Global precipitation measurement (GPM) progress

Global Precipitation Measurement (GPM) is an international Earth observing "System of Systems" that will initiate the measurement of precipitation, a key climate factor, globally. GPM is a joint initiative with the Japan Aerospace Exploration Agency (JAXA) and other international partners. It integrates previously planned and dedicated missions in a scalable and evolving constellation of multiple spacecraft and data processing and validation ground systems. Its science objectives are: - To improve ongoing efforts to predict climate by providing near-global measurement of precipitation, its distribution, and physical processes; - To improve the accuracy of weather and precipitation forecasts through more accurate measurement of rain rates and latent heating; and - To provide more frequent and complete sampling of the Earth's precipitation. GPM is a potential NASA contribution to the Global Earth Observation System of Systems (GEOSS) as envisioned by the intergovernmental ad hoc Group on Earth Observations (GEO) through the U.S. Group on Earth Observations (US GEO). GPM directly supports three of the nine societal benefits identified by the GEO. GPM is envisioned to consist of a core spacecraft to measure precipitation structure and to provide a calibration standard for the constellation spacecraft, an international constellation of NASA and contributed spacecraft to provide frequent precipitation measurements on a global basis, calibration/validation sites distributed globally with a broad array of precipitation-measuring instrumentation, and a global precipitation data system to produce and distribute global rain maps andclimate research products. GPM is now in formulation phase and recently began the acquisition of the GPM Microwave Imager (GMI), NASA's principal instrument. GPM launches are targeted to begin in 2010.