IRAF is the Image Reduction and Analysis Facility, a general purpose software system for the reduction and analysis of scientific data. IRAF is written and supported by the IRAF programming group at the National Optical Astronomy Observatories (NOAO) in Tucson, Arizona. IRAF includes a good selection of programs for general image processing and graphics applications, plus a large number of programs for the reduction and analysis of optical astronomy data within the NOAO package. External or layered packages are also available for the analysis of HST, XRAY and EUV data. IRAF provides a complete programming environment, which includes the Command Language script facility, the IMFORT Fortran programming interface, and the fully featured SPP/VOS programming environment in which the portable IRAF system is written.
There are basically three reasons to get IRAF: The first one is that you have astronomical data that needs to be processed and you are looking for a mature, Unix-, PC-, or VMS-based, image processing system to do the work. The second reason is that you would like to develop some astronomical software and are looking for a popular astronomical software package - one with a broad selection of tools - to build on to lessen your work. IRAF provides the software developer with a rich programming environment that includes file management tools, interactive graphics and display, portability, and much MUCH more. The third reason to acquire IRAF is to process data that is similar to astronomical data, and the basic interactive graphics, display tools, and image operators provided by IRAF would be useful for your application.
The IRAF core system is the basic IRAF system and does not include the suite of reduction packages known as the NOAO package. (But note that the NOAO package is included in all IRAF distributions.) The IRAF core system provides tools for reading and writing data in the transportable FITS format (although other i/o tools are available), interactive graphics and image display tools for examining your data, tools for image registration and cleaning bad pixels, a variety of smoothing operators, and tools for image arithmetic, image statistics and combining image frames.
IRAF has a rich selection of tools for spectral reduction and analysis in the NOAO package that spans 1-d, 2-d, echelle, and fibor spectroscopy. These tools include basic CCD reductions and flat fielding, distortion corrections for 2-d data, extraction of 2-d and echelle frames, wavelength and flux calibration, radial velocity analysis, and a multitude of tasks for manipulating spectra in general. The tasks provide the user with the option of batch or interactive processing.
Besides the image operators provided by the basic core system (see earlier FAQ) the NOAO package in IRAF provides tools for basic CCD reductions, mosaicing, aperture and PSF-fitting (DAOPHOT) photometry, and photometric calibration. A package for surface photometry is planned and will be added at a later date.
The many reduction packages within the IRAF system are not limited to use with NOAO instruments. The tasks within IRAF have been developed to be as generic as possible to encompass a wide range of uses.
IRAF is available free of charge over the network. Use anonymous FTP to connect to node iraf.noao.edu (126.96.36.199) and "get README". Each level of the archive has a README file to assist you with your selections or with your transfers.
If acquiring IRAF over the network is not an option for you (but we do prefer you retrieve it that way) then an orderform is available. A small recovery fee is charged for mailed distributions along with any shipping and handling fees. Typical orders in the US run about $58 (US), and foreign shipments run between $100-$250 (when documentation is included).
Although IRAF is available free of charge over the network to anyone who may find it useful it is not considered public domain software since it is copyrighted. Here is part of the copyright notice that appears in the distributed system. ----------------- Copyright(c) 1986 Association of Universities for Research in Astronomy Inc. The IRAF software is publicly available, but is NOT in the public domain. The difference is that copyrights granting rights for unrestricted use and redistribution have been placed on all of the software to identify its authors. You are allowed and encouraged to take this software and use it as you wish, subject to the restrictions outlined below. Permission to use, copy, modify, and distribute this software and its documentation is hereby granted without fee, provided that the above copyright notice appear in all copies and that both that copyright notice and this permission notice appear in supporting documentation, and that references to the Association of Universities for Research in Astronomy Inc. (AURA), the National Optical Astronomy Observatories (NOAO), or the Image Reduction and Analysis Facility (IRAF) not be used in advertising or publicity pertaining to distribution of the software without specific, written prior permission from NOAO. NOAO makes no representations about the suitability of this software for any purpose. It is provided "as is" without express or implied warranty. NOAO DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO EVENT SHALL NOAO BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
For a typical, single-user, workstation environment you will need a minimum of 64Mb of memory and ~128Mb of swap space. You will need about 128 of diskspace for the IRAF system (this varies a bit with the platform), although it can be stripped to about half that after the installation. If you are configuring a server your memory and swap space needs will be more (maybe much more!).
The current version of IRAF varies a bit with the platform.
