The first WetNet precipitation intercomparison project (PIP‐1)

Abstract
Precipitation is an important environmental parameter but also one which is very inadequately measured and monitored across the surface of Earth. In recent years increasing attention has been paid to the use of satellites for improved rainfall measurement and monitoring, and interest has grown in projects aimed at intercomparing and where possible “validating” different satellite rainfall evaluation algorithms. This paper introduces the first Precipitation (algorithm) Intercomparison Project (PIP‐1) organized by and for the Precipitation Working Group of the NASA‐led WetNet activity, through reference to its objectives, Steering Committee, data sets, general and specific requirements for rainfall estimates solicited from participating laboratories based on passive microwave DMSP‐SSM/I data for the months of July through November 1987, and by detailing its agreed schedule.