A probabilistic approach to remote compositional analysis of planetary surfaces
A probabilistic approach to remote compositional analysis of planetary surfaces
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DOI：
10.1002/2016je005248
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发表时间：
2017-05-01
影响因子：
4.8
通讯作者：
Minson, S. E.
中科院分区：
文献类型：
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作者：
Lapotre, M. G. A.;Ehlmann, B. L.;Minson, S. E.
从行星表面反射的光提供信息，包括矿物/冰的成分和颗粒大小，通过研究吸收和吸收特征作为波长的函数。然而，反褶积光谱中的成分信号是复杂的反问题的非唯一性。矿物丰度和粒度之间的权衡设置反射率，仪器噪声和系统误差的正演模型是潜在的不确定性来源，这往往是无法量化的。在这里，我们采用贝叶斯实现的Hapke模型，以确定可接受的适合的矿物组合，而不是单一的最佳拟合的解决方案。我们量化的误差和不确定性，矿物丰度和粒度所产生的仪器噪声，组成端元，光学常数，和系统的前向模型误差的两套三元混合物（橄榄石顽火辉石钙长石和橄榄石绿脱石玄武玻璃）在一系列的六个实验中可见短波红外（VSWIR）波长范围。我们表明，晶粒尺寸一般不受VSWIR光谱。绝对丰度和粒度的权衡导致典型的丰度误差为1wt%（偶尔高达5wt%），而数据中类似于3%的噪声会增加误差高达2wt%。系统误差进一步将不准确性增加了4倍。最后，具有低光谱对比度或不准确光学常数的相位可进一步增加误差。总的来说，典型的大量错误是
Reflected light from planetary surfaces provides information, including mineral/ice compositions and grain sizes, by study of albedo and absorption features as a function of wavelength. However, deconvolving the compositional signal in spectra is complicated by the nonuniqueness of the inverse problem. Trade-offs between mineral abundances and grain sizes in setting reflectance, instrument noise, and systematic errors in the forward model are potential sources of uncertainty, which are often unquantified. Here we adopt a Bayesian implementation of the Hapke model to determine sets of acceptable-fit mineral assemblages, as opposed to single best fit solutions. We quantify errors and uncertainties in mineral abundances and grain sizes that arise from instrument noise, compositional end members, optical constants, and systematic forward model errors for two suites of ternary mixtures (olivine-enstatite-anorthite and olivine-nontronite-basaltic glass) in a series of six experiments in the visible-shortwave infrared (VSWIR) wavelength range. We show that grain sizes are generally poorly constrained from VSWIR spectroscopy. Abundance and grain size trade-offs lead to typical abundance errors of 1wt % (occasionally up to similar to 5wt %), while similar to 3% noise in the data increases errors by up to similar to 2wt %. Systematic errors further increase inaccuracies by a factor of 4. Finally, phases with low spectral contrast or inaccurate optical constants can further increase errors. Overall, typical errors in abundance are