Comparisons of remotely sensed and model-simulated soil moisture over a heterogenous watershed

Soil moisture estimates from a distributed hydrologic model and two microwave airborne sensors (Push Broom Microwave Radiometer and Synthetic Aperture Radar) are compared with ground measurements on two different scales, using data collected during afield experiment over a 7.4-km 2 heterogeneous watershed located in central Pennsylvania. It is found that both microwave sensors and the hydrologic model successfully reflect the temporal variation of soil moisture. Watershed-averaged soil moistures estimated by the microwave sensors are in good agreement with ground measurements. The hydrologic model initialized by stream flow records yields estimates that are wetter than observations. The preliminary test of utilizing remotely sensed information as a feedback to correct the initial state of the hydrologic model shows promising results. (author)