Book excerpt: This report describes modifications that were made to the POLO procedures to treat infrared absorption by the gaseous molecules in the atmosphere. Also described are the results of studies performed with the POLO procedure to compute time-dependent scattered light fluxes at satellite receivers for (1) 0.4278-, 0.75-, and 1.07-micrometer wavelength anisotropic point sources; (2) 0.4278-, 0.5-, 0.6-, 0.75-, and 1.07-micrometer wavelength point isotropic sources in a 40-km meteorological range atmosphere; (3) point isotropic sources emitting in the 2.7-micrometer wavelength band; and (4) point isotropic 0.4278-, 0.75-, and 1.07-micrometer wavelength sources in model atmospheres containing a cloud layer. Three computer codes are described which were developed for convoluting the POLO-calculated wavelength- and time-dependent atmospheric scattering data with wavelength- and time-dependent source data for thermal radiation sources. A calculational method is described that can be used to compute the Legendre polynomial coefficients required in discrete ordinates codes for defining the phase function for light scattering by aerosols and cloud particles.