Polarisation handling
Polarisation handling is intended to implement the Hamaker-Bregman-Sault formalism.
For imaging:
Types of polarisation allowed are stokesIQUV, stokesI, linear, circular.
These are defined in
rascil.data_models.polarisation.PolarisationFrameImages may be defined as stokesI, stokesIQUV, linear, or circular
To convert from Stokes image to polarised image see
rascil.processing_components.image.operations.convert_stokes_to_polimage()To convert from polarised image to Stokes image
rascil.processing_components.image.operations.convert_polimage_to_stokes()SkyComponents may be defined as stokesI, stokesIQUV, linear, or circular
Visibility may be defined as stokesI, stokesIQUV, linear, or circular.
Dish/station voltage patterns are described by images in which each pixel is a 2 x 2 complex matrix.
For calibration, the Jones matrices allowed are:
T = scalar phase-only term i.e. complex unit-amplitude phasor times the identity [2,2] matrix
G = vector complex gain i.e. diagonal [2, 2] matrix with different phasors
B = Same as G but frequency dependent