Significant Wave Height Estimation Using Multi-Satellite Observations from GNSS-R

Abstract

This study proposes a significant wave height (SWH) retrieval method based on multi-satellite observations using Global Navigation Satellite System Reflectometry (GNSS-R). The algorithm obtains the signal-to-noise ratio (SNR) through delay-Doppler maps (DDMs) and introduces an offset correction that combines the differences between the elevation angles of multi-satellites. The correction improves the correlation between SNR and SWH and thus enables the estimation of SWH. The feasibility of the proposed algorithm was verified by experiments and a performance comparison with the traditional estimation method based on SNR. The estimation results of the proposed algorithm, with a mean absolute percentage error of 8.26%, a root mean square error of 0.1671 m, and a maximum error of 0.32 m, better matched the true values than the traditional SNR-based method. The method is intended to improve the retrieval accuracy of SWH based on the GNSS-R technique, and to provide services for sea-state information monitoring and ship navigation.