On the basis of the GOMETRAN radiative code, calculations of spectral covariance matrices of outgoing radiation in the 240-700 nm spectral range have been performed. It gave a possibility to examine the information content of measurement data simulated at different measurement designs (various measurement geometry and errors; different conditions of sun illumination and surface albedo) and to estimate the optimal number of measurement channels. The numbers of independently measurable parameters at measurement errors ranging from 0.1 to 1.0% are 8-11, 1-2 for atmospheric content of the ozone and NO₂, respectively; 6-12 and 5-8, describing the aerosol optical characteristics and atmospheric density, respectively.