Boulder, Colorado – The Ball Aerospace & Technologies Corp. Global Precipitation Measurement (GPM) Microwave Imager (GMI) successfully launched on NASA's GPM Core Observatory satellite from Tanegashima Space Center, Japan at 1:37 p.m. EST on Feb. 27, 2014. The 4-ton satellite flew onboard a H-IIA launch vehicle.
The GPM Core Observatory, a joint Earth-observing mission between NASA and the Japan Aerospace Exploration Agency (JAXA), separated from the rocket 16 minutes after launch, at an altitude of 247 miles (398km). The solar arrays deployed 10 minutes after spacecraft separation, to power the spacecraft.
The GPM Core Observatory will improve upon the capabilities of the Tropical Rainfall Measurement Mission (TRMM), a joint NASA-JAXA mission launched in 1997 and still in operation. While TRMM measured precipitation in the tropics, the GPM Core Observatory expands the coverage area from the Arctic Circle to the Antarctic Circle. GPM will also be able to detect light rain and snowfall, a major source of available fresh water in some regions.
Built for NASA, Ball's GMI is a multi-channel, conical-scanning microwave radiometer that flies aboard the GPM Core Observatory. GMI is an essential part of an international satellite mission that will capture next-generation observations of rain and snow worldwide every three hours. The GPM Core Observatory will deliver 3D views of hurricanes and snowstorms and contribute to monitoring and forecasting weather events such as droughts, floods, and landslides.
"GMI will provide significantly more accurate data to forecasters tracking extreme weather," said Ball Aerospace President Rob Strain. "GMI's greater accuracy will also enhance the global precipitation dataset used by the world's scientists."
The Ball Aerospace GMI, will deliver more frequent and higher quality data collection than currently available. The 8ft-tall GMI instrument rotates at 32rpm and uses four extremely stable calibration points on each revolution to calibrate the data it scans. The instrument minimizes solar intrusion for added accuracy and features higher frequency channels to measure smaller particles of precipitation such as light rain and snow.
GMI's design is based on successful microwave sensors built previously by Ball Aerospace, including the Shuttle Radar Topography Mission (SRTM), the Spaceborne Imaging Radar-C (SIR-C), the GEOSAT Follow-On (GFO-2) and the Submillimeter Wave Astronomy Satellite (SWAS).
The GPM Core Observatory was assembled at NASA's Goddard Space Flight Center in Greenbelt, Md., and is the largest spacecraft ever built at the center. It carries two instruments to measure rain and snowfall. The GPM Microwave Imager will estimate precipitation intensities from heavy to light rain, and snowfall by carefully measuring the minute amounts of energy naturally emitted by precipitation. The Dual-frequency Precipitation Radar (DPR), developed by JAXA, will use emitted radar pulses to make detailed measurements of three-dimensional rainfall structure and intensity, allowing scientists to improve estimates of how much water the precipitation holds.
Sources: Ball Aerospace & Technologies Corp. and NASA