; RLCAL ;--------------------------------------------------------------- ;! Determines instrumental right-left phase versus time (a self-cal) ;# TASK UV CALIBRATION POLARIZATION ;----------------------------------------------------------------------- ;; Copyright (C) 2011 ;; 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 ;----------------------------------------------------------------------- RLCAL LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC RLCAL Task to do right - left phase self-cal 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 Source to use (only 1) QUAL -10.0 Calibrator qualifier -1=>all CALCODE Calibrator code ' '=>all 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 Lowest IF number 0=>all EIF 0.0 100.0 Highest IF number 0=>all ANTENNAS Antennas to solve for. UVRANGE 0.0 UV range in kilolamdba SUBARRAY 0.0 1000.0 Subarray, 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. CLEAN map (optional) DOPOL -1.0 10.0 If >0 correct polarization. PDVER PD table to apply (DOPOL>0) 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. ICHANSEL Array of start and stop chan numbers, plus a channel increment and IF to be used to select channels to sum to find the right-left phase 0 => all channels IN2NAME Cleaned map name (name) IN2CLASS Cleaned map name (class) IN2SEQ 0.0 9999.0 Cleaned map name (seq. #) IN2DISK 0.0 9.0 Cleaned map disk unit # INVERS -1.0 46655.0 CC file version #. NCOMP # comps to use for model. 1 value per field FLUX Lowest CC component used. NMAPS 0.0 4096.0 No. Clean map files CMETHOD Modeling method: 'DFT','GRID',' ' CMODEL Model type: 'COMP','IMAG' 'SUBI' (see HELP re images) PMODEL Source poln. model SPECPARM Spectral index: I Q U V for each CALSOUR SOLINT Soln. interval (min) 0=>10. PRTLEV 0.0 10.0 Print statistics 0=>none 1 = some, 2 = lots. Use 1. BADDISK 0.0 9.0 Disk no. not to use for scratch files. --------------------------------------------------------------- PCAL Task: This task reads a UV file and applies the calibration to the RL and LR polarizations writing to a scratch file. It then computes visibility models for Q and U using either PMODEL and SPECPARM or Q and U images with Clean Components. For each solution interval determined by SOLINT and the index table if any, it determines the one phase to be added to all left-hand solutions to bring the model and data as close together as possible. An SN table is written. A spectral mode has not been introduced since it is believed that the right-left instability is not particularly channel dependent. 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....The one source name to be used. QUAL.......Only sources with a source qualifier number in the SU table matching QUAL will be used if QUAL is not -1. CALCODE....Calibrators may be selected on the basis of the calibrator code: ' ' => any calibrator code selected '* ' => any non blank code (cal. only) '-CAL' => blank codes only (no calibrators) anything else = calibrator code to select. NB: The CALCODE an QUAL adverbs allow correct selection of a single source in cases where more than "source" in a data set has the same name. The following may be used for all data files (except as noted): 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. 0 => 1. If the models are rather frequency dependent, then one may have to do solutions one IF at a time. EIF........Highest IF to process. 0=>all higher than BIF ANTENNAS...A list of the antennas to be used in the solution process. UVRANGE....Range of projected spacings to be included in 1000's of wavelengths. 0 => 1, 1.E10 SUBARRAY...Subarray number to use. 0=>all. 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. DOPOL......If > 0 then correct data for instrumental polarization as represented in the AN or PD table. This correction is only useful if PCAL has been run or feed polarization parameters have been otherwise obtained. See HELP DOPOL for available correction modes: 1 is normal, 2 and 3 are for VLBI. 1-3 use a PD table if available; 6, 7, 8 are the same but use the AN (continuum solution) even if a PD table is present. PDVER......PD table to apply if PCAL was run with SPECTRAL true and 0 < DOPOL < 6. <= 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 done. 