A least-squares deconvolution technique for the photoelectric Fabry-Perot spectrometer

A method is described for deconvolving into Voigt profiles a spectrum obtained with a Fabry-Perot spectrometer. This technique removes many of the limitations of some recently discussed schemes for analytically describing such spectroscopic data and reducing it to Voigt profiles. The use of a digital computer is assumed for all computations. The analytical description of the spectrometer includes all the important instrumental parameters as well as four adjustable profile parameters (position, amplitude, Lorentzian width, and Gaussian width) for each line present in the source spectrum. A least-squares adjustment of all nonfixed profile parameters is performed such that the sum of the individually fitted lines reproduces the recorded spectrum. This technique has been successfully applied to the thirteen fine structure components of the 4686-A line of He ii obtained with a double etalon Fabry-Perot spectrometer.