LABORATORY REFLECTIVE SPECTROSCOPY INVESTIGATIONS OF HEAVY FUELS, PLASTICS AND GEOMATERIALS FOR HYPERSPECTRAL REMOTE SENSING BASED ENVIRONMENTAL MONITORING

Petroleum products spilled, leaked, or disposed in the environment are well known to rapidly contaminate water supplies and soil. As such identifying these products quickly and in a cost effective way is an important first step towards mitigation and remediation. Hyperspectral remote sensing (HRS) is rapidly expanding as a means for environmental monitoring over time. Fuel and petroleum spills are one area where there is great potential for utilizing HRS, provided that robust libraries are built on an array of relevant materials. Here results are provided on laboratory reflective spectroscopy investigations that could support HSR library development for petroleum products and plastics for study in the environment. Previous studies have been done on crude oil, diesel, gasoline, ethanol, and motor oil, but creating a spectral library of fuels on various substrates is necessary to accurately identify petroleum products. Reflectance spectra (350 nm to 2500 nm) of diesel, kerosene, and jet fuel A were measured using an ASD FieldSpec 4 Spectroradiometer on sand substrates and on a Spectralon panel. Plastic materials were also investigated to determine the ability to spectrally differentiate between plastics and fuels. Results indicate that diesel, jet fuel A and kerosene are marginally distinguishable from each other but collectively have features that enable them to be identified on common substrates. Under laboratory conditions these fuels also show promise for detailed age estimation, however changes in features with time appear to be after 2 weeks and substrate type matters significantly. Qualitatively, smaller grain sizes seem to correlate with longer retention times, pointing to surface area as a major control on fuel evaporation. Although significant refinement needs to be carried out, these findings show that fuels could reasonably be identified using HRS. Although petroleum product spectra may be challenging to distinguish from some plastics, spatial contexts should be sufficient to discriminate these objects in terrestrial environments.