Using the wave spectrum, irregular waves can produce by any desired steps.

thanks for your answer.

I want really data.

If you can identify the resources to provide this information.

Accuracy is required, a second.

wavelet analysis will give you the time history of waves. you can down load and refer the following paper for more information.

"A DISCRETE WAVELET ANALYSIS OF FREAK

WAVES IN THE OCEAN" by EN-BING LIN AND PAUL C. LIU

Contact me directly through my University email.  I have data collected at 5Hz for 20 minutes in North Sea that may be possible to share.

A set of time histories of sea wave elevation can be found in the WAFO MATLAB software package, which you can easily download for free (along with this statistical suite).

 Referring to Seyed Mehdi Enderami's comments, that should be the most simplistic and practical way to get a time series of an irregular wave. Further, you can add random phases also. For real data for any particular sea, you need to get hold of some measured data from some reliable sources.

thanks for your answers.

Mr 'Colin Macfarlane' sent me what I need.

Why do you want 'real' data?

A 'real' wave is much more than surface elevation at one point (wave length, wave direction; orbital motions in the horizontal plane).

If one arbitrary 20 minutes 1 s sample of surface elevation at one point is sufficient for the purpose, I would prefer a synthetic sample from a stationary long- crested seastate, represented by a wave spectrum (surface elevation variance distribution over frequency). 

If nonlinearity in the waves is the issue, then I think faster sampling, longer duration, and direction spreading measurement, in addition to the surface elevation, is required.

Ivar

I sent data for three sensors spatially separated at one site on same time control sampled at 5 hz  and  in a number of storm intervals.

I agree with you, however, that there is a lot of benefit in developing deterministic simulations and, maybe Hadi should also try this.

Colin