Submitted to: Specialist Meeting on Microwave Remote Sensing
Publication Type: Abstract only
Publication Acceptance Date: 7/5/2001
Publication Date: N/A
Citation: Interpretive Summary:
Technical Abstract: The Tropical Rainfall Measuring Mission (TRMM) was launched in November of 1997. TRMM Microwave Imager (TMI) provides a least a daily coverage over the southern Continental US (up to 38N latitude). TMI is a dual- polarization passive microwave conical scanning radiometer. The goal of this project is to develop a soil moisture pathfinder data set using TMI observations. This is the first attempt to map daily soil moisture from space over an extended period of time. TMI provides multiple orbits over the southern US at varying times of observation. Methods to adjust for diurnal changes associated with this temporal variability and how to mosaic these orbits are explored. The algorithm for deriving soil moisture and temperature from TMI observations is based on a physical model of microwave emission from a layered soil-vegetation-atmosphere medium. The model is derived from theory and experimental data, and is considered to be valid for 10.65 GHz. An iterative, least-squares-minimization method is employed in the retrieval algorithm. Soil moisture estimates were compared with ground measurements over the US Southern Great Plains (SGP) in Oklahoma and the Little River Watershed, GA. The soil moisture experiment in Little River was conducted in June 2000. During both the experiments, the region was dry at the onset of the experiment, and experienced moderate rainfall throughout the watershed during the course of the experiment. These preliminary results demonstrate the potential of the approach and the value of the data for large scale hydrology.