wavepropfrompsd#

[Hm0, fp, Tp, Tm01, Tm02, m0, m1, m2] = wavepropfrompsd(Syy, f, fcL, fcH, dispout)

Description#

Calculate wave properties from a power spectral density

Inputs#

Syy

Power spectral density (m^2/Hz)

f

Frequency (Hz)

fcL=0;

Low cut-off frequency, between 0*fs to 0.5*fs (Hz)

fcH=max(f);

High cut-off frequency, between 0*fs to 0.5*fs (Hz)

dispout=’no’;

Define to display outputs or not (‘yes’: display, ‘no’: not display)

Outputs#

Hm0

Zero-Moment Wave Height (m)

fp

Peak wave frequency (Hz)

Tp

Peak wave period (second)

Tm01

Wave Period from m01 (second), Mean Wave Period

Tm02

Wave Period from m02 (second), Mean Zero Crossing Period

m0

Zero-Moment of the power spectral density (m^2)

m1

First-Moment of the power spectral density (m^2)

m2

Second-Moment of the power spectral density (m^2)

Examples#

N=2^11; %Total number of points
fs=8; %Sampling frequency
df=fs/N; %Frequency difference
f(:,1)=[0:df:fs/2]; %Frequency vector
f(1,1)=f(2,1)/2; %Assign temporarily non-zero value to fisrt element of f to prevent division by zero
Syy=0.016.*9.81.^2./((2.*pi).^4.*(f.^5)).*exp(-1.25.*(0.33./f).^4); %Calculating Spectrum
f(1,1)=0;
Syy(1,1)=0;
[Hm0,fp,Tp,Tm01,Tm02,m0,m1,m2]=wavepropfrompsd(Syy,f,0,8/2,'yes');

References#