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.