Estimation of abundances in two-component mineral mixtures using mid-infrared laser reflectance ratios

The mid-infrared spectral region (8-14 μm wavelength) is emerging as a viable geologic remote sensing tool due to the presence of reststrahlen bands for minerals such as silicates and carbonates. An experimental study was carried out to characterize the mid-infrared laser reflectance of mineral mixtures, and to explore the potential of laser remote sensing systems to estimate mineral abundances in two-component mixtures. An empirical model was developed to establish a relationship between laser reflectance ratios at judiciously selected wavelengths and percentage of one of the minerals in the mixture. It was found that the abundances can be estimated to within 2% using this technique. This method shows promise for remote estimation of mineral abundances in applications such as planetary remote sensing since the use of reflectance ratios obviates the need for absolute calibration