; SPCAL ;--------------------------------------------------------------- ;! Determines instrumental polzn. for spec. line UV data ;# Task UV Calibration ;----------------------------------------------------------------------- ;; Copyright (C) 1995-1997, 2000, 2002-2004, 2006-2007, 2009 ;; 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 ;----------------------------------------------------------------------- SPCAL LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC SPCAL Task to compute instrumental polzn. for spec. line data 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 # Data selection (multisource): CALSOUR Sources to calibrate with TIMERANG Time range to use. SELBAND Bandwidth to select (kHz) SELFREQ Frequency to select (MHz) FREQID Freq. ID to select. BIF 0.0 100.0 IF number. ANTENNAS Antennas to solve for. UVRANGE 0.0 UV range in kilolamdba SUBARRAY 0.0 1000.0 Subarray, 0=>all BCHAN 0.0 2048.0 Lowest channel number 0=>all ECHAN 0.0 2048.0 Highest channel number 0=>all Cal. info for input: DOCALIB -1.0 101.0 > 0 calibrate data & weights > 99 do NOT calibrate weights GAINUSE CAL table to apply. BLVER BL table to apply. FLAGVER Flag table version DOBAND -1.0 10.0 If >0 apply bandpass cal. Method used depends on value of DOBAND (see HELP file). BPVER Bandpass table version SMOOTH Smoothing function. See HELP SMOOTH for details. SOLINT Soln. interval (min) 0=>10. SOLTYPE Soln. type: 'ZAPR': zero. lin. pol. 'RAPR': similarity method PRTLEV 0.0 10.0 Print statistics 0=>none 1 = some, 2 = lots. Use 1. REFANT 0.0 90.0 Reference antenna, 0=none. BADDISK 0.0 9.0 Disk no. not to use for scratch files. --------------------------------------------------------------- SPCAL Task: This task reads a spectral line uv-data file, applies calibration and determines the feed polarization parameters for each antenna for the selected IF. The instrumental polarization parameters are recorded in the AN table and can be applied in LISTR, SPLIT or other tasks by setting DOPOL>0. 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. The following are used for multisource data files only: CALSOUR....List of sources for which calibration constants are to be determined. '*' = all; 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. All ' ' =>all. TIMERANG...Time range of the data to be used. In order: Start day, hour, min. sec, end day, hour, min. sec. Days relative to ref. date. SELBAND....Bandwidth of data to be selected. If more than one IF is present SELBAND is the width of the first IF required. Units = kHz. For data which contain multiple bandwidths/frequencies the task will insist that some form of selection be made by frequency or bandwidth. SELFREQ....Frequency of data to be selected. If more than one IF is present SELFREQ is the frequency of the first IF required. Units = MHz. FREQID.....Frequency identifier to select (you may determine which is applicable from the OPTYPE='SCAN' listing produced by LISTR). If either SELBAND or SELFREQ are set, their values override that of FREQID. However, setting SELBAND and SELFREQ may result in an ambiguity. In that case, the task will request that you use FREQID. BIF........First IF to process. Old values for feed parameters and calibrator polarizations for unprocessed IFs are unchanged. 0=>all. ANTENNAS...A list of the antennas to have solutions determined. If any number is negative then all antennas listed are NOT to be used to determine solutions and all others are. All 0 => use all. The following may be used for all data files (except as noted): UVRANGE....Range of projected spacings to be included in 1000's of wavelengths. 0 => 1, 1.E10 SUBARRAY...Subarray number to use. 0=>all. BCHAN......Lowest channel number included; 0 -> 1 ECHAN......Highest channel number included; 0 -> max DOCALIB....If true (>0), calibrate the data using information in the specified Cal (CL) table for multi-source or SN table for single-source data. Also calibrate the weights unless DOCALIB > 99 (use this for old non-physical weights). GAINUSE....version number of the CL or SN table to apply to the data. 0 => highest. BLVER......Version number of the baseline based calibration (BL) table to appply. <0 => apply no BL table, 0 => highest. FLAGVER....Specifies the version of the flagging table to be applied. 0 => highest numbered table. <0 => no flagging to be applied. DOBAND.....If true (>0) then correct the data for the shape of the antenna bandpasses using the BP table specified by BPVER. The correction has five modes: (a) if DOBAND=1 all entries for an antenna in the table are averaged together before correcting the data. (b) if DOBAND=2 the entry nearest in time (including solution weights) is used to correct the data. (c) if DOBAND=3 the table entries are interpolated in time (using solution weights) and the data are then corrected. (d) if DOBAND=4 the entry nearest in time (ignoring solution weights) is used to correct the data. (e) if DOBAND=5 the table entries are interpolated in time (ignoring solution weights) and the data are then corrected. BPVER......Specifies the version of the BP table to be applied. <0 => no bandpass correction to be applied. SMOOTH.....Specifies the type of spectral smoothing to be applied to a uv database . The default is not to apply any smoothing. The elements of SMOOTH are as follows: SMOOTH(1) = type of smoothing to apply: 0 => no smoothing To smooth before applying bandpass calibration 1 => Hanning, 2 => Gaussian, 3 => Boxcar, 4 => Sinc To smooth after applying bandpass calibration 5 => Hanning, 6 => Gaussian, 7 => Boxcar, 8 => Sinc SMOOTH(2) = the "diameter" of the function, i.e. width between first nulls of Hanning triangle and sinc function, FWHM of Gaussian, width of Boxcar. Defaults (if < 0.1) are 4, 2, 2 and 3 channels for SMOOTH(1) = 1 - 4 and 5 - 8, resp. SMOOTH(3) = the diameter over which the convolving function has value - in channels. Defaults: 1,3,1,4 times SMOOTH(2) used when input SMOOTH(3) < net SMOOTH(2). SOLINT.....Time interval to average data before determining correction in min. 0 => 10 min. SOLTYPE....Solution type: 'ZAPR': assumes zero linear polarization. 'RAPR': assumes linear polarization is scaled version of the total intensity. else -> ZAPR PRTLEV.....If this value is larger than 0.0 then the intermediate diagnostics and solutions will be given on the monitor terminal and the message file. REFANT.....Reference antenna to use. If none is specified, the program will pick the lowest numbered, most extensively used one. The technique of using no reference antenna has been found not to work well. BADDISK....Disk numbers on which scratch files are not to be placed. --------------------------------------------------------------- SPCAL: Task to determine effective feed polarization parameters for spectral line data. Documentor: A. J. Kemball Related Programs: CALIB, LISTR, SPLIT, CLCOR, LPCAL, PCAL PCAL, SPCAL or LPCAL? --------------------- PCAL was designed for the VLA and works well for unresolved or slightly resolved calibrators with uniform polarization. LPCAL was designed for VLBI and allows the use of calibrators that have significant structure and differential polarization across the source. It will also handle unpolarized calibrators. SPCAL was designed for spectral line experiments and solves for frequency dependent D-terms. Like PCAL SPCAL demands an unresolved calibrator.