A New Spectral Transformation Approach and Quantitative Analysis for MarSCoDe Laser-Induced Breakdown Spectroscopy (LIBS) Data

Abstract

Zhurong rover successfully landed on the southern of Utopia Planet of Mars on 15 May 2021. One laser-induced breakdown spectroscopy (LIBS) system, the main payload of the Mars Surface Composition Detector (MarSCoDe), was installed on the Zhurong rover aimed to measure the elements and their abundance in Martian regolith. Now, there are three sets of LIBS system (ChemCam, SuperCam and MarSCoDe) working on Mars at difference landing sites with diverse geologic features. For Mars exploration, cross-validation is necessary to expand the model compatibility, test data validity, and get more available data of the same type payloads. Spectral transformation approach is the first step and crucial for cross-validation of LIBS analysis model. Herein, a new 4-step spectral transformation approach was proposed to transform the LIBS spectra between three different LIBS systems (i.e., ChemCam, MarSCoDe, SDU-LIBS (recorded by self-built LIBS system)), whose data were partly different in spectral characteristics. Based on this approach, SDU-LIBS and MarSCoDe spectra data were transformed into ChemCam uniform and then the three kinds of LIBS data can have more similar spectral features and share one PLS (partial least squares) model for quantitative analysis. Our approach enables to make up the signal differences between different LIBS systems and gets acceptable quantitative analysis results of SDU-LIBS and MarSCoDe spectra using quantitative PLS model built by ChemCam calibration sample set. This work verified feasibility and availability of our approach for cross validation of different LIBS systems. Based on this method, MarSCoDe data were analyzed and got the preliminary satisfying results although no analysis model of laboratory replica payload was available under the existing conditions.

A new method for cross-calibration between LIBS systems based on a domain adaptive fully connected network

“…The application of LIBS technology to the quantitative analysis of elements has emerged as a hot research area. [15][16][17][18] Quantitative elemental analysis commonly employed in LIBS spectroscopy can be categorized into two categories: (1) univariate quantitative analysis methods including absolute spectral intensity with an internal standard method 19 and free calibration method; 20 (2) multivariate quantitative analysis methods represented by machine learning such as regression, 21 least squares, and neural networks. 22,23 When the compositions of the samples to be tested is diverse and complex, the analysis results of the currently widely used internal standard method would be highly affected.…”

Quantification of H2O in Amorphous and Crystalline Ferric Sulfates Relevant to Mars

“…LIBS is a rapid, portable, in situ atomic spectroscopy technique used to measure the concentration of major and trace elements in solid, liquid, or air samples, or to record the chemical signature of a material (Harmon et al, 2013;Pathak et al, 2012). LIBS is a spot analysis technique, it is possible to evaluate spatial changes in material composition and also to average shots taken from many different locations on the materials to obtain a bulk composition (Jin et al, 2022;Liu et al, 2022;Meslin et al, 2013). As a powerful spectroscopic technology for chemical composition analysis, LIBS helps to extract the elemental information of the rocks, minerals, and soil of Mars (Jin et al, 2022;Liu et al, 2022;Meslin et al, 2013;Schröder et al, 2015).…”

“…LIBS is a spot analysis technique, it is possible to evaluate spatial changes in material composition and also to average shots taken from many different locations on the materials to obtain a bulk composition (Jin et al, 2022;Liu et al, 2022;Meslin et al, 2013). As a powerful spectroscopic technology for chemical composition analysis, LIBS helps to extract the elemental information of the rocks, minerals, and soil of Mars (Jin et al, 2022;Liu et al, 2022;Meslin et al, 2013;Schröder et al, 2015). LIBS technology has been deployed on Mars aboard different rovers since 2012, including ChemCam on Mars Science Laboratory Rover Curiosity, MarSCoDe on Tianwen-1 Rover Zhurong, and SuperCam on Mars 2020 Rover Perseverance (Jin et al, 2022;Liu et al, 2022;Wiens et al, 2012Wiens et al, , 2021.…”

Water Quantification of Amorphous and Crystalline Ferric Sulfates Relevant to Mars

“…LIBS is a spot analysis technique, it is possible to evaluate spatial changes in material composition and also to average shots taken from many different locations on the materials to obtain a bulk composition (Jin et al, 2022;Liu et al, 2022;Meslin et al, 2013). As a powerful spectroscopic technology for chemical composition analysis, LIBS helps to extract the elemental information of the rocks, minerals, and soil of Mars (Jin et al, 2022;Liu et al, 2022;Meslin et al, 2013;Schröder et al, 2015). LIBS technology has been deployed on Mars aboard different rovers since 2012, including ChemCam on Mars Science Laboratory Rover Curiosity, MarSCoDe on Tianwen-1 Rover Zhurong, and SuperCam on Mars 2020 Rover Perseverance (Liu et al, 2022;Jin et al, 2022;Wiens et al, 2012;Wiens et al, 2021).…”

“…As a powerful spectroscopic technology for chemical composition analysis, LIBS helps to extract the elemental information of the rocks, minerals, and soil of Mars (Jin et al, 2022;Liu et al, 2022;Meslin et al, 2013;Schröder et al, 2015). LIBS technology has been deployed on Mars aboard different rovers since 2012, including ChemCam on Mars Science Laboratory Rover Curiosity, MarSCoDe on Tianwen-1 Rover Zhurong, and SuperCam on Mars 2020 Rover Perseverance (Liu et al, 2022;Jin et al, 2022;Wiens et al, 2012;Wiens et al, 2021). Based on the measured results of LIBS on Mars, the major, minor, and trace elements were quantified using emission intensities of the respective elements, including Fe, Mg, Ca, Li, Rb, Sr, Ba, etc.…”