ska_sdp_instrumental_calibration.data_managers.sky_model.local_sky_component module

class ska_sdp_instrumental_calibration.data_managers.sky_model.local_sky_component.LocalSkyComponent(direction=None, frequency=None, name=None, flux=None, shape='Point', polarisation_frame=<ska_sdp_datamodels.science_data_model.polarisation_model.PolarisationFrame object>, params=None)[source]

Bases: SkyComponent

static create_from_component(comp, freq, *_)[source]

Construct a LocalSkyComponent from a Component.

All sources are unpolarised and specified in the linear polarisation frame using XX = YY = Stokes I.

After deconvolving the gaussian for a given component, components with non-zero widths after this process are stored with shape = "GAUSSIAN". Otherwise shape = "POINT".

Parameters:

  • comp (Component) -- An instance of Component

  • freq (ndarray) -- An array of frequency values in Hz

Returns:

An instance of LocalSkyComponent

Return type:

LocalSkyComponent

create_vis(uvw, phasecentre, antenna1, antenna2, beams=None, faraday_rot_matrix=None)[source]

Create visibility for a given LocalSkyComponent.

Parameters:

  • uvw (np.ndarray) -- UVW coordinates of shape (time, frequency, baselineid, spatial).

  • phasecentre (SkyCoord) -- Phase centre of the observation.

  • antenna1 (np.ndarray) -- The indices of 1st antenna in each pair of baseline. Must be of shape (baselineid,).

  • antenna2 (np.ndarray) -- The indices of 2nd antenna in each pair of baseline. Must be of shape (baselineid,).

  • beams (BeamsLow, optional) -- Beams object containing the primary beam.

  • faraday_rot_matrix (np.ndarray, optional) -- 4D faraday rotation matrix of shape (antenna, frequency, 2, 2).

Returns:

Visibility for the given LocalSkyComponent. This has shape (time, frequency, baselineid, polarisation).

Return type:

np.ndarray