Extraction of the fine structure from x-ray absorption spectra

We propose two methods for obtaining the atomic-like background for the x-ray absorption fine structure (XAFS): the methods of smoothing spline and of Bayesian smoothing. Both are capable of using the prior information, calculated or experimental, about the background. The XAFS signals obtained by these techniques are shown to be significantly corrected in comparison with standard methods. The method of Bayesian smoothing is the only method that gives the errors of approximation of the atomic-like background by an artificial smooth function. These errors are shown to be the main source of the uncertainty of the XAFS function.