Steven P. Neeck

The Global Precipitation Measurement Mission

Precipitation affects many aspects of our everyday life. It is the primary source of freshwater and has significant socioeconomic impacts resulting from natural hazards such as hurricanes, floods, droughts, and landslides. Fundamentally, precipitation is a critical component of the global water and energy cycle that governs the weather, climate, and ecological systems. Accurate and timely knowledge of when, where, and how much it rains or snows is essential for understanding how the Earth system functions and for improving the prediction of weather, climate, freshwater resources, and natural hazard events. The Global Precipitation Measurement (GPM) mission is an international satellite mission specifically designed to set a new standard for the measurement of precipitation from space and to provide a new generation of global rainfall and snowfall observations in all parts of the world every 3 h. The National Aeronautics and Space Administration (NASA) and the Japan Aerospace and Exploration Agency (JAXA) ...

International Global Precipitation Measurement (GPM) Program and Mission: An Overview

Eric A. Smith , Ghassem Asrar , Yoji Furuhama , Amnon Ginati , Christian Kummerow , Vincenzo Levizzani , Alberto Mugnai , Kenji Nakamura , Robert Adler , Vincent Casse , Mary Cleave , Michele Debois , John Durning , Jared Entin , Paul Houser , Toshio Iguchi , Ramesh Kakar , Jack Kaye , Masahiro Kojima , Dennis Lettenmaier , Michael Luther , Amita Mehta , Pierre Morel , Tetsuo Nakazawa , Steven Neeck , Ken’ichi Okamoto , Riko Oki , Garudachar Raju , Marshall Shepherd , Erich Stocker , Jacques Testud , and Eric Wood 19

The NASA Earth Science Flight Program: an update

Earth’s changing environment impacts every aspect of life on our planet and climate change has profound implications on society. Studying Earth as a single complex system is essential to understanding the causes and consequences of climate change and other global environmental concerns. NASA’s Earth Science Division (ESD) shapes an interdisciplinary view of Earth, exploring interactions among the atmosphere, oceans, ice sheets, land surface interior, and life itself. This enables scientists to measure global and climate changes and to inform decisions by government, other organizations, and people in the United States and around the world. The data collected and results generated are accessible to other agencies and organizations to improve the products and services they provide, including air quality indices, disaster prediction and response, agricultural yield projections, and aviation safety. ESD’s Flight Program provides the space based observing systems and infrastructure for mission operations and scientific data processing and distribution that support NASA’s Earth science research and modeling activities. The Flight Program currently has 21 operating Earth observing space missions, including the recently launched Global Precipitation Measurement (GPM) mission, the Orbiting Carbon Observatory-2 (OCO-2), the Soil Moisture Active Passive (SMAP) mission, and the International Space Station (ISS) RapidSCAT and Cloud-Aerosol Transport System (CATS) instruments. The ESD has 22 more missions and instruments planned for launch over the next decade. These include first and second tier missions from the 2007 Earth Science Decadal Survey, Climate Continuity missions and selected instruments to assure availability of key climate data sets, operational missions to ensure sustained land imaging provided by the Landsat system, and small-sized competitively selected orbital missions and instrument missions of opportunity belonging to the Earth Venture (EV) Program. Some examples are the NASA-ISRO Synthetic Aperture Radar (NISAR), Surface Water and Ocean Topography (SWOT), ICESat-2, SAGE III on ISS, Gravity Recovery and Climate Experiment Follow On (GRACE FO), Tropospheric Emissions: Monitoring of Pollution (TEMPO), Cyclone Global Navigation Satellite System (CYGNSS), ECOsystem Spaceborne Thermal Radiometer Experiment on Space Station (ECOSTRESS), and Global Ecosystem Dynamics Investigation (GEDI) Lidar missions. An overview of plans and current status will be presented.

Global Precipitation Measurement (GPM) launch, commissioning, and early operations

The Global Precipitation Measurement (GPM) mission is an international partnership co-led by NASA and the Japan Aerospace Exploration Agency (JAXA). The mission centers on the GPM Core Observatory and consists of an international network, or constellation, of additional satellites that together will provide next-generation global observations of precipitation from space. The GPM constellation will provide measurements of the intensity and variability of precipitation, three-dimensional structure of cloud and storm systems, the microphysics of ice and liquid particles within clouds, and the amount of water falling to Earth’s surface. Observations from the GPM constellation, combined with land surface data, will improve weather forecast models; climate models; integrated hydrologic models of watersheds; and forecasts of hurricanes/typhoons/cylcones, landslides, floods and droughts. The GPM Core Observatory carries an advanced radar/radiometer system and serves as a reference standard to unify precipitation measurements from all satellites that fly within the constellation. The GPM Core Observatory improves upon the capabilities of its predecessor, the NASA-JAXA Tropical Rainfall Measuring Mission (TRMM), with advanced science instruments and expanded coverage of Earth’s surface. The GPM Core Observatory carries two instruments, the NASA-supplied GPM Microwave Imager (GMI) and the JAXA-supplied Dual-frequency Precipitation Radar (DPR). The GMI measures the amount, size, intensity and type of precipitation, from heavy-tomoderate rain to light rain and snowfall. The DPR provides three-dimensional profiles and intensities of liquid and solid precipitation. The French Centre National d’Études Spatiales (CNES), the Indian Space Research Organisation (ISRO), the U.S. National Oceanic and Atmospheric Administration (NOAA), the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), and the U.S. Department of Defense are partners with NASA and JAXA. The GPM Core Observatory was launched from JAXA’s Tanegashima Space Center on an H-IIA launch vehicle on February 28, 2014 Japan Standard Time (JST). The mission has completed its checkout and commissioning phase and is in Operations Phase. The current status and early results will be discussed.

