IMPROVEMENT EFFECT OF POSITIONING BY GNSS CONVERSION OF BOUY-TYPE GPS WAVE GAGE

Abstract

 Generally, wave observations are conducted using seabed-mounted oceanographic instruments or offshore cylindrical buoys equipped with RTK-GPS oceanographic instruments. In buoy-type RTK-GPS positioning, the baseline length between the onshore base station and the buoy observation station is limited to about 20 km at most, which may not provide sufficient water depth for wave observations in deep-sea waves. In this report, a demonstration test of a buoy-type oceanographic instrument that has been RTK-GNSS-enabled by adding the Quasi-Zenith Satellite System (QZSS) to GPS was conducted in the waters off Shirahama, Wakayama Prefecture. As a result, it was confirmed that the baseline length could be extended to 30 km without degrading the positioning accuracy, expanding the possibility of observing deep-sea waves. Furthermore, although some issues were found in certain areas, it was confirmed that the operational rate of wave observations and the quality of positioning could be improved.