Internal Use of CASA in Green Bank

As part of the standard computing infrastructure at NRAO, we maintain many versions of CASA for use by our staff and visitors. These versions of CASA are categorized into four types of products. The correct product and version for your use may vary depending on the task you are doing. Please note that this describes the behavior on Red Hat Enterprise Linux systems under the management of the NRAO Computing Infrastructure Group.

Please read carefully, as the definitions of the product types has changed.

All of the versions are accessed in the same way:

casa[-product] [-r version number]

To see all available versions for a given product:

casa[-product] -ls

The default product is assumed to be the release version, thus

casa -ls

will produce a list of all the currently-installed CASA releases:

available versions:

Current version is 4.3.1-el6

To run the CASA 4.2.2 release:

casa -r 4.2.2

Similarly to run the CASA viewer from the 4.2.2 release:

casaviewer -r 4.2.2

To run a different product from the release (in this example prerelease) type

casa-prerelease [-r version number]


casaviewer-prerelease [-r version number]

In all cases, the latest version of each product is the default.

Product Types

  • Release

    This version underwent a large suite of code testing, including interactive tests. The documentation, including the Reference Manual & Cookbook, as well as the scripts on the CASA homepage and the CASAguides Wiki are written and updated for each Release.

    Access these products using casa, casaviewer and casaplotms

  • Stable

    A stable build has passed all of the automated regression tests and is updated fairly frequently (often several times a week). It has not gone through any manual testing nor has the documentation been updated. Manual user testing of new features should normally be performed on the stable package.

    Access these products using casa-stable, casaviewer-stable and casaplotms-stable

  • Monthly

    For those looking for a less dynamic version than Stable but still looking for more recent functionality, the Monthly is a snapshot of the Stable at the beginning of each month. No additional testing beyond the testing of a stable is done.

    Access these products using casa-monthly, casaviewer-monthly and casaplotms-monthly

  • Test

    Test builds are performed nightly and have had minimal testing performed (they are known to start). Any version that has passed all of the automated regression tests has been promoted to a stable, so versions that are only tests are known to have at least one failure.

    Access these products using casa-test, casaviewer-test and casaplotms-test

  • Pipe

    Versions of CASA which contain the CASA pipeline are also maintained for general use. The accepted version is set as the default versions with other versions available (via the -r option) for testing purposes. It is still necessary to use the "--pipeline" option to load the pipeline tasks.

    Access these products using casa-pipe, casaviewer-pipe and casaplotms-pipe

  • Prerelease (only available prior to a new public release)

    This version is only normally available for a few weeks prior to a new release version. It has undergone a large suite of code testing, including interactive tests. It will contain all the new features of the upcoming release version, but is still undergoing final manual testing. When available, manual user testing should be performed on this version.

    Access these products using casa-prerelease, casaviewer-prerelease and casaplotms-prerelease

In addition to all of the above, certain other standalone tasks may also be run for all of the above. These include casabrowser, casafeather and casalogger, all of which may be started in a similar manner.

User Support for internal NRAO CASA Users

The primary references for CASA use are listed on our Using CASA webpage. If you need someone to for questions or help, please contact the CASA Project Scientist, Juergen Ott (jott, in Socorro) directly.

For internal NRAO and ALMA/EVLA project users, CASA uses JIRA as its issue tracking system. Registered NRAO JIRA users can submit issues and maintain contact with CASA until resolution.

External users are encouraged to register with the NRAO Interactive Services portal There, registered users can access the CASA HelpDesk. Internal users can access this also (assuming they have a login), if for some reason you do not want to use one of the above methods (or you are asked to by your local rep).

CASA Version Numbers

A more self-consistent numbering method for version identification has been adopted for CASA 4.3 onwards.

All current and future CASA versions are identified by a number of the format X.Y.Z-TYPE (e.g. 4.3.1-REL) which is reported when CASA is launched. The X.Y.Z number is also reflected in the filename of the corresponding downloadable tarball.

  • X: This is the main CASA version number. An increase of X is rare, and denotes some major change to the package as a whole.

  • Y: An increase in this number normally denotes the issue of a semi-annual CASA public release version (unless X has just been incremented, in which case it will be reset to "0").

  • Z: This number denotes the specific sub-version of the package. For public release versions, a non-zero value denotes a patch release.

  • TYPE: This is either DEV or REL. It denotes whether the package is a development version (DEV) or a (pre)release version (REL). Development versions include test, stable and monthly packages.


In this example, we will consider the case for which CASA 4.27 would be the next public release version:

Development versions are initially numbered 4.27.Z-DEV (where Z = 0, 1, 2, ...). When no more new features remain to be added for the upcoming release version (4.27.0-REL), the 4.27.Z-DEV development versions stop. Production of the 4.27 prerelease versions is then started (initially based on the last 4.27.Z-DEV version). From this point on, the X.Y = 4.27 numbering is only retained for new (pre)release versions. These prerelease packages may still receive fixes for any problems found, but no additional new features will be added.

Since subsequent development work potentially contains new features intended for inclusion in the future 4.28.0-REL release version (but not the imminent 4.27.0-REL release version), all new development versions are identified as 4.28.Z-DEV (where Z = 0, 1, 2, ...).

When a release version is publicly issued, it is simply designated as CASA X.Y.0-REL (e.g. CASA 4.27.0-REL). Should there be a need to release patches to this public release version, then Z is incremented. In this example, therefore, the release version containing the first patch would be identified as CASA 4.27.1-REL, the second patch release version would be CASA 4.27.2-REL, etc.
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