RADIATIVE-TRANSFER THEORY FOR POLARIMETRIC REMOTE-SENSING OF PINE FOREST AT P-BAND

In this paper, the radiative transfer (RT) theory for clustered vegeta tion structures is developed and used to interpret polarimetric radar backscattering measurement data from pine forest. The RT theory has be en widely used to calculate radar backscattering coefficients from lay ered geophysical media and to interpret the measurement data. However, the conventional RT theory ignores the relative phase information ass ociated with structured scatterers, which may play an important role i n the overall scattering behaviour. To take into account the clustered structures with the RT theory, the scattering function of each cluste r is calculated by incorporating the phase interference of scattered f ields from each component. Subsequently, the resulting phase matrix is used in the radiative transfer equations to calculate the polarimetri c backscattering coefficients from layered random media embedded with vegetation clusters. A multi-scale structure model of pine forest, whi ch includes trunks, primary and secondary branches, is used to interpr et and simulate polarimetric radar response at P band (0.44 Hz). The t heoretical calculations are shown to be in good agreement with the bac kscattering data measured at the Landes maritime pine forest during th e MAESTRO 1 Campaign.