Glossary for Geospatial Science

spectral band or spectral region:  A well-defined, continuous wavelength range in the spectrum of reflected or radiated electromagnetic energy.  Red, green, and blue are all spectral regions within the portion of the spectrum that is visible to humans as light.  Color-infrared images are composed of red, green, and a spectral region commonly called the photoinfrared, which is not in the visible portion of the electromagnetic spectrum.  (See also: color-infrared, electromagnetic spectrum.)