; VLBAFRNG ;--------------------------------------------------------------- ;! Fringe fit data and apply calibration ;# PROCEDURE VLBI UTILITY CALIBRATION ;----------------------------------------------------------------------- ;; Copyright (C) 1995-2001; 2006 ;; 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 ;----------------------------------------------------------------------- VLBAFRNG LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC VLBAFRNG: Procedure to fringe fit and calibrate data Input uv data. INNAME UV file name (name) INCLASS UV file name (class) INSEQ 0.0 9999.0 UV file name (seq. #) INDISK 0.0 9.0 UV file disk drive # CALSOUR Source list to fringe fit TIMERANG Time range to use. BCHAN 0.0 2048.0 Lowest channel number 0=>all FOR SPEC. LINE EXP. ONLY ECHAN 0.0 2048.0 Highest channel number FOR SPEC. LINE EXP. ONLY GAINUSE CL table to apply. REFANT Reference antenna SUBARRAY 0.0 1000.0 Subarray, 0=>all SEARCH 0.0 1000.0 Prioritized reference antenna list - supplements REFANT SOLINT Solution interval (min) 0 => 10 min DPARM for strong sources, it is only necessary to set DPARM(4), DPARM(7) and for spec line exp DPARM(8). 4=int. time (sec) 0 => min. found in data 7 >0 => don't rereference phase; this should be 1 for polarization exp 8 > 0 => activate zero'ing options for rest see HELP VLBAFRNG SOURCES Source list to calibrate: If sources are listed they are each calibrated with separate runs of CLCAL INTERPOL Interpolation function: '2PT','SIMP','AMBG','CUBE', 'SELF' BADDISK 0.0 15.0 Disk no. not to use for scratch files. ---------------------------------------------------------------- VLBAFRNG Type: Procedure Use: This procedure does antenna based fringe fitting using FRING and then applies those corrections using CLCAL. For more information on FRING and CLCAL see their respective HELP/EXPLAIN files. If you are doing a phase reference experiment use VLBAFRGP. Type RUN VLBAUTIL to make the VLBAFRNG 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. CALSOUR....List of sources for which calibration constants are to be determined, i.e. the calibrator sources All ' ' = all sources; a "-" before a source name. means all except ANY source named. Note: solutions for multiple sources can only be made if the sources are point sources at their assumed phase center and with the flux densities given in the source (SU) table. TIMERANG...Time range of the data to be used. In order: Start day, hour, min. sec, end day, hour, min. sec. Days relative to reference date. BCHAN......First channel to use. 0=>all. ECHAN......Highest channel to use. 0=>all higher than BCHAN GAINUSE....(multisource) version number of the CL table to apply to the data. 0 => highest. REFANT.....The desired reference antenna for phases. SUBARRAY...Subarray number to use. 0=>all. SEARCH.....List of Prioritized antennas to be used when APARM(9)>0. This adverb supplements REFANT. It is recommended that SEARCH be filled with a list of antennas whose order reflects the user's notion of which baselines will be easiest to find fringes on. All baselines to each antenna in SEARCH will be searched in order looking for fringes. All remaining baselines will then be searched. Choosing SEARCH wisely will speed the FFT portion of FRING. The antenna chosen in REFANT is treated as SEARCH(0), ie all baselines to it are searched first. SOLINT.....The solution interval (min.) You really should set this; longer values are allowed beginning with 15OCT96. 0 => 10 minutes for all inputs If SOLINT > Scan/2 (in Multisource) SOLINT = Scan. Delay-rate control parameters: DPARM......Delay rate parameters. DPARM(1)...Number of baseline combinations to use in the initial, coarse fringe search (1-3). Larger values increase the point source sensitivity but reduce the sensitivity to extended sources when an accurate model is not available. 0=>3. DPARM(2)...The delay window to search (nsec) centered on 0 delay. 