; VLBAMPCL ;--------------------------------------------------------------- ;! Calculates and applies manual instrumental phase calibration ;# PROCEDURE VLBI UTILITY CALIBRATION ;----------------------------------------------------------------------- ;; Copyright (C) 2002, 2006, 2015 ;; 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 ;----------------------------------------------------------------------- ;--------------------------------------------------------------- VLBAMPCL LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC VLBAMPCL: Procedure to manually correct instrumental phases You must type RUN VLBAUTIL to see all the inputs to this procedure. INNAME Input UV file name (name) INCLASS Input UV file name (class) INSEQ 0.0 9999.0 Input UV file name (seq. #) INDISK 0.0 9.0 Input UV file disk unit # TIMERANG Time range of a calibrator 1-4 = start day,hr,min,sec 5-8 = end day,hr,min,sec MUST BE SPECIFIED BCHAN 0.0 2048.0 Lowest channel number 0=>all ECHAN 0.0 2048.0 Highest channel number REFANT 0.0 20.0 Ref. antenna, 0=>the first SUBARRAY 0.0 9999.0 Subarray; 0 => all. CALSOUR Calibrator source name; blank => any GAINUSE CL table to use; 0=>highest ADVERBS IF 2 SCANS MUST BE USED TO CORRECT ALL ANTENNAS: OPCODE 'CALP' if you are using 2 scans, otherwise '' TIME2 Time range of a calibrator 1-4 = start day,hr,min,sec 5-8 = end day,hr,min,sec SOURCES Calibrator source name for TIME2 scan; blank => any ANTENNAS antennas for which manual phase corrections should be obtained for the scan in TIME2 (i.e. that cannot be corrected with TIMERANG). ---------------------------------------------------------------- VLBAMPCL Type: Procedure Use: VLBAMPCL is a procedure that creates a CL table which corrects the instrumental phases and delays using FRING. It will run FRING twice if there are no scans that have good fringes on all antenna. This should be run after VLBACALA (or VLBAPANG for polarization experiments) but before VLBAFRNG/VLBAKRNG. Type RUN VLBAUTIL to make the VLBAMPCL procedure available. Adverbs: INNAME.....Input UV file name (name). Standard defaults. INCLASS....Input UV file name (class). Standard defaults. INSEQ......Input UV file name (seq. #). 0 => highest. INDISK.....Disk drive # of input UV file. 0 => any. TIMERANG...Time range of the calibrator to be used. In order: Start day, hour, min. sec, End day, hour, min. sec. Days relative to reference date. MUST BE SPECIFIED. Pick a scan on a calibrator where ALL antennas are present and have strong fringes. If there is no such scan, then use OPCODE, TIME2 and ANTENNAS another scan and set of antennas. BCHAN......First channel to use. 0=>all. ECHAN......Highest channel to use. 0=>all higher than BCHAN You may want to select BCHAN and ECHAN to leave out edge channels if those are bad and will affect the phase and delay solutions. REFANT.....Reference antenna, 0 => the first in the antenna list Set to a stable antenna that is preferably in the entire experiment SUBARRAY...The subarray to use. 0 => all CALSOUR....Calibrator source name for scan in TIMERANG; blank => any. GAINUSE....Number of CL table with all calibration up to this point. 0 => highest OPCODE.....OPCODE in CLCAL; use the default if only one scan is needed to correct all the antennas. If OPCODE is set to 'CALP' and ANTENNAS and TIME2 are set then instrumental phase correction will be found for a second set of antennas (listed in ANTENNAS) for another scan (specified by TIME2). If OPCODE='CALP' but ANTENNAS and TIME2 are not set then only the phase corrections that are corrected by the scan specified in TIMERANG will be corrected. See EXPLAIN file for a detailed explanation of how to deal with antennas which are not corrected after VLBAMPCL. TIME2......Time range of the calibrator to be used for second scan. In order: Start day, hour, min, sec, End day, hour, min, sec. Days relative to reference date. MUST BE SPECIFIED IF OPCODE AND ANTENNAS ARE SPECIFIED. Pick a scan on a calibrator where antennas listed in ANTENNAS have strong fringes. SOURCES....Calibrator source name for scan in TIME2; blank => any. ANTENNAS...Antennas that will not be corrected with the scan specified in TIMERANG but will be corrected by the scan specified in TIME2. OPCODE must be set to 'CALP' for this option. 0=> do not find manual phase correction for a second scan. MUST BE SPECIFIED IF TIME2 IS SPECIFIED. ---------------------------------------------------------------- VLBAMPCL: Procedure to correct the instrumental phases using FRING. It can find corrections for a second scan if there are no scans that contain all antennas. Documenter: Amy Mioduszewski Related Programs: VLBAUTIL, CLCAL, FRING, VLBAPCOR This procedure should be used if there are no good phase cals (e.g. spectral line experiments), otherwise use VLBAPCOR. This should be done after sampler corrections (VLBACCOR) and before the bandpass (VLBABPSS). After VLBAMPCL is run it is ESSENTIAL to check the solutions in POSSM setting GAINUSE to the CL table output by VLBAMPCL. VLBAMPCL assumes: 1. there is only one FREQID 2. that all IFs should be calibrated 6. that the highest FG table is the one that should be applied Steps in VLBAMPCL: 1. Runs FRING, TIMERANG, CALSOUR, GAINUSE and REFANT as specified; DOCAL=2, APARM(1)=2 and DPARM=1 0 0 0 0 0 0 1. 2. Runs CLCAL, with input OPCODE; ANTENNAS=0; INTERPOL=''; SNVER= SN table out of FRING; GAINVER = input GAINUSE; and GAINUSE= highest CL table +1. Output should be highest CL table. *3. Runs FRING, using the GAINUSE used in CLCAL in step 2. ANTENNAS=ANTENNAS, REFANT, rest the same as in step 1. If FRING reports any "failed solutions" you MUST find another scan and run again, after you have deleted the SN and CL tables that VLBAPCOR has created. Unless there is a good reason for failed solutions, such as an entire IF has been flagged for a certain antenna. *4. Runs CLCAL with ANTENNAS equal to the input ANTENNAS GAINVER equal to input GAINUSE; SNVER equal to output SN table from FRING; GAINUSE equal to the CL table which is output in step 2; TIMERANG =0; and CALSOUR = ''. *NOTE: Steps 3 and 4 only take place if OPCODE='CALP' and TIME2 and ANTENNAS <> 0.