An inversion method to estimate the winter wheat water content based on vegetation optical depth

In this study, winter wheat water content was retrieved using a parameterized relationship between the winter wheat water content and its structure parameters, i.e. radius, length and thickness of the leaves. The parameterized relationship was constructed from a large quantity of simulated attenuation cross section (Q_e) of the winter wheat leaves based on the Generalized Rayleigh-Gans approximation (GRG) and the Mätzler vegetation dielectric constant model. The study was conducted at 6.925GHz and under the assumption that there was no significant polarization difference between the vegetation signals. This new method were applied to ground-based brightness temperature observations to retrieve winter wheat water contents, which were further compared with the corresponding filed measurements. Results show that the retrieved winter wheat water contents are consisted with the field measurements. It proves that the winter wheat inversion method proposed in this study is feasible. Moreover, the method is promising to apply to the satellite observations.