%0 Journal Article %A Imazu, Hayama %T Evaluation Method of Collision Risk by Using True Motion %J TransNav, the International Journal on Marine Navigation and Safety of Sea Transportation %V 11 %N 1 %P 65-70 %D 2017 %U ./Article_Evaluation_Method_of_Collision_Imazu,41,699.html %X It is necessary to develop a useful application to use big data like as AIS for safety and efficiency of ship operation. AIS is very useful system to collect targets information, but this information is not effective use yet. The evaluation method of collision risk is one of the cause disturb. Usually the collision risk of ship is evaluated by the value of the Closest Point of Approach (CPA) which is related to a relative motion. So, it becomes difficult to find out a safety pass in a congested water. Here, Line of Predicted Collision (LOPC) and Obstacle Zone by Target (OZT) for evaluation of collision risk are introduced, these values are related to a true motion and it became visible of dangerous place, so it will make easy to find out a safety pass in a congested water. %@ 2083-6473 %R 10.12716/1001.11.01.06