Analysis of raw data is based on th

Analysis of raw data is based on the so-called ‘stochastic model’ . In this approach, the sea surface elevation is considered to be a Gaussian random variable (linear model). One of the most common techniques used for the calculation of directional wave spectra is the use of accelerometers or inclinometers on board the buoys which measure the heave acceleration or the vertical displacement of the buoy hull during the wave acquisition time. A Fast Fourier Transform (FFT) is applied to the data by the processor usually on board the buoy to transform the data from the temporal domain into the frequency domain. Note that the raw acceleration or displacement measurements may or may not transmitted shore-side. Post-processing techniques are then performed on the transformed data to account for both hull and electronic noise. It is from this transformation that non-directional spectral wave measurements(i.e., wave energies with their associated frequencies) are derived. Along with the spectral energies, measurements such as significant wave height (Hm0), average wave period (SprTp), and dominant period (Mdir) are also derived from the transformation.