SKA SDP Pointing Offset Calibration Pipeline
============================================

This is a `repository`_ for the SDP pointing offset calibration pipeline. This
repository reads Measurement Sets, optionally applies a static RFI mask (pulled
from `ska-telmodel-data`_ in real time) and/or select some frequency range of
interest, and then fits the 2-D Gaussian primary beams to the visibility or
gain amplitudes.

The fitted parameters are the Gaussian centre (which provides the
Cross-elevation and Elevation offsets), width (the fitted beamwidth), and
height (in arbitrary units) and their uncertainties. These fitted parameters
are then written to an HDF5 file created from a
:external+ska-sdp-datamodels:class:`~ska_sdp_datamodels.calibration.PointingTable`
and a text file generated by :func:`~.export_data.export_pointing_offset_data`
for further analysis (see :ref:`data_products`).

The pipeline reads Measurement Sets using the
:external+ska-sdp-datamodels:class:`~ska_sdp_datamodels.visibility.Visibility`
class from `ska-sdp-datamodels`_. When an RFI mask is applied and/or some
frequency range is selected, the modified visibility is created with the
:external+ska-sdp-datamodels:class:`~ska_sdp_datamodels.visibility.Visibility`
class for gain calibration (un-normalised G terms) or provides easy access to
the visibilities and their associated parameters when fitting to them. These
gains of each dish are solved for using the gain solver in the
`ska-sdp-func-python`_ library. The primary beam modelling and fitting is
performed with `scikits.fitting`_ following the procedure used by the `SARAO`_
team for computing the pointing offsets for the MeerKAT array.

The implementation of the pointing offset calibration pipeline is described in
detail in the :ref:`observing_modes` section.

The current pipeline can be executed as a CLI-based command line app (see
:ref:`Pointing Offset CLI Module <cli>`), or deployed in SDP using the 
:external+ska-sdp-script:doc:`scripts/pointing-offset`. 


.. toctree::
   :maxdepth: 1
   :caption: Installation

   installation/install
   installation/docker

.. toctree::
   :maxdepth: 1
   :caption: Releases

   changelog

.. toctree::
   :maxdepth: 2
   :caption: Design

   algorithms
   observations/observing_modes
   vis_chunking
   rfi_mask
   corrupted_pointing
   averaging
   pointing_offsets/fitting_qa
   pointing_offsets/avg_pol
   pointing_offsets/sep_pol

.. toctree::
   :maxdepth: 1
   :caption: Operation

   operation/sdp
   operation/standalone

.. toctree::
   :maxdepth: 1
   :caption: Data products and outputs

   data_product

.. toctree::
   :maxdepth: 1
   :caption: API

   api/index

.. toctree::
   :maxdepth: 1
   :caption: Contents:


Indices and tables
------------------

* :ref:`genindex`
* :ref:`modindex`
* :ref:`search`


.. _repository: https://gitlab.com/ska-telescope/sdp/science-pipeline-workflows/ska-sdp-wflow-pointing-offset
.. _ska-telmodel-data: https://gitlab.com/ska-telescope/ska-telmodel-data
.. _ska-sdp-datamodels: https://gitlab.com/ska-telescope/sdp/ska-sdp-datamodels
.. _ska-sdp-func-python: https://gitlab.com/ska-telescope/sdp/ska-sdp-func-python
.. _scikits.fitting: https://github.com/ska-sa/scikits.fitting
.. _SARAO: https://www.sarao.ac.za