Installing CASA under Ubuntu

To install CASA (Common Astronomy Software Applications) on Ubuntu, follow these steps. CASA is commonly used in radio astronomy, especially for data from instruments like ALMA and the VLA.

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✅ Step 1: Choose the Correct CASA Version

CASA has two main variants:

1. CASA (classic) – Monolithic software package.
2. CASA6 – Modular and Python-based, installed via pip or conda.

If you’re starting fresh, CASA6 is recommended due to its flexibility and support.

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📦 Option 1: Installing CASA6 (Recommended for most users)

🔧 Prerequisites

Make sure Python 3.8+ and pip are installed:

sudo apt update

sudo apt install python3 python3-pip

🐍 Install CASA6 via pip

You can install CASA6 into a virtual environment to avoid conflicts:

python3 -m venv casa_env

source casa_env/bin/activate

pip install casatools casatasks

You now have CASA6 installed with casatools and casatasks.

▶️ Running CASA6

To use CASA:

python3

Then:

from casatools import image

from casatasks import importfits

# and so on...

To leave the environment:

deactivate

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🧱 Option 2: Installing Classic CASA (Monolithic .tar.xz Package)

If you specifically need the classic version (e.g., CASA 5.6 or 6.1 bundled):

🔽 Download CASA Classic

1. Go to: https://casadocs.readthedocs.io/en/stable/getting_started/download.html
2. Choose Linux 64-bit and download the appropriate .tar.xz file.

📦 Extract and Install

tar -xvf casa-*.tar.xz

cd casa-*

No installation is needed; it’s self-contained. You can run CASA from this folder:

./casa

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🧪 Verifying CASA

Run:

which casa

Or within Python:

import casatools

print(casatools.version())

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📝 Tips

• CASA6 works better with modern workflows and Jupyter notebooks.
• If you’re using it for Radio JOVE or custom antennas (e.g., dipoles), CASA6 is usually sufficient.

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