Spectra example - USGS Spectral LIbrary

Comparison of spectra for alunite from four sensors with different spectral resolutions. Landsat Thematic Mapper (TM) with six bands in the visible to near-infrared spectrum cannot resolve any absorptions typical in minerals. The MODerate resolution imaging spectrometer (MODIS) has enough spectral channels to barely resolve some spectral features in the visible portion of the spectrum but not in the important near-infrared. The National Aeronautics and Space Administration airborne visible and infrared imaging spectrometer (AVIRIS), however, has sufficient spectral range and resolution to resolve many common absorption bands found in a wide variety of minerals and other compounds. Figure 6 from USGS Circular 1413, http://dx.doi.org/10.3133/cir1413.