GNSS-IR Inshore Tide Measurement Based on Low-cost Chipset

Abstract

Multipath signals that impact positioning accuracy are progressively being utilized to recover land and ocean geophysical information with the introduction of Global Navigation Satellite Systems (GNSS). An interference signal-based approach is GNSS-interferometry reflectometry (GNSS-IR). In this work, interference signals are gathered for sea surface altimetry using a low-cost GNSS signal receiver outfitted with a right-handed circularly polarized antenna, which can reduce cost of tide measurement. This study decompose the raw signal-to-noise ratio and extracts several frequency components using an empirical mode decomposition technique. The vertical distance between the antenna phase center and the sea surface is then calculated using Lomb-Scargle periodogram after the spectra of various frequency components has been analyzed. The final inversion tide is then obtained by removing the wild spots using the sinusoidal fitting approach. According to the results, there is a 0.89 correlation between the measured and recovered tides, and the RMSE is 0.23 m.