\chapter{Literature Review} In this chapter, literature relevant to the present study will be reviewed. \section{Separating incident and reflected components from wave buoy data} The separation of incident and reflected waves is a crucial step in numerically modeling a seastate. Using the raw data from a buoy as the input of a wave model will lead to incorrect results in the domain as the flow velocity at the boundary will not be correctly generated. Several methods exist to extract incident and reflected components in measured seastates, and they can generally be categorised in two types of methods: array methods and PUV methods \parencite{inch2016accurate}. Array methods rely on the use of multiple measurement points of water level to extracted the incident and reflected waves, while PUV methods use colocated pressure and velocity measurements to separate incident and reflected components of the signal. \subsection{Array methods} \begin{itemize} \item \cite{mansard1980measurement}: Presentation of least-square method to separate incident and reflected spectra. Requires simultaneous measurement at 3 positions, on a line parallel to the direction of wave propagation. \parencite{gaillard1980} \item \cite{frigaard1995time}: Separate 2D wave field into waves propagating towards and away from a structure, using 2 gauges. Method quite efficient, even with small filters. SIRW Method, realtime. \item \cite{baldock1999separation}: Starting from \textcite{frigaard1995time}, arbitrary 2D bathymetry using linear shoaling. Small error for large reflection coefficients, larger for low reflection. \item \cite{suh2001separation}: Technique to separate incident and reflected waves on a known current. \item \cite{inch2016accurate}: creation of a lookup table to correct noise-induced bias in array methods. \item \cite{andersen2017estimation}: estimation of incident and reflected components for non-linear waves. \item \cite{roge2019estimation}: extension to irregular waves. \end{itemize} \subsection{PUV methods} \begin{itemize} \item ?? \cite{guza1977resonant}: model of the surf zone as a standing wave combined with a progressive wave. Accurate results of surface elevation and runup for reflectivities over 0.3. \item ?? \cite{guza1984}: \item \cite{tatavarti1989incoming}: Decompose colocated random field measurements of wave elevation and currenct velocity into incoming and outgoing components. Less sensitive to noise. \item \cite{kubota1990}: comparison between different wave theories: quasi-nonlinear long-wave theory gave the best results. \itemĀ \cite{walton1992}: application to beaches, possibility to have higher reflected energy than incident energy. \item \cite{hughes1993}: colocated horizontal and vertical velocities or horizontal velocity and surface elevation. Validation for full reflection of irregular non breaking waves. \item \cite{huntley1999use}: principal component analysis technique to avoid noise-induced bias. \item \cite{sheremet2002observations}: \end{itemize} \section{Modeling wave impact on a breakwater} \subsection{SPH models} \subsection{VARANS models} \section{Modeling block displacement}