THE SIMPLIFIED TRANSFORMATION METHOD OF DISCRIMINATING THE ASPECT ANGLE USING POSITIONS OF THE SHIPS NAVIGATION LIGHTS
 
Murai, K., Hayashi, Y. and Miyoshi, Y., Kobe University of Mercantile Marine and Inokuchi, S., Osaka University, Japan
 
Navigators would transform information obtained by visually looking at the navigation lights of the other ship into the aspect angle using their cognitive function. Although the locations of the navigation lights on the ship are prescribed by the international regulations for preventing collision at sea, their spatial relationship is not necessarily fixed with every ship. Eventually, variance in positions of the lights was analyzed to find to give rise to the error in estimating the ship's aspect angle via the navigation lights. The aspect estimation error comes from human cognitive capacity as well. The purpose of this paper is to collect and analyze data on the positions of navigation lights in actual ships and to find a way to optimize this aspect angle transformation process by cognitive empowerment by pre-learning and by modifying positional arrangement of navigation lights. Transformation error is measured by simulation study with the arrangement of navigation lights of actual ships and the result shows the effectiveness of experiencing known aspect angles before actual simulation study. In the end, simplified transformation method was proposed and tested by simulation with the modified arrangement of navigation lights. Although this modification might not be easily viable in reality, the result was favorable.