Campus, PAB 232
The Mars Rover carries onboard an instrument, ChemCam, designed to measure the composition of rocks using laser-induced breakdown spectroscopy (LIBS). The disaggregation of component elements given these spectra is complicated by so-called matrix effects, which influence the relative height of emission lines. The time intensive plasma physics code ATOMIC has been used to model these spectra, but using it for forward models is intractable given the large parameter space to explore. In particular, for disaggregation one must identify which elements are in the potentially very complex sample, as well as their proportions. Emulators have been proposed as a fast way to do this analysis. Last summer, I worked in the statistics group at Los Alamos National Lab, using dimensionality reduction methods and Gaussian processes to build such an emulator. The goal was to show a proof of concept and estimate the constituent element proportions for a simple two element compound (NaCu).
I’ll give a short overview of Gaussian processes in addition to showing results for this particular problem.