The purpose of the IUESIPS system was to provide standard processed data and output products for IUE Guest Observers and archival users. The standardized extraction techniques generally worked best on well-exposed, point-source, continuum spectra (similar to the calibration stars). For many types of spectra, such as extended sources and weak spectra, customized extraction techniques may provide better quality data. To assist IUE data users in this, the archived IUE data files include all the major steps in the processing. Users may therefore employ customized techniques or algorithms at any point in the processing.
Because the IUESIPS system was in use for over 18 years, it went through a number of changes. However the basic processing steps and output files remained essentially the same.
During the observations, an image header was generated documenting the details of the acquisition and the status of the instrument. Added to this header was a record of the image processing steps applied. The image header was appended to the output data files.
The output data files are stored in IUEGO format, an IUE-specific format that predates the common usage of FITS.
A complete description of the IUESIPS processing system is given in the IUESIPS Image Processing Information Manual. In addition, several published papers and IUE Newsletter articles describe various aspects of the processing and calibrations.
A list of the major changes in the processing system, as well as the complete IUESIPS Software Chronology, are also available.