  The currently operating space missions, as well as those that will be
launched in the near future, (will) deliver high-quality data for millions of
stellar objects. Since the majority of stellar astrophysical applications still
(at least partly) rely on spectroscopic data, an efficient tool for the
analysis of medium- to high-resolution spectroscopy is needed. We aim at
developing an efficient software package for the analysis of medium- to
high-resolution spectroscopy of single stars and those in binary systems. The
major requirements are that the code has a high performance, represents the
state-of-the-art analysis tool, and provides accurate determinations of
atmospheric parameters and chemical compositions for different types of stars.
We use the method of atmosphere models and spectrum synthesis, which is one of
the most commonly used approaches for the analysis of stellar spectra. Our Grid
Search in Stellar Parameters (GSSP) code makes use of the OpenMPI
implementation, which makes it possible to run in parallel mode. The method is
first tested on the simulated data and is then applied to the spectra of real
stellar objects. The majority of test runs on the simulated data were
successful in the sense that we could recover the initially assumed sets of
atmospheric parameters. We experimentally find the limits in signal-to-noise
ratios of the input spectra, below which the final set of parameters gets
significantly affected by the noise. Application of the GSSP package to the
spectra of three Kepler stars, KIC11285625, KIC6352430, and KIC4931738, was
also largely successful. We found an overall agreement of the final sets of the
fundamental parameters with the original studies. For KIC6352430, we found that
dependence of the light dilution factor on wavelength cannot be ignored, as it
has significant impact on the determination of the atmospheric parameters of
this binary system.
