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Basic Information 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 polarisation feed angle information.
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.
Generated by miriad@atnf.csiro.au on 21 Jun 2016