JOINT SIMULATION OF BIDIRECTIONAL REFLECTANCE AND BACKSCATTER COEFFICIENT OF CORN CANOPY SCENE

Because bidirectional reflectance (BRF) and backscattering coefficient (Sigma0) are sensitive to LAI (Leaf Area Index) and LWC (Leaf Water Content) in different growth stages, fusing optical and microwave remote sensing data is useful to accurately monitor the two parameters. Joint simulation is one way to find the sensitive optical wavelength or microwave frequency of the unified canopy scene. Due to the inputs of the optical and microwave model are different, in the paper, three intermediate models were used to achieve the integration of critical inputs for joint simulation. They were leaf radiative transfer model PROSPECT, exponential soil reflectance model, and a transforming model. The simulation results indicated that BRF lambda=680 and BRF lambda=660 were sensitive to LAI when it is lesser than 3.5, while Sigma0(X-band,) (VV) and Sigma0(C-band, HH) were sensitive to LAI when it is between 3.5 and 6. Besides, Sigma0(X-band,) (HH) can reflect LWC variation independent on structural parameters.