The NASA NPOL and D3R (IMAGE) NASA/Goddard Space Flight Center Caption The NASA NPOL (left) and D3R (right) precipitation radars deployed south of Waterloo, Iowa, for the Iowa Flood Studies ground measurement campaign. Credit NASA/Matt Schwaller Usage Restrictions None License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.