Determination of phase velocities from optical images of the sea surface
A.S. Zapevalov1,2
1Marine Hydrophysical Institute National Academy of the RAS, Sevastopol, Russia
2Sevastopol State University, Sevastopol, Russia
Keywords: оптическое изображение, волнографические измерения, дисперсионное соотношение, фазовая скорость, optical image, wave measurements, dispersion ratio, phase velocity
Abstract
The contradiction between the results of determining the phase velocities of sea waves from optical images of the sea surface and data of in situ measurements by an array of wave sensors is analyzed. The phase velocity estimates obtained from optical images well correspond to the theoretical values derived from the linear dispersion relation for gravitational waves. For in situ waveform measurements, the phase velocities exceed the theoretical values. It is shown that the excess is caused by the fact that when in situ measurements are made, the contribution to the phase spectrum is given by waves that come from different directions and have different projections of the phase velocity in the direction in which it is determined.
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