Global Precipitation Measurement (GPM) status

Global Precipitation Measurement (GPM) is a global space endeavor conceived by the US and Japan that has sparked global interest. Building upon the success of the Tropical Rainfall Measuring Mission (TRMM), it will initiate the measurement of global precipitation, a key climate factor. 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. It has received endorsements from the World Climate Research Programme, the World Meteorological Organization, and the Committee on Earth Observation Satellites. 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 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 and climate research products. The National Aeronautics and Space Administration (NASA) plans to provide the core spacecraft, a constellation spacecraft and its launch, microwave radiometers, the precipitation processing system, the mission operations system, and an array of ground calibration and validation sites. The Japan Aerospace Exploration Agency (JAXA) plans to contribute the radar for and launch of the core spacecraft. The European Space Agency (ESA) has studied a European constellation satellite contribution. India and France have expressed their interest in participating through the Megha-Tropiques project. South Korea has proposed the contribution of regional ground validation sites. Other nations are also expected to play major a role in GPM. GPM is now in formulation phase and is one of the highest priority new Earth science missions for which NASA seeks final approval. GPM launches are targeted to begin in 2010.