Bidirectional Reflectance Distribution Function B.R.D.F cos θ,Total Integrated Scattering T.I.S and Power Spectal Density P.S.D
In FILMSCATTER software we use three theoretical framework to calculate the quantities B.R.D.F cos θ and the T.I.S. They are first-order vector perturbation theories for a multilayer stack with random roughness at each interface. The interfaces can be correlated or not. I highly advise you to consult the references below for the validity of these models before you use the software.
The Bidirectional Reflectance Distribution Function cos θ is calculated versus the scattering angle.
The Total Integrated Scattering is calculated versus the wavelength.
The Power Spectral Density.