NWP Ocean Calibration for the CFOSAT Wind Scatterometer

The unique rotating fan-beam feature of SCAT onboard CFOSA T leads to varying geometries across the swath and furthermore leads to varying wind retrieval performance across the swath. In order to improve the wind retrieval, two kinds of NWP Ocean Calibration (NOC) are applied. One is a NOC as a function of incidence angle (NOCinc). The other one is a newly developed NOC as a function of incidence angle and antenna azimuth angle (NOCant). The results show that NOCant correction improves the wind speed Probability Distribution Function per WVC and reduces the average wind direction bias and the relative wind direction (relative to the satellite motion direction) biases, as compared to NOCinc correction. Overall the performance of the proposed NOCant correction is better than NOCinc and improves the wind statistics.