A Caltech Library Service

The SIP Convention for Representing Distortion in FITS Image Headers

Shupe, David L. and Moshir, Mehrdad and Li, Jing and Makovoz, David and Narron, Robert and Hook, Richard N. (2005) The SIP Convention for Representing Distortion in FITS Image Headers. In: Astronomical Data Analysis Software and Systems XIV. ASP Conference Series. No.347. Astronomical Society of the Pacific , San Francisco, CA, pp. 491-495. ISBN 1-58381-215-6.

PDF - Published Version
See Usage Policy.


Use this Persistent URL to link to this item:


The SIP (Simple Imaging Polynomial) convention provides a convenient means for representing non-linear geometric distortion as polynomials in FITS header keywords. This scheme has been incorporated by the Spitzer Science Center (SSC) into its imaging products, and it is under consideration for wider use. The SIP keywords are read and applied by the SSC's MOPEX mosaicking software, and by several standard analysis tools, including WCSTools, SAOImage, DS9, GAIA/Starlink AST, IDL ASTROLIB, and Drizzle. We provide definitions of how these keywords are used together with standard FITS World Coordinate System (WCS) keywords to relate pixel coordinates to the sky. Some examples illustrate the application of this scheme to actual distorted data.

Item Type:Book Section
Related URLs:
URLURL TypeDescription
Shupe, David L.0000-0003-4401-0430
Additional Information:© 2005 Astronomical Society of the Pacific. We are grateful to Mark Calabretta for significant comments and suggestions, and Jane Morrison for discussions of MIPS distortions and the CD matrix. We thank Doug Mink, Wayne Landsman, David Berry, and Booth Hartley for implementing SIP in their software. The work carried out at the SSC was funded by NASA under contract 1407 to the California Institute of Technology and the Jet Propulsion Laboratory.
Funding AgencyGrant Number
Series Name:ASP Conference Series
Issue or Number:347
Record Number:CaltechAUTHORS:20110811-134701768
Persistent URL:
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:24809
Deposited By: Tony Diaz
Deposited On:12 Aug 2011 15:44
Last Modified:03 Oct 2019 03:00

Repository Staff Only: item control page