Kuniharu TAKIZAWA, Yoshihiro YOSHIDA and Nobuo SAITO¹

Department of Materials and Life Science, Faculty of Science and Technology, Seikei University, 3-3-1 Kichijoji-kitamachi, Musashino, Tokyo 180-8633, Japan
¹Science and Technical Research Laboratories, Japan Broadcasting Corporation, 1-10-11 Kinuta, Setagaya-ku, Tokyo 157-8510, Japan

(Received December 1, 2005; Accepted March 31, 2006)

This paper describes a television camera system that automatically captures exclusive images of an oil slick on the sea. The system includes two optical wavelength filters (WFs), two charge coupled devices (CCDs), and a differential image circuit that produces an absolute value of a difference signal between two output images from CCDs. The operating principle is based on the fact that, due to the multiple-beam interference in the oil slick, there is a marked difference of intensity between light reflected from the surface of the sea and that from the slick. The probabilities to sense slicks under various conditions were calculated using two types of WF, i.e., a space-invariant WF and a space-variant WF, and it was found that the latter was far superior to the former.

Key words: oil slick, sensor, television camera, interference, wavelength filter