Astronomical Signal Components

Components that put a sky into the model state, as opposed to the astronomical visibility components, which turn a sky into visibilities.

FixedDiscreteSky reads a catalogue of discrete sources — points and elliptical Gaussians, with known positions, fluxes and shapes — and writes it into the state as constants. It carries no free parameters, which is the point: a per-antenna gain is only identifiable against a sky the gain cannot deform. It pairs with DiscreteSkyVis, which must be listed after it. See ast.point_sources for the catalogue formats and the component ordering.