For many regions on Mars, the surface composition and its geological history have been debated in the literature. Because of the limited surface coverage of in situ measurements, either new data or new processing methodologies are required to get a better understanding of the Martian geology. This paper presents the results of a multivariate, unsupervised, analysis on underutilized CRISM (Compact Reconnaissance Imaging Spectrometer) multispectral mapping mode data set for surface type analysis. The devised summary products of Pelkey et al. (2007) and Viviano‐Beck et al. (2014) are averaged for the CRISM ~5° × 5° mosaic grids and used to analyze the variability in this data set. The averaged summary product values are studied using correlation coefficients calculated between summary products, as well as the correlation with dust coverage and elevation. The degree of correlation is used to interpret the summary products for the global distribution of mafic and secondary minerals and the effect of external factors such as ice, atmosphere, and dust coverage. With unsupervised clustering, all grid pixels are classified based on the spectral variability. These clusters are plotted as global maps and interpreted for geological variations in the CRISM data. Some clusters spatially correspond with previously recognized compositional distinct regions Northern Lowlands, Southern Highlands, Meridiani Planum, Syrtis Major, and Nili Fossae. Several other clusters are described here for the first time such as Solis Planum, Ophir Planum, and Hellas Basin. These regions cover known geological units, but the interpretation of the spectral variability is uncertain whether it relates to geological or external factors.

中文翻译：

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使用全球CRISM摘要产品图定义火星的表面类型

对于火星上的许多地区，地表成分及其地质历史在文献中已有争议。由于原位测量的地表覆盖范围有限，因此需要新的数据或新的处理方法来更好地了解火星地质。本文介绍了对用于表面类型分析的未充分利用的CRISM（紧凑侦察成像光谱仪）多光谱映射模式数据集进行的多变量，无监督分析的结果。Pelkey等人的设计摘要产品。（2007）和Viviano-Beck等。（2014）是CRISM〜5°×5°镶嵌网格的平均值，并用于分析此数据集中的变异性。使用汇总产品之间计算的相关系数研究汇总产品的平均值，以及与灰尘覆盖率和海拔高度的相关性。相关程度用于解释用于镁铁质和次生矿物的全球分布以及外部因素（例如冰，大气和灰尘覆盖）的影响的摘要产品。在无监督聚类的情况下，所有网格像素均基于光谱变异性进行分类。这些群集被绘制为全局图，并解释为CRISM数据中的地质变化。一些星团在空间上对应于先前认识到的北部低地，南部高地，Meridiani Planum，Syrtis Major和Nili Fossae的组成不同区域。这里首次描述了其他几个星团，例如Solis Planum，Ophir Planum和Hellas盆地。这些区域涵盖了已知的地质单位，