Abstract
The measurement method of a small-amplitude wave was proposed, in which a diffuse reflection spot was used as an index point. An equation to obtain the still water depth was introduced. This equation was confirmed experimentally by using a laser displacement sensor which is equivalent to a camera-index-point-film system in principle. To confirm the applicability of this method to the wave form measurement, the numerical simulation of the measurement by this method were carried out on sinusoidal waves and a composed wave. The results of these simulations show that the small-amplitude waves can be measured accurately enough when the water surface inclination is small enough.
