The biggest difference between selfcal
is in the
handling of polarisation
and dual feeds.
can handle multiple pointings and frequency ranges,
it assumes that the antenna gain is independent of feed (i.e. the X
and Y gains are the same). It also only handles Stokes-I models
(and ignores visibilities that are unrelated to determining Stokes-I).
is intended for telescopes with dual feeds (either linear
or circular), such as the ATCA. Indeed, it will fail for other sorts of data.
solves for the two feeds either totally independently, or
with the constraint that the XY (or RL) phase of an antenna must
be constant with time.
converts between Stokes parameters and raw polarisations.
It can take multiple input models for different Stokes parameters. However,
if a model of a particular Stokes parameter is not given, it is assumed to
be zero. For example, if you give it models of I, Q and U, but not V, then
the source is assumed to have no circular polarisation.
uses the antenna polarisation leakage table
if this information is present. If it is not present, leakages are assumed
to be zero.
- Unlike selfcal, gpscal
cannot take models from
multiple pointings or from different frequency ranges. All
models must correspond to the same pointing and same frequency range.