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Boat-based water-surface cross sectional elevation surveys along the upper Willamette River, Oregon, March, 2015

October 12, 2016

The NASA SWOT satellite, which is scheduled for launch in 2020, will monitor the earths fresh water with better resolution and precision than what had previously been possible for a space-based platform. The primary SWOT measurements will be used to generate estimates of river discharge that are meant to obtain river fluxes globally at high accuracy and reach lengths of tens of kilometers, even in inaccessible areas of the world or areas where in-situ measurements are not available. Prior to the launch of the SWOT satellite, the wide-swath interferometer is attached to an airplane for thorough calibration and validation (at which time it is referred to as AirSWOT). The Willamette River in northwest Oregon is one site used to calibrate and validate AirSWOT measurements and discharge calculations because it is large enough for the resolution of the SWOT equipment, it is relatively accessible for intensive collection of ground-based data, it is studied by regional agencies, and it has a high density of streamflow-gaging stations. The U.S. Geological Survey (USGS) and University of Oregon (UO) collected ground-based survey measurements for validation with AirSWOT surveys of the Willamette River in the spring of 2015. In addition to the validation goals, these datasets may be useful for other studies along the reach including hydraulic models and habitat assessments.