2615 20160701171708.0 ASTROimport-772 Hensberge, H. 2007 Removal of Instrumental Signatures in Echelle Spectra The use of echelle spectra in astronomy is occasionally hampered by imprecize merging of spectral orders. Analysis of time-dependent instrumental signatures in extracted spectral orders, before the merging, allows to identify various types of bias and to suggest improvements in the data reduction process. Experience with echelle spectrographs during 20 years is used to define the needs for a performant data reduction pipeline, differential in nature and including continuous evaluation of the validity of the data reduction procedure. The Future of Photometric, Spectrophotometric and Polarimetric Standardization 364 2007 275 http://esoads.eso.org/abs/2007ASPC..364..275H published in NONREF