The astronomical community has adopted the
Flexible Image Transport System
(i.e. FITS) format as the default standard
for the exchange of data between institutions. The FITS file format is
platform independent, supported by many institutions, and endorsed by
both NASA and the IAU. For these reasons FITS is the recommended file
format for archiving data at STScI. A description of the
MAST data format recommendations can be found in the
MAST Data Format Guidelines
MAST and the HST project, following the recommendations of the
IVOA, has been developing a standard for
storing spectral data in FITS format. As shown in our
FITS File Formats table,
spectral data has been stored in a wide variety of
formats, making it difficult for Virtual Observatory developers to write
programs for coplotting spectra from various missions.
The proposed format uses binary tables to store vectors
of flux, wavelength etc. with each row in the table
representing a single spectrum.
Once completed, this will become the recommended format for
projects planning to archive spectral data within MAST.
The somewhat out of date
FITS Standard Document Version 2.0
and the even more out of date FITS User's
Guide are both available locally.
The User's Guide provides examples and infomation on the early history of
FITS as well as a thorough description of the early formats, but does
not include changes made after 1997. Note that although the Version 2.0
standard is now out-of-date, it may be more appropriate for describing
archived FITS files created prior to 2008.