Spectral Mapping Methods: Many Problems, Some Solutionsφ

Spectral reflectance in the visible and near-infrared offers a rapid and inexpensive technique for determining the mineralogy of samples and obtaining information on chemical composition. Absorption-band parameters such as the position, depth, width, and asymmetry of the feature have been used to quantitatively estimate composition of samples from hyperspectral field and laboratory reflectance data. The parameters have also been used to develop mapping methods for the analysis of hyperspectral image data. This has resulted in techniques providing surface mineralogical information (e.g., classification) using absorption-band depth and position, however no attempt has been made to prepare images of the absorption-band parameters. In this paper, a simple linear interpolation technique is proposed in order to derive absorption-band position, depth and asymmetry from hyperspectral image data. It is demonstrated that these absorption band maps provide basic information for surface compositional mapping. Next, we look at stratified image analysis approaches and data integration techniques. Lastly we use contextual information for image analysis. Geoinversion approaches are applied to hymap data on a sedimentary terrain making use of the systematic sequence stratigraphy.