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Next: Wavelength calibration Up: FEROS Previous: Order extraction


Since the flat-fields are also taken through the fiber, the FEROS spectra cannot reasonably be flat-fielded in a 2-D way. Instead the extracted spectra of the object and the flat-field lamp are divided to remove the pixel-to-pixel variations. This division also removes the blaze function of the echelle grating with good precision. However, this requires that the background subtraction is sufficiently accurate. The command corresponding is FLAT/FEROS.

Petra Nass