What is Montage?

Montage is a toolkit for assembling Flexible Image Transport System (FITS) images into custom mosaics. Key features for end users are:

Preserves spatial and calibration fidelity of input images
Runs on all common Linux/Unix platforms
Runs on desktops, clusters and computational grids
Open source code and user documentation available for download
Supports all World Coordinate System (WCS) projections and common coordinate systems
Processes 40 million pixels in up to 32 minutes on 128 nodes on a Linux cluster
Independent engines for analyzing the geometry of images on the sky; re-projecting images; rectifying background emission to a common level; co-adding images
Tools for managing and manipulating large image files


February 9, 2017
Four new tutorials on using Montage have been added to the Documentation page.
December 21, 2016
Version 5 released. See Release of Montage Version 5.0 on the home page or the Download page.
August 16, 2016
We've posted a new tutorial for Montage novices called Getting Started: Creating Your First Mosaic.
November 16, 2015
We have released our YouTube channel that has four videos of image cubes created with Montage, including the GALFA movie shown at the ADASS conference in Sydney in October. Also, Montage is now on Twitter as @montage_mosaics.
September 30, 2015
Version 4 Released. See Release of Montage Version 4.0 on the home page.
February 18, 2015
Mac users should see the note on the left regarding patching the software.
July 23, 2014
The Montage license has been changed to a BSD 3-Clause License, which permits unlimited redistribution of Montage code for any purpose as long as its copyright notices and the license's disclaimers of warranty are included.
January 19, 2011
Montage now has a published Wikipedia article.
December 15, 2010
Montage version 3.3 released! Plus, new C-shell scripts contributed by Colin Aspin and new publications on using Montage in cloud computing and Web 2.0. Also, read the new Montage blog and "Like" us on Facebook.
July 1, 2010
Our new User-Contributed Software page now contains a link to Dr. Tom Robitaille's Python API for Montage. The software enhances Montage functionality, including functions for accessing individual Montage commands and facilitating mosaicking and re-projecting.
March 22, 2010
The on-request mosaic Web service now serves the DR7 data set from the Sloan Digital Sky Survey (SDSS).
October 4, 2007
IRSA and the NVO announce an on-request mosaic Web service. The service runs on a compute cluster and uses Montage to return mosaics from 2MASS, SDSS and DSS.

Four New Tutorials on Using Montage

We have released four new tutorials, as follows:

You may also access these from the Tutorials and Scripts section of Documentation page.

Release of Montage Version 5.0

Version 5.0 is a major new release of Montage. The distribution is available from GitHub at https://github.com/Caltech-IPAC/Montage and from the Montage web page at http://montage.ipac.caltech.edu/docs/download.html. Version 5.0 includes a new reprojection module, mProjectQL, that is suitable for creating images for visualization; support for FITS files containing data written in the HEALPix sky-tesselation scheme, and support for creating images organized in the TOAST sky-tesselation scheme that can be consumed by the WorldWide Telescope (WWT). This release also allows the most commonly used modules to be built and used as a statically or dynamically linked library.

Montage is written in ANSI-compliant C and intended for use on all common Unix-based platforms. It was tested formally on RedHat Enterprise Linux Server 5.9 and on Mac OS X 10.11.

In detail:

  • mProjectQL uses the Lanczos image interpolation scheme to provide higher performance in reprojection at the expense of conservation of flux; we recommend mProjectQL primarily for creating images for visualization rather than for science analysis. It offers a speed-up of approximately x20 over mProject. It can can be invoked in the executive modules mProjExec and mExec by using the "-q" switch.
  • Support for HEALPix and TOAST: Montage treats HEALPix and TOAST as if they were spherical projections that can processed with the existing reprojection routines, and managed through a local version of the WCStools library (users who prefer to use the library released by SAO should note that they will lose HEALPix and TOAST support).
  • WWT consumes PNG or JPEG files organized and named to conform to the TOAST sky-tessellation scheme. Montage includes custom routines to organize TOAST files for display in the WWT. The web interface for the WWT requires that these files, once processed, must be in URL-accessible locations.
  • A tutorial for visualizing HEALPix data is available at http://bit.ly/2dZtOwe, and a tutorial for creating images for consumption by the WWT is at http://bit.ly/2cRcDHZ.
  • The Montage library is built at the same time as the toolbox modules with the make command; no special build procedure is needed. A list of the library functions and the library API is at http://montage.ipac.caltech.edu/docs/MontageLib.html.

Featured Mosaic

This image represents an average of the central 10 velocity planes of a mosaic of five data cubes released as part of the Galactic Arecibo L-band Feed Array HI (GALFA-HI) survey (Peek et al., 2011, Ap J Suppl, 194, 20; DOI 10.1088/0067-0049/194/2/20; ADS Bibcode 2011ApJS..194...20P). GALFA is a high-resolution (~4'), large-area (13,000 deg2), high spectral resolution (0.18 km s-1), and wide band (-700 km s -1 < v LSR < +700 km s-1) survey of the Galactic interstellar medium in the 21 cm line hyperfine transition of neutral hydrogen conducted at Arecibo Observatory. See the Data Cube Mosaics tutorial on how to compute a data cube mosaic such as this.