AIPS NRAO AIPS HELP file for RLCAL in 31DEC18



As of Fri Sep 21 20:56:58 2018


RLCAL: Task to do right - left phase self-cal

INPUTS

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.

HELP SECTION

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.

EXPLAIN SECTION


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