A new difference equation of radiative transfer is derived, including the angular dependence of the radiation and the particle scattering properties. The scattering by the particles in close-packed media is treated in terms of suitably defined near-field differential cross sections. The new equation agrees with the standard differential equation in application to typical atmospheric aerosols, but disagrees in application to all close-packed media. Examples are given which imply that the new equation should be significantly more accurate than the standard one in the treatment of strongly reflecting or absorbing paints, powders, and coatings.
© 1977 Optical Society of AmericaPDF Article