In picture (see below) seen the fragment of Solar spectrum obtained in dufferent observational modes and with different observational conditions (the depth of telluric lines (O2) are unequal).
The analysis of CCD data performed on the IBM PC compatible computers (AT386+) using the image and spectra processing system DECH developed by Galazutdinov G.A. (Special Astrophysical Observatory, Preprint #92, 1992). This system permits us to realize all the steps in echelle-spectra processing - dark current and background substraction, one-dimensional spectra extraction (particularly, by using the "optimal extraction" method (K. Horne, 1986, PASP, V.98, P.609), flat-field corrections, wavelength calibration, continuum placement and rectification, line identification, equivalent widths and radial velocity measuremnts. The system operates under MS-DOS and can be used with portable computer.