; VLBAEOPS ;--------------------------------------------------------------- ;! Corrects Earth orientation parameters ;# PROCEDURE VLBI UTILITY CALIBRATION ;----------------------------------------------------------------------- ;; Copyright (C) 2005-2007, 2012, 2013 ;; 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 ;----------------------------------------------------------------------- VLBAEOPS LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC VLBAEOPS: Procedure to fix EOPs used by the VLBA correlator INNAME Input file name INCLASS Input file class INSEQ Input file sequence number INDISK Disk number for input file VLBAEOPS is defined in the VLBAUTIL run file. ---------------------------------------------------------------- VLBAEOPS Type: Procedure Use: VLBAEOPS is a procedure that fixes the Earth Orientation Parameters (EOPs) used by the VLBA correlator. This requires the existence of a CT table (which contains the old EOPs). This is HIGHLY recommended if you are doing phase referencing and astrometry in particular. From 5-May-2003 to 9-Aug-2005 the VLBA correlator used old predicted EOPs which could be significantly wrong and will effect all phase referencing experiments. Before and after this time better predictions are used but there is still a chance for large error and almost certainly small errors exist, so it is recommended for all phase referencing experiments. See HELP CLCOR for more details on the fix. Type RUN VLBAUTIL to make the VLBAEOPS procedure available. INNAME.....The name of the file to be corrected. Wildcard characters are allowed. INCLASS....The class of the file to be corrected. Wildcard characters are allowed. INSEQ......The sequence number of the file to be corrected. Zero defaults to the highest sequence number matching INNAME, INCLASS, and INDISK. INDISK.....The disk drive number of the file to be corrected. Zero defaults to any disk. ---------------------------------------------------------------- VLBAEOPS: Procedure to correct the Earth Orientation Parameters used by the VLBA correlator Documentor: Amy Mioduszewski Related Programs: CLCOR, VLBAUTIL You should run VLBAEOPS after you have run VLBAFIX. It can be run anytime before the final fringe fit. VLBAEOPS corrects the Earth Orientation Parameters (EOPs) used by the VLBA correlator. It requires the existence of a CT table which has the EOPS used by the correlator and a file, supplied by USNO, which contains the final values. Having good EOPs is important for all phase referencing projects, especially astrometry. Particularly bad EOPs can cause position shifts and distortions in phase referenced images, some to the degree that the target could be smeared to the point of non-detection. This procedure will automatically download the USNO file and run CLCOR. It does the downloading with wget, curl or ncftpget. For Mac users, wget and ncftpget seem to be available in FINK. If you do not have any of these comands on your computer you can download the file manually from: http://gemini.gsfc.nasa.gov/solve_save/usno_finals.erp and use CLCOR (OPCODE='EOPS'). VLBAEOPS is intended for all levels of VLBA users.