Wave cycles are pairs of a maximum value and a corresponding minimum value. There are many different methods to select the pairs, and here are a few of them, which can be analysed in the WAT toolbox:
A trough2crest wave cycle is the pair of the minimum value in the interval between a downcrossing and the following upcrossing of a reference level, and the maximum value in the following interval between the downcrossing and the next upcrossing.
The crest front wavelength is the distance between the minimum and the maximum.
A min2Max cycle is a pair of a local minimum and the following local maximum.
A rainflow cycle is a max/min-pair of a maximum and a certain minimum. For a local maximum at a level u the minimum is selected as the minimum which is reached when one wants to return above u (in the forward or backward direction) with an as small downward excursion as possible. Min/max rainflow pairs are defined analogoulsy