A ship-to-ship (STS) lightering operation takes place in order to transfer cargo (e.g. crude oil or petroleum products) between an ocean-going ship and a service ship alongside it. Instrumental measurements to accurately determine the relative speeds and distances during the approach between the vessels would benefit the operational safety and efficiency. A velocity information GPS (VI-GPS) system, which uses the instantaneous velocity measures from carrier-phase Doppler measurement, has been applied in a field observation onboard a service ship (Aframax tanker) approaching a ship-to-be-lightered (VLCC) in open waters. This article proposes to apply VI-GPS as the input sensor to a guidance and decision-support system aiming to provide accurate velocity information to the officer in charge of an STS operation. A method for precise velocity measurement using VI-GPS was described and the measurement results were compared each other with the results of Voyage Data Recorder (VDR) and VI-GPS that showed the concept of a guidance and decision-support system applying VI-GPS with the field test results during STS operations. Also, it turned out that VI-GPS has sufficient accuracy to serve as an input sensor from the field test results.

1. Introduction
2. Velocity information GPS
3. Experiment
4. Conclusion
Acknowledgements
References

• Yun-Ja Yoo(New Growth Research Division, Korean Register of Shipping) Corresponding author
• Egil Pedersen(Department of Engineering and Safety, UiT The Arctic University of Norway)
• Nobuyoshi Kouguchi(Faculty of Maritime Sciences, Kobe University)
• Chae-Uk Song(Division of Navigation Science, Korea Maritime and Ocean University)