Characterizing AirSWOT Elevation Accuracy on the Willamette River, Oregon
Tuozzolo, S., Overstreet, B.T., Mangano, J., Minear, J.T., Stringham, C., Chen, C.W., Pavelsky, T., Frasson, R.P.M., Fonstad, M.A., Wei, R., and Durand, M.T. (13-Dec-16)
The upcoming Surface Water and Ocean Topography (SWOT) mission aims to map the world's freshwater resources using Ka-band interferometric radar. In anticipation of the SWOT mission, an airborne calibration/validation system, AirSWOT, has been developed to generate SWOT-like measurements of oceanic and surface waters. AirSWOT's payload includes the Ka-band SWOT Phenomenology Airborne Radar (KaSPAR) and an NIR camera for land-water delineation. Here, we show AirSWOT data from March 2015 on a 75km stretch of the Willamette River in Western Oregon. KaSPAR measurements of water surface elevation, coherence, and backscatter, as well as NIR imagery, are examined in conjunction with in-situ water surface elevation measurements collected using GPS drifters, pressure transducers, and a motorboat-mounted RTK-GPS. We characterize KaSPAR backscatter and coherence characteristics over land and water as a function of incidence angle, and compare AirSWOT and in-situ measurements of water surface elevation and reach-averaged slope to assess AirSWOT's accuracy over the study area.