; CLINV ;----------------------------------------------------------------------- ;! copy CL/SN file inverting the calibration ;# TASK TABLE CALIBRATION ;----------------------------------------------------------------------- ;; Copyright (C) 1999, 2007 ;; 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 ;----------------------------------------------------------------------- CLINV LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC CLINV task to invert SN/CL tables INNAME Input uv data name (name) INCLASS Input uv data name (class) INSEQ 0.0 9999.0 Input uv data name (seq. #) INDISK 0.0 9.0 Input uv data disk unit # INEXT Input table extension type INVERS Input table file version no. OUTNAME Output uv data name (name) OUTCLASS Output uv data name (class) OUTSEQ -1.0 9999.0 Output uv data name (seq. #) OUTDISK 0.0 9.0 Output uv data disk unit #. OUTVERS Output table file version. OPTYPE 'PHAS' => invert phase only (output amplitude gain = 1) 'AMPL' => invert amp. only (output phase = 0) otherwise completely invert the calibration ---------------------------------------------------------------- CLINV Task: CLINV inverts the calibration in an AIPS CL or SN extention table. The specified output table should not exist before the execution of CLINV. Adverbs: INNAME.....Input uv data set name (name). Standard defaults. INCLASS....Input uv data set name (class). Standard defaults. INSEQ......Input uv data set name (seq. #). 0 => 1. INDISK.....Disk drive # of input uv data set. 0 => any. INEXT......Extention table type (e.g. 'CL') ' ' => 'SN' INVERS.....Version number of table to copy, 0=>highest no. OUTNAME....Output uv data set name (name). Standard defaults. OUTCLASS...Output uv data set name (class). Standard defaults. OUTSEQ.....Output uv data set name (seq. #). 0 => highest unique. OUTDISK....Disk drive # of output uv data set. 0 => highest disk number with sufficient space. OUTVERS....Output version number, 0=> next higher. OPTYPE.....'PHAS' => invert phase only (output amplitude gain = 1) 'AMPL' => invert amplitude only (output phase = 0) otherwise completely invert the calibration ---------------------------------------------------------------- CLINV Task: Calibration inversion IF an AIPS CL or SN table has been applied to a data set and one wants to undo the calibration (or the phase or amplitude part of the calibration), one may use CLINV to produce an inverse table which may then be applied to the data with SPLIT. The example that caused this task to be written is a field with a strong source at the half-power point of the beam. Pointing errors make calibration found with this strong source inaccurate for sources near the center of the field, but one has to self-cal on the strong source in order to remove it. Therefore: 1. Calibrate in the normal way and SPLIT 2. Self-calibrate with a strong source in/near the field 3. Run UVSUB to subtract that strong source 4. Run CLINV on the self-calibration SN table attaching the inverse table to the output of UVSUB 5. Undo the strong-source self-cal from the residual data by running SPLIT on the UVSUB/CLINV output file.