Imaging Spectrometry And Geological Applications

Abstract

Reflectance and emittance spectra have been used for many years to obtain compositional information about the Earth’s surface. Electronic transition and charge trans- fer processes associated with transition-metal ions such as Fe, Ti, Cr, and so on produce diagnostic absorption fea- tures in the visible and near-infrared (VNIR) wavelength region of the spectra of minerals and rocks, while vibra- tional processes in H2O and OH? produce fundamental overtone absorptions in the shortwave infrared (SWIR) portion of the spectrum. Field and laboratory studies have demonstrated that reflectance spectroscopy can be used for mineral identification and further geological studies. The translation of these measurements to imaging data led to the development of the field of imaging spectrometry in remote sensing. Imaging spectrometers acquire images in a large number of narrow contiguous spectral bands to enable the extraction of reflectance spectra at a pixel scale that can be directly compared with similar spectra mea- sured either in the field or in a laboratory. In this chapter, the use of imaging spectrometer data for geological appli- cations is discussed by describing the processing chain of data analysis from the raw data acquisition to prospective applications. Several topics are addressed. Anappraisal of future spaceborne imaging spectrometer missions and potential prospective applications provides insight