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Basic Information on gpedit
Task: gpedit
Purpose: Edit the gain table.
Categories: calibration
Gpedit is a MIRIAD task which modifies calibration tables.
See also: GPLIST
Key: vis
The input visibility file, containing the gain file to modify.
No default.
Key: select
Normal uv data selection commands. See the help on select for
more information. Currently only antenna, time, and amplitude
selection is supported. The amplitude selection applies to the
gains, not the uv-data, and can be used to flag or replace bad
gain amplitudes. The default is to select everything.
Key: feeds
The polarisation feeds affected (e.g. R, L, X or Y). Default is
all feeds.
Key: gain
This gives the complex-valued gain used in the `multiply' and
`replace' options (see below). It is given as an amplitude
and phase (in degrees). For example gain=2,90 produces a gain
with a amplitude of 2 and phase of 90 degrees. The default is 1,0.
Key: options
This gives extra processing options. Several values can be given,
separated by commas. Option values can be abbreviated to uniqueness.
The following options operate on the gains:
replace The existing gains are replaced by the value
given by the `gain' keyword. NOTE: If no other
options are given, the replace option is performed.
multiply The existing gains are multiplied by the gain
given by the `gain' keyword.
flag The existing gains are flagged as bad.
amplitude The phases of the existing gains are set to 0.
phase The amplitudes of the existing gains are set to 1.
scale The phase of the gains is multiplied by the factor
given by the `gain' keyword.
dup Convert a single-polarization gain table into a dual
polarization table.
The following option operates on the polarization leakages:
reflect The existing leakages are made to possess a
symmetry: For each antenna, we make
DX = -conjg(DY).
zmean Subtract an offset, so that the mean leakage is 0.
Example:
gpedit vis=cyga gain=14.4,90 select=ant(1,2) feeds=X