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1. Development of a High Min-Entropy Quantum Random Number Generator Based on Amplified Spontaneous Emission

Author

Charlotte K. Duda, Kristina A. Meier, and Raymond T. Newell

Subjects
quantum random number generator, amplified spontaneous emission, min-entropy, Science, Astrophysics, QB460-466, Physics, QC1-999
Abstract

We present the theory, architecture, and performance characteristics of a quantum random number generator (QRNG) which operates in a PCI express form factor-compatible plug-and-play design. The QRNG relies on a thermal light source (in this case, amplified spontaneous emission), which exhibits photon bunching according to the Bose–Einstein (BE) statistics. We demonstrate that 98.7% of the unprocessed random bit stream min-entropy is traceable to the BE (quantum) signal. The classical component is then removed using a non-reuse shift-XOR protocol, and the final random numbers are generated at a 200 Mbps rate and shown to pass the statistical randomness test suites FIPS 140-2, Alphabit, SmallCrush, DIEHARD, and Rabbit of the TestU01 library.

Published
2023
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2. Post-Landing Major Element Quantification Using SuperCam Laser Induced Breakdown Spectroscopy

Author

Ryan B Anderson, Olivier Forni, Agnes Cousin, Roger C Wiens, Samuel M Clegg, Jens Frydenvang, Travis S J Gabriel, Ann M Ollila, Susanne Schroder, Olivier Beyssac, Erin Gibbons, David S Vogt, Elise Clave, Jose-Antonio Manrique, Carey Legett IV, Paolo Pilleri, Raymond T Newell, Joseph Sarao, Sylvestre Maurice, Gorka Arana, Karim Benzerara, Pernelle Bernardi, Sylvian Bernard, Bruno Bousquet, Adrian J Brown, Cesar-Alvarez Llamas, Baptiste Chide, Edward Cloutis, Jade Comellas, Stephanie Connell, Erwin Dehouck, Dorothea M Delapp, Ari Essunfeld, Cecile Fabre, Thierry C Fouchet, Cristina Garcia-Florentino, Laura Garcia-Gomez, Patrick Gasda, Olivier Gasnault, Elisabeth Hausrath, Nina L Lanza, Javier Laserna, Jeremie Lasue, Guillermo Lopez, Juan Manuel Madariaga, Lucia Mandon, Nicolas Mangold, Pierre-Yves Meslin, Anthony E Nelson, Horton Newsom, Adriana L Reyes-Newell, Scott Robinson, Fernando Rull, Shiv Sharma, Justin I Simon, Pablo Sobron, Imanol Torre Fernandez, Arya Udry, Dawn Venhaus, Scott M McLennan, Richard V Morris, and Bethany Ehlmann

Subjects
Geosciences (General)
Abstract

The SuperCam instrument on the PerseveranceMars 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 andspectra are normalized to minimize signal fluctuations and effectsof target distance.In some cases, the spectra are also standardized or binned prior to quantification. To determine quantitative elemental compositionsof 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 oreand sodalite), andreplicates of the sintered SuperCam calibration targets (SCCTs) onboardthe 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 fourfolds 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 3m. 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.

Published
2021
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3. The SuperCam Instrument Suite on the NASA Mars 2020 Rover: Body Unit and Combined System Tests

