; VBCAL ;--------------------------------------------------------------- ;! Scale visibility amplitudes by antenna based constants ;# TASK VLBI CALIBRATION ;----------------------------------------------------------------------- ;; Copyright (C) 1995, 2009, 2012 ;; 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 ;----------------------------------------------------------------------- VBCAL LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC VBCAL Task to multiply antenna amplitude gain factors. 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 # OUTNAME Output UV file name (name) OUTCLASS Output UV file name (class) OUTSEQ -1.0 9999.0 Output UV file name (seq. #) OUTDISK 0.0 9.0 Output UV file disk unit #. APARM Control info. 1-4 => start day,hr,min,sec 5-8 => end day,hr,min,sec 0's => all. 9 => first ant. no. + (array no.-1)*100 10 => 0=RCP, 1=LCP, 2=both. FPARM antennas 1-30 factor RPARM antennas 31-60 factor VPARM antennas 61-90 factor factor=SQRT(fac1*fac2) DOWEIGHT -1.0 1.0 > 0 => correct weights too ---------------------------------------------------------------- VBCAL Type: Task Use: Scale visibility amplitudes by antenna based constants. 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. OUTNAME....Output UV file name (name). Standard defaults. OUTCLASS...Output UV file name (class). Standard defaults. OUTSEQ.....Output UV file name (seq. #). 0 => highest unique OUTDISK....Disk drive # of output UV file.0 => highest w room APARM........Control information. 1-4 => start day, hour, min, sec 5-8 => end day, hour, min, sec 9 => first antenna number plus 100*(array #-1) If antenna number = 0, all baselines of the specified array will be multiplied by FPARM(1). If < 0, all baselines of all arrays will be multiplied by FPARM(1). Use APARM(9)=1 in most cases. 10 => 0=RCP, 1=LCP, 2=BOTH FPARM......1-30 are antenna factors for antennas 1-30. Factor =SQRT(fac1*fac2) RPARM......1-30 are antenna factors for antennas 31-60. Factor =SQRT(fac1*fac2) FPARM......1-30 are antenna factors for antennas 61-90. Factor =SQRT(fac1*fac2) DOWEIGHT...> 0 => correct weights too (normally a good idea). --------------------------------------------------------------- VBCAL: Task to scale some antenna calibrations by constants. DOCUMENTOR: R. C. Walker NRAO/CV RELATED PROGRAMS: VBFIT,UVFLG PURPOSE VBCAL will multiply the amplitudes in a uv data set by antenna based calibration constants. Data to be corrected can be selected by timerange, antenna and array. The program is primarily intended to be useful in calibrating VLB data, but can be used to scale any type of data. It can be used to apply a global, constant scale factor to any data, for instance, if the flux density calibration of an experiment is found to be wrong. COMMENTS APARM: The desired timerange is specified with the APARM array. The first four elements are the start time and the next four are the stop time, both specified as day,hour,minute,sec. Times are the IAT as displayed by programs such as LISTER at the VLA. The first day of the experiment is day 0. For example, to select all data in the range: day 0, 07:30:15 to day 1, 12:34:00, specify BPARM=0,7,30,15,1,12,34,00 APARM(9) is used to specify the first antenna to be processed. If the uv data base contains data from more than one array, the array number is specified with the hundreds digit which is set to the array number minus one. eg: if the first antenna is number 9 of only one array, use APARM(9)=9. If the first antenna is number 5 of the third array, use APARM(9)=205. If the antenna number specified is zero, all antennas of the specified array will be multiplied by BPARM(1). Note that if APARM(9)=0, all antennas of array one and only array one will be multiplied. If APARM(9) is less than zero, all antennas of all arrays are multiplied by BPARM(1). APARM(10) is used to specify the polarization to be scaled. 0 for RCP, 1 for LCP, and 2 for both. For spectral line data, all data of the requested polarization will be processed. BPARM is used to input the scale factors for the 10 antennas beginning with the one specified in APARM. A value of 0 is replaced by 1.0. EXECUTION TIMES: 100,000 Visibility records can be processed in about 60 seconds of cpu time. In an empty machine, the program only seems to be able to use about 50% of the available cpu so the run time will be at least twice the cpu time.