AIPS NRAO AIPS HELP file for VHCAL in 31DEC24



As of Tue Nov 12 10:12:04 2024


VHCAL: Divide I, Q, U, models into linear polarization data

INPUTS

INNAME                             Input UV data name (name)
INCLASS                            Input UV data name (class)
INSEQ             0.0     9999.0   Input UV data name (seq. #)
INDISK            0.0        9.0   Input UV data disk unit #
IN2NAME                            Input I model UV (name)
IN2CLASS                           Input I model UV (class)
IN2SEQ            0.0     9999.0   Input I model UV (seq. #)
IN2DISK           0.0        9.0   Input I model disk unit #
IN3NAME                            Input Q model UV (name)
IN3CLASS                           Input Q model UV (class)
IN3SEQ            0.0     9999.0   Input Q model UV (seq. #)
IN3DISK           0.0        9.0   Input Q model disk unit #
IN4NAME                            Input U model UV (name)
IN4CLASS                           Input U model UV (class)
IN4SEQ            0.0     9999.0   Input U model UV (seq. #)
IN4DISK           0.0        9.0   Input U model disk unit #
CALSOUR                            (1) Calibration source name
DOCALIB          -1.0      101.0   > 0 calibrate data & weights
                                   > 99 do NOT calibrate weights
GAINUSE                            CL (or SN) 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
OUTNAME                            Output UV data name (name)
OUTCLASS                           Output UV data name (class)
OUTSEQ                             Output UV data name (seq)
OUTDISK                            Output UV data disk unit #
BADDISK                            Disk to avoid for scratch

HELP SECTION

VHCAL
Task:  This task takea an input UV data set in linear polarization and
       divides by a model taken from matching I, Q, and U model data
       sets. Typically, the procedure VHCALIB produces these from the
       input data set and model images using SPLIT and UVSUB.

       The output UV file is a divided file suitable for input to CALIB
       with APARM(2)=1.  The model is
                VV = I + Q cos(p1+p2) + U sin (p1+p2)
                HH = I - Q cos(p1+p2) - U sin (p1+p2)
       where p1 and p2 are the two antennas' parallactic angles
       (functions of time) and I, Q, U are the Stokes visibility
       functions of location in the u,v plane.  The input data after
       DOCALIB, DOBAND, and FLAGVER must exactly align with the I, Q,
       U model data sets.
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.
  IN2NAME....Input I UV model name (name).       Standard defaults.
  IN2CLASS...Input I UV model name (class).      Standard defaults.
  IN2SEQ.....Input I UV model name (seq. #).     0 => highest.
  IN2DISK....Disk drive # of input I UV model.   0 => any.
  IN3NAME....Input Q UV model name (name).       Standard defaults.
  IN3CLASS...Input Q UV model name (class).      Standard defaults.
  IN3SEQ.....Input Q UV model name (seq. #).     0 => highest.
  IN3DISK....Disk drive # of input Q UV model.   0 => any.
  IN4NAME....Input U UV model name (name).       Standard defaults.
  IN4CLASS...Input U UV model name (class).      Standard defaults.
  IN4SEQ.....Input U UV model name (seq. #).     0 => highest.
  IN4DISK....Disk drive # of input U UV model.   0 => any.
  CALSOUR....(1) Calibration source name.  (2)-(30) ignored.
  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.
  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.
  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
  BADDISK....The disk numbers to avoid for scratch files (sorting

EXPLAIN SECTION


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