Assessment of different models on estimation of Amir Abad port waves spectrum

The present research assessed spectral density function of Caspian Sea waves in Amirabad port by using the data derived from Iranian wave scan buoy. This buoy is set at the depth of 25 meter and registers seasurface oscillations at 4 Hz. At first Wave spectrum were extracted using Fast Fourier Transformation and the accuracy of Jonswapmodel on estimation of wave spectrum was determined and the results indicated that the model with default coefficients is inefficient in these port. As a result, optimum coefficients were extracted using the least squares method in curve fitting. Afterwards, the effect of bandwidth parameter n on model estimation accuracy was assessed and it was observed thatin narrow spectra (v<0/4), Krylov model was best efficient but in wide spectra (v>0/45), Neuman model yielded the best results for these spectra.The results obtained for the spectra between these two ends revealed that Jonswap model yielded the best results at these spectra. Generally it can be concluded that wave spectrum in south Caspian Sea have a good fitting with common models with considering of spectrum widths.