Inspecting MIVIS capability to retrieve chemical-mineralogical information: evaluation and analysis of VNIR-SWIR data acquired on a volcanic area

Abstract

This work is a contribution to the assessment of MIVIS (Multispectral Infrared and Visible Imaging Spectrometer) airborne imaging spectrometer capability in applications of surface characterization. The focus is on the visible and near-infrared-short wave infrared (VNIR-SWIR) spectral region, using a dataset acquired in 1994 on Vulcano Island (Italy), to retrieve chemical mineralogical information on the altered deposits related to volcanic activity. The main processing steps include data quality evaluation in terms of signal-to-noise ratio, atmospheric and topographic corrections and spectral interpretation of the image. Estimation of surface reflectance is based on atmospheric modelling by MODTRAN3.5 and 6S radiative transfer codes. Representative MIVIS reflectance spectra of the main surface units are compared with spectra measured in the laboratory on field samples, and interpreted to characterize the mineralogy on the basis of their spectral features. A thematic map of the main alteration units is then produced by applying spectral mapping techniques to the surface reflectance image, using a set of channels selected on the basis of their data quality and image-derived end-member spectra.