The effect of leaf geometry on the microwave backscatter from angiosperm leaves

An understanding of the microwave backscatter from canopies is required in the development of methods to derive biophysical parameters from synthetic aperture radar (SAR) data. Physically-based microwave backscatter models of canopies rely upon simulating the average scatter properties of plant components accurately. This paper compares the radar cross section (RCS) of idealised shapes (i.e. curved plates, rectangular plates, elliptical discs) used in the currently available radiative transfer simulations with the observed scatter from real leaves´ at a frequency of 10 GHz using VV polarisation. To examine whether leaf geometry has an influence on the validity of these models stereo vision measurements of the leaves measured have been utilised. This preliminary work suggests that the models do not characterise the backscatter from planar or non-planar leaves adequately. Effects associated with the surface roughness of leaves are observed to be particularly important