An Imaging Technique for Measuring Wave Surface Shapes

Abstract

A novel imaging technique for identifying the locations of free-surface shapes was applied to three-dimensional hydraulic tests of coastal structures. Three-dimensional wave fields, consisting of superposed local reflected and diffracted waves, were measured around a breakwater and the mouth of a model harbor in a laboratory wave basin, and the results are consistent with the predictions of a Boussinesq-type equation model. The new technique was applied to surf zone waves to describe the organized deformation of breaking wave faces that evolve during wave propagation. Typical finger-shaped jets form in the wake of plunging jets, and a local depression trails behind a breaking wave front.

Observation of surf zone wave transformation using LiDAR

“…A time series of water elevation is measured by these instruments at a distance from the surface of the water, usually from directly above (Irish et al, 2001). Innovative techniques have been devised to measure wave properties such as using light projection (Kouyi et al, 2003), 3-D PIV (Du & Li, 2009), colour block projection (Watanabe et al, 2011), and in the field, RADAR for breaking wave detection (Haller & Lyzenga, 2003). Preliminary research on shallow angle LiDAR indicated that sea surface elevations could be measured remotely and across the spatial domain (Horwood et al, 2005).…”