Hyperspectral Remote Sensing Ruiliang Pu Center for Assessment and Monitoring of Forest and Environmental Resources Department of Environmental Science, Policy, and Management University of California at Berkeley 145 Mulford Hall Berkeley, CA Tel: , Fax:

Contents Basic concepts Prospective Analysis techniques Applications

Basic concepts The basic concept of imaging spectroscopy is shown in Fig. 1. Reflectance solar electromagnetic energy from the Earth surface is dispersed in a spectrometer. Hyperspectral remote sensing refers to the use of many narrow, continuous spectral bands (2-10 nm) that can cover nm(Fig. 2). The technique allows us to identify the diagnostic narrow band spectral features. Diagnostic spectral features in most terrestrial materials are typical nm in width (Hunt, 1980) (Figure 3 and 4).

Fig. 1.

Fig. 2. Wavelength (nm)

Fig. 4.Fig. 3. Tremolite Talc Band 7 Pyrophyllite Gypsum Montmorillonite Calcite Dolomite Epidote Chlorite Muscovite lllite Alunite Kaolinite 512 nm reso. Gibbsite 256 nm reso. 128 nm reso. 64 nm reso. 32 nm reso. 16 nm reso. 8 nm reso. 4 nm reso.

Basic concepts The hyperspectral data in contiguous 10 nm wide spectral bands with sufficient resolution can provide the direct identification of those materials with diagnostic features. Traditional remote sensing uses a few wide spectral bands ( nm) Less sensitive to subtle spectral changes such as phenological changes, mineral mixture proportional changes, vegetation stress, etc. Harder to extract quantitative information

Prospective Typical development stages of imaging spectroscopy technique The 1 st generation of airborne imaging spectrometer system, AIS, 1983, ~10 nm, 128 bands, 0.8 – 2.4  m. The 2 nd generation of airborne imaging spectrometer system, AVIRIS, 1987, 10 nm, 224 bands, 0.4 – 2.5  m. (CASI). Earth Observation System (EOS) and EO-1 mission EO-1 carries three sensors: ALI, Hyperion and AC, Hyperion, space-based imaging system, similar to AVIRIS, 220 bands, 10 nm band width, 30 m pixel size. See sample image for ALI, Hyperion, AC and AVIRIS (Argentina study site, Fig. 5).

Prospective In the future, Landsat 8 may carry imaging spectroscopy system similar to Hyperion. Hyperspectral remote sensing will be very useful for assessment of various Earth system processes, including: Hydrological processes, e.g., water vapor, Biogeochemical processes, e.g., land ecosystems, and Atmospheric processes, e.g., aerosols detection.