Panchromatic Digital Images
"Panchromatic" is a term used for images that recorded all the photons in a very broad wavelength band. This simple interpretation can be a little misleading, however, if you misinterpret "all colors" to mean all wavelengths--panchromatic usually only refers to all visible photons, i.e. ROYGBIV. Furthermore, a filter is sometimes used to remove blue photons from the image because these photons often are associated with haze, which degrades the image quality. Hence, these "panchromatic" images really only include ROYG. Since all the photons in a panchromatic image are grouped in a single bandwidth bin, panchromatic images are presented as black and white images.
Satellites with panchromatic data products commonly used in vegetation detection include Landsat 7, EROS, SPOT, and IKONOS. These satellites and their data products are discussed later in this primer.