A Novel Technique for Free-Surface Elevation Mapping

Recently, there has been an increased interest in the interaction of vortices and turbulence with free surfaces. A central issue in understanding the free surface turbulence is to relate the surface elevation to the near-surface flow field. In that respect, the lack of a global surface mapping technique which could reveal the temporal evolution of the surface elevation has prevented the progress of viable research. Therefore, in this abstract we present a new technique, integrating optics, colorimetry, and digital image processing, to measure the three-dimensional surface elevation for a time-evolving flow. The basic idea is to color code the surface slopes by light beams of different colors. This is achieved by first using a diffused white light source to illuminate a specially designed color palette.