Requirements for Global Precipitation Measurement

The measurement of precipitation on a global basis has many scientific and societal benefits. The National Aeronautics and Space Administration´s (NASA´s) Tropical Rainfall Measuring Mission (TRMM), developed in cooperation with the National Space Development Agency (NASDA) of Japan, was launched in 1997, and is widely viewed as a highly successful mission. TRMM has successfully addressed many science issues, has identified areas relating to precipitation where additional research is required, and has also demonstrated the value of precipitation measurements to other disciplines, including hydrology and weather forecasting. In response to substantial interest in precipitation measurement, NASA has established a Project Office to begin planning for Global Precipitation Measurement (GPM). This paper will provide a brief overview of the needs for precipitation measurement, identify the top-level requirements, and provide details concerning the spacecraft and instruments that comprise the space segment of the concept mission.