MarSCoDe Passive Reflectance Spectroscopy Analysis for Martian Minerals

Mineral analysis is one of the most vital missions in Mars exploration. Laser-induced breakdown spectroscopy (LIBS) is suitable for in situ analysis of minerals on Mars because of its ability to substantially remove dust and analyze most major elements. However, the longevity of active LIBS technology is susceptible to the Martian atmosphere and environmental temperature. Assuming that the LIBS laser had a malfunction, reflectance spectra of surface materials could be acquired in passive mode to analyze minerals and rocks, as is done on the ChemCam and SuperCam instruments on the Mars Science Laboratory and Mars 2020 rover missions, respectively. In addition, passive reflectance can provide constraints on the mineral structure and depositional environment of the rocks encountered by the rover. In this work, we present a passive reflectance spectra method based on the MarSCoDe ground simulator using the spectrometer module of the prototype system to test its ability to acquire visible reflectance spectra. The work presents the reflectance spectra of 24 National Reference Materials from which we computed the spectral parameters of minerals and rocks. Chemometrics based on particle swarm optimization-support vector classification (PSO-SVC) are used to accomplish the recognition of various materials. The results show that the passive spectral method could acquire targeted visible reflectance information and identify materials effectively.