; 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. ----------------------------------------------------------------