Introduction

Before being able to actually reduce and analyse a new set of observations, the observer has to prepare, sort out and arrange the data. That is, for instance, make a first quality check, classify data according to a set of rules and associate with each science frame a set of relevant calibration frames . This task can be cumbersome because of the complexity of the instruments and the large number and the diversity of the data files they produce. For instance, the EMMI instrument mounted on the New Technology Telescope allows a wide range of observing modes from wide-field imaging to high-dispersion spectroscopy, including long-slit, multiple-object spectroscopy and a dichroic mode where spectra are taken simultaneously in the blue and in the red arm of the instrument. The FITS files that are produced contain more than 50 different keywords, and making sense of this information without a proper tool may be very difficult.

The Data Organizer is built entirely on existing capabilities of the MIDAS Table File System. Therefore the astronomer does not have to learn any new computer jargon, change environments, or convert data formats. The output files created by the Data Organizer are MIDAS Tables and can therefore be used by any reduction package.

The concept of a Data Organizer tool is new and this first implementation may be subject to revisions as experience with processing of large amounts of data is obtained.