Participants are advised to install this software well in advance and familiarise themselves with the environment. Note that this section will be frequently updated, so check back here regularly.
To help with the installation of the software there will be three helper sessions:
- Tuesday 30 May at 17:00UT: zoom link / recording
- Wednesday 31 May at 07:00UT: zoom link / recording
- Thursday 1 June at 12:00UT: zoom link (the information is identical to the previous two, pick any of those recordings)
Before you arrive here, please make sure you have installed the following:
- CASA 6.5.5-21 (required)
- CASA helper scripts (required)
- download the data files for N14C3
- git (recommended for helper scripts and notebook installation)
If you have the time, you can also try to install:
For the meeting itself we will use:
- Mattermost: you will receive an invite link, it can run in your browser
NOTE: after joining the server you need to join the public channels. Click on the little + sign next to the server name, and select 'Browse channels'. We recommend you to join all public channels. - Zoom: zoom information will be shared via the Mattermost channel Zoom links.
CASA
For the tutorials, participants need to install the CASA version 6.5.5-21, this is currently the latest release. You can find instructions for this on the NRAO website. For help in finding your way in CASA, have a look at the documentation page: CASA Docs and CASA Guides are both good starting points.
Helper scripts
For the initial steps in the processing some helper scripts are required. These can be downloaded from GitHub. With git installed on your system you can obtain the scripts using:
git clone https://github.com/jive-vlbi/casa-vlbi
Alternatively you can download the scripts as a zipfile:
https://github.com/jive-vlbi/casa-vlbi/archive/refs/heads/master.zip
and unzip it.
After installation, make sure your Python installation can find these scripts by setting the path:
export PYTHONPATH="<path to script directory>":$PYTHONPATH
EVN dataset N14C3
Many of the tutorials will use this data, so it is helpful to ensure you have this ready to go before arrival:
- n14c3_1_1.IDI1 (1.9 GB), n14c3_1_1.IDI2 (0.9 GB)
- Calibration metadata: ANTAB and UVFLG files
JupyterCASA notebooks
Some hands-on tutorials will use a JupyterCASA notebook to demonstrate data calibration. For MacOS machines the Vagrant installation is recommended. After following the link, scroll down until you see 'Installation' and a few lines further down it says 'Vagrant', that is where the instructions start.
After launching jupyter lab inside the vagrant environment you need to copy and paste the html link from your terminal to a browser window. There will be three options, from experience the last one (starting with http://127.0.0) works best.
For MacOS you will also need Docker Desktop. Make sure to disable the 'Experimental features' in the Settings --> Features in development --> Experimental features.
Troubleshooting
The installation of the JupyterCASA notebooks can be a challenge. Typical issues seen:
- Running the docker pull penngwyn/jupytercasa command: this is NOT needed if you use the Vagrant installation. Your first command should be git clone https://github.com/aardk/jupyter-casa.git
- Docker Desktop giving a Fatal Error Docker.Setting.Error error 0 message upon launch: restart your Mac. If that doesn't work, try removing the files listed in the third post here and restart again.
- A linux permission error masking as a message that the VM box is not found: this can be fixed by adding your username to the docker group in the file /etc/group.
- sudo vim /etc/group
- Type G to go to the end of the file
- Where you see 'docker:<something>:' add your name after the colon
- Save the file, log out and back in
- If browser link asks you for a token, try using a different port. The standard one is 8888, change this to another number.
- Docker is consuming all the CPU and causing a meltdown of MacOS: disable the Experimental features in Settings --> Features in development --> Experimental features
Reference papers
Please cite the CASA Reference Paper for any publications using the CASA package:
The CASA Team, et al., “CASA, the Common Astronomy Software Applications for Radio Astronomy”, PASP, 134, 114501
DOI: 10.1088/1538-3873/ac9642
CASA VLBI paper:
van Bemmel, I., Kettenis, M., Small, D., et al. 2022, “CASA on the fringe – Development of VLBI processing capabilities for CASA”, PASP, 134, 114502
DOI: 10.1088/1538-3873/ac81ed
Please cite the CARTA paper for publications using this package:
DOI: 10.5281/zenodo.3377984
VLBI20-30 roadmap publication on arxiv
