The Global Precipitation Measurement mission, or GPM, provides the next generation of rainfall measurements from space. The mission is designed to tap into the observational power of nine independent satellites flying around Earth, and combine their precipitation data into a single, global data set every three hours. With combined measurements, the GPM constellation becomes a powerful tool for observing rainfall worldwide.
To measure and study incoming storms, meteorologists and scientists often use ground radar. Individual radars can cover an average area of 50,000 square miles (a range of 125 miles in each direction), and when combined with other radars in a network, a more complete picture of the coming precipitation takes shape. Even in countries with excellent radar coverage, however, gaps still exist, especially for higher altitude clouds that are out of reliable radar range and over mountain ranges that can block the radar signals.
GPM's Core Observatory carries sophisticated instruments that can measure heavy tropical rains near the equator and detect light rain and falling snow near the poles. It will serve as a reference standard for all nine satellites and unify their measurements to provide a global precipitation data set that covers the area from the Arctic Circle to the Antarctic Circle (65 degrees north and 65 degrees south) every three hours.
Also: Learn more about precipitation measurement missions.
