Investigation of fully polarimetric TerraSAR-X data for soil parameters estimation

The potential of estimating soil moisture from fully polarimetric satellite X-band SAR data is analysed for the first time. The Physical Optics model has been combined with an azimuthally rotation distribution, forming a socalled Extend-PO-model (X-PO), for the scattering process representation which includes a cross-polarized component. In addition, the eigen-based decomposition approach has been used to interpret the scattering mechanisms and to estimate the soil parameters. The developed inversion approach has been applied to data acquired by the German satellite TerraSAR-X over the Wallerfing region in April 2009. Simultaneously to the overpasses, soil moisture and vegetation measurements have been collected on agricultural fields. Finally the estimated soil moistures from the proposed algorithm have been compared with the measured soil moistures collected over bare soil fields resulting in a root mean square error of ~10Vol.%.