0 => full Nyquist range defined by the frequency spacing. If DPARM(2) < 0.0 no delay search will be performed. DPARM(3)...The rate window to search (mHz) centered on 0 rate. 0 => full Nyquist range defined by the integration time. DPARM(4)...The minimum integration time of the data (sec); 0 => search the data to find the minimum integration time. The correct minimum of all baselines should be supplied. DPARM(5)...If > 0 then don't do the least squares solution. If the least squares solution is not done then only the coarse search is done and much less accurate solutions are obtained. DPARM(6)...If > 0 then the output data will not be averaged in frequency else, all frequencies in each IF will be averaged. Affects single source files only. DPARM(7)...If > 0 then the phase, rate and delays will not be re-referenced to a common antenna. This option is only desirable for VLBI polarization data. DPARM(8)...DPARM(8)>0 allows zero'ing of RATE, DELAY, and/or PHASE solutions. ** Note that the ZEROing is done _AFTER_ the FRING solution is found, this is not the mechanism for turning off the DELAY, RATE, or PHASE search, see DPARM(2-3) for that capability. ** DPARM(8) value zero RATES? zero DELAYs? zero PHASEs? 0 No No No 1 Yes No No 2 No Yes No 3 Yes Yes No 4 No No Yes 5 Yes No Yes 6 No Yes Yes 7 Yes Yes Yes SOURCES....Sources to calibrate. If this is left blank then all the sources are calibrated at once using the INTERPOL (i.e. CLCAL is only run once). If sources are listed then CLCAL is run once for each source using the interpolation method stated in INTERPOL. This second option is recommended, see EXPLAIN file. INTERPOL...The type of interpolation to be applied to the SN table: ' ' = linear vector interpolation with no SN smoothing. '2PT ' = linear vector interpolation with no SN smoothing. 'SELF' = Use only SN solution from same source which is closest in time. 'SIMP' = Simple linear phase connection between SN phase entries, assumes phase difference less than 180 degrees. 'AMBG' = Linear phase connection using rates to resolve phase ambiguities. 'CUBE' = As AMBG but fit third order polynomial to phases and rates. BADDISK....A list of disk numbers to be avoided when creating scratch files. ---------------------------------------------------------------- VLBAFRNG: Procedure to perform antenna based fringe fitting using FRING and then apply these corrections using CLCAL. If you are doing phase referencing use VLBAFRGP. Documenter: Amy Mioduszewski Related Programs: VLBAUTIL, FRING, CLCAL, VLBAKRNG, VLBAFRGP This should be done after solving for the instrumental phase corrections (VLBAPCOR) and before applying all the calibration and averaging (SPLIT/SPLAT). After VLBAFRNG is run it is ESSENTIAL to check the solutions in POSSM setting GAINUSE to the CL table output by VLBAFRNG. VLBAFRNG will produce the highest SN and CL table. For details on FRING and CLCAL see their HELP/EXPLAIN files. VLBAFRNG assumes: 1. there is only one FREQID 2. that all IFs should be calibrated 3. that all antennas should be calibrated 4. that the entire uv range should be calibrated 5. that the highest FG table is the one that should be applied 6. that this is a multisource file Steps in VLBAFRNG: 1. Runs FRING, which will do antenna based fringe fits. This will produce the highest SN table. 2. Runs CLCAL, with OPCODE 'CALI', SNVER output SN table from FRING; GAINVER input GAINUSE and GAINUSE = highest CL table +1. Output should be highest CL table. If SOURCES is blank then CLCAL is run only once. If SOURCES is not blank then CLCAL will be run for each SOURCE individually setting both CALSOUR and SOURCES to the same single source in the SOURCES list. This is recommended because of CLCAL is run for all the sources at once with any INTERPOL except 'SELF' then incorrect solutions may be applied for a few minutes before and after a source change. CLCAL will output the highest CL table. After VLBAFRNG is run and the solutions are checked in POSSM SPLIT or SPLAT should be run with GAINUSE set to the CL output from VLBAFRNG and DOCAL=2.