Experimental Results of Ship-To-Ship Lightering Operations Applied Velocity Information GPS

Yoo, Yun Ja; Pedersen, Egil; Kouguchi, Nobuyoshi; Song, Chae Uk

Journal of Navigation and Port Research 2014;38(6):577-583.
Published online December 31, 2014.

Experimental Results of Ship-To-Ship Lightering Operations Applied Velocity Information GPS

Yun Ja Yoo, Egil Pedersen, Nobuyoshi Kouguchi, Chae Uk Song

Abstract

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.

Key Words: ship-to-ship lightering;ship-to-be-lightered;service ship;kinematic GPS;carrier-phase-derived Doppler measurement;velocity information GPS;Voyage Data Recorder