rtavis

This repository hosts a custom visibility tool rtavis for real-time analysis.

Environment and package installation

To create a virtual environment with all required dependencies:

conda env create --name <envname> --file=environment.yaml

Note that you should already have anaconda installed: https://www.anaconda.com/

You can then proceed to install the software:

pip install .

for editable installation:

pip install -e .

Instrument Response Functions

To complete the environment be sure to download and install the correct IRFs (only prod2 comes with ctools installation). Public IRFs can be downloaded from here: https://www.cta-observatory.org/science/cta-performance/

Configuration

Under cfg you can find a sample configuration file. Description of each parameter is commented within. This file will serve as input when running the code.

Compute source visibility

After adjusting the configuration file to your needs, you can run the code as follows:

python runCatVisibility.py -f cfg/config.yaml

Reading the visibility table

The output is saved via numpy as a binary NPY file. You can run an example of how to access data like this:

python readVisTable -f path/to/output.npy

Notebook: plot the visibility

A notebook for useful plot and checks on the visibility is provided in the notebooks folder.

Check source and Moon visibility in a time window (ASTRI)

A dedicated script is available to check source visibility at ASTRI over a custom UTC time window, including Moon information:

• Moon presence (altitude)
• Moon-source angular distance (if a source is provided)
• Moon illumination
• Moon phase

Script:

python rtavis/checkVisibilityWindow_ASTRI.py --help

Main options

• --start and --end: UTC time window
• --date: convenience single-night mode (YYYY-MM-DD)
• --moon-only: evaluate Moon only, without a source
• --source or --source-name: resolve source name
• --ra and --dec: provide source coordinates directly
• --plot: save output plot

Example commands

Moon only, single night:

python rtavis/checkVisibilityWindow_ASTRI.py --moon-only --date "2025-12-11" --plot moon_night.png

Moon only, custom window:

python rtavis/checkVisibilityWindow_ASTRI.py --moon-only --start "2026-04-28" --end "2026-05-10" --plot moon_window.png --phase-label-step-deg 45

With source name:

python rtavis/checkVisibilityWindow_ASTRI.py --start "2026-04-28" --end "2026-05-10" --plot source_window.png --source "Mrk 501"

With source coordinates:

python rtavis/checkVisibilityWindow_ASTRI.py --start "2026-04-28" --end "2026-05-10" --plot source_window.png --ra "16:56:28" --dec "+39:45:36"