GRAND ISLAND NORTH, MI - 268 Classic View
Energy spectrum data
Wave data are plotted with frequency on the x axis and time on the y axis. The elevation of a "mountain" corresponds to the energy density, with the scale to the right of the plot. Every fourth data run is plotted with one of four colors. Derived from a fast fourier transform of approximately 30 minutes of wave data.
This plot is useful for observing the evolution of wave energy over all the measured frequencies during the month.