Global Precipitation Measurement (GPM) L-6

The Global Precipitation Measurement (GPM) mission will advance the measurement of global precipitation, making possible high spatial resolution precipitation measurements. GPM will provide the first opportunity to calibrate measurements of global precipitation across tropical, mid-latitude, and polar regions. The GPM mission has the following scientific objectives: (1) Advance precipitation measurement capability from space through combined use of active and passive remote-sensing techniques; (2) Advance understanding of global water/energy cycle variability and fresh water availability; (3) Improve climate prediction by providing the foundation for better understanding of surface water fluxes, soil moisture storage, cloud/precipitation microphysics and latent heat release in the Earths atmosphere; (4) Advance Numerical Weather Prediction (NWP) skills through more accurate and frequent measurements of instantaneous rain rates; and (5) Improve high impact natural hazard (flood/drought, landslide, and hurricane hazard) prediction capabilities. The GPM mission centers on the deployment of a Core Observatory carrying an advanced radar / radiometer system to measure precipitation from space and serve as a reference standard to unify precipitation measurements from a constellation of research and operational satellites. GPM, jointly led with the Japan Aerospace Exploration Agency (JAXA), involves a partnership with other international space agencies including the French Centre National d’Études Spatiales (CNES), the Indian Space Research Organisation (ISRO), the U.S. National Oceanic and Atmospheric Administration (NOAA), the European Organisation for the Exploitation of Meteorological Satellites (EUMETSAT), and others. The GPM Core Observatory is currently being prepared for shipment to Japan for launch. Launch is scheduled for February 2014 from JAXA’s Tanegashima Space Center on an H-IIA 202 launch vehicle.

Surface Water and Ocean Topography (SWOT) mission

The Surface Water Ocean Topography (SWOT) mission was recommended in 2007 by the National Research Council’s Decadal Survey, “Earth Science and Applications from Space: National Imperatives for the Next Decade and Beyond”, for implementation by NASA. The SWOT mission is a partnership between two communities, the physical oceanography and the hydrology, to share high vertical accuracy and high spatial resolution topography data produced by the science payload, principally a Ka-band radar Interferometer (KaRIn). The SWOT payload also includes a precision orbit determination system consisting of GPS and DORIS receivers, a Laser Retro-reflector Assembly (LRA), a Jason-class nadir radar altimeter, and a JASON-class radiometer for tropospheric path delay corrections. The SWOT mission will provide large-scale data sets of ocean sea-surface height resolving scales of 15km and larger, allowing the characterization of ocean mesoscale and submesoscale circulation. The SWOT mission will also provide measurements of water storage changes in terrestrial surface water bodies and estimates of discharge in large (wider than 100m) rivers globally. The SWOT measurements will provide a key complement to other NASA spaceborne global measurements of the water cycle measurements by directly measuring the surface water (lakes, reservoirs, rivers, and wetlands) component of the water cycle. The SWOT mission is an international partnership between NASA and the Centre National d’Etudes Spatiales (CNES). The Canadian Space Agency (CSA) is also expected to contribute to the mission. SWOT is currently nearing entry to Formulation (Phase A). Its launch is targeted for October 2020.

Global Precipitation Measurement (GPM) implementation

The Global Precipitation Measurement (GPM) mission will provide enhanced space-based precipitation measurements with sufficient coverage, spatial resolution, temporal sampling, retrieval accuracy, and microphysical information to advance the understanding of Earths water and energy cycle and to improve predictions of its climate, weather, and hydrometeorological processes. Such improvements will in turn improve decision support systems in broad societal applications (e.g. water resource management, agriculture, transportation, etc). GPM is a partnership between NASA and the Japan Aerospace Exploration Agency (JAXA), building upon their highly successful partnership on the Tropical Rainfall Measuring Mission (TRMM). The GPM architecture consists of NASA satellites operating in partnership with other earth-observing satellites and instruments to produce global precipitation science data. The current generation of multi-satellite global precipitation products based on microwave/infrared sensors from uncoordinated satellite missions has for its anchor the TRMM precipitation radar and the TRMM Microwave Imager measurements over the tropics and subtropics (+/- 35 degrees latitude), with a mean sampling time of approximately 17 hours. The GPM mission will deploy a spaceborne Core Observatory as a reference standard to unify a space constellation of research and operational microwave sensors aimed at providing uniformly calibrated precipitation measurements globally every 2-4 hours. The Core Observatory measurements will provide, for the first time, quantitative information on precipitation particle size distribution needed for improving the accuracy of precipitation estimates by microwave radiometers and radars. In addition, the GPM will also include a second microwave radiometer and a Tracking and Data Relay Satellite (TDRS) communications subsystem for near real time data relay for a future partner-provided constellation satellite. This second GPM Microwave Imager (GMI) instrument, flown in a low-inclination orbit, combined with the Core Observatory will provide an improvement over TRMM in both global coverage and sampling rate (+/- 65 degrees, 10 hour mean sampling time). GPM is well into its final design and fabrication (Phase C) with planned launches in 2013 and 2014.

