IMAGE SEQUENCE ANALYSIS OF OCEAN WIND WAVES

Almost no measurements of the small-scale spatial structure of the ocean surface are presently available. New optical techniques, which take image sequences of the slope of the short wind­-waves, have been used recently in wind-wave facilities and will soon be available for oceanic field measurements. Here, we discuss various image processing techniques for wave slope image sequences which allow for a deeper insight into the kinematics and dynamics of the wind-driven ocean surface, specifically, energy input by wind, non-linear wave-wave interaction, phase speed, interaction with the turbulent shear flow, and wave dissipation. These techniques are demonstrated using images recently taken in the large wind-wave facility of Delft Hydraulics, the Netherlands.