Radar Rainfall Estimation and Rain Gauge Comparison Studies at Wallops Island, Virginia

Between June 2004 and April 2005, the NASA S-Band polarimetric Doppler radar (NPOL) observed precipitation events along the Eastern Shore of Virginia. The radar was deployed in Oyster, VA, which is located about 75 km SSW of Wallops Flight Facility. In collaboration with NASA, Howard University and the University of North Dakota, designed and implemented a dense rain gauge network (15 rain gauges located over a distance of about 8 km) at Wallops Island, VA. The network is being used for detailed comparisons with NPOL radar rainfall estimates.

Observed radar rainfall error consists of inherent radar system error (hardware) and an apparent error due to the natural rainfall variability within a radar sample volume. This method of verification is known as the radar rainfall error separation method (ESM). The main focus of the study will be to analyze the dense rain gauge network and NPOL radar observations for a period of July 2004-April 2005 in an effort to improve our understanding of the NPOL radar rainfall estimation error. An overview of the project, a description of the rain gauge design and observational network, and a discussion of the methodology and results will be presented in the study.