Multitemporal monitoring of soil moisture with RADARSAT SAR during the 1997 Southern Great Plains hydrology experiment

Multitemporal RADARSAT Synthetic Aperture Radar (SAR) imagery was evaluated for monitoring soil moisture during the Southern Great Plains 1997 Hydrology Experiment (SGP97). Over the 1-month experiment a total of 10 RADARSAT (C-band; 5.3 GHz; HH polarized) acquisitions were obtained. After co-registration of the images, the dependence of the backscattering coefficient (°) on incidence angle () was evaluated. An angular correction scheme was applied to the data and the correlation of ° values with volumetric soil moisture measurements was determined. A high positive correlation between the two was observed for wheat stubble fields, whereas no correlation could be observed for pasture fields. A change detection approach yielded a correlation of soil moisture changes to ° changes for wheat stubble fields, indicating the potential of this method for soil moisture monitoring.