Spectral Deconvolution Analysis on Olivine-Orthopyroxene Mixtures with Simulated Space Weathering Modifications

TL;DR

This study develops a spectral deconvolution method using a modified Gaussian model to accurately estimate mineral abundances in olivine-orthopyroxene mixtures, accounting for space weathering effects, improving remote sensing analysis.

Contribution

It introduces a new empirical spectral analysis procedure that outperforms traditional band area ratio methods for mineral abundance estimation.

Findings

Empirical procedure estimates mineral abundances with 15% accuracy.

Space weathering causes underestimation of olivine content in celestial bodies.

Modified Gaussian model improves spectral deconvolution accuracy.

Abstract

Olivine and pyroxene are important mineral end-members for studying the sur-face material compositions of mafic bodies. The profiles of visible and near-infraredspectra of olivine-orthopyroxene mixtures systematically varied with their compositionratios. In our experiments, we combine the RELAB spectral database with a new spec-tral data obtained from some assembled olivine-orthopyroxene mixtures. We found thatthe commonly-used band area ratio (BAR, Cloutis et al. 1986) does not work well onour newly obtained spectral data. To investigate this issue, an empirical procedure basedon fitted results by modified Gaussian model is proposed to analyze the spectral curves.Following the new empirical procedure, the end-member abundances can be estimatedwith a 15% accuracy with some prior mineral absorption features. In addition, the mix-ture samples configured in our experiments are also irradiated by pulsed lasers to simulateand investigate the space weathering effects. Spectral deconvolution results confirm thatlow-content olivine on celestial bodies are difficult to measure and estimate. Therefore,the olivine abundance of space weathered materials may be underestimated from remotesensing data. This study may be used to quantify the spectral relationship of olivine-orthopyroxene mixtures and further reveal their correlation between the spectra of ordi-nary chondrites and silicate asteroids.