GPM

Global Precipitation Measurement (GPM) is an international satellite mission to measure precipitation around the globe and provide standardized, near real-time, and historical data for meteorology, hydrology, and climate research. The mission is led by NASA in partnership with the Japan Aerospace Exploration Agency (JAXA) and serves as a successor to the Tropical Rainfall Measuring Mission (TRMM).

Core Observatory equipment: Dual-frequency Precipitation Radar (DPR) with Ka-band and Ku-band radars; GPM Microwave Imager (GMI). These instruments allow measurement of precipitation types and estimates of rain rate, snow, and ice precipitation; DPR provides vertical structure, whereas GMI measures microwave radiances across multiple channels.

Operations and data products: The Core Observatory acts as a calibration and data standard for a constellation of partner satellites. The combined data extend coverage to approximately 65 degrees north and south, enabling near-global precipitation retrievals. Data products include Level 1 radiances, Level 2 precipitation rate, Level 3 monthly and gridded datasets, and near real-time precipitation estimates used by weather agencies and researchers.

Impact and applications: GPM data improve weather forecasts, flood and drought monitoring, and climate research; support for disaster response and infrastructure planning; widely used by meteorological agencies, researchers, and policymakers. Data are publicly available through NASA's and JAXA's portals and mirror archives.