A Technique to Measure Wave Height Using Projected Light Distribution on the Screen Near the Water Surface

Abstract

It is generally known that the light from the bottom of tank is refracted when it passes through water surface. So the light distribution projected on a screen near the wave surface has strong relation with the wave height and pattern. This report describes about the relation between them and it propose a new technique to mesure wave height from the light distribution using the relation. The light distribution is represented by second order differentials of wave pattern, and the pattern is calculated using the Fast Fourier Transform method. Obtained results show good agreement when the screen is arranged near the water surface.