Author

Roger C. Wiens, Sylvestre Maurice, Scott H. Robinson, Anthony E. Nelson, Philippe Cais, Pernelle Bernardi, Raymond T. Newell, Sam Clegg, Shiv K. Sharma, Steven Storms, Jonathan Deming, Darrel Beckman, Ann M. Ollila, Olivier Gasnault, Ryan B. Anderson, Yves André, S. Michael Angel, Gorka Arana, Elizabeth Auden, Pierre Beck, Joseph Becker, Karim Benzerara, Sylvain Bernard, Olivier Beyssac, Louis Borges, Bruno Bousquet, Kerry Boyd, Michael Caffrey, Jeffrey Carlson, Kepa Castro, Jorden Celis, Baptiste Chide, Kevin Clark, Edward Cloutis, Elizabeth C. Cordoba, Agnes Cousin, Magdalena Dale, Lauren Deflores, Dorothea Delapp, Muriel Deleuze, Matthew Dirmyer, Christophe Donny, Gilles Dromart, M. George Duran, Miles Egan, Joan Ervin, Cecile Fabre, Amaury Fau, Woodward Fischer, Olivier Forni, Thierry Fouchet, Reuben Fresquez, Jens Frydenvang, Denine Gasway, Ivair Gontijo, John Grotzinger, Xavier Jacob, Sophie Jacquinod, Jeffrey R. Johnson, Roberta A. Klisiewicz, James Lake, Nina Lanza, Javier Laserna, Jeremie Lasue, Stéphane Le Mouélic, Carey Legett, Richard Leveille, Eric Lewin, Guillermo Lopez-Reyes, Ralph Lorenz, Eric Lorigny, Steven P. Love, Briana Lucero, Juan Manuel Madariaga, Morten Madsen, Soren Madsen, Nicolas Mangold, Jose Antonio Manrique, J. P. Martinez, Jesus Martinez-Frias, Kevin P. McCabe, Timothy H. McConnochie, Justin M. McGlown, Scott M. McLennan, Noureddine Melikechi, Pierre-Yves Meslin, John M. Michel, David Mimoun, Anupam Misra, Gilles Montagnac, Franck Montmessin, Valerie Mousset, Naomi Murdoch, Horton Newsom, Logan A. Ott, Zachary R. Ousnamer, Laurent Pares, Yann Parot, Rafal Pawluczyk, C. Glen Peterson, Paolo Pilleri, Patrick Pinet, Gabriel Pont, Francois Poulet, Cheryl Provost, Benjamin Quertier, Heather Quinn, William Rapin, Jean-Michel Reess, Amy H. Regan, Adriana L. Reyes-Newell, Philip J. Romano, Clement Royer, Fernando Rull, Benigno Sandoval, Joseph H. Sarrao, Violaine Sautter, Marcel J. Schoppers, Susanne Schröder, Daniel Seitz, Terra Shepherd, Pablo Sobron, Bruno Dubois, Vishnu Sridhar, Michael J. Toplis, Imanol Torre-Fdez, Ian A. Trettel, Mark Underwood, Andres Valdez, Jacob Valdez, Dawn Venhaus, and Peter Willis

Published
2020
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5. Reflectance of Jezero crater floor: 1. Data processing and calibration of the Infrared Spectrometer (IRS) on SuperCam

Author

Clement Royer, Thierry Fouchet, Lucia Mandon, Franck Montmessin, Francois Poulet, Olivier Forni, Jeffrey R. Johnson, Carey Legett, Stephane Le Mouelic, Olivier Gasnault, Pierre Beck, Cathy Quantin-Nataf, Erwin Dehouck, Ann M. Ollila, Cédric Pilorget, Pernelle Bernardi, Jean-Michel Reess, Paolo Pilleri, Adrian Jon Brown, Raymond T Newell, Edward Cloutis, Sylvestre Maurice, and Roger C. Wiens

Published
2022

6. Observing rocks in Jezero crater, Mars: results of the first months of operation of the SuperCam VISIR spectrometer

Author

Lucia Mandon, Cathy Quantin-Nataf, Pierre Beck, Thierry Fouchet, Clément Royer, Franck Montmessin, Olivier Forni, Jeffrey R. Johnson, Olivier Gasnault, Erwin Dehouck, François Poulet, Adrian Brown, Jesse D. Tarnas, Stéphane Le Mouélic, Pernelle Bernardi, Jean-Michel Reess, Raymond T. Newell, Sylvestre Maurice, Roger C. Wiens, Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Pôle Planétologie du LESIA, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, PLANETO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Institut national des sciences de l'Univers (INSU - CNRS)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Johns Hopkins University Applied Physics Laboratory [Laurel, MD] (APL), Institut d'astrophysique spatiale (IAS), Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Plancius Research LLC, Jet Propulsion Laboratory (JPL), NASA-California Institute of Technology (CALTECH), Laboratoire de Planétologie et Géodynamique [UMR 6112] (LPG), Université d'Angers (UA)-Université de Nantes - UFR des Sciences et des Techniques (UN UFR ST), Université de Nantes (UN)-Université de Nantes (UN)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), and Los Alamos National Laboratory (LANL)

Subjects
[SDU]Sciences of the Universe [physics], ComputingMilieux_MISCELLANEOUS
Abstract

