The Global Precipitation Measurement (GPM) mission unites data from ten U.S. and international satellites that measure rainfall and snowfall. The partnership, co-led by NASA and the Japan Aerospace Exploration Agency, is anchored by the GPM Core Observatory, launched on February 27, 2014. Carrying two advanced precipitation instruments, the GPM Microwave Imager and Dual-frequency Precipitation Radar, the Core Observatory measures the full range of precipitation types from heavy rainfall to, for the first time, light rain and snowfall. With an orbit that cuts across the path of the other satellites it is also used as a reference standard so that data from all the partner satellites can be meaningfully compared. The combined data from all ten satellites allows scientists to collect precipitation data from all parts of the world in under three hours.
This animation shows rain data collected by the GPM Core Observatory and the partner satellites currently in orbit on March 17, 2014. The end of the animation focuses in on a storm system that moved over the eastern United States, showing GPM Microwave Imager data of rain and snow rates. This is the first time a single satellite has collected simultaneous data on rain and snow for a single storm.
GCMD keywords can be found on the Internet with the following citation:
Olsen, L.M., G. Major, K. Shein, J. Scialdone, S. Ritz, T. Stevens, M. Morahan, A. Aleman, R. Vogel, S. Leicester, H. Weir, M. Meaux, S. Grebas, C.Solomon, M. Holland, T. Northcutt, R. A. Restrepo, R. Bilodeau, 2013. NASA/Global Change Master Directory (GCMD) Earth Science Keywords. Version 18.104.22.168.0