LAUSR

The problem of the sunlight transfer equation in the atmosphere in a gas absorption band is considered. The structure of the spectral dependence of the brightness coefficient (reflectance) of the radiation, reflected by the atmosphere–surface system is studied. The low-parametrical approximations of the reflectance as an expansion of the inverse logarithm of the reflectance by the degrees of the absorption section are constructed. The approximation are a synthesis of the Bouguer-Lambert-Beer law. The explicit algorithm for calculating the approximation parameters based on known values of reflectance is described. It is shown how the constructed approximations can be used to reduce the time of the line-by-line calculations of reflectance.