TRMM

The Tropical Rainfall Measuring Mission.  Launched in 1997, TRMM provided critical precipitation measurements in the tropical and subtropical regions of our planet.  The Precipitation Radar (PR) was the first meteorological radar in space, whose three-dimensional data provided new insights into tropical storm structure and intensification.  The TRMM Microwave Imager (TMI) measured microwave energy emitted by the Earth and its atmosphere to quantify the water vapor, the cloud water, and the rainfall intensity in the atmosphere. Learn more: http://pmm.nasa.gov/trmm