Recalibration of the Mars Science Laboratory ChemCam instrument with an expanded geochemical database
Recalibration of the Mars Science Laboratory ChemCam instrument with an expanded geochemical database
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DOI：
10.1016/j.sab.2016.12.003
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发表时间：
2017-03-01
影响因子：
3.3
通讯作者：
Maurice, Sylvestre
中科院分区：
文献类型：
--
作者：
Clegg, Samuel M.;Wiens, Roger C.;Maurice, Sylvestre
火星科学实验室（MSL）探测器Currency上的ChemCam激光诱导击穿光谱（LIBS）仪器自2012年在Gale Crater着陆以来，已经获得了超过300，000个岩石和土壤分析目标的光谱，这些光谱可能是最大的公开LIBS数据集。报告为氧化物（SiO2，TiO2，Al（2）O（3），FeOT，MgO，CaO，Na2O，K2O）的主要元素的组成已经使用实验室LIBS仪器，火星样大气条件和一组比以前使用的更大的标准（408）进行了重新校准。新的校准使用偏最小二乘（PLS 1）和独立成分分析（伊卡）算法的组合，以及校准传递矩阵，以最大限度地减少在实验室中分析标准品的条件与火星上的条件之间的差异。虽然以前的模型在接近平均火星表面成分的成分范围内提供了良好的结果，但新模型更适合极端成分。例子给出了斜长石长石，硅显着高估了以前的模型，和硫酸钙脉，硅成分接近零是不准确的。主要元素丰度的不确定性被描述为丰度的函数，并且总体上显著低于以前的模型，从而能够对数据进行重要的新的地球化学解释。(C)2017爱思唯尔B.V.保留所有权利。
The ChemCam Laser-Induced Breakdown Spectroscopy (LIBS) instrument onboard the Mars Science Laboratory (MSL) rover Curiosity has obtained > 300,000 spectra of rock and soil analysis targets since landing at Gale Crater in 2012, and the, spectra represent perhaps the largest publicly-available LIBS datasets. The compositions of the major elements, reported as oxides (SiO2, TiO2, A1(2)O(3), FeOT, MgO, CaO, Na2O, K2O), have been re-calibrated using a laboratory LIBS instrument, Mars-like atmospheric conditions, and a much larger set of standards (408) that span a wider compositional range than previously employed. The new calibration uses a combination of partial least squares (PLS1) and Independent Component Analysis (ICA) algorithms, together with a calibration transfer matrix to minimize differences between the conditions under which the standards were analyzed in the laboratory and the conditions on Mars. While the previous model provided good results in the compositional range near the average Mars surface composition, the new model fits the extreme compositions far better. Examples are given for plagioclase feldspars, where silicon was significantly over-estimated by the previous model, and for calcium-sulfate veins, where silicon compositions near zero were inaccurate. The uncertainties of major element abundances are described as a function of the abundances, and are overall significantly lower than the previous model, enabling important new geochemical interpretations of the data. (C) 2017 Elsevier B.V. All rights reserved.