An automatic pattern recognition method for the processing of longslit spectral images

摘要

A pattern recognition method for the reduction of stellar andnebular spectra is presented. This method automatically corrects thegeometrical and optical distortions of long-slit spectra and morespecifically of bidimensional photographic image-tube spectra. Anyphotographic plate surrounded by two comparison spectra can beprocessed. The presented spectral reduction method is fully independentof the spectrograph and of the image-tube characteristics; no a prioriknowledge of the different distortions is required. SPECTRA software,developed on VAX 11/780, has been included in the ESO Observatory'simage processing system (MIDAS), and was successfully applied to platesoriginating from the Haute Provence Observatory (OHP), the ESOObservatory at la Silla, and the Canada-France-Hawaii telescope