The S-Pol radar is a portable Doppler radar developed at the National Center for Atmospheric Research for use by NCAR and university scientists. S-Pol is a polarimetric radar--its polarized signals gather information in vertical and horizontal orientations, which allows rain and hail to be distinguished from each other. It was used at the Severe Thunderstorm Electrification and Precipitation Study (STEPS), a field program held on the High Plains of the central United States in 2000. STEPS helped provide a better understanding of the interactions between air motion, precipitation production, and electrification in severe thunderstorms. Pictured: Atmospheric scientist Charles Knight
