Combine ALMA and ACA OST output images
If you have selected a combined array configuration e.g ALMA+ACA or independently created ALMA and ACA images for the
same object, we provide the following Python/CASA script for combining these images.
To download the script right click on the following link and select the 'Save Link As...' option: ost_combine.py
How it works
- First, the script asks for two image file names, one ALMA and one ACA, which can be of either CASA .image file or .FITS. (i.e. the
two image file formats output by the OST). These should be located in the same
directory as the script.
- The script then confirms the file type of each image and will convert any .FITS into .image
for the image combination.
- Once both the ALMA and ACA image are in .image format the script initialises the CASA single
dish software packages (as this contains the CASA task to combine data in the image plane).
- After this it regrids the ACA data to match that of the ALMA image.
- Finally, using the task CASA Feathering the images are
combined in the image plane. This will create a file with name *ALMAplusACA.feather (or if both your inputs were .FITS
a *ALMAplusACA.fits aswell), this is the combined image.
How to run the script
This script needs to be run within CASA. To execute the script:
- Type execfile('ost_combine.py') and hit return.
- Fill in the requested file names and hit return.
More on Feathering
For more information on feathering please refer to this CASA guides page
or Section 5.5 of
the CASA Cookbook.
We welcome any feedback/bug reports that may occur. Please email Adam