EDP Sciences Journals List
Advanced Search
Subscriber Authentication Point
Home All issues Volume 395/3 Article
Free access article

Issue A&A
Volume 395, Number 3, December I 2002
Page(s) 1061 - 1075
Section Instruments, observational techniques and data processing
DOI http://dx.doi.org/10.1051/0004-6361:20021326



A&A 395, 1061-1075 (2002)
DOI: 10.1051/0004-6361:20021326

Representations of world coordinates in FITS

E. W. Greisen1 and M. R. Calabretta2

1  National Radio Astronomy Observatory, PO Box O, Socorro, NM 87801-0387, USA
2  Australia Telescope National Facility, PO Box 76, Epping, NSW 1710, Australia

(Received 24 July 2002 / Accepted 9 September 2002)

Abstract
The initial descriptions of the FITS format provided a simplified method for describing the physical coordinate values of the image pixels, but deliberately did not specify any of the detailed conventions required to convey the complexities of actual image coordinates. Building on conventions in wide use within astronomy, this paper proposes general extensions to the original methods for describing the world coordinates of FITS data. In subsequent papers, we apply these general conventions to the methods by which spherical coordinates may be projected onto a two-dimensional plane and to frequency/wavelength/velocity coordinates.


Key words: methods: data analysis -- techniques: image processing -- astronomical data bases: miscellaneous

Offprint request: E. W. Greisen, egreisen@nrao.edu




© ESO 2002


What is OpenURL?

The OpenURL standard is a protocol for transmission of metadata describing the resource that you wish to access. An OpenURL link contains article metadata and directs it to the OpenURL server of your choice. The OpenURL server can provide access to the resource and also offer complementary services (specific search engine, export of references...). The OpenURL link can be generated by different means.
  • If your librarian has set up your subscription with an OpenURL resolver, OpenURL links appear automatically on the abstract pages.
  • You can define your own OpenURL resolver with your EDPS Account. In this case your choice will be given priority over that of your library.
  • You can use an add-on for your browser (Firefox or I.E.) to display OpenURL links on a page (see http://www.openly.com/openurlref/). You should disable this module if you wish to use the OpenURL server that you or your library have defined.