availability may lead to more accurate models. Thus, all the models could perform better for spectra obtained on Mars because they will have more emission lines from which to build their models. The ultimate goal of this thesis is to determine the best method(s) for determining the elemental compositions of Mars rocks from LIBS spectral data. SPLS, lasso, and elastic net not only provide models with accuracies comparable to PLS model accuracies, but they also give interpretable models. These methods can improve understanding of how Mars evolved by painting a researchers’ clearer picture of elemental compositions and interactions in rocks. FUTURE WORK DATA PREPROCESSING: AVERAGED VERSUS UNAVERAGED SPECTRA Spectra from each of the 50 shots for each sample were averaged in this thesis, which resulted in 100 averaged spectra that were used for analysis. This was done to average out noise. This is permissible because the samples are homogenous (rock powders). However, the spectra from MSL will be from rocks, which by their nature are heterogeneous. Each shot could contain distinct compositional information. In the context of this application, information about
availability may lead to more accurate models. Thus, all the models could perform better for spectra obtained on Mars because they will have more emission lines from which to build their models. The ultimate goal of this thesis is to determine the best method(s) for determining the elemental compositions of Mars rocks from LIBS spectral data. SPLS, lasso, and elastic net not only provide models with accuracies comparable to PLS model accuracies, but they also give interpretable models. These methods can improve researchers’ understanding of how Mars evolved by painting a clearer picture of elemental compositions and interactions in rocks. FUTURE WORK DATA PREPROCESSING: AVERAGED VERSUS UNAVERAGED SPECTRA Spectra from each of the 50 shots for each sample were averaged in this thesis, which resulted in 100 averaged spectra that were used for analysis. This was done to average out noise. This is permissible because the samples are homogenous (rock powders). However, the spectra from MSL will be from rocks, which by their nature are heterogeneous. Each shot could contain distinct compositional information. In the context of this application, information about