Some Properties of the Reflection Coefficient of the Optically Thick Slab

Properties of the reflection coefficient of a semi-infinite homogeneous plane-parallel layer are considered for low incidence and reflection angles. An approximate formula is proposed for the reflection coefficient that describes the azimuth reflection for arbitrary incidence and sighting angles. The numerical calculations confirm suitability of this formula for non-strong anisotropic phase function. A method to retrieve the phase function and single-scattering albedo that uses the measurements of the reflected radiation is proposed. The accuracy of this method is estimated using the numerical experiment.