Journal article
Recalibration of the Mars Science Laboratory ChemCam instrument with an expanded geochemical database
Spectrochimica acta. Part B: Atomic spectroscopy, Vol.129, pp.64-85
03/01/2017
DOI: 10.1016/j.sab.2016.12.003
Abstract
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, Al2O3, 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.
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•A LIBS spectral database from 408 geochemical standards has been compiled.•This database was used to generate new ChemCam multivariate calibration models for the major elements.•The results of this model produce more accurate geochemical results for the ChemCam Mars observations.•The ChemCam accuracies and precisions have been improved.
Details
- Title: Subtitle
- Recalibration of the Mars Science Laboratory ChemCam instrument with an expanded geochemical database
- Creators
- Samuel M. Clegg - Los Alamos National LaboratoryRoger C. Wiens - Los Alamos National LaboratoryRyan Anderson - USGS Flagstaff, USAOlivier Forni - Institut de Planétologie et d'Astrophysique de GrenobleJens Frydenvang - Los Alamos National LaboratoryJeremie Lasue - Institut de Planétologie et d'Astrophysique de GrenobleAgnes Cousin - Institut de Planétologie et d'Astrophysique de GrenobleValérie Payré - Université de LorraineTommy Boucher - University of Massachusetts (USA)M. Darby Dyar - Mount Holyoke CollegeScott M. McLennan - Stony Brook UniversityRichard V. Morris - Johnson Space CenterTrevor G. Graff - Johnson Space CenterStanley A. Mertzman - Franklin & Marshall CollegeBethany L. Ehlmann - Jet Propulsion LaboratoryInes Belgacem - University of New MexicoHorton Newsom - University of New MexicoBen C. Clark - Space Science Institute, USANoureddine Melikechi - University of Massachusetts LowellAlissa Mezzacappa - College of New JerseyRhonda E. McInroy - Los Alamos National LaboratoryRonald Martinez - Los Alamos National LaboratoryPatrick Gasda - Los Alamos National LaboratoryOlivier Gasnault - Institut de Planétologie et d'Astrophysique de GrenobleSylvestre Maurice - Institut de Planétologie et d'Astrophysique de Grenoble
- Resource Type
- Journal article
- Publication Details
- Spectrochimica acta. Part B: Atomic spectroscopy, Vol.129, pp.64-85
- DOI
- 10.1016/j.sab.2016.12.003
- ISSN
- 0584-8547
- eISSN
- 1873-3565
- Publisher
- Elsevier B.V
- Language
- English
- Date published
- 03/01/2017
- Academic Unit
- Earth and Environmental Sciences
- Record Identifier
- 9984294926702771
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