Estimation of water cloud parameters using time series aquarius middle beam data

Using time series Aquarius middle beam scatterometer observations, the two vegetation parameters C and D in water cloud model were estimated. Vegetation backscatter was derived using two models: Oh model was used to describe the scattering from bare soil surface, while water cloud model was implemented to account for the effect of vegetation canopy. The vegetation parameters were estimated by minimizing the deviations between the Aquarius scatterometer observations and backscatter coefficients simulated by the water cloud model. The retrieved vegetation parameters are vegetation-specific, which are assumed constant for each vegetation types. By using the retrieved parameters to simulate the scatterometer observations, it was found that the error of the simulation (RMSE) was less than 3 dB in most areas. This research demonstrated that the water cloud model could be applied to global scatterometer observations if the vegetation parameters are appropriately set.