Definition of the Flexible Image Transport System (FITS), version 3.0
Astronomy and Astrophysics
The Flexible Image Transport System (FITS) has been used by astronomers for over 30 years as a data interchange and archiving format; FITS files are now handled by a wide range of astronomical software packages. Since the FITS format definition document (the "standard") was last printed in this journal in 2001, several new features have been developed and standardized, notably support for 64-bit integers in images and tables, variable-length arrays in tables, and new world coordinate system
... entions which provide a mapping from an element in a data array to a physical coordinate on the sky or within a spectrum. The FITS Working Group of the International Astronomical Union has therefore produced this new version 3.0 of the FITS standard, which is provided here in its entirety. In addition to describing the new features in FITS, numerous editorial changes were made to the previous version to clarify and reorganize many of the sections. Also included are some appendices which are not formally part of the standard. The FITS standard is likely to undergo further evolution, in which case the latest version may be found on the FITS Support Office Web site at http://fits.gsfc.nasa.gov/, which also provides many links to FITS-related resources. Article published by EDP Sciences Page 1 of 40 A&A 524, A42 (2010) We caution that this presentation of the standard is for the convenience of the community, and that it may be superseded by newer versions. We refer the reader to the extensive set of resources on the FITS Support Office at NASA/GSFC web site 1 which contains the latest version of the standard document as well as a comprehensive collection of FITS-related documents, software for validating and viewing FITS files, and sample FITS files from a variety of sources. This web site also provides a registry of common FITS conventions that are in use within the community. Although these conventions are not part of the official standard, they may be helpful to designers of new FITS data products. Acknowledgments The members of the three technical panels that produced this standard are shown below.