The identification of the objects present on the plate and the extraction of their spectra is presently made by us with a catalogue-driven procedure, written by Prof. R. Nesci as an IRAF script, including two simple FORTRAN programs for format conversion and checks.

·         First, a list of all the objects present in the USNO-A2 catalogue down to the plate limit and included in sky area covered by a given plate is converted into pixel coordinates with the IRAF task cctran.

·         Then an image section of 21x150 pixels including one well exposed star is selected and the spectrum is extracted with IRAF/apall in interactive mode (the typical FWHM of a spectrum is 5 pixels and the length 106). This process allows derive the orientation of the spectra on the plate and defines the template for subsequent automatic extractions.

·         Finally all the spectra of the list are extracted automatically by apall, assuming as sky value the mode of an area 21x150 pixel centered on each spectrum.