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

Ryan B. Anderson (1) , Olivier Forni (2) , Agnes Cousin (2) , Roger C. Wiens (3) , Samuel M. Clegg (3) , Jens Frydenvang (4) , Travis S. J. Gabriel (1) , Ann Ollila (3) , Susanne Schröder (5) , Olivier Beyssac (6) , Erin Gibbons (7) , David S. Vogt (5) , Elise Clavé (8) , Jose-Antonio Manrique (9) , Carey Legett (3) , Paolo Pilleri (2) , Raymond T. Newell (3) , Joseph Sarrao (3) , Sylvestre Maurice (2) , Gorka Arana (10) , Karim Benzerara (6) , Pernelle Bernardi (11) , Sylvain Bernard (6) , Bruno Bousquet (8) , Adrian J. Brown (12) , César Alvarez-Llamas (13) , Baptiste Chide (2) , Edward Cloutis (14) , Jade Comellas (3) , Stephanie Connell (14) , Erwin Dehouck (15) , Dorothea M. Delapp (3) , Ari Essunfeld (3) , Cecile Fabre (16) , Thierry Fouchet (11) , Cristina Garcia-Florentino (10) , Laura García-Gómez (13) , Patrick Gasda (3) , Olivier Gasnault (2) , Elisabeth M. Hausrath (17) , Nina L. Lanza (3) , Javier Laserna (13) , Jeremie Lasue (2) , Guillermo Lopez (9) , Juan Manuel Madariaga (10) , Lucia Mandon (11) , Nicolas Mangold (18) , Pierre-Yves Meslin (2) , Anthony E. Nelson (3) , Horton Newsom (19) , Adriana L. Reyes-Newell (3) , Scott Robinson (3) , Fernando Rull (9) , Shiv Sharma (20) , Justin I. Simon (21) , Pablo Sobron (22) , Imanol Torre Fernandez (10) , Arya Udry (17) , Dawn Venhaus (3) , Scott M. Mclennan (23) , Richard V. Morris (21) , Bethany Ehlmann (24)

1 US Geological Survey [Flagstaff]
2 IRAP - Institut de recherche en astrophysique et planétologie
3 LANL - Los Alamos National Laboratory
4 Globe Institute
5 DLR Institute of Optical Sensor Systems
6 IMPMC - Institut de minéralogie, de physique des matériaux et de cosmochimie
7 McGill University = Université McGill [Montréal, Canada]
8 CELIA - Centre d'Etudes Lasers Intenses et Applications
9 UVa - Universidad de Valladolid [Valladolid]
10 UPV/EHU - University of the Basque Country/Euskal Herriko Unibertsitatea
11 LESIA - Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics
12 Plancius Research LLC
13 Universidad de Málaga [Málaga] = University of Málaga [Málaga]
14 University of Manitoba [Winnipeg]
15 LGL-TPE - Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement
16 GeoRessources
17 WGU Nevada - University of Nevada [Las Vegas]
18 LPG - Laboratoire de Planétologie et Géodynamique [UMR 6112]
19 The University of New Mexico [Albuquerque]
20 UHM - University of Hawai‘i [Mānoa]
21 JSC - NASA Johnson Space Center
22 SETI - Search for Extraterrestrial Intelligence Institute
23 State University of New York at Stony Brook
24 Division of Geological and Planetary Sciences [Pasadena]

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, FeO_T, 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.

Keywords: Laser induced breakdown spectroscopy; LIBS; Mars; Multivariate regression; Regression; Chemometrics; Calibration

Domains: Sciences of the Universe [physics]

Ryan B. Anderson, Olivier Forni, Agnes Cousin, Roger C. Wiens, Samuel M. Clegg, et al.. Post-landing major element quantification using SuperCam laser induced breakdown spectroscopy. Spectrochimica Acta Part B: Atomic Spectroscopy, 2022, 188, pp.106437. ⟨10.1016/j.sab.2021.106347⟩. ⟨insu-03663667⟩