International audience; The Perseverance rover (Mars 2020 mission, NASA) landed in the ancient lakebed of Jezero crater, Mars on February 18th, 2021. The main science objectives of the mission are the characterization of past habitable environments, the search for preserved biosignatures and the collection of samples to be returned to Earth by the next MSR (Mars Sample Return, NASA/ESA) mission [1]. The payload includes the SuperCam instrument (under the leadership of LANL, USA and IRAP, France), which plays a critical role in the exploration strategy, as it combines various remote-sensing techniques to investigate the elemental and mineralogical composition of rocks and soils: high-resolution color imaging, laser-induced breakdown spectroscopy, Raman spectroscopy, visible and near-infrared (VISIR) reflectance spectroscopy, and acoustic sensing [2, 3, 4, 5]. In particular, the near-infrared spectrometer is a novel instrument on the Martian surface. The spectra, together with data from two additional visible spectrometers, cover 0.39-0.85 µm (VIS) and 1.3-2.6 µm (IR), which allows the identification of a wide variety of minerals.Figure 1. Enhanced-color mosaic of images taken by the Mastcam-Z Left camera of the rover workspace on sol 78 [6]. NASA/Caltech-JPL/MSSS/ASU. Orbital data show that the landing site exhibits diverse mineralogical assemblages in various geological contexts, attesting in particular of an ancient aqueous activity during the Noachian and Hesperian eras (> 3 Ga), and including mafic minerals, carbonates, phyllosilicates and opaline silica [7, 8, 9].We present the initial results of the SuperCam VISIR spectrometers, with calibrated [10] spectral data collected in the first months of operation of the instrument, with a focus on the rocks and soils present in the rover workspace and explored so far. Spectra have been obtained on nearby rocks so far within 50 m of the Octavia E. Butler landing site, at the boundaries of the Crater Floor Fractured Rough (CF-Fr) and Crater Floor Fractured (CF-F) units, which from orbit exhibit the spectral signatures of pyroxene and olivine, respectively [7]. A comparison with orbital data is presented in [11].Most of the rocks analyzed in the close vicinity of the rover so far consists of light-toned `pavers' and upstanding dark-toned rocks (Fig. 1). Some variability in reflectance levels and absorption bands is observed within and between the rocks (Fig. 2), but overall they share similar spectral characteristics in the VISIR. In particular, they all exhibit an absorption band near 1.9 µm (a spectral signature indicating the presence of the water molecule), a band that is usually not observed in the soils - at least not with the same depth. This absorption near 1.9 µm is also present in spectral observations of outcrops a few kilometers away from the rover [11]. In addition to this absorption at ~1.9 µm, a blue slope in the 2.1-2.5 µm region and subtle absorption bands near 1.4 µm and 2.28 µm show up locally, which suggests the presence of hydrated mineral species, such as an iron-rich phyllosilicate (like nontronite or hisingerite), potentially mixed with an oxy-hydroxide such as ferrihydrite (Fig. 2). The intensity of these absorption bands is consistent with at least a few weight percent of these hydrated species in the observed target, either in the bulk of the rock or in a varnish/coating. Finally, fewer spectra exhibit a weak absorption at 2.2 µm, suggesting the additional presence of an Al-OH or Si-OH-bearing phase. Overall, the detection of these widespread hydration features supports some pervasive water-rock interactions during the past, in the landing site of Perseverance. CRISM data suggest that we have landed in a relatively low hydration region, and that the rover will be driving through progressively increasing hydration throughout the mission, as it moves onto the delta, the olivine-carbonate and the region outside of Jezero crater. Future in situ measurements on these potentially more hydrated and diverse rocks are expected to bring new insights into the past aqueous environment at Jezero crater.Figure 2. Example of a SuperCam observation on a rock present in the workspace of the rover: 10x1 raster on target Bidziil. (a) RMI mosaic taken at 2.3 m from the rover mast on sol 56 with the IRS 68% field of view annotated in red. (b) Corresponding IRS spectra in color, compared to laboratory spectra of known minerals in black and grey. References[1] Farley, K. A. et al., 2020. Space Sci. Rev.; [2] Wiens, R.C. et al., 2017. Spectroscopy; [3] Maurice, S. et al., 2021 Space Sci. Rev.; [4] Cousin, A. et al., this conference; [5] Chide, B. et al., this conference; [6] Bell, J. F. et al., 2021. Space Sci. Rev. [7] Goudge, T. A. et al., 2015. J. Geophys. Res. Planets; [8] Ehlmann, B. L. et al., 2008. Science; [9] Tarnas, J. D. et al., 2019. Geophys. Res. Lett.; [10] Royer, C. et al., this conference; [11] Quantin-Nataf et al., this conference.

