Correlation length from intensity profile

[marif]

I want to calculate the correlation length of a rough surface from the intensity profile of diffuse and specular reflectance from that rough surface.

By fitting with the Gaussian curve, I calculated FWHM of the intensity profile.Generally it is considered thatcorrelation length = 2/FWHMI also found that, correlation length = 2*pi/FWHMUnder what conditions of the rough surface, the correlation length = 2*pi/FWHMThanks for any help.

 

[marcusl]

I'm not an expert in this area, but since you've received no answers I'll try to help. Do you know that your diffuse intensity is Gaussian distributed, or did you just choose that distribution? I would expect it to be Rayleigh distributed, and if you add a specular component it would become a Rician distribution.