TY - JOUR

T1 - Post-landing major element quantification using SuperCam laser induced breakdown spectroscopy

AU - Anderson, Ryan B.

AU - Forni, Olivier

AU - Cousin, Agnes

AU - Wiens, Roger C.

AU - Clegg, Samuel M.

AU - Frydenvang, Jens

AU - Gabriel, Travis S. J.

AU - Ollila, Ann

AU - Schröder, Susanne

AU - Beyssac, Olivier

AU - Gibbons, Erin

AU - Vogt, David S.

AU - Clavé, Elise

AU - Manrique, Jose-Antonio

AU - Legett, Carey

AU - Pilleri, Paolo

AU - Newell, Raymond T.

AU - Sarrao, Joseph

AU - Maurice, Sylvestre

AU - Arana, Gorka

AU - Benzerara, Karim

AU - Bernardi, Pernelle

AU - Bernard, Sylvain

AU - Bousquet, Bruno

AU - Brown, Adrian J.

AU - Alvarez-Llamas, César

AU - Chide, Baptiste

AU - Cloutis, Edward

AU - Comellas, Jade

AU - Connell, Stephanie

AU - Dehouck, Erwin

AU - Delapp, Dorothea M.

AU - Essunfeld, Ari

AU - Fabre, Cecile

AU - Fouchet, Thierry

AU - Garcia-Florentino, Cristina

AU - García-Gómez, Laura

AU - Gasda, Patrick

AU - Gasnault, Olivier

AU - Hausrath, Elisabeth M.

AU - Lanza, Nina L.

AU - Laserna, Javier

AU - Lasue, Jeremie

AU - Lopez, Guillermo

AU - Madariaga, Juan Manuel

AU - Mandon, Lucia

AU - Mangold, Nicolas

AU - Meslin, Pierre-Yves

AU - Nelson, Anthony E.

AU - Newsom, Horton

AU - Reyes-Newell, Adriana L.

AU - Robinson, Scott

AU - Rull, Fernando

AU - Sharma, Shiv

AU - Simon, Justin I.

AU - Sobron, Pablo

AU - Fernandez, Imanol Torre

AU - Udry, Arya

AU - Venhaus, Dawn

AU - Mclennan, Scott M.

AU - Morris, Richard V.

AU - Ehlmann, Bethany

N1 - Publisher Copyright: © 2022

PY - 2022

Y1 - 2022

N2 - The SuperCam instrument on the Perseverance Mars 2020 rover uses a pulsed 1064 nm laser to ablate targets at a distance and conduct laser induced breakdown spectroscopy (LIBS) by analyzing the light from the resulting plasma. SuperCam LIBS spectra are preprocessed to remove ambient light, noise, and the continuum signal present in LIBS observations. Prior to quantification, spectra are masked to remove noisier spectrometer regions and spectra are normalized to minimize signal fluctuations and effects of target distance. In some cases, the spectra are also standardized or binned prior to quantification. To determine quantitative elemental compositions of diverse geologic materials at Jezero crater, Mars, we use a suite of 1198 laboratory spectra of 334 well-characterized reference samples. The samples were selected to span a wide range of compositions and include typical silicate rocks, pure minerals (e.g., silicates, sulfates, carbonates, oxides), more unusual compositions (e.g., Mn ore and sodalite), and replicates of the sintered SuperCam calibration targets (SCCTs) onboard the rover. For each major element (SiO2, TiO2, Al2O3, FeOT, MgO, CaO, Na2O, K2O), the database was subdivided into five “folds” with similar distributions of the element of interest. One fold was held out as an independent test set, and the remaining four folds were used to optimize multivariate regression models relating the spectrum to the composition. We considered a variety of models, and selected several for further investigation for each element, based primarily on the root mean squared error of prediction (RMSEP) on the test set, when analyzed at 3 m. In cases with several models of comparable performance at 3 m, we incorporated the SCCT performance at different distances to choose the preferred model. Shortly after landing on Mars and collecting initial spectra of geologic targets, we selected one model per element. Subsequently, with additional data from geologic targets, some models were revised to ensure results that are more consistent with geochemical constraints. The calibration discussed here is a snapshot of an ongoing effort to deliver the most accurate chemical compositions with SuperCam LIBS.

AB - The SuperCam instrument on the Perseverance Mars 2020 rover uses a pulsed 1064 nm laser to ablate targets at a distance and conduct laser induced breakdown spectroscopy (LIBS) by analyzing the light from the resulting plasma. SuperCam LIBS spectra are preprocessed to remove ambient light, noise, and the continuum signal present in LIBS observations. Prior to quantification, spectra are masked to remove noisier spectrometer regions and spectra are normalized to minimize signal fluctuations and effects of target distance. In some cases, the spectra are also standardized or binned prior to quantification. To determine quantitative elemental compositions of diverse geologic materials at Jezero crater, Mars, we use a suite of 1198 laboratory spectra of 334 well-characterized reference samples. The samples were selected to span a wide range of compositions and include typical silicate rocks, pure minerals (e.g., silicates, sulfates, carbonates, oxides), more unusual compositions (e.g., Mn ore and sodalite), and replicates of the sintered SuperCam calibration targets (SCCTs) onboard the rover. For each major element (SiO2, TiO2, Al2O3, FeOT, MgO, CaO, Na2O, K2O), the database was subdivided into five “folds” with similar distributions of the element of interest. One fold was held out as an independent test set, and the remaining four folds were used to optimize multivariate regression models relating the spectrum to the composition. We considered a variety of models, and selected several for further investigation for each element, based primarily on the root mean squared error of prediction (RMSEP) on the test set, when analyzed at 3 m. In cases with several models of comparable performance at 3 m, we incorporated the SCCT performance at different distances to choose the preferred model. Shortly after landing on Mars and collecting initial spectra of geologic targets, we selected one model per element. Subsequently, with additional data from geologic targets, some models were revised to ensure results that are more consistent with geochemical constraints. The calibration discussed here is a snapshot of an ongoing effort to deliver the most accurate chemical compositions with SuperCam LIBS.

KW - Calibration

KW - Chemometrics

KW - Laser induced breakdown spectroscopy

KW - LIBS

KW - Mars

KW - Multivariate regression

KW - Regression

U2 - 10.1016/j.sab.2021.106347

DO - 10.1016/j.sab.2021.106347

M3 - Journal article

AN - SCOPUS:85122615015

VL - 188

JO - Spectrochimica Acta Part B: Atomic Spectroscopy

JF - Spectrochimica Acta Part B: Atomic Spectroscopy

SN - 0584-8547

M1 - 106347

ER -