function [f,psd]=terrain_psd(A,B,C,alpha,beta,gamma,u_moy,n,u_var)
%n=0.008:0.001:1;
f=n;
%f=n*10/u_moy;
for i=1:length(f)
psd(i)=((A*((f(i))^gamma))/(C+(B*((f(i))^alpha)))^beta)*(u_var(i)/n(i));
end
