The Global Precipitation Measurement (GPM) mission to be launched by NASA and the Japan Aerospace Exploration Agency (JAXA) in 2013 will use advanced space-borne instruments to provide next-generation global precipitation data products from a constellation of satellites operated by a consortium of international partners. Currently the Tropical Rainfall Measuring Mission (TRMM) observes rainfall between 35°S and 35°N, providing insights into tropical cyclone structure, latent heat release, and hydroclimatologic feedbacks within the tropics and subtropics. The GPM Mission will extend these capabilities into the middle and high latitudes (65°N to 65°S) using a combination of advanced active and passive instruments. As a science mission with integrated application goals, GPM will establish a new reference standard for precipitation measurements from space to gain new insights into precipitation processes and provide unified global data products to improve numerical weather prediction skills, near real-time natural hazard monitoring and assessment, as well as hydroclimatologic modeling capabilities.

GPM ground validation (GV), which encompasses direct statistical, physical process, and integrated hydrologic validation activities, plays a central role in pre-launch algorithm development and post-launch product evaluation. Field campaigns are a key component of the GPM GV program. Recent campaigns include the Light Precipitation Validation Experiment (LPVEx) and the Mid-Latitude Continental Convective Clouds Experiment (MC3E), which provided valuable ground and airborne data to better characterize light precipitation processes and intense continental convective systems over land. In 2013 NASA and NOAA plans to jointly carry out a field campaign on hydrological validation in the U.S. Southeast to assess the performance of satellite precipitation products in hydrologic and water resources applications. The campaign will seek to address how four-dimensional quantitative precipitation estimation (QPE) and associated uncertainties be effectively used within the framework of global water and energy cycle applications including climate and weather prediction and how associated uncertainties can be effectively used in hydrometeorological applications such as soil moisture estimation, decision support for flood forecasting, and water resource management. For hydrological applications that require very high-resolution precipitation data, GPM is pursuing innovative methods to downscale (both statistically and dynamically) precipitation information from satellite pixel scales to 1-2 km resolution, as well as the development of a rigorous statistical framework for merging ground-based and satellite-derived precipitation information to produce variable-resolution global precipitation products. An overview of GPM activities aimed at improving the benefits of satellite precipitation data in hydrometeorological applications will be presented.