TY - JOUR

T1 - Quantification of manganese for ChemCam Mars and laboratory spectra using a multivariate model

AU - Gasda, Patrick J.

AU - Anderson, Ryan B.

AU - Cousin, Agnes

AU - Forni, Olivier

AU - Clegg, Samuel M.

AU - Ollila, Ann

AU - Lanza, Nina

AU - Frydenvang, Jens

AU - Lamm, Sarah

AU - Wiens, Roger C.

AU - Maurice, Sylvestre

AU - Gasnault, Olivier

AU - Beal, Roberta

AU - Reyes-Newell, Adriana

AU - Delapp, Dorothea

N1 - Funding Information: The authors acknowledge NASA, CNES, and the Jet Propulsion Laboratory for the development of ChemCam instrument suite and the Curiosity rover, respectively. JPL for their support and the operation of the Curiosity rover mission on Mars. NASA Mars Exploration Program and CNES for funding. J. Frydenvang acknowledges the Carlsberg Foundation for funding. The authors acknowledge Travis Gabriel, Sarah Black, Ari Essunfeld, Jade Comellas, and the two anonymous reviewers for their useful comments on the manuscript. Any use of trade, firm, or product names is for descriptive purposes only and does not imply endorsement by the U.S. Government. Publisher Copyright: © 2021 Elsevier B.V.

PY - 2021

Y1 - 2021

N2 - We report a new calibration model for manganese using the laser-induced breakdown spectroscopy instrument that is part of the ChemCam instrument suite onboard the NASA Curiosity rover. The model has been trained using an expanded set of 523 manganese-bearing rock, mineral, metal ore, and synthetic standards. The optimal calibration model uses the Partial Least Squares (PLS) and Least Absolute Shrinkage and Selection Operator (LASSO) multivariate techniques, with a novel “double blending” technique. We determined the detection limit for manganese is 82 ppm using a method blank procedure and is possibly as low as 27 ppm based on visual inspection of the spectra. Based on a representative test set consisting of measurements on 93 standards, the double blended multivariate model shows a Root Mean Squared Error of Prediction (RMSEP) accuracy of 1.39 wt% MnO for the full blended model. Employing a local RMSEP estimate where the model performance is evaluated based on nearby test samples, the accuracy is 0.03 wt% at the quantification limit (0.05 wt% MnO), 0.4 wt% accuracy at 1.0 wt% MnO, and 4.4 wt% accuracy at 100 wt% MnO. Precision is estimated using the standard deviation of the test set measurements, and is ±0.01 wt% MnO at the quantification limit, ±0.09 wt% MnO at 1.0 wt% MnO, and ± 2.1 wt% MnO at 100 wt% MnO (all 1 standard deviation). This new calibration is important for understanding the variation of manganese in the bedrock with the Curiosity rover on Mars, which provides insight into past redox conditions on Mars.

AB - We report a new calibration model for manganese using the laser-induced breakdown spectroscopy instrument that is part of the ChemCam instrument suite onboard the NASA Curiosity rover. The model has been trained using an expanded set of 523 manganese-bearing rock, mineral, metal ore, and synthetic standards. The optimal calibration model uses the Partial Least Squares (PLS) and Least Absolute Shrinkage and Selection Operator (LASSO) multivariate techniques, with a novel “double blending” technique. We determined the detection limit for manganese is 82 ppm using a method blank procedure and is possibly as low as 27 ppm based on visual inspection of the spectra. Based on a representative test set consisting of measurements on 93 standards, the double blended multivariate model shows a Root Mean Squared Error of Prediction (RMSEP) accuracy of 1.39 wt% MnO for the full blended model. Employing a local RMSEP estimate where the model performance is evaluated based on nearby test samples, the accuracy is 0.03 wt% at the quantification limit (0.05 wt% MnO), 0.4 wt% accuracy at 1.0 wt% MnO, and 4.4 wt% accuracy at 100 wt% MnO. Precision is estimated using the standard deviation of the test set measurements, and is ±0.01 wt% MnO at the quantification limit, ±0.09 wt% MnO at 1.0 wt% MnO, and ± 2.1 wt% MnO at 100 wt% MnO (all 1 standard deviation). This new calibration is important for understanding the variation of manganese in the bedrock with the Curiosity rover on Mars, which provides insight into past redox conditions on Mars.

KW - ChemCam

KW - Laser induced breakdown spectroscopy

KW - Manganese

KW - Mars Science Laboratory

KW - Multivariate calibration

U2 - 10.1016/j.sab.2021.106223

DO - 10.1016/j.sab.2021.106223

M3 - Journal article

AN - SCOPUS:85107089709

VL - 181

JO - Spectrochimica Acta Part B: Atomic Spectroscopy

JF - Spectrochimica Acta Part B: Atomic Spectroscopy

SN - 0584-8547

M1 - 106223

ER -