レーダ画像処理による船形の推定

Abstract

When we are encountering many vessels at sea, it is very useful that the information on these vessels, for example, course, speed, size of vessel, destination and intention of maneuvering, can be obtained instantly. Some of these information are provided by a navigational aids like an ARPA. But it takes at least a half minute to observe the vessel and to calculate the vessel's course and speed, also it is an old value of a half minute at least. The authors made attempt to estimate gross tonnage, shape and aspect angle of the vessel by simple image processing of radar echoes. An ultra high speed analogue to digital converted echo images of radar gives us special information not as before. The experiments were practiced using the X-band radar with narrow beam width antenna. The aspect angles of the vessel were able to estimate in relative certainty. The characteristics of radar echo are thought as follows. There are many constructions like as bridge house, derricks, fore castle and others on the upper deck. The radar image is influenced by these constructions. Some echoes are strong intensity because of large reflection areas, and one another echoes became long blip because of multiple reflection into the constructions. The authors think that it will be possible to estimate characteristics of vessel from these clue to analyze. Furthermore they are also thinking the images using radar are similar to the image with naked eye in some point, and it is possible to estimate the characteristic of vessels.