  Prediction of incident waves to wave energy converters (WEC) is essential to
maximize the energy absorption by controlling the WEC. Nevertheless, little
work has been done on the deterministic prediction of bi-directional waves
whose wave directions of components are 180 [deg.] opposite. To decompose and
predict such bi-directional waves, an array of three wave-rider buoys are
considered. Buoys on both sides are used for decomposing bi-directional waves
into progressive and regressive wave components, and the surface elevation of
the middle buoy is predicted by these decomposed waves. The deterministic wave
prediction is based on the impulse response function, and a cosine-filtered
impulse response function is proposed to reduce an error due to the truncation
of the infinite length of the function. Predictions of initial uniform
bi-directional waves are shown to demonstrate the performance of the impulse
response function method to time-series prediction. Both numerical and
experimental comparisons are carried out to validate our proposals.
