Image Measurement of Wave Height Distribution around a Ship Model

Abstract

A measurement system for were height distribution using visualized image has been developed and applied in towing tank. When a laser sheet illumination is given from the bottom of the tank, the free surface is visualized as the boundary of bright and dark area on the image. The high contrast image is obtained by large light scattering in water. Combining the visualization and a image processing technique, present image measurement system has been developed by the authors, and is modified so as to apply on the measurement in towing tank. High power laser is needed to obtain a enough contrast on the visualized image in large size towing tank, and the simple coordinate transformation should be considered to make up a practical system. Two camera system is used to obtain a wide range distribution in same spatial resolution. The measured result shows that the present system can be applied on the wave measurement around not only a high speed craft but also a ordinary displacement type ship model.