[G06-P] Poster

[G06-P-06] Comparison of GNSS-R Ocean Surface Wind Speed Estimates from TDS-1 against Airborne Scatterometer Data in the Baltic Sea

Gerhard Ressler¹, Josep Rosello¹, Tania Casal¹, ^○Michael Kern¹, Martin Unwin², Philip Jales², Christine Gommenginger³, Giuseppe Foti³, Juha Kainulainen⁴ (1.European Space Agency, 2.Surrey Satellite Technology Ltd, Guildford, UK, 3.National Oceanography Centre, Southampton, UK, 4.Harp Technologies Ltd, Espoo, Finland)

The focus of this study is on the validation of airborne ocean surface wind speed data from the AWVS (Airborne Wind Vector Scatterometer) flight campaign and satellite wind speed observations from the SGR-ReSI payload on board the technology demonstration satellite TechDemoSat-1 (TDS-1). TDS-1 GNSS-Reflectometry (GNSS-R) observations from November 3rd 2015 were processed to L1b Delay-Doppler-Maps and to L2 ocean surface wind speed estimates to compare it with simultaneously measured data from the Airborne Wind Vector Scatterometer. The AWVS flight campaign was conducted in the area south of Helsinki in the Baltic Sea. Additionally independent data from Automatic Weather Stations (AWS) located close to the area of interest as well as satellite observations from the ASCAT instrument (MetOp-A) were taken into account for validation. All sensor types revealed low ocean surface wind speed conditions and minor wind speed variability over the observation period. Furthermore it was shown that for GNSS-R level L2 retrieval the considered signal space in the L1 Delay-Doppler Maps is essential, especially because of a specific event of signal interference in the relevant data set. The regional analysis indicated good agreement between measurements from independent GNSS-R satellite and AWVS airborne observations and confirmed resulting wind speed estimates within the 2-3 m/s range.