reflection, <of radiation>
process by which radiation is returned by a surface or a medium, without change in the frequency of its monochromatic components
Note 1 to entry: Part of the radiation falling on a medium is reflected at the surface of the medium ("surface reflection"); another part can be scattered back from the interior of the medium ("volume reflection").
Note 2 to entry: The frequency is unchanged only if there is no Doppler effect due to the motion of the materials from which the radiation is returned.
Note 3 to entry: This entry was numbered 845-04-42 in IEC 60050-845:1987.
Note 4 to entry: This entry was numbered 17-1065 in CIE S 017:2011.