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). ICHANSEL.. Array of start, stop, and increment channel numbers plus an IF used for channel selection in the averaging to compute the average values used for solving for the phase difference. Up to 20 sets if channels/IF may be entered. The first having ICHANSEL(2,i) <= 0 terminates the list. ICHANSEL(4,i) is the IF number, with <= 0 meaning all IFs. If an IF has no ICHANSEL set for it, then all channels are used. IN2NAME....Cleaned map name (name). Standard defaults. Note: a CLEAN image for only a single source may be given although it may be in a multi-source file. A Qpol and a Upol image of the same name are expected. If the source table contains a flux, then that flux will be used to scale the components model to obtain the stated total flux. This is needed since initial Cleans may not obtain the full flux even though they represent all the essentials of the source structure. IN2NAME and IN2CLASS cause PMODEL to be ignored. IN2CLASS...Cleaned map name (class). The value given should be for the Qpol image, the U pol image will be assumed to be the same except for an initial U in the class. IN2SEQ.....Cleaned map name (seq. #). These should be the same for Q and U images. IN2DISK....Disk drive # of cleaned map. 0 => any. INVERS.....CC file version #. 0=> highest numbered version NCOMP......Number of Clean components to use for the model, one value per field. If all values are zero, then all components in all fields are used. If any value is not zero, then abs(NCOMP(i)) (or fewer depending on FLUX and negativity) components are used for field i, even if NCOMP(i) is zero. If any of the NCOMP is less than 0, then components are only used in each field i up to abs(NCOMP(i)), FLUX, or the first negative whichever comes first. If abs(NCOMP(i)) is greater than the number of components in field i, the actual number is used. For example NCOMP = -1,0 says to use one component from field one unless it is negative or < FLUX and no components from any other field. This would usually not be desirable. NCOMP = -1000000 says to use all components from each field up to the first negative in that field. NCOMP = -200 100 23 0 300 5 says to use no more than 200 components from field 1, 100 from field 2, 23 from field 3, 300 from field 5, 5 from field 6 and none from any other field. Fewer are used if a negative is encountered or the components go below FLUX. FLUX.......Only components > FLUX in absolute value are used in the model. NMAPS......Number of image files to use for model. For multi-scale models, set NMAPS = NFIELD * NGAUSS to include the Clean components of the extended resolutions. If more than one file is to be used, the NAME, CLASS, DISK and SEQ of the subsequent image files will be the same as the first file except that the LAST 3 or 4 characters of the CLASS will be an increasing sequence above that in IN2CLASS. Thus, if INCLASS='ICL005', classes 'ICL005' through 'ICLnnn' or 'ICnnnn', where nnn = 5 + NMAPS - 1 will be used. Old names (in which the 4'th character is not a number) are also supported: the last two characters are '01' through 'E7' for fields 2 through 512. In old names, the highest field number allowed is 512; in new names it is 4096. CMETHOD....This determines the method used to compute the model visibility values. 'DFT' uses the direct Fourier transform, this method is the most accurate. 'GRID' does a gridded-FFT interpolation model computation. ' ' allows the program to use the fastest method. NOTE: when using a model derived from data with different uv sampling it is best to use 'DFT' CMODEL.....This indicates the type of input model; 'COMP' means that the input model consists of Clean components, 'IMAG' indicates that the input model consists of images. 'SUBI' means that the model consists of a sub-image of the original IMAGR output. If CMODEL is ' ' Clean components will be used if present and the image if not. SUBI should work for sub-images made with DO3DIM true and sib-images of the central facet made with DO3DIM false, but probably will not work well for shifted facets with DO3DIM false. Use BLANK rather than SUBIM in such cases. CALIB will set a scaling factor to correct image units from JY/BEAM to JY/PIXEL for image models. If the source table contains a flux, then that flux will be used to scale the components model to obtain the stated total flux. This is needed since initial Cleans may not obtain the full flux even though they represent all the essentials of the source structure. PMODEL.....A single component model to be used instead of a CLEAN components model; if PMODEL(1) > 0, then use of this model is requested. PMODEL(1) = I flux density (Jy) PMODEL(2) = Q flux density (Jy) PMODEL(3) = U flux density (Jy) PMODEL(4) = V flux density (Jy) PMODEL(5) = X offset in sky (arcsec) PMODEL(6) = Y offset in sky (arcsec) PMODEL(1) must be > 0 to request use of PMODEL for the model even though the I value is not otherwise used. PMODEL is ignored if either IN2NAME or IN@CLASS is not blank. SPECPARM...The spectral index in I, Q, U, and V for each source to be used only when PMODEL is used. SOLINT.....Time interval to average data before determining correction in min. 0 => scan average or 10 minutes if no NX table. 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. BADDISK....Disk numbers on which scratch files are not to be placed. ---------------------------------------------------------------