The Southern Great Plains 1997 (SGP97) Hydrology Experiment originated from an interdisciplinary investigation, "Soil Moisture Mapping at Satellite Temporal and Spatial Scales" (PI Thomas J. Jackson, USDA ARS). The core of this field experiment involves the deployment of the L-band Electronically Scanned Thinned Array Radiometer (ESTAR) for daily mapping of soil moisture over an area > 10000 km² and a period on the order of a month. The region selected for investigation is the best instrumented site for surface soil moisture, hydrology and meteorology in the world. This includes the USDA/ARS Little Washita Watershed, the USDA/ARS facility at El Reno, Oklahoma, the ARM/CART central facility, as well as the Oklahoma Mesonet. The region covered by the experiment is 34.5 to 37 North latitude and 97 to 99 West longitude. The aircraft mapping took place over the period 18 June to 18 July 1997.

Objectives:

1. Establish that the retrieval algorithms for surface soil moisture developed at higher spatial resolution using truck- and aircraft-based sensors can be extended to the coarser resolutions expected from satellite platforms
2. Verify spatial-temporal estimators of soil moisture and to examine the utility of pedotransfer function in hydrologic modeling
3. Examine the feasibility of inferring soil moisture and temperature profiles using surface observations in conjunction with in situ measurements
4. Examine the effect of soil moisture on the evolution of the atmospheric boundary layer and clouds over the Southern Great Plains during the warm season.