North is up on the paper and east to the right.
The circles indicate wavelengths 75m, 150m and 300m. The directional ocean wave spectrum represents the most important information about the sea-state, and is often used to characterize it. Quantities like wave height, wave length and wave propagation direction can easily be extracted from the wave spectrum. The application of the wave spectrum is important in fields like naval architecture, coastal and harbor engineering, offshore operations, ship routing, wave energy and wave modelling. However, in order to utilize the SAR data complicated post-processing is needed.