Biangular reflectance for an absorbing and isotropically scattering medium

A comparison between theory and actual data is presented for the biangular reflectance of a thin cryodeposit formed on a cryogenically cooled substrate. The analytical model employed the discrete ordinate formulation to the radiative transport equation, and a numerical finite difference scheme was employed for solution. The participating medium was considered to be an absorbing and isotropically scattering medium bounded by a semitransparent refracting and reflecting top interface and a specular (Fresnel) opaque substrate. Because these deposits are highly scattering in the solar wavelength region, the results are presented for an albedo value of unity.