The radiation or reflection characteristics of a surface differ at
different wavelengths. Because of the absorption and reflection of
light by chlorophyll in leaves and the subsequent reflection and
dispersion of the absorbed light within the internal structure of the
leaves, vegetation has unique spectral characteristics: it absorbs
visible light between 380 and 500 nm, 600 and 760 nm, and reflects
green light. In the near-infrared wavelengths, the spectrum mainly
features reflection (Pratt and Ellyett, 1979; Liu et al., 2002).