Using CASA on the RTDC
CASA Introduction
CASA (Common Astronomy Software Applications package) is a software package developed to calibrate and image data from ALMA and other arrays. It can be used to both calibrate and image SMA data.
Converting SMA data to CASA Format
If you wish you do any reduction using CASA you will need to convert SMA data into a CASA compatible format. You can find a description of the options at Converting SMA Data Format.
CASA on RTDC Computers
The link below lists where to find the different versions of CASA on the RTDC and CF computers. The latest release will be aliased to the casa
command unless you overwrite that in your own setup files.
Accessing CASA on RTDC computers
Be sure you do not run CASA on NFS mounted disks as this will slow it down considerably. CASA is partly multi-threaded so many of the tasks can be run in parallel.
The Status of Processing SMA Data with CASA
The release of pyuvdata now allows users to easily convert raw SMA data into casa measurement sets. This conversion is not without its cavceats however:
• CASA struggles to derive solutions for solor system based flux calibrators. This can make flux calibration using planets, the common method with the SMA, somewhat challenging. Users may wish to use a stable gain calibrator for flux calibration.
• CASA is currently unable to handle SMA polarization data.
• CASA doesn not record system temperatures in the same way. If system temperatures are applied by pyuvdata
, these permanently change the visibilites, rather than being written to reverable gains tables.
Parallelization Tests
With CASA becoming the software of choice for imaging SMA data, there is a demand to speed up the process. As such we are conducting a series of tests to assess the parallelization of CASA using their inbuilt mpicasa framework.
Checking the output of parallelized tclean with CASA 5.3.0
Checking the output of parallelized tclean with CASA 5.1.2
Testing the best way to run CASA on RTDC
Instructions for running CASA in parallel