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Basic Information on tmcvt
Task: tmcvt
Purpose: Convert time-multiplexed polarization visibilities to Stokes.
Categories: uv analysis
TMCVT converts time-multiplexed polarization observations to
Stokes parameters, applying any leakage correction in the process.
For an observation where polarizations are time multiplexed
(i.e. four polarization states are not simultaneously measured),
there is no simple way to convert between raw polarization
visibilities and Stokes parameters. This task operates by finding
the four polarizations measurements at a given instant which result in
the minimum time mismatch. It then uses this set in the conversion process.
Key: vis
The names of the input uv data sets. Wildcards are supported.
No default.
Key: line
Standard line parameter, with standard defaults. See the help on
line for more information.
Key: select
Standard visibility data selection. See the help on select for
more information. The default is to select all data.
Key: out
The name of the output uv data set. No default.
Key: stokes
Several Stokes parameters of the output. Possible values are
i, q, u and v. There is no default - this parameter must be
specified.
Key: interval
Time interval tolerance, in minutes. This sets the maximum mismatch
between polarization correlations that can be tolerated. The default
is 10 minutes,
Key: options
Extra processing options. Several options can be given,
separated by commas. Minimum match is supported.
nopol Do not apply polarization leakage correction.
nocal Do not apply antenna gain correction.
nopass Do not apply bandpass calibration correction.
pseudo By default, tmcvt generates a visibility stream where
the error from time mismatches is minimized for each output
Stokes visibility. This usually results with different
Stokes visibilities for a given baseline having different
time tags. The "pseudo" option causes tmcvt to generate an output
dataset where all the Stokes visibilities for a given baseline
are pseudo-simultaneous (same time tag). This results in larger
errors, but may be more convenient if you must form an output
image where the beams are the same for the different Stokes
parameters, or where you are going to written out to a FITS
file.
Generated by miriad@atnf.csiro.au on 02 Jun 2021