Estimation of X-band scattering properties of tree components

An X-band FM-CW very fine range resolution scatterometer was used to acquire backscattering data for a number of tree species. Using a model to describe the scattering source function and an experimental procedure for selected removal of plant parts allows the estimation of the volume backscatter coefficient and the volume extinction coefficient. It is found that: (1) leaves are strong attenuators as well as scatterers; (2) the albedo at a given angle of incidence is nearly independent of the tree type; (3) the tree limbs are good attenuators but rather poor scatterers; and (4) the albedo changes as a function of the angle of incidence and for deciduous trees is also a function of the season.