An Assessment of the Performance of ISRO’s SCATSAT-1 Scatterometer

SCATSAT-1 is a continuity mission for the Oceansat-2 scatterometer, OSCAT-1, which provided useful ocean vector wind observations used in, among others, oceanography, numerical weather prediction (NWP) and nowcasting. The purpose of this paper is to review the findings of the SCATSAT-1 CalVal team regarding the stability and performance of version 1.1.3 of the SCATSAT-1 data. The international CalVal team organized by ISRO included participants from various institutions in India, ISRO’s Space Applications Centre, KNMI from the Netherlands, and from the USA, NOAA, and NASA’s JPL. To perform the evaluation, different centres processed the data independently using heritage processors and made comparisons against NASA’s Ku-band QuikSCAT mission, in situ data, and NWP models. We also provide a preliminary assessment of the impact of the SCATSAT-1 data on operational forecasts in India and Europe. We conclude that the SCATSAT-1 data shows significantly improved performance relative to ISRO’s OSCAT-1 on Oceansat-2, and that the instrument seems to be stable, given the limited period of observation. The CalVal team has also identified features in the data that could benefit from calibration and processing changes, potentially leading to further improvements on data quality.