This example demonstrates how to compute reflected signal from a multilayered sample with surface roughness. All the experiment layout is exactly the same as the one described in reflectometry tutorial, but now all the layers (except the ambient media) have roughness on the top surface. The roughness is characterized by root-mean-square deviation from the mean surface position $\sigma = 1$ nm.
When comparing the result of the simulation to the result obtained in the reflectometry tutorial, one can notice up to two orders of magnitude attenuation of the reflected signal due to the roughness of the sample.
Please note that other roughness characteristics (like Hurst parameter or lateral and cross correlation lengths) previously described in example on correlated roughness do not affect the result of the simulation. The computation model takes into account only the rms-deviation from the mean surface position.