ADAPTATION OF THE MIMICS BACKSCATTERING MODEL TO THE AGRICULTURAL CONTEXT - WHEAT AND CANOLA AT L AND C BANDS

This paper presents the results obtained from the MIMICS (Michigan Microwave Canopy Scattering) forest backscattering model which was modified to accommodate agricultural parameters. In the MIMICS model, the forest canopy is divided in three regions: the crown layer, the trunk region, and the underlying rough ground. The crop cover situation is simulated by a rough ground and a crown layer composed of scatterers with different forms, distributions, and dielectric constants. We omit trunks from the final agricultural representation because these components are of the same order as the wavelength, contrary to the model's implicit assumptions. The simulation results are compared to ground based scatterometer data of wheat and canola. The paper describes the simulation results for the two crops at L and C bands and the two like polarizations. An analysis of the different backscattering mechanisms is also given for each crop. Good simulation results were obtained at L and C bands for HH polarization for both these crops throughout the growing season. An error analysis indicates that the soil moisture can be predicted with a precision better than 0.04 g/cm3 for both crops, if all other model parameters are known. In addition, if the moisture is known, the height of the stems and the diameter of the leaves of the canola crop can be estimated with a precision better than +/-5 cm and +/-0.5 cm, respectively.