Design
=======

The following diagram summarises the main steps performed by the CLI tool:

.. image:: _static/control-flow.png
   :alt: Control flow diagram
   :align: center
   :width: 400px

Input Products
--------------
The CLI tool takes the following mandatory positional arguments:

- **fits_image:** A FITS image file output by ``WSClean``.
- **oskar_lsm:** An ``OSKAR``-compatible `fixed-format ASCII LSM <https://ska-telescope.gitlab.io/sim/oskar/sky_model/sky_model.html#sky-model-file-fixed-format>`_ file that serves as the reference sky model for source matching.

Output Products
---------------
``ska-sdp-continuum-imaging-qa`` produces the following output files:

- ``*_matched_catalogue.csv`` The catalogue of sources matched between the input image and the reference sky model.
- ``*_flux_density_ratios.npy`` The flux density ratios of the matched sources.
- ``*_positional_offsets.npy`` The positional offsets of the matched sources.
- ``*_qametrics.txt`` A text file containing the computed QA metrics.
- ``*_qa_summary.png`` A summary plot of the QA metrics.