; SOLTYPE
;---------------------------------------------------------------
;! Solution type
;# ADVERB CALIBRATION
;-----------------------------------------------------------------------
;; Copyright (C) 1995, 2004
;; Associated Universities, Inc. Washington DC, USA.
;;
;; This program is free software; you can redistribute it and/or
;; modify it under the terms of the GNU General Public License as
;; published by the Free Software Foundation; either version 2 of
;; the License, or (at your option) any later version.
;;
;; This program is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;;
;; You should have received a copy of the GNU General Public
;; License along with this program; if not, write to the Free
;; Software Foundation, Inc., 675 Massachusetts Ave, Cambridge,
;; MA 02139, USA.
;;
;; Correspondence concerning AIPS should be addressed as follows:
;; Internet email: aipsmail@nrao.edu.
;; Postal address: AIPS Project Office
;; National Radio Astronomy Observatory
;; 520 Edgemont Road
;; Charlottesville, VA 22903-2475 USA
;-----------------------------------------------------------------------
SOLTYPE LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC
----------------------------------------------------------------
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.
----------------------------------------------------------------