orca.utils.beam
===============

.. py:module:: orca.utils.beam

.. autoapi-nested-parse::

   Primary beam models for OVRO-LWA observations.

   Provides abstract base class and implementations for computing beam
   response as a function of position. Includes analytic approximations
   and simulation-derived beam models (Woody beam).



Attributes
----------

.. autoapisummary::

   orca.utils.beam.BEAM_FILE_PATH


Classes
-------

.. autoapisummary::

   orca.utils.beam.BaseBeam
   orca.utils.beam.AnalyticBeam
   orca.utils.beam.WoodyBeam
   orca.utils.beam.jones


Module Contents
---------------

.. py:data:: BEAM_FILE_PATH
   :value: b'.'


.. py:class:: BaseBeam(msfile: str)

   Bases: :py:obj:`abc.ABC`


   Abstract base class for beam models.

   Defines the interface for computing beam response at arbitrary
   sky positions.


   .. py:method:: srcIQUV(az: float, el: float) -> Tuple[float, float, float, float]
      :abstractmethod:


      Get beam response in Stokes I, Q, U, V at given position.

      :param az: Azimuth in degrees.
      :param el: Elevation in degrees.

      :returns: Tuple of (I, Q, U, V) beam response values.



.. py:class:: AnalyticBeam(msfile: str)

   Bases: :py:obj:`BaseBeam`


   Simple analytic beam model using sin(el)^1.6 approximation.


   .. py:method:: srcIQUV(az: float, el: float) -> Tuple[float, float, float, float]

      Compute analytic beam response.

      :param az: Azimuth in degrees (unused).
      :param el: Elevation in degrees.

      :returns: Tuple of (I, 0, 0, 0) with I = sin(el)^1.6.



.. py:class:: WoodyBeam(msfile: str)

   Bases: :py:obj:`BaseBeam`


   Simulation-derived LWA dipole beam model.

   Uses pre-computed beam grids from DW beam simulations interpolated
   to the observation frequency. Supports full Stokes (I, Q, U, V).


   .. py:attribute:: CRFREQ


   .. py:attribute:: path


   .. py:attribute:: azelgrid


   .. py:attribute:: gridsize


   .. py:attribute:: beamIQUVfile


   .. py:attribute:: beamIQUV


   .. py:attribute:: Ibeam


   .. py:attribute:: Qbeam


   .. py:attribute:: Ubeam


   .. py:attribute:: Vbeam


   .. py:method:: srcIQUV(az, el)

      Compute beam scaling factor
      :param az: azimuth in degrees
      :param el: elevation in degrees

      Returns: [I,Q,U,V] flux factors, where for an unpolarized source [I,Q,U,V] = [1,0,0,0]




   .. py:method:: plotbeam()

      Show the IQUV beams at MS center frequency, and azimuth,elevation grids.



.. py:class:: jones(msfile)

   For loading and returning LWA dipole beam values (derived from DW beam simulations) on the ASTM.
   Last edit: 11 September 2020


   .. py:attribute:: CRFREQ


   .. py:attribute:: path


   .. py:attribute:: beamjonesfile


   .. py:method:: srcjones(l, m)

      Compute beam scaling factor
      :param (l:
      :param m) coordinates:

      Returns: Jones matrix at coordinates (l,m)