In order to tell for sure which version of CASA was used for calibration and imaging, check the data reduction script. The data were calibrated and imaged in, for example, CASA 3.4 if the script contains the line:
if re.search('^3.4', casadef.casa_version) == None:
If this line is not in the script, the data were calibrated and imaged in CASA 3.3.
When users download publicly available Cycle 0 data products from the ALMA archive, they will come with the Python script that was used to reduce the data in CASA. However, the scripts were tailored to the version of CASA available at the time of the original data reduction. Users will need to know which version in order to know whether they can run the scripts as provided, or need to modify them.
Cycle 0 data products were produced in one of the following combinations:
- The earliest data reductions were imported, calibrated, and imaged with CASA 3.3.
- As of May 30, 2012, data had to be imported using CASA 3.4, but were calibrated and imaged using CASA 3.3.
- Data from the later parts of Cycle 0 (about Sept. 1, 2012 but there were a few earlier) were imported, calibrated, and imaged in CASA 3.4.
In most cases, the scripts should be used as a guide for redoing the data reduction. Users are urged to consult the ALMA CASAguides for the proper steps and syntax for ALMA data reduction; the CASAguides are always updated to the latest released version of CASA. The different versions of CASA are available here. The downloads section will contain links to the most recently released version of CASA. Older versions are available from "Older releases"
For some reasons why you should care which version of CASA was used, please see the following associated helpdesk articles:
Will re-reduction improve the Cycle 0 data products provided by the archive?