It is common practice to relate the response of a structure to the incident wave parameters at the toe. Estimation of the incident wave parameters at the toe is thus an essential part of the analysis of experimental data. In many cases, the design conditions at the toe are given by waves that are depth-limited or at least close to that limit. In such situations where waves are breaking and nonlinear, it is known to be very difficult to estimate the incident wave parameters accurately. The aim of the paper is to provide guidelines on the accuracy of reflection separation algorithms when applied to nonlinear waves over sloping foreshores. The guidelines will present examples of the error of the estimated incident wave parameters depending on the wave nonlinearity and the foreshore slope. Moreover, a first methodology for reflection separation of nonlinear waves on steep sloping foreshores will be provided.
