Since the space between a scene and a remote sensing device may be cluttered by some intervening medium, the remotely sensed information may be contaminated by extraneous effects, such as an intervening medium which selectively absorbs some of the radiation. In this cartoon, a semi-transparent filter is located between scene and sensor which has the effect of blocking some wavelengths (colors) but not others. The remote inference based on the contaminated radiation sensed by the eyeball can be very different than the scene itself. Virtually all satellite remote sensing systems have to be corrected, in some way, for effects of radiation passing through the not quite transparent atmosphere. In non-visible wavelengths, the effect of the atmosphere on radiation may be very large.