Documentation on uvredo

Task: uvredo
Purpose: Recompute various derived quantitues in a uv data-set
Categories: uv analysis

        UVREDO recomputes various derived quantities in a uv data-set.
        This may be needed if the derived quantities are wrong for some
        reason, or if there is a need to change a coordinate system.
        For example uvredo can recompute velocity information, thus
        allowing conversion between different velocity rest frames.

        NOTE: The recomputation relies on a number of parameters in the
        data-set, such as "time". It is assumed that this information is
        correct. Uv variables that are important are:
        For velocity: time and latitu,longitu (or telescop is these are
        missing).

Key: vis
        The name of the input uv data set. No default.

Key: select
        The normal uv selection commands. The default is to select everything.

Key: line
        The normal uv linetype in the form:
          line,nchan,start,width,step
        The default is all channels. Note that if there are multiple
        spectral windows, the fitting process is performed on each window
        separately.

Key: stokes
        The polarization/Stokes parameters to be copied to the output
        data-set. The default is to copy the polarisation/Stokes parameters
        unchanged.

Key: out
        The name of the output uv data-set. There is no default name.

Key: options
        This gives extra processing options. Several options can be given,
        each separated by commas. They may be abbreviated to the minimum
        needed to avoid ambiguity. Possible options are:
           'velocity'    Recompute velocity information.
           'chi'         Recompute parallactic angle information.
           'jupaxis'     Set planet parameters for Jupiter.
        The following options can be used to turn off calibration corrections.
        The default is to apply any calibration present.
           'nocal'       Do not apply the gains table.
           'nopass'      Do not apply bandpass corrections.
           'nopol'       Do not apply polarizatiopn corrections.

Key: velocity
        If options=velocity, this gives the rest frame of the output
        data-set. Possible values are 'observatory', 'lsr' and 'barycentric'.
        The default is the rest frame of the input data-set.