GNSS Signals for Sea Wave Measurements

Sea wave measurements are usually carried out through wave buoys carrying specific sensors to measure buoy displacement due to sea motion. Nowadays inertial sensors are typically used, whilst satellite measurements are under investigation. Since satellite measurements of the vertical position have generally a lower accuracy than surface measurements, the aim of this investigation is to characterize satellite measurement of the periodic vertical motion due to sea waves by a dry simulator and considering different types of antennas. The simulator is equipped with a reference sensor, and it is preliminary verified indoor by an external reference instrument. Then several wave motions are simulated outdoor and measured by different antennas, using direct altitude measurement or the integration of the vertical velocity, when available. In the range of frequencies and amplitudes considered, the GNSS antenna that covers multiple transmission bands has demonstrated to perform with an accuracy comparable to inertial sensors, while a single band antenna has shown some criticalities.