An active remote sensing scattering model for a coniferous forest

A two-layer model for scattering from a coniferous canopy has been developed which accounts for the branch size distribution, leaf orientation distribution, and branch orientation distribution for each size. The upper layer consists of needles and finite-length cylinders representing leaves and branches, respectively. The lower layer represents the trunks modeled as randomly positioned vertical cylinders above an irregular soil surface. The Eulerian angles of orientation are used to describe the leaf and the branch orientations. By using a radiative transfer formulation and a first-order solution, the scattering coefficient appears as a simple sum of terms representing contributions from a single component or a pair of forest components. Thus, the scattering attenuation effect of each forest component can be modeled independently. Numerical results are presented for the backscattering coefficient. It is found that leaves have no pronounced effects on the total backscattering coefficient at low frequencies, while their effect as attenuators or scatterers becomes significant at high frequencies.<>