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 individual branches 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, an estimation was made of eta , the volume backscatter coefficient, and kappa , the volume extinction coefficient. It is found that: (1) leaves are strong attenuators as well as scatterers; (2) the albedo (the ratio eta / kappa ), 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) te albedo changes as a function of the angle of incidence and for deciduous trees is also a function of the season.<
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