Attenuation of collimated light beams in scattering media

The effect of singly side-scattered light on the attenuation of collimated light beams in turbid media is investigated. Correction formulas for the exponential attenuation law are derived for the case where the viewing angles of the receiving system and radiation source are equal. The ranges in which the corrections are important in the propagation of light beams in haze, fog, and rain are indicated. It is shown that the range of solid angles in which the angular dependence of the scattered light can be neglected is defined by the inequality 1.1, where p is the Mie parameter; the solid angle determines the divergence of the light beam, which is equal in this case to the viewing angle of the receiving system.