User's Manual

FutureWaves™ User Manual

FutureWaves™ v1.7.0.1

Two Dimensional Power Spectrum (2DPS)

The

2DPS

panel displays a 2DPS either calculated from current radar data or from a NOAA

forecast spectra obtainable by download from NOAA NCEP. This is displayed in Figure 12.

The graph shows the wave energy surrounding the ship. The distance from the center represents

the wave period: the outermost edge represents 4 second periods, while the inner ring is 27

seconds. Whereas significant wave height provides an average value for the highest 1/3 of all

waves, the 2DPS provides more detail. It shows wave energy from all directions at many

different frequencies.

The time displayed in the upper right corner is the time that the last forecast was received. When

updating normally with live radar data, the power spectrum attempts to update as often as the

system processor can support. The current system should refresh roughly every minute or so.

Figure 12: The

2DPS

panel

If more than 3 minutes elapses without a fresh forecast, an indicator immediately below the

forecast valid time is displayed (view Figure 13). The time late indicator will periodically update

the forecast age until a new forecast is received. When a new valid forecast is received, the time

late indicator is removed automatically.

Figure 13: The

2DPS

panel with an old time indicator