HR: 14:15h
AN: H13J-03    [Abstracts]
TI: WatER: The proposed Water Elevation Recovery satellite mission
AU: * Alsdorf, D
EM: alsdorf.1@osu.edu
AF: Department of Geological Sciences, the Ohio State University, Columbus, OH 43210 United States
AU: Mognard, N
EM: nelly.mognard@cnes.fr
AF: Laboratoire d'Etudes en G‚ophysique et Oc‚anographie Spatiales, 18 avenue E. Belin, BPi 3200, Toulouse, 31401 France
AU: Rodriguez, E
EM: ernesto.rodriguez@jpl.nasa.gov
AF: California Institute of Technology, Jet Propulsion Laboratory, Pasadena, CA 91109 United States
AU: Participants, W
EM: alsdorf.1@osu.edu
AF: over 150 people from more than 20 countries, www.geology.ohio-state.edu/water/participants.php, Columbus, OH 43210
AB: Surface fresh water is essential for life, yet we have surprisingly poor knowledge of the spatial and temporal dynamics of surface water storage and discharge globally. The core mission objective is to describe and understand the continental water cycle and the hydrological processes (e.g., floodplain hydraulics) at work in a river basin. The key question that will be answered by WatER is: "Where is water stored on Earth's land surfaces, and how does this storage vary in space and time?" WatER will facilitate societal needs by (1) improving our understanding of flood hazards; (2) freely providing water volume information to countries who critically rely on rivers that cross political borders; and (3) mapping the variations in water bodies that contribute to disease vectors (e.g., malaria). Conventional altimeter profiles are, without question, incapable of supplying the measurements needed to address scientific and societal questions. WatER will repeatedly measure the spatially distributed water surface elevations (h) of wetlands, rivers, lakes, reservoirs, etc. Successive h measurements yield dh/dt, (t is time), hence a volumetric change in water stored or lost. Individual images of h yield dh/dx (x is distance), hence surface water slope, which is necessary for estimating streamflow. WatER's main instrument is a Ka-band radar interferometer (KaRIN) which is the only technology capable of supplying the required imaging capability of h. KaRIN has a rich heritage based on (1) the many highly successful ocean observing radar altimeters, (2) the Shuttle Radar Topography Mission (SRTM), and (3) the development effort of the Wide Swath Ocean Altimeter (WSOA). The interferometric altimeter is a near-nadir viewing, 120 km wideswath based instrument that uses interferometric SAR processing of the returned pulses to yield single-look 5m azimuth and 10m to 70m range resolution, with an elevation accuracy of approximately 50 cm. Polynomial based averaging of heights along the water body increases the height accuracy to about 3 cm. The entire globe is covered twice every 16 days and orbit subcycles allow the average visit to be about half this time at low to mid-latitudes, and almost daily at high latitudes. The WatER mission is an international effort with a large, supporting scientific community. It is already proposed as an ESA Earth Explorer Core mission and will also be jointly submitted to NASA's Earth System Science Pathfinder program. WatER is designed to meet high priority targets for all nations and will provide essential data for the EU Water Framework Directive and the European Flood Alert System. WatER will meet the United Nations call for a "greater focus on water related issues", responds to the hydroclimatological needs of the International Working Group on Earth Observations, and answers the U.S. federal government call to focus on our "ability to measure, monitor, and forecast U.S. and global supplies of fresh water".
UR: http://www.geology.ohio-state.edu/water
DE: 1836 Hydrological cycles and budgets (1218, 1655)
DE: 1855 Remote sensing (1640)
DE: 1860 Streamflow
DE: 1890 Wetlands (0497)
DE: 1895 Instruments and techniques: monitoring
SC: Hydrology [H]
MN: Fall Meeting 2005