AIPS NRAO AIPS HELP file for SOLTYPE in 31DEC20



As of Tue Oct 20 22:31:54 2020



HELP SECTION

SOLTYPE
Type:  Adverb  (string(4))
Use:   This adverb specifies the least squares solution type used in
       calibration routines.  Values used for single-pass solutions
          '    ' => normal least squares,
          'L1  ' => L1 solution,
          'GCON' => least squares which may include gain constraint
       Values for multi-pass "robust" solutions are
          'R   ' => normal least squares,
          'L1R ' => L1 solution,
          'GCOR' => least squares which may include gain constraint
       Note that all three use different mathematical methods even if
       no actual gain constraint is applied.
Null value:
       '    '   => normal least squares.

Discussion:
   Each gain solution routine does the following:
      FOR i = I1,10
          Using only unflagged data:
             find gain-set (i)
             determine deviation of data from gains = rms(i)
          Unflag the temporarily flagged data if any
          Temporarily flag any data deviating from gain-set(i)
             by > rms(i) * FF(i)
          END
   where
          FF /7., 5., 4., 3.5, 3., 2.8, 2.6, 2.4, 2.2, 2.5/
   and FF(10) may be replaced by a user-selected value.  In CALIB,
   the user selects FF(10) with DOFLAG and may choose to have the
   temporary flags generated at the last pass used to flag the data in
   a more permanent way.  I1 = 10 for non-robust methods and I1 = 1
   for the robust methods.
Tasks:
   BPASS.....Computes spectral bandpass correction table.
   CALIB.....Determines antenna calibration: complex gain.
   KRING.....Fringe fit data to determine antenna calibration, delay,
             rate.  SOLTYPE controls what types of searches are
             performed (FFT and/or least squares).
   PCAL......Determines instrumental polarization for UV data.  SOLTYPE
             determines the type of polarization solved: APPR, RAPR,
             ORI-.
   SCIMG.....Full-featured imaging plus self-calibration loop with
             editing.
   SCMAP.....Imaging plus self-calibration loop with editing.
   SPCAL.....Determines instrumental polarization. for spectral line UV
             data.  SOLTYPE determines what is assumed about the linear
             polarization.
Procedures:
   IMSCAL....Large image self-cal with IM2CC and OOCAL,
   OOCAL.....Determines antenna complex gain with frequency-dependent
             models.
   PEELR.....Calibrates interfering sources in multi-facet imges.
"Verbs":
   OBITPEEL..Access to OBIT task Imager with self-cal and peeling.
             SOLTYPE offers normal and L1 only.
   OBITSCAL..Access to OBIT task Imager with self-cal, NOT peeling
             SOLTYPE offers normal and L1 only.

EXPLAIN SECTION



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