incidentreflectedwave#

[Kr, EtaInc, EtaRef, aInc, aRef, t, f] = incidentreflectedwave(Eta1, Eta2, dx, h, fs, fmin, fmax, SepMethod, kCalcMethod, dispout)

Description#

Separate incident and reflected waves

Inputs#

Eta1: Wave signal at position x1 in (m), should have same size as Eta2
Eta2: Wave signal at position x2 in (m), should have same size as Eta1
dx: Distance between x1 and x2 in (m), dx=x2-x1
h: Mean water depth in (m)
fs=2;: Sampling frequency that data collected at in (Hz), if fs=1 then output is equivalent to normalized filter
fmin=0;: Minimum frequency to be considered in (Hz)
fmax=fs/2;: Maximum frequency to be considered in (Hz)
SepMethod=’goda’;: Incident and reflected waves Separation method

‘goda’: Goda and Suzuki (1977)

‘ma’: Ma et al. (2010)

‘frigaard’: Frigaard and Brorsen (1995)
kCalcMethod=’beji’;: Wave number calculation method

‘hunt’: Hunt (1979), ‘beji’: Beji (2013), ‘vatankhah’: Vatankhah and Aghashariatmadari (2013)

‘goda’: Goda (2010), ‘exact’: calculate exact value
dispout=’no’;: Define to display outputs or not (‘yes’: display, ‘no’: not display)

Outputs#

Kr: Reflection coefficient
EtaInc: Incident wave (m)
EtaRef: Reflected wave (m)
aInc: Amplitude of incident wave (m)
aRef: Amplitude of reflected wave (m)
t: Time (s)
f: Frequency (Hz)

Examples#

h=1;
fs=2;
dt=1/fs;
duration=1024;
t(:,1)=linspace(0,duration-dt,duration*fs);
x1=1;
x2=3.7;
dx=x2-x1;
W1=0.5.*cos(0.412.*x1-2.*pi.*0.2.*t);
W2=0.5.*cos(0.739.*x1-2.*pi.*0.34.*t);
EtaIncGauge1(:,1)=(W1+W2);
W3=0.5.*cos(0.412.*x2-2.*pi.*0.2.*t);
W4=0.5.*cos(0.739.*x2-2.*pi.*0.34.*t);
EtaIncGauge2(:,1)=(W3+W4);
W5=0.1.*cos(0.412.*x1+2.*pi.*0.2.*t);
W6=0.1.*cos(0.739.*x1+2.*pi.*0.34.*t);
EtaRefGauge1(:,1)=(W5+W6);
W7=0.1.*cos(0.412.*x2+2.*pi.*0.2.*t);
W8=0.1.*cos(0.739.*x2+2.*pi.*0.34.*t);
EtaRefGauge2(:,1)=(W7+W8);
Eta1=EtaIncGauge1+EtaRefGauge1;
Eta2=EtaIncGauge2+EtaRefGauge2;

[Kr,EtaInc,EtaRef,aInc,aRef,t,f]=incidentreflectedwave(Eta1,Eta2,dx,h,fs,0,fs/2,'goda','beji','yes');

References#

Beji, S. (2013). Improved explicit approximation of linear dispersion relationship for gravity waves. Coastal Engineering, 73, 11-12.

Baldock, T. E., & Simmonds, D. J. (1999). Separation of incident and reflected waves over sloping bathymetry. Coastal Engineering, 38(3), 167-176.

Frigaard, P., Brorsen, M., 1995. A time domain method for separating incident and reflected irregular waves. Coastal Eng. 24, 205–215

Goda, Y., & Suzuki, Y. (1977). Estimation of incident and reflected waves in random wave experiments. In Coastal Engineering 1976 (pp. 828-845).

Goda, Y. (2010). Random seas and design of maritime structures. World scientific.

Hunt, J. N. (1979). Direct solution of wave dispersion equation. Journal of the Waterway Port Coastal and Ocean Division, 105(4), 457-459.

Ma, Y., Dong, G., Ma, X., & Wang, G. (2010). A new method for separation of 2D incident and reflected waves by the Morlet wavelet transform. Coastal Engineering, 57(6), 597-603.

Mansard, E. P., & Funke, E. R. (1980). The measurement of incident and reflected spectra using a least squares method. In Coastal Engineering 1980 (pp. 154-172).

Vatankhah, A. R., & Aghashariatmadari, Z. (2013). Improved explicit approximation of linear dispersion relationship for gravity waves: A discussion. Coastal engineering, 78, 21-22.

incidentreflectedwave

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