Radiometric temperature for a coniferous forest at the microwave band

In passive remote sensing techniques, the radiometric temperature emitted from a forested canopy is related to the canopy biophysical characteristics. In this study the radiative transfer theory is applied to study the radiometric temperature of a coniferous forest at the microwave band. The forest is modeled as layer above a rough soil surface. The layer is occupied by the leaves and the branches which are modeled as randomly oriented needles and finite-length cylinders respectively. Thermal emission sources are expressed in terms of the temperature profiles and the absorption coefficients of the scatterers within the layer. A perturbation technique is employed to solve the radiative transfer equations governing the radiometric temperature for such a medium. Both the zeroth and the first order solutions are obtained. Numerical results are presented to illustrate the relation between the radiometric temperature and the biophysical characteristics of the forest components (leaves and branches).