Soil moisture and biomass retrieval using ALOS/PALSAR data

Soil moisture and its distribution in space and time plays a key role in many scientific applications like agriculture, hydrology, meteorology or flood and landslide prediction. Measurements over large areas are only feasible by means of airborne or spaceborne systems. The Japanese ALOS/PALSAR was the first and only satellite to operate a polarimetric L-band SAR, thus providing the highest potential for quantitative soil moisture observations. PALSAR soil moisture estimates are calculated using different theoretical and (semi-)empirical retrieval models. Estimates of vegetation biomass are calculated by means of a semi-empirical approach. The estimation accuracies for the different models range between 4.1 and 14.2 Vol.-%. The sensitivity of the backscattering intensities and the scattering entropy towards the canopy properties enables estimation of winter wheat biomass with accuracy in the order of 1 kg/m².