in which T is wave period in seconds.
Also, by observing the frame by frame video image for wave crest and wave trough over the
vertical ruler the wave height was obtained with an accuracy of about ±5mm.
Wavelength was obtained from photos taken from wave motion, in which two consecutive crests
were observable on two horizontal rulers, shown in Fig 6.
The fixed distance between the two horizontal rulers is taken into account for measuring the
wavelength for each wave frequency. The accuracy of this measurement was about ±50 mm.
Using this verification method, it was found out that the results obtained for wave amplitude by
the wave probes and DAS slightly differ with that obtained by cameras. The cause was due to
frequency response of the transducer. By comparing the two results a correction coefficient was
obtained and introduced to the DAS. It was seen that introduction of this coefficient to DAS
system, did not affect any other wave parameters. Fig 7 shows the time series of wave with
particular frequency generated by the plunger wave maker obtained by DAS before and after
implementation of the correction coefficient.