The discrete Fourier transform of the above time series is as shown in Fig 8. From this figure,
regularity of generated wave by the plunger wave maker is ensured.
Apart from measuring the wavelength by the still camera, the wavelength can be calculated using
Eq. 2 which is valid for deep water conditions
In this equation “d” is the water depth in m and “L” is the wavelength in m. Using this equation
the wavelength is obtained by the wave period which was already calculated by DAS.
Results obtained by cameras and those calculated by DAS using equations (1) and (2) are shown
in table 2.