Self Calibration
From CASA Guides
Overview
If a target is sufficiently bright, it will be possible (and likely advantageous) to perform calibration on that source after, or perhaps in lieu of, applying calibration from a separate source. While simple in principle, there are subtleties to this approach as well -- for example, if you start with self-calibration and do not have any external phase calibration, absolute position information will be lost, and the source will be placed at the phase center. This and other effects are discussed below.
