In this study, we investigated the potential of high precision GNSS technology to support automatic berthing and pilot-assisted ship control. While some pilots already use commercial ship maneuver visualization software based on RTK-GNSS, the suitability of RTK accuracy for berthing operations remains unclear. To address this, we developed a similar system to measuring maneuver and validated its effectiveness through onboard experiments. The system comprises three RTK-GNSS units with LTE module and a tablet device. The tablet displays real-time distances from the bow, stern, and sides of the ship to the wharf with an accuracy of several centimeters, along with the vessel’s attitude. We present the results of this experiment. Additionally, we propose a method to estimate the position of specific ship-side locations where GNSS antenna installation is problematic. By using two GNSS antennas mounted on the line of bow and stern, combined with IMU-derived attitude data, we estimated the shipside position with a horizontal accuracy under 20 cm during second onboard experiments. The results of this second experiment are also presented in this paper. However, this 20 cm accuracy is based on experimental results from small boat and may differ from the results obtained when the proposed method is implemented on larger vessels.
