EFFECTS OF EMPIRICAL VERSUS MODEL-BASED REFLECTANCE CALIBRATION ON AUTOMATED-ANALYSIS OF IMAGING SPECTROMETER DATA - A CASE-STUDY FROM THE DRUM MOUNTAINS, UTAH

Data collected by the Airborne Visible/Infrared imaging Spectrometer ( AVIRIS) have been calibrated to surface reflectance using an empirical method and an atmospheric model-based method. Single spectra extracte d from both calibrated data sets for locations with known mineralogy c ompared favorably with laboratory and field spectral measurements of s amples from the same locations. Generally, spectral features were some what subdued in data calibrated using the model-based method when comp ared with those calibrated using the empirical method. Automated featu re extraction and expert system analysis techniques have been successf ully applied to both data sets to produce similar endmember probabilit y images and spectral endmember libraries. Linear spectral unmixing pr ocedures applied to both calibrated data sets produced similar image m aps. These comparisons demonstrated the utility of the model-based app roach for atmospherically correcting imaging spectrometer data prior t o extraction of scientific information. The results indicated that ima ging spectrometer data can be calibrated and analyzed without a priori knowledge of the remote target.