Spectral modeling of meteorites at UV-vis-NIR wavelengthsOPEN ACCESS 

Julia Martikainen, Antti Penttilä, Maria Gritsevich, Hannakaisa Lindqvist, Karri Muinonen

Journal of Quantitative Spectroscopy and Radiative Transfer, Volume 204, January 2018, Pages 144-151


• A ray-optics code was used to derive imaginary part of refractive indices for pyroxene.
• Reflectance spectra of three meteorite pieces were modeled with the ray-optics code.
• Good matches between the modeled and measured reflectance spectra were found.”

“We present a novel simulation framework for assessing the spectral properties of meteorite specimens. The framework utilizes a ray-optics code, which simulates light scattering by Gaussian-random-sphere particles large compared to the wavelength of the incident light and accounts for internal diffuse scatterers. The code uses incoherent input and computes phase matrices by utilizing incoherent scattering matrices. Reflectance spectra are modeled by introducing a combination of olivine, pyroxene, and iron, the most common materials present in meteorites that dominate their spectral features. The complex refractive indices of olivine and iron are obtained from existing databases. The refractive indices of pyroxene are derived using an optimization that utilizes our ray-optics code and the measured spectrum of the material. We demonstrate our approach by applying it on the measured meteorite reflectance spectra obtained with the University of Helsinki integrating-sphere UV–vis-NIR spectrometer.”