The New Spectral Image Processing System, known as NEWSIPS, is the
second (and final) generation standard production processing system
used for IUE data. The processing system
incorporated a number of improvements and enhancements in the reduction
algorithms, calibrations, documentation, and output formats of the IUE data.
The NEWSIPS-processed data, known as the IUE Final Archive,
generally provide improved signal-to-noise,
improved absolute calibration, and more homogeneous results for IUE
data than the IUESIPS-processed data.
Among the major enhancements are the following:
Improved construction of Intensity Transfer Functions (ITFs; linearization
calibration files)
Improved registration between ITFs and science data images using
cross-correlation techniques
Improved spectral extraction in low dispersion, using
optimal extraction techniques and corrections for aperture and temperature
Improved background correction using full-image modelling
techniques for high-dispersion spectra
Improved wavelength calibration, using new line library
Improved absolute calibration, based on white-dwarf models
Output files stored in FITS format for easier access
The history behind the development of the NEWSIPS system and creation of
the Final Archive, a discussion of the reduction techniques and new
calibrations, and an examination of the resulting processed data are discussed
in a paper by
Nichols and Linsky 1996.
Data Search & Retrieval