.. _bst_reading_doc:

Beamlet STatistics (BST)
========================

`NenuFAR <https://nenufar.obs-nancay.fr/en/astronomer>`_ delivers BST statistical data from the *LaNewBA* receiver.
Beamlet STatistics (BST) are the beamlet outputs per polarization averaged at 1 s resolution

BST reading interface
---------------------

`nenupy` offers a graphical interface to ease quick reading of a BST file.
Once the package is installed, the user should be able to call the script ``nenupy_bst_vis`` from anywhere:

.. code-block::

    nenupy_bst_vis

.. figure:: ../_images/script_images/bst_vis_0.png
    :width: 450
    :align: center

    BST reading interface, one can either enter the path toward the BST file to open or select a file in your working environment.

.. figure:: ../_images/script_images/bst_vis_1.png
    :width: 450
    :align: center

    Once the BST file is selected, the first digital beam recording is shown in NW polarization.


.. figure:: ../_images/script_images/bst_vis_2.png
    :width: 450
    :align: center

    It is possible to set the digital beam value (here #2) and the polarization channel. The content of the dynamic spectrum is automatically updated.


.. figure:: ../_images/script_images/bst_vis_3.png
    :width: 450
    :align: center

    A right click displays both time and frequency profiles at the corresponding position in the dynamic spectrum.

.. figure:: ../_images/script_images/bst_vis_4.png
    :width: 450
    :align: center

    Left click, then drag and drop motion allows to zoom in a particular time and frequency region.
    The button 'Reset' enables to go back to the full original dynamic spectrum.

BST reading
-----------

:class:`~nenupy.io.bst.BST`

.. code-block:: python

    from nenupy.io.bst import BST

    bst = BST("/path/to/BST.fits")


BST data selection
------------------

.. code-block:: python

    data = bst.get(
        frequency_selection="<=52MHz",
        time_selection=">=2022-01-24T11:08:10 & <2022-01-24T11:14:08",
        polarization="NW",
        beam=8
    )

``data`` is a :class:`~nenupy.io.io_tools.ST_Slice` object.
See ... for this class usage.