the particle sizes is all within their measured range. The range of modeled SMFe for highland samples is 0.01%0900090.5%, and for mare samples it is 0.03%0900091%. The linear trend between SMFe and ferromagnetic resonance (Is) for all the LSCC samples is consistent with laboratory measurements. For quantifying lunar mineral abundances, the results show that the R squared for the training samples (Is/FeO 0909¤ 65) are over 0.65 with plagioclase having highest correlation (0.94) and pyroxene having the lowest correlation (0.68). In future work, the model needs to be improved for handling more mature lunar soil samples.

简要介绍了不同太空风化条件下 尖晶石的光谱特性,特别是利用Hapke模型计算了不同太空风化条件下尖晶石的二向性反射率分布特征。模拟的结果显示,对M3数据,可比较0.6μm和 1.9μm附近的吸收特征;对IIM数据,则需要先分析太空风化程度,然后比较0.6μm和0.9μm附近的吸收特征来判断是否为尖晶石。该结论为选择探 月传感器的波段组合识别尖晶石提供了依据,也为应用M3数据和"嫦娥1号"IIM数据的尖晶石判别奠定了基础。

月表太空风化会改变月壤光谱特征,影响月壤元素遥感反演精度.研究太空风化对月壤光谱的影响有助于开发月壤成熟度光谱解耦算法,提高月壤成分遥感反演精度.直接对比月壤风化前后光谱的变化能最真实反映太空风化对光谱的影响,但无法获取未风化的月壤样品,利用实验室模拟方法开展研究也存在缺陷.本文提出了一种简便的方法来研究太空风化对月壤光谱的影响,并以月海样品为例进行探讨.利用Hapke模型对月海样品组成矿物光谱按照实测含量进行非线性混合,并通过对比混合后的光谱与实测的月壤光谱,研究太空风化过程对月壤光谱的影响.研究结果表明,月壤在遭受太空风化后反射率降低,波长越短降低越显著;月壤背景吸收斜率增大,月壤变得更红,月壤矿物特征吸收峰深度降低,光谱对比度变弱,长波吸收峰（2.0μm附近）深度降低程度超过短波吸收峰（1.0μm附近）深度.未来在利用遥感技术反演月壤元素含量时,必须考虑这些因素.

月表物质成分探测是月球探测的 重要组成部分。研究矿物在光学波段的吸收特征,可以达到识别月表矿物的目的。作为月岩的风化产物,月壤的成分包括了主要的月球成岩矿物:斜长石、橄榄石、 辉石等。本课题以斜长石和单斜辉石作为研究对象,旨在研究单矿物的二向性反射特性。影响月壤反射率的因素包括成分、表面物理特性等多种因素,研究中选用美 国ASD公司Filedspec3光谱仪,测量单矿物不同颗粒粒度状态下350~2500nm的二向性反射特征。结果表明,观测几何角度变化对反射率的影 响较大,有明显的二向性特征,在方位角180°及0°方位热点较明显。反射率随粒径降低而增加。实验结果可为月表矿物反演研究提供有力的证据。二向性反射 方向的研究也为合理选择观测几何条件提高月表信息获取精度成为可能。

The variety of evidence bearing on the nature of space weathering is reviewed. The effects of space weathering include spectral darkening, reddening and subdued absorption bands, and the distinctive magnetic electron spin resonance caused by single-domain metallic iron particles. Ever since the Apollo missions, two paradigms have dominated the thinking of the planetary science community concerning space weathering: (1) the optical effects are caused by impact-vitrified glass in agglutinates, and (2) the submicroscopic metallic iron results from the reduction of ferrous iron by the impact melting of minerals whose surfaces have been saturated with hydrogen from the solar wind. However, studies carried out since the Apollo program showed that both of these paradigms are invalid. A hypothesis first suggested by the author and his colleagues 26 years ago, but not generally accepted at that time, now appears to be essentially correct: Both the optical and magnetic effects are caused by metallic iron particles smaller than the wavelength in ubiquitous vapor-deposited coatings on soil particle surfaces and inside agglutinates. The vapor is generated by both solar wind sputtering and micrometeorite impact vaporization and injected preferentially downward into the porous regolith. The iron is reduced by a physical process, the selective loss of oxygen that occurs during deposition of the vapor, and does not require heating, melting, or a reducing environment. A mathematical theory that describes the optical effects of the submicroscopic iron quantitatively is derived and applied to the regoliths of the Moon, Mercury and an S asteroid.

