This paper proposes a method for bearings measurement of ships that detected using navigational image sequence. This proposal method can measure bearings of ships by three data. There are the arrangement between a camera and a hull, the course of own ship, and coordinates of ships detected from the image. We evaluated the effectiveness of the present method by applying it to images taken at Tokyo Bay. In this experiment, on board the ship, we obtained approximately 6-h running video images. These included approximately 2-h of running images that captured other ships crossing in front of monitor's own ship. The result by the proposal technique was compared with the result of measuring in the visual observation by navigator. In 159 measurements, the difference was within 1-degree on 92% of comparison result. The integration of navigation equipment as typified by ECDIS and the image processing system presented in this paper would improve navigation information systems.
