I'm trying to generate a randomly rough surface(isotropic surface). Suppose I have the absolute values of fourier components of the surface in "H" and H has symmetry with respect to center of the array. Now, I need to define some random phase for the fourier series which are between -pi to pi (due to fftshift) as in:
phi = -pi + (pi+pi)*rand(n);
Now, I don't know what to do to make the output of my surface real..
Here is the gist of the code I used so far:
[a,b] = pol2cart(phi,H);
H_complex = complex(a,b);
z = ifft2(ifftshift((H_complex)));
If I need to apply conjugate symmetry to the fourier components, how should I do it? The output is complex and I need a real surface.
Please help! Thanks a lot.