close all
clear all


U = 20.0;

f = .01:.005:.3;
w = 2*pi*f;

a = .0081;
b = 0.74;
g = 9.81;

S = a*g^2*exp(-b*((g/U)./w).^4)./(w.^5);

t = 0:.05:60;

H = zeros(1,length(t));

for i = 1:length(w)
H = H + sqrt(S(i))*cos(w(i).*t);
end