| Abstract: | ![]()
The importance of the wake-free-surface interaction in the detection, classification, and tracking of submerged objects has led to the development of a simple but effective free-surface visualization technique for use in controlled water-tunnel experiments. An experiment was performed to verify the effectiveness and the applicability of this method. Digital images of a spatially varying sinusoidal grid were acquired as seen through the disturbance pattern on the water surface. Image-processing techniques were used to perform phase demodulation of the distorted image. The resulting image details the outline, location, and extent of the surface deformation in a gray-scale format. Optimal digital filter specifications and spatial grid frequencies were determined experimentally for various surface-flow conditions. |
