AIPS HELP file for CHANNEL in 31DEC26

As of Tue Feb 10 1:47:25 2026

HELP SECTION

CHANNEL
Type:  Adverb  (scalar)
Use:   To set a single, usually spectral, "channel" number, where the
       definition of channel will depend on the particular verb or task.
Null value:
       0   => continuum, all, or 1 depending.
Procedures:
   LINIMAGE......Build image cube from multi-IF data set.  CHANNEL is
                 passed to IMAGR.
Tasks:
   AVSPC.........Averages uv spectral channels; CHANNEL is number to
                 average together
   FGCNT.........Counts samples comparing two flag tables or detailed
                 count from <= 1
   FRMAP.........Build an image using fringe-rate spectra; CHANNEL is
                 the reference channel.
   IMAGR.........Images and Cleans uv data; CHANNEL is the restart
                 spectral channel.
   IMERG.........Merges images of different spatial resolutions.
                 CHANNEL selects the plane number.
   OOSUB.........Subtracts/divides a model from/into a uv data base
                 CHANNEL selects a single channel to be changed.
   PRTSD.........Prints single-dish data.  CHANNEL selects the first
                 spectral channel to be printed.
   PRTUV.........Prints uv data.  CHANNEL selects the first spectral
                 channel to be printed.
   SDLSF.........Least squares fit to channels and subtracts from SD uv
                 data.  CHANNEL selects the frequency of the fit to be
                 output in a uv data set.
   SPLAT.........Applies calibration and splits or assemble selected
                 sources.  CHANNEL sets number spectral channels
                 averaged in one of the averaging options.
   UVADC.........Fourier transforms a Clean point model and corrects for
                 geometric distortions and adds to a uv data set.
                 CHANNEL selects the spectral channel to be altered.
   UVDIF.........Prints differences between two uv data sets.  CHANNEL
                 sets the first spectral channel printed.
   UVFND.........Prints data found by various criteria.  CHANNEL sets
                 the first spectral channel to be examined and printed.
   UVLSD.........Fits continuum to uv spectral data and divides by it;
                 CHANNEL selects a channel at which the fit is output.
   UVLSF.........Fits continuum to uv spectral data and subtracts it;
                 CHANNEL selects a channel at which the fit is output.
   UVMAP.........Fourier transforms uv data to make an image and beam.
                 CHANNEL selects the spectral channel to be imaged.
   UVPRM.........Measures uv range, total flux, observing time,
                 reference antenna from a uv database.  CHANNEL selects
                 the spectral channel at which the parameters are found.
   UVPRT.........Prints uv data, optionally with calibration.  CHANNEL
                 sets the first spectral channel printed.
   UVSUB.........Subtracts/divides a model from/into a uv data base.
                 CHANNEL selects a single channel to be changed.

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