Radiative transfer in dense plant canopies with azimuthal symmetry

The exact solution to the radiative transfer equation is obtained in assembleges of leaves (called plant canopies) with soil reflectance neglected. A leaf area scattering phase function characteristic of leaves oriented at a single angle is assumed for the first case. The analytical theory is based on Chandrasekhar's classical solution to the radiative transfer equation in a plane semi-infinite medium and therefore specifies the exiting intensity in terms of the well known H-functions. The solution method is next applied to a more general area scattering phase function of which the Suits model is a special case. Finally, the predicted reflectance factor for soybean and maize canopies are compared to field data. The solutions obtained can be used to guide the development of comprehensive transport algorithms as well as to interpret remote sensing data.