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TABLE

      CLIC\TABLE Name [OLD|NEW] [/COMPRESS tmax uvmax]
      [/RESAMPLE nc ref val inc code shape width]  [/FFT]
      [/FREQUENCY name rest-freq] [/DROP  n1 n2]
      [/NOCHECK [SOURCE|POINTING|PHASE|EPOCH]]

  This command will create an UV data Table from the current index.  is  not
  given,  the  most  recently created table will be extended.  Next argument
  may be OLD (default value if not specified) to extend and existing  table,
  or NEW to create a new table.

  The bands and subbands used must have been given by the command SET SELEC-
  TION. The weighting mode can be modified by the command SET WEIGHTS.

  TABLE /RESAMPLE nc ref val inc code [shape width /FFT]

      Option /RESAMPLE enables to resample data on a new spectral grid  (for
      line  data).   'nc' is the output number of channels, 'ref' the refer-
      ence channel, 'val' the value of velocity or  frequency  offset  (with
      respect  to  the  rest  frequency) at the reference channel, 'inc' the
      resolution, 'code' is "V" if the value 'val' and the resolution  'inc'
      are in velocity units, "F" for frequency units.

      The reference channel thus corresponds to the given 'val' velocity, or
      to the offset 'val' in MHz from the  rest  frequency  present  in  the
      header or modified by option /FREQUENCY.

      Resampling  is  done  by default through linear interpolation of input
      channel data. Resampling may also  be  done  (using  option  /FFT)  in
      Fourier  space  by cut-off or extrapolation (by zeroes) of the Fourier
      components, after deconvolution by the channel response of the  corre-
      lator  (due  to on-line apodization), and followed by reconvolution to
      produce frequency channels of the given 'shape' and  'width'.  Allowed
      shapes are:
        TBox = a box in delay space (unapodized correlator)
        Ppar = a parabola in delay space (apodized correlator) (the default)
        FBox = a box in frequency space (square filter)
        FTri = a triangle in frequency space (Hanning smoothed  square  fil-
          ter)
      The width is the channel width in units of channel separation (default
      1).

      Option /FFT is not recommended when joining together several  subbands
      to produce a single spectrum, with a limited number of broad channels.
      In those cases using the FFT could produce a spectrum with "holes"  at
      the points between subbands with limited overlap.

  TABLE /FREQUENCY  name rest-freq

      Option  /FREQUENCY is used to redefine the rest frequency (in MHz) and
      line name for the output table.  The velocity scale  is  computed  ac-
      cordingly.  This rest frequency will correspond to the reference chan-
      nel in option RESAMPLE.

  TABLE /NOCHECK [SOURCE|POINTING|PHASE|EPOCH]

      When processing each scan, CLIC checks whether a  number  of  position
      parameters  are consistent with those defined in the table header. Op-
      tion /NOCHECK allows to switch off this checking.   Arguments  can  be
      given to switch off only part of the parameters (SOURCE name, POINTING
      direction, PHASE center, EPOCH of coordinates). This option is intend-
      ed  for  building tables with inconsistent parameters (typical exemple
      is a different source name...). It is potentially dangerous and is  to
      be used with caution.

  TABLE /DROP n1 n2 --- THIS OPTION IS OBSOLETE

      Option /DROP enables to drop the first 'n1' and last 'n2'  channels in
      each subband of the OLD spectral correlator. For the NEW spectral cor-
      relator (data taken since summer 1992), it is replaced by the commands
      SET GIBBS and SET DROP.

  TABLE /COMPRESS tmax uvmax

      Option /COMPRESS is used to compress the data   before   writing   the
      table.    This   works  like the COMPRESS command, but no intermediate
      file is written. Very seldom used.


Subsections

Gildas manager 2011-09-07