从月壤光谱中挖掘矿物含量信息是月球遥感探测的重要内容之一, 矿物光谱混合规律复杂, 光谱特征对测试环境、 粒度、 地形、 背景极为敏感是难点。 提出并试验了一种基于光谱分解反演矿物含量的方法。 在光谱分解前采用光谱连续统去除突出光谱谱形, 分解中综合运用了光谱反射峰(介于两个吸收谷之间的光谱曲线向上凸起的部分)与吸收谷, 分解后采用Hapke模型修正光谱非线性混合的影响, 在混合端元光谱、 端元化学成分与粒度未知情况下, 实现了对月壤四种主要矿物橄榄石、 斜方辉石、 单斜辉石、 斜长石的43条混合光谱的盲分解与矿物含量反演, 反演的残差、 误差、 线性拟合相关系数(反演含量与真实含量)均值分别为5.0 Vol%, 14.4 Vol%, 0.92。 该方法与反演结果可为月球高光谱矿物识别与填图提供参考与依据。

月表主要矿物含量的定量反演是月球科学领域的重要课题之一,对未来月表矿物信息解译有重要指导意义,因此提出一种对月表高光谱遥感数据线性分解获取矿物含量的方法.首先,利用Hapke辐射传输模型将Relab光谱库中的5种矿物(单斜辉石、斜方辉石、斜长石、橄榄石和钛铁矿)非线性混合的反射光谱转换为线性混合的单次反照率;然后,按照比例随机生成混合像元;最后基于全约束线性光谱分解方法建立上述5种矿物分解含量与真实含量的统计关系模型.利用Apollo登陆采样点实测数据对该模型进行验证的结果表明,辉石、斜长石、橄榄石和钛铁矿的反演结果与实测结果的相关系数分别为0.83,0.86,0.72和0.77.采用上述方法,利用印度探月卫星Chandrayaan-1搭载的月球矿物制图仪(moon mineralogy mapper,M3)高光谱数据得到月表虹湾地区矿物的含量分布图,表明利用全约束线性分解对高光谱矿物识别和含量反演是一种行之有效的方法.

Global maps of the distribution of plagioclase, orthopyroxene, clinopyroxene and olivine on the Moon were derived from radiative transfer analysis of 400,000 Clementine UVVIS spectra. Plagioclase inversely correlates with iron while clinopyroxene positively correlates with iron showing these are the major carriers of aluminum and iron respectively. The distribution of olivine in the maria agrees with previous studies; in the highlands the abundance of olivine is low but ubiquitous at a few percent, except within the South Pole-Aitken basin where it is only present in very small exposures. In the very anorthositic farside highlands, olivine is often the sole mafic mineral. The abundance of orthopyroxene is generally low, excepting elevated abundances in the nearside highlands and in areas near and within South Pole-Aitken basin. Mare units with elevated abundances of orthopyroxene are found in some mare and cryptomare deposits distant from the sample return sites.

分析了矿物在可见光及近红外区光谱生成的机理，介绍了月球表面最为主要的四种矿物——辉石、斜长石、橄榄石、钛铁矿，并分析了它们各自光谱特征及生成原因，讨论了造成同种矿物光谱差异的原因，给出了它们各自的标志性特征。

The last major phase of lunar volcanism produced extensive high-titanium mare deposits on the western nearside which remain unsampled by landing missions. The visible and near-infrared reflectance properties of these basalts are examined using Clementine multispectral images to better constrain their mineralogy. A much stronger 1 0204m ferrous absorption was observed for the western high-titanium basalts than within earlier maria, suggesting that these last major mare eruptions also may have been the most iron-rich. These western basalts also have a distinctly long-wavelength, 1 0204m ferrous absorption which was found to be similar for both surface soils and materials excavated from depth, supporting the interpretation of abundant olivine within these deposits. Spectral variation along flows within the Imbrium basin also suggests variations in ilmenite content along previously mapped lava flows as well as increasing olivine content within subsequent eruptions.