PLATFORM CURRENT RELEASE RELEASE DATE -------- --------------- ------------
AIX4 V2.11.3 15 December 1999 DUNX V2.11.3 15 December 1999 HPUX V2.11.3 15 December 1999 IRIX V2.11.3 15 December 1999 PCIX V2.11.3 7 December 1999 SSOL V2.11.3 7 December 1999 VMS7 V2.11.3 15 December 1999
It is always difficult for us to predict exact release dates, so the best thing to do is check the archive (iraf.noao.edu) occasionally for new distributions.
The X11IRAF project is being developed independently of the normal IRAF system development. They are X based tools for support of vector graphics and image display, the long awaited replacements for Xterm and SAOimage. Versions of XGterm, XImtool and XTapemon are available in the /iraf/x11iraf directory on iraf.noao.edu. A new version was recently made available that contains many enhancements, especially to ximtool (e.g. hardcopy capability, image load/save, on-line help, etc). All tasks are now fully documented and easily buildable from source on all supported iraf platforms. A bug-fix release was made available in Aug 97, most users should upgrade to this version. Another version to support the prototype science GUIs (XAPPHOT, SPECTOOL, and XRV) is planned for the near future that will also include many bug fixes and necessary system enhancements (contact site support for updates)
IRAF runs on the following platforms:
AIX4 IBM/RS6000 AIX 4.x DUNX Digital Unix 4.0 (OSF, Compaq Tru64) HPUX HP-UX 10.20 IRIX SGI IRIX 6.x PCIX FreeBSD 3.3 PCIX Slackware Linux 4.0 PCIX RedHat Linux 5.x PCIX RedHat Linux 6.x PCIX SuSE Linux 6.x PCIX Solaris 7 for Intel SSOL SunOS 4.x SSOL Solaris 5.5, 5.6, 5.7, 5.8 VMS7 VAX/VMS 7.1
The V2.11 IRAF system for PCs running Linux/FreeBSD is now available from the iraf.noao.edu archives or on the V2.11 CD-ROM by filling out the IRAF orderform. No port is planned for DOS/Windows 95/98 since it is an insufficient operating system to support IRAF.
Minor upgrades to the OS do not normally affect the operation of IRAF, but major changes to the OS may. It should be stressed however, that after ANY operating system upgrade which affects the system /dev or /usr directories, it is necessary to rerun the IRAF install script to recreate image display fifo pipes in /dev and symbolic links for /usr/include/iraf.h. The install script in this case must be run on all IRAF client machines in order to re-establish to critical system links needed by all IRAF machines.
The average individual will probably have great difficulty in porting IRAF to their own system - IRAF is a big and complex system and one should not underestimate the amount of work involved in a port. We have had very few successful ports done by people who were not highly skilled systems people with some large degree of knowledge about IRAF internals. Unfortunately, the IRAF group does not have the resources to assist with private ports, so anyone attempting this challenge is more or less on their own. For more information about IRAF ports see the README file in iraf/v210/PORT in the IRAF network archive on the node iraf.noao.edu (188.8.131.52).
The only supported window system is X, any X window manager should be sufficient. If you use X Windows then you will want to use XGterm for your graphics terminal and XImtool as your image display server, these can be downloaded as part of the X11IRAF package from /iraf/x11iraf in our archives. Note that IRAF itself is not dependent on a window system, many non-graphics tasks can be run from the raw console and older terminal such as VT640 may also be used and would lack only an image display.
The IRAF installation is straightforward but not trivial. Source code, object libraries, and executable are included in all distributions. Installation guides and site managers guides are available for each distribution in the same directory. If the instructions are followed your installation should go smoothly. (One step of the installation does require root privileges.)
Since IRAF is available freely over the network we are only able to estimate the number of sites or users. Our records suggest there are approximately 5000 users at about 1500 sites throughout the world. Our newsletter mailing list has roughly 1500 recipients. These numbers indicate that IRAF is a major software package in the US and abroad.
There are two papers appropriate as references for IRAF in a publication. They are:
Tody, D. 1986, "The IRAF Data Reduction and Analysis System" in Proc. SPIE Instrumentation in Astronomy VI, ed. D.L. Crawford, 627, 733
Tody, D. 1993, "IRAF in the Nineties" in Astronomical Data Analysis Software and Systems II, A.S.P. Conference Ser., Vol 52, eds. R.J. Hanisch, R.J.V. Brissenden, & J. Barnes, 173.
The more recent paper includes more references. Both are available from the anonftp archive on iraf.noao.edu in iraf/docs (see README). No special acknowledgement is required as a matter of policy so we don't blatantly state these anywhere, but a mention is always appreciated. A footnote describing IRAF may also be used when appropriate:
"IRAF is distributed by the National Optical Astronomy Observatories, which are operated by the Association of Universities for Research in Astronomy, Inc., under cooperative agreement with the National Science Foundation."