SPECTRAL REFLECTANCE INVESTIGATION OF GEOLOGIC MATERIALS FOR CREATION OF REFERENCE LIBRARY TOOL

Remote sensing using drones, aircraft or satellites has numerous geologic applications. While spectral reflectance references are available for many geologic materials, the need for a more comprehensive spectral reflectance library exists. As high-resolution satellite imagery becomes more readily available there is an increased need to understand how physical and chemical properties of geologic materials and varying conditions affect their spectral reflectance signatures. Spectral reflectance investigations were conducted using an ASD FieldSpec4 spectroradiometer in the 350-2500 nm range. Of interest were how varying surficial conditions such as weathered vs unweathered surfaces, the presence of clay coatings, and the degree to which sediment samples were saturated with water, affected the absorption/reflectance of light for geologic substrates in attempt to mimic the variability of potential obscurants found in nature. Preliminary results suggest that these varying surficial conditions may drown out absorption features present in ambient/pristine samples making them more difficult to distinguish or leading to misidentification. This is part of an ongoing study seeking to create a spectral reflectance database of geologic substrates along with extensive metadata (e.g., mineralogy, grain size and shape) to support the dataset.