  Grazing incidence x-ray scattering provides nanostructural information for
thin film samples, but single images generally do not provide information on
film thickness or the full complex index of refraction. Additionally, for thin
films that possess stratification of scatterers vertically within a sample, it
can be difficult to determine where those scatterers are positioned. We present
an in-situ method to extract film thickness, the index of refraction, and depth
information using scattering images taken across a range of incident angles.
The underlying theory is presented, and we validate the technique using two
sets of polymer thin films. Finally, we discuss how it can be implemented as a
general beamline procedure. This technique is applicable to any thin-film
material and has potentially far-reaching impact by enabling depth-sensitive
information in situ at any grazing incidence-capable beamline.
