Image Measurement of Free-surface Shapes and its Application to Breaking Waves

The novel imaging technique for measuring planar free-surface shapes using a PC projector and digital camera is examined through model tests of planar wave field with coastal structures. The measured results reasonably represent local reflected and diffraction waves behind a breakwater and near a port mouth, which are consistent with computed ones. This technique is also applicable to the measurement of complex surface shapes of breaking waves. Typical finger-shaped jets formed after plunging overturning jets and local depression stretched behind a breaking-wave front are able to be obtained using the current technique.