How to read INES Data

INES data are written in standard FITS format. Low and high dispersion spectra have the same format. The files can be read with any FITS reader, in particular with those included in the most common Data Analysis Packages. No special purpose software is required to read INES files.

MIDAS

IDL

IRAF

The INES FITS Format

INES data are stored as FITS binary tables, with a primary header holding the basic FITS keywords and several selected "Core Data Items", and an extension header. Since no primary data is included, the extension header follows the primary FITS header. Each row of the binary table includes four columns:

1. Vacuum wavelength in Å
2. Flux in erg/cm² s Å
3. Sigma in erg/cm² s Å
4. Quality flags

The first three vectors are stored as single precision floating points numbers, and the quality flags as 16-bit integers. The INES primary header contains:

• 8 mandatory FITS keywords
• A subset of the Core Data Items
• The IUE Vicar Header
• Part of NEWSIPS Image Processing History and, for low dispersion files, the INES Image Extraction History

The extension header includes:

• 25 basic FITS keywords
• The Filename keyword