KU-Band Sensitivity to Soil Moisture. An Evaluation Study for Monitoring Temporal Soil Moisture Change Detection Over the NAFE06 Study Area

The combination of radiometer and radar observations is a very promising technique for spatial disaggregation of soil moisture. The enhanced QuikSCAT sigma-0 product (2.225 km) offers a possibility for overcoming the temporal and spatial limitations of the available radar systems. The current study investigates QuikSCAT sensitivity to soil moisture and its capability to accurately monitor and capture change in soil moisture. The research was undertaken for the National Airborne Field Experiment area located in the Murrumbidgee catchment, SE Australia. Validation of the temporal change detection analysis was undertaken using an airborne soil moisture product derived from the Polarimetric L-band Multibeam Radiometer (PLMR). The main propose of the PLMR use was to assess accuracy in terms of spatial patterns distribution. The results reveal expected temporal variability and adequate response of the active sensor to change in meteorological conditions. The presence of irrigation and standing water (rice fields) in the region challenges the spatial agreement throughout the study area.