SEASTAR is an innovative satellite mission concept submitted in 2020 by the National Oceanography Centre (NOC) and its large international science team in response to the ESA Earth Explorer 11 call for mission ideas. SEASTAR is one of four mission candidates recommended by ESA’s Advisory Committee for Earth Observation (ACEO) to proceed to Phase 0.
The SEASTAR Synthetic Aperture Radar (SAR) instrument is an along-track interferometer (ATI) that can measure the phase difference between two SAR images of the same scene taken within a short time-lag. The system is currently assumed to function in Ku-band. SEASTAR has two pairs of antennas looking 45° forward and 45° backward to provide squinted ATI measurements, accompanied by a broadside beam, to provide measurements for a total of three different azimuth directions. As such, simultaneous total surface current vector (TSCV) and ocean surface vector wind (OSVW) can be derived from the instantaneous measuments at very high spatial resolution (around 1 km from a satellite platform, and only a few meters from an aircraft platform).
The main task of ICM is to analyse the feasibility of the new airborne demonstrator, the so-called Ocean Surface Current Airborne Radar (OSCAR), to derive high-resolution, high quality OSVW data. In particular, ICM will perform ocean target based calibration, i.e., numerical ocean calibration, of the OSCAR backscatter measurements. In addition, ICM will adapt the official scatterometer wind data processor, i.e., the EUMETSAT Numerical Weather Prediction Satellite Application Facility (NWP-SAF) Pencil-beam Wind data Processor (PenWP), to retrieve OSVW from OSCAR data and perform a preliminary analysis of the OSVW data quality.