Enabling global precipitation measurement (GPM)

Of all the water on the Earth, only 3% is drinkable and two thirds of that water is locked away in polar ice. Precipitation constantly renews our fresh water resources and the latent heat it releases is the principal source of energy that drives atmospheric circulation and weather disturbances. It is the principal indicator of the rate of global water cycle and can also be used effectively as input for numerical weather forecasting. The Global Precipitation Measurement (GPM), a cooperative effort of the National Aeronautics and Space Administration (NASA) and Japans National Space Development Agency (NASDA), aims to gather precipitation and related data globally. It will build upon the legacy of the extremely successful Tropical Rainfall Measuring Mission and will extend the spatial and temporal coverage of precipitation measurement to identify trends in the Earths global water cycle, further explore the structure of rainfall to improve efforts to predict climate, and provide high quality rainfall accumulation products. GPM envisions a core satellite, up to eight constellation satellites, local ground validation sites and regional high quality rain gauge networks, and a global precipitation data system. It is anticipated that NASDA will provide the core satellites dual frequency precipitation radar, its launch vehicle, and a constellation satellite. GPMs flexible architecture enables other international and domestic participants to provide enhancements incrementally as plans permit. The European Space Agency (ESA) is currently studying contribution satellite, EGPM, as an Earth Explorer Opportunity Mission. GPM is now in the Formulation Phase and is one of the highest priorities among the new missions for which NASAs Earth Science Enterprise seeks final approval. GPM launches are targeted to begin in 2007.

NASA Earth Science Flight Program

Earth is a complex, dynamic system we do not yet fully understand. The Earth system, like the human body, comprises diverse components that interact in complex ways. We need to understand the Earths atmosphere, lithosphere, hydrosphere, cryosphere, and biosphere as a single connected system. Our planet is changing on all spatial and temporal scales. The purpose of NASAs Earth Science Division (ESD) is to develop a scientific understanding of Earths system and its response to natural or human-induced changes, and to improve prediction of climate, weather, and natural hazards. A major component of NASA’s ESD and residing in its Flight Program is a coordinated series of satellite and airborne missions for long-term global observations of the land surface, biosphere, solid Earth, atmosphere, and oceans. This coordinated approach enables an improved understanding of the Earth as an integrated system. NASA is completing the development and launch of a set of Foundational missions, Decadal Survey missions, and Climate Continuity missions. As a result of the recent launches of the Aquarius/SAC-D and Soumi National Polar-orbiting Partnership (NPP) satellites, 16 missions are currently operating on-orbit and the Flight Program has three mission in development and a further eight Decadal Survey and Climate Continuity missions under study. Technology development is continuing for a remaining five third tier Decadal Survey mission. The first Earth Venture low to moderate cost, small to medium-sized full orbital mission, EV-2 was competitively selected and its early development activities have commenced. The EV-1 sub-orbital projects continue in implementation. Instruments for orbital missions of opportunity and the second set of EV sub-orbital projects are also being planned. An overview of plans and current status will be presented.

NASA's Earth science missions overview

Earth is a complex and dynamic system we do not yet fully understand. The Earth system, like the human body, is comprised of diverse components that interact in complex ways. We need to understand the Earths atmosphere, lithosphere, hydrosphere, cryosphere, and biosphere as a single connected system. Our planet is changing on all spatial and temporal scales. The purpose of NASAs Earth science program is to develop a scientific understanding of Earths system and its response to natural or human-induced changes, and to improve prediction of climate, weather, and natural hazards. NASAs role is unique and highly complements those of other U.S. Federal agencies (such as the National Oceanic and Atmospheric Administration (NOAA), National Science Foundation (NSF), U.S. Geological Survey (USGS), and Environmental Protection Agency (EPA)) by continually advancing Earth system science from space, creating new remote sensing capabilities, and enhancing the operational capabilities of other agencies and collaborating with them to advance national Earth science goals. International collaborations are also a feature of many of these NASA Earth science activities. Continuous global observations of variability and change are required to reveal natural variability and the forces involved, the nature of the underlying processes and how these are coupled within the Earth system. NASAs Earth Science Division (ESD) provides these observations through its orbital and suborbital flight programs. Currently, NASA has 15 operating Earth science space missions with 6 more in development and 9 under study. In the next decade, ESD will develop and demonstrate new sensors and interacting constellations of satellites to address critical science questions and enable advances in operational capabilities in response to the National Research Councils Decadal Survey of Earth Science and Applications.