Title: Estimating Ocean Vector Winds and Currents with DopplerScatt
Presenting Author: Alexander Wineteer
Organization: JPL
Co-Author(s): Alexander Wineteer, Dragana Perkovic-Martin, Ernesto Rodriguez, Tamas Gal, Noppasin Niamsuwan, Raquel R. Monje, and Fabien Nicaise

Abstract:
DopplerScatt is an airborne Ka-band Doppler Scatterometer capable of wide swath simultaneous measurements of ocean vector winds and surface currents. Developed under NASA's Instrument Incubator and AITT programs, DopplerScatt serves not just as a scientific enabler for measurements of high resolution sub-mesoscale wind and current phenomena, but also as a technology pathway to measuring these fundamental climate variables from space. Over the last year, as DopplerScatt has moved from instrument development into algorithm and operational development, the team has begun publishing scientific results from field campaigns off the coast of Louisiana, Oregon, and California. This talk will focus first on wind and current retrievals and then on a few scientific results at a high level. Scatterometry is a proven method for measuring vector winds. DopplerScatt relies on this heritage for estimating wind speed and direction, but incrementally advances the state of the art by operating at Ka-band, which enables higher resolution and a smaller instrument package. Using the same radar, DopplerScatt exploits the Doppler shift of the ocean surface to estimate surface currents. An overview of these techniques will be shown, including evidence for Ka/Ku band scatterometry continuity, and evidence for vector current retrieval feasibility. Retrievals from a campaign near the outlet of the Mississippi river will be shown. The ocean and the atmosphere interact and exchange energy at their common boundary — the ocean surface. DopplerScatt is uniquely suited to estimating the kinetic portion of this energy exchange via the interaction of ocean surface currents and winds, the two primary variables DopplerScatt measures. Maps of kinetic energy flux and wind/current structure functions will be shown to this end.