This article describes an electromagnetic model which simulates the mi
crowave polarimetric backscatter of agricultural fields. The model is
based on radiative transfer theory and solves the relevant equation by
means of a numerical algorithm, namely matrix doubling, which include
s multiple scattering effects. The backscatter coefficient may be simu
lated for any pair of incidence and scattering elliptical polarization
s; also, the phase difference between VV and HH channels is computed.
Model simulations are compared with experimental results obtained at L
band (1.2 GHz) by the NASA-JPL AIRSAR, in the framework of the MAC Eu
rope '91 campaign, over sunflower fields belonging to an Italian site
named Montespertoli. A satisfactory agreement is observed between pred
icted and measured polarimetric quantities of vegetated fields, while
for bare soils (particularly at VV polarization) backscatter coefficie
nts are overestimated, due to inaccuracies of surface models available
at present.