; SPLIT ;--------------------------------------------------------------- ;! converts multi-source to single-source UV files w calibration ;# Task UV Calibration ;----------------------------------------------------------------------- ;; Copyright (C) 1995-1998, 2000, 2002, 2004, 2006, 2010, 2015-2016 ;; 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 ;----------------------------------------------------------------------- SPLIT LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC SPLIT Task to split multi-source uv data to single source also works on single files. 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 # SOURCES Source list QUAL -1.0 Source qualifier -1=>all CALCODE Calibrator code ' '=>all TIMERANG Time range to copy STOKES Stokes type to pass. ANTENNAS Antennas to include or omit 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 BCHAN 0.0 2048.0 Lowest channel number 0=>all ECHAN 0.0 2048.0 Highest channel number SUBARRAY 0.0 1000.0 Subarray, 0=>all DOCALIB -1.0 101.0 > 0 calibrate data & weights > 99 do NOT calibrate weights GAINUSE CL (or SN) table to apply 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. 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 #. DOUVCOMP -1.0 1.0 1 (T) => compressed data APARM Control information: 1 = 1 => avg. freq. in IF multi-channel out = 2 => avg. freq. in IF single channel out = 3 => avg IF's also 2 = Input avg. time (sec) 3 > 0 => Drop subarrays 4 > 0 => calibrate weights 5 = 0 pass only xc data = 1 pass xc and ac data = 2 pass only ac data 6 > 0 add full source name to header NCHAV Number of chan. to average. (used if APARM(1) = 1) <= 0 -> ALL CHINC Channel incr. between output channels (used if APARM(1)=1) ICHANSEL Array of channel start, stop, and increment numbers and IF number to be used when averaging in frequency. (used if APARM(1) = 2, 3) BADDISK 0.0 9999.0 Disks to avoid for scratch ---------------------------------------------------------------- SPLIT Task: Split a multi-source uv data set into single-source data files. Multiple sources may be processed in a single run. Optionally, calibration, editing and spectral averaging may be applied. Fully flagged data will not be copied. The flagging and spectral averaging functions may also be applied to a single-source input file. SPLIT will also apply an unapplied SN table to a single-source file. This may be done by copying an appropriate SN table to the input file. A warning message may appear if the SN table had previously been applied to any dataset. SPLIT differs from SPLAT in that it cannot write a multi-source output file and that it does not copy any calibration tables even if they were not applied. 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. SOURCES....Source list. One output file will be made per source. '*' = all; a "-" before a source name means all except ANY source named. QUAL.......Only sources with a source qualifier number in the SU table matching QUAL will be used if QUAL is >= 0. If QUAL < 0, all qualifiers will be written. These qualifiers will be written to separate output files. Note that OUTSEQ must be zero in this case. CALCODE....Sources may be selected on the basis of the calibrator code given in the SU table. ' ' => 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 test is applied in addition to the other tests, i.e. SOURCS and QUAL, in the selection of sources to process. TIMERANG...Time range of the data to be copied. In order: Start day, hour, min. sec, end day, hour, min. sec. Days relative to ref. date. STOKES.....The desired Stokes type of the output data: 'I','V','Q','U','IQU','IQUV','IV','RR','LL','RL', 'LR','HALF' (=RR,LL), 'FULL' (=RR,LL,RL,LR) ANTENNAS...A list of the antennas to include in the output data set. If any number is negative then all antennas listed are NOT to be included. 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 overide 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 copy. 0=>all. EIF........Highest IF to copy. 0=>all higher than BIF BCHAN......First channel to copy. 0=>all. ECHAN......Highest channel to copy. 0=>all higher than BCHAN If APARM(1) = 1, the actual # of output channels will be (BCHAN-ECHAN+1-NCHAV)/CHINC + 1 Thus, ECHAN is the highest channel in the input averaged into the output and is the highest output channel only if NCHAV and CHINC are 1. SUBARRAY...Subarray number to copy. 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 table to apply to multi-source files or the SN table for single-source files. 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 if DOBAND > 0. 0 => highest numbered table. <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). OUTCLASS...Output UV file name (class). Standard defaults. The output file name will be the first 12 characters of the name of the source. If more than one "source" has the same name, the affected output file names have the CALCODE and QUAL inserted in characters 9-12. For single-source files, the output name will be INNAME. OUTSEQ.....Output UV file name (seq. #). 0 => highest unique If QUAL = -1, OUTSEQ must be zero if there are in fact more than one qualifier for a given source name. OUTDISK....Disk drive # of output UV file. 0 => highest with space for the file. DOUVCOMP...If true (DOUVCOMP > 0) the output data is written in compressed format which can result in a substantial reduction in disk space needed. DO NOT USE THIS OPTION if there is channel-dependent flagging and and you are doing spectral averaging (APARM(1) > 0). If there is IF-dependent flagging and you are using IF averaging (APARM(1) > 2.5) this option is also not recommended. APARM......Control information: (1) If 0 < APARM(1) <= 1.5, then a boxcar spectral smoothing is applied to the spectra after calibration and before output under control of NPOINTs and CHINC. If APARM(1) > 1.5, then all frequency channels in each IF (under control of ICHANSEL) will be averaged in the output. If APARM(1) > 2.5, then all IF's will be averaged also, providing a one pass process for spectral averaging of calibrated VLBI data. WARNING: the output frequency will be corrected to the averaged frequency as will the values of u,v,w, but any IF-dependent editing will make this correction less than accurate. Also the output data are computed by a weighted average while the frequency is a straight average. If weights vary significantly between IFs (and they often do) then the corrections to u,v,w will not have been correct and the error will be sample dependent. (2) If phase rate corrections are to be done as part of the calibration, then the integration time of the input data must be given in APARM(2) to allow for an amplitude correction to correct for the effect of time smearing on the data. Default is no correction. There is no time averaging of the output data. (3) If APARM(3) > 0 then drop the subarray code from the visibility records. (5) If APARM(5) = 0 then SPLIT will pass only cross-power data, this is the default mode. If APARM(5)=1 then both cross-power and total-power data will be passed; if APARM(5)=2 then only total-power data will be passed. (6) If APARM(6) > 0, the full 16 character source name is added to the header. The first 8 characters in keyword SOURNAM1, the second 8 in keyword SOURNAM2. NCHAV......If APARM(1) = 1, the number of channels to be averaged together in each output channel. 0 => ALL. If this value is less than the total number of channels, then a multi-channel data set will result. CHINC......If APARM(1) = 1, the number of input channels to skip between output channels. 0 => NCHAVG ICHANSEL...The channels to be averaged when APARM(1) > 1.5 in the form of an array of start and stop channels plus a channel increment and the IF to which they apply. All 0 => BCHAN, ECHAN, 1, 0. ICHANSEL(4,i) gives the IF and 0 means all IFs. Up to 20 groups of these 4 numbers may be specified. Note that the channel numbers are absolute numbers; they are NOT relative to BIF and BCHAN. For instance if your data had a spectral line covering channels 56 - 80, and you wished to exclude channels 1 - 10 and 121 - 128 because of bandpass effects, then you could set APARM(1) = 2, and ICHANSEL = 11, 55, 1, 0, 81, 121, 1, 0 for a 1-IF data set. If you only wished to use every other channel from the second group then you would set ICHANSEL = 11, 55, 0, 0, 81, 121, 2, 0. BADDISK....A list of disks on which scratch files are not to be placed. This will not affect the output file. ----------------------------------------------------------------