Simulation of waves with highly inaccurate input

This paper deals with wave simulations for which the input data are highly inaccurate. Inaccuracies can consistent of high levels of noise or strongly mutilated wave forms. Such inaccuracies can occur in various applications, one of which is in coastal wave prediction using remotely observed waves upstream. Wave data from radar images obtained at a ship or at the coast is already used to determine statistical properties of the approaching wave field, properties such as significant wave height, period and wavelength. For various modern coastal engineering applications it is desired to obtain time accurate information of incoming waves. To predict the incoming waves, we propose new methods to improve the inaccurate input in a dynamic simulation model that calculates the evolution of the waves towards the vessel. For the dynamic evolution we use a linear spectral code with exact dispersion. This model calculates the elevation from input that consists of the elevation at one or more specified positions upstream. The input is processed in an embedded way, i.e. by a source in the governing dynamic equation. We will show effects of inaccuracies at the input positions and show that averaging of multiple in puts will increase the prediction at the position of the vessel. Using synthetic data, the improvement is shown for inaccuracies caused by noise and caused by mutilations that remove partly or completely the waveform below the still water level.