Published
2021

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

Author

Ryan B. Anderson, Olivier Forni, Agnes Cousin, Roger C. Wiens, Samuel M. Clegg, Jens Frydenvang, Travis S.J. Gabriel, Ann Ollila, Susanne Schröder, Olivier Beyssac, Erin Gibbons, David S. Vogt, Elise Clavé, Jose-Antonio Manrique, Carey Legett, Paolo Pilleri, Raymond T. Newell, Joseph Sarrao, Sylvestre Maurice, Gorka Arana, Karim Benzerara, Pernelle Bernardi, Sylvain Bernard, Bruno Bousquet, Adrian J. Brown, César Alvarez-Llamas, Baptiste Chide, Edward Cloutis, Jade Comellas, Stephanie Connell, Erwin Dehouck, Dorothea M. Delapp, Ari Essunfeld, Cecile Fabre, Thierry Fouchet, Cristina Garcia-Florentino, Laura García-Gómez, Patrick Gasda, Olivier Gasnault, Elisabeth M. Hausrath, Nina L. Lanza, Javier Laserna, Jeremie Lasue, Guillermo Lopez, Juan Manuel Madariaga, Lucia Mandon, Nicolas Mangold, Pierre-Yves Meslin, Anthony E. Nelson, Horton Newsom, Adriana L. Reyes-Newell, Scott Robinson, Fernando Rull, Shiv Sharma, Justin I. Simon, Pablo Sobron, Imanol Torre Fernandez, Arya Udry, Dawn Venhaus, Scott M. McLennan, Richard V. Morris, Bethany Ehlmann, US Geological Survey [Flagstaff], United States Geological Survey [Reston] (USGS), Institut de recherche en astrophysique et planétologie (IRAP), Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire Midi-Pyrénées (OMP), Institut de Recherche pour le Développement (IRD)-Université Toulouse III - Paul Sabatier (UT3), Université de Toulouse (UT)-Université de Toulouse (UT)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Institut de Recherche pour le Développement (IRD)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National d'Études Spatiales [Toulouse] (CNES)-Centre National de la Recherche Scientifique (CNRS)-Météo-France -Centre National de la Recherche Scientifique (CNRS), Los Alamos National Laboratory (LANL), Globe Institute, Faculty of Health and Medical Sciences, University of Copenhagen = Københavns Universitet (UCPH)-University of Copenhagen = Københavns Universitet (UCPH), DLR Institute of Optical Sensor Systems, Deutsches Zentrum für Luft- und Raumfahrt [Berlin] (DLR), Institut de minéralogie, de physique des matériaux et de cosmochimie (IMPMC), Muséum national d'Histoire naturelle (MNHN)-Institut de recherche pour le développement [IRD] : UR206-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS), McGill University = Université McGill [Montréal, Canada], Centre d'Etudes Lasers Intenses et Applications (CELIA), Université de Bordeaux (UB)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Centre National de la Recherche Scientifique (CNRS), Universidad de Valladolid [Valladolid] (UVa), University of the Basque Country/Euskal Herriko Unibertsitatea (UPV/EHU), Laboratoire d'études spatiales et d'instrumentation en astrophysique = Laboratory of Space Studies and Instrumentation in Astrophysics (LESIA), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Sorbonne Université (SU)-Centre National de la Recherche Scientifique (CNRS)-Université Paris Cité (UPCité), Plancius Research LLC, Universidad de Málaga [Málaga] = University of Málaga [Málaga], University of Manitoba [Winnipeg], Laboratoire de Géologie de Lyon - Terre, Planètes, Environnement (LGL-TPE), École normale supérieure de Lyon (ENS de Lyon)-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Université de Lyon-Institut national des sciences de l'Univers (INSU - CNRS)-Université Jean Monnet - Saint-Étienne (UJM)-Centre National de la Recherche Scientifique (CNRS), GeoRessources, Institut national des sciences de l'Univers (INSU - CNRS)-Centre de recherches sur la géologie des matières premières minérales et énergétiques (CREGU)-Université de Lorraine (UL)-Centre National de la Recherche Scientifique (CNRS), University of Nevada [Las Vegas] (WGU Nevada), Laboratoire de Planétologie et Géosciences [UMR_C 6112] (LPG), Université d'Angers (UA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Nantes université - UFR des Sciences et des Techniques (Nantes univ - UFR ST), Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ)-Nantes Université - pôle Sciences et technologie, Nantes Université (Nantes Univ)-Nantes Université (Nantes Univ), The University of New Mexico [Albuquerque], University of Hawai‘i [Mānoa] (UHM), NASA Johnson Space Center (JSC), NASA, Search for Extraterrestrial Intelligence Institute (SETI), State University of New York at Stony Brook, Stony Brook University [SUNY] (SBU), State University of New York (SUNY)-State University of New York (SUNY), Division of Geological and Planetary Sciences [Pasadena], and California Institute of Technology (CALTECH)

Subjects
LIBS, Mars, Multivariate regression, Laser induced breakdown spectroscopy, Regression, Atomic and Molecular Physics, and Optics, Analytical Chemistry, [SDU]Sciences of the Universe [physics], Calibration, Chemometrics, Laser induced breakdown spectroscopy LIBS Mars Multivariate regression Regression Chemometrics Calibration, Instrumentation, Spectroscopy
Abstract

International audience; 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.

Published
2022

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