ERIS2024 Tutorials

Welcome to the European Radio Interferometry School (ERIS) 2024 where we hope that you learn how to go from telescope to science-ready images when using an interferometer. This website hosts the tutorials that you will do to get hands-on practice with data. This homepage will guide you in installing CASA, testing your installation and downloading the tutorial data.

If you have completed this already, head down to the bottom of the page where you can find the links to start the tutorial. Or go back to the main ERIS2024 school webpage.

Installing CASA

Note: due to issues with the Linux and Mac OS, we will be using different versions of CASA (v6.5.4 on Linux and 6.6.5 on Mac OS). They are functionally the same, but please follow the instructions below carefully.

Linux

  • Please use the following link to download the CASA version for your Linux distribution
  • Once downloaded, extract the package into an appropriate folder. E.g., you can use the tar command in the command line / terminal to do this: 
    tar xvf casa-6.5.4-9-pipeline-2023.1.0.125-py3.8.tar.xz
  • This will make a folder named casa-6.5.4-9-pipeline-2023.1.0.125 in the directory you extracted in.
  • You can run CASA by running casa-6.5.4-9-pipeline-2023.1.0.125/bin/casa in your command line.
  • An easier way is to set a bash alias so that you can run CASA by just typing casa into the command line (from anywhere!). This can be done using the following code (where you want to replace (path_to_CASA_folder) with the CASA folder path (you can find your current path with the command pwd). Note that this command will modify your .bashrc file in your home directory by adding a line at the end of the file: 
    echo 'alias casa=(path_to_CASA_folder)/casa-6.5.4-9-pipeline-2023.1.0.125/bin/casa' >> ~/.bashrc
    For example, if I untarred CASA in my home folder, this command would be 
    echo 'alias casa=/home/radcliff/casa-6.5.4-9-pipeline-2023.1.0.125/bin/casa' >> ~/.bashrc
  • Test that this alias works by opening a new terminal and type casa into it. This should open up CASA and the logger window.

Mac OS

  • Please use the following link to download the correct CASA version for your Mac OS version. Note that the ARM corresponds to the Apple Silicon systems (i.e. designated as the M1, M2 and M3 processors). If you have an Intel system install the ARM Mac OS 12 / Intel CASA.
  • Open the Terminal and type in the following command. This will create a directory named data inside the hidden casa configuration directory in your home folder 
    mkdir ~/.casa; mkdir ~/.casa/data
  • You should have already downloaded a disk image file (.dmg) file that should be similarly named as casa-6.6.5.31-XX.0-py310.dmg where the XX corresponds to your Mac OS version.
  • Open the Finder and double click on the file to get it to mount. This opens another Finder window where there will be CASA and a README.md file.
  • Open another Finder window and open the Applications folder. Copy CASA (or drag and drop) into the Applications folder
  • Within the applications folder, right click and open CASA so that we can override the Apple security safeguard. If this doesn't allow you to open first time, try again. This should finish with a Terminal window opening and the CASA prompt present.
  • Within the CASA prompt type: !create-symlinks and follow the prompts.
  • Leave the CASA window open, and go to System Settings → Privacy & Security → Full Disk Access and make CASA, and the Terminal apps have full disk access.
  • Once complete, close CASA and the Terminal app completely (i.e. right-click on the Mac dock to quit). Open a new Terminal tab/window and type in casa. This should open up CASA and the logger window.
  • The CASA viewer has been discontinued on Mac OS, therefore we need to install the new casagui so that you can do interactive cleaning. Enter the following command in the CASA prompt to install it: 
    !pip3 install casagui==0.3.70

If these steps have run with no errors, please follow the instructions below to test your CASA installation.

Installing CARTA

We also need to install the CARTA tool which will be used to visualise images. Follow the instructions on the following webpage to install it https://cartavis.org/#download. You will want to install the stand-alone application.

Downloading the data

Before continuing, you should download all the following tar bundles using the links below. Ensure that your drive has at least 10GB of space free. If you have already tested your CASA installation, you may already have the ERIS24_calibration_tutorial.tar.gz file.

Alternatively, you can use enter the following in the command line to download these data,

wget https://eris2024.iaa.csic.es/data/ERIS24_calibration_tutorial.tar.gz
wget https://eris2024.iaa.csic.es/data/ERIS24_imaging_tutorial.tar.gz
wget https://eris2024.iaa.csic.es/data/ERIS24_adv_imaging_tutorial.tar.gz

Testing your CASA installation

With CASA installed, you want to follow the next set of instructions on the following webpage to check that your installation is working correctly

Installation instructions for the Advanced Tutorials

Follow this page to download the data needed for the Advanced Tutorials and install the required software:

Starting the tutorials

Below you can find the various links to the tutorials we are going to do during ERIS2024. Please ensure you have completed the tests of your CASA installation before starting here. Your tutors will instruct you on which tutorial you should be completing. Note that not all tutorials are hosted here but you will get instructions on how to proceed from your tutors.

If you wish to do the tutorial in its entireity, follow the link below:

The advanced tutorial on polarisation is also hosted here. Please follow the link below to download the data and complete the tutorial.