; DOCALIB
;---------------------------------------------------------------
;! specifies whether a gain table is to be applied or not
;# ADVERB CALIBRATION
;-----------------------------------------------------------------------
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;-----------------------------------------------------------------------
DOCALIB   LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC
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DOCALIB
Type: Adverb  (Logical,  > 0  =>  true)
Use:  Standard data selection adverb. True (> 0) means apply the
      selected gain table before the specified operation on the
      uv data.  False (<= 0) means do not apply calibration.

      True also tells AIPS tasks to apply the amplitude calibration to
      the data weights as well as applying the amplitude and phase
      calibration to the visibilities.  This should be used with all
      VLBI data and with any VLA data loaded by FILLM with weights set
      by the nominal sensitivities.  The option to do this was added
      to the 31DEC00 (then called 31DEC99) version of FILLM on March
      25, 2000.

      For data in which the weights are not in uncalibrated 1/Jy^^2,
      set DOCAL > 99 (i.e. 100).   Data loaded with FILLM prior to
      2000 have weights that simply reflected a count of 10-sec
      records and so should not have the calibration applied to them.
      Note that any VLA data (including observations way before 2000)
      that are loaded after 2000 will probably have weights dependent
      on the nominal sensitivities and hence suitable to calibration.

      AIPS tries to keep track of whether the weights are real for EVLA
      data (so that gains should be applied) or have not yet had TYAPL
      applied.  The correct thing is usually done but setting DOCALIB =
      100 forces there to be no scaling of weights.
Null value:  false (-1)
Verbs:
   OBITIMAG......Access to OBIT task Imager without self-cal or peeling.
   OBITPEEL......Access to OBIT task Imager with self-cal and peeling.
   OBITSCAL......Access to OBIT task Imager with self-cal, NOT peeling.
Procedures:
   LINIMAGE......Build image cube from multi-IF data set.
   STUFFR........Averages together data sets in hour angle.
   VLACALIB......Runs CALIB and LISTR for VLA observation.
Tasks:
   ACCOR.........Corrects cross amplitudes using auto correlation
                 measurements.
   ACFIT.........Determine antenna gains from autocorrelations.
   ACLIP.........Edits suto-corr data for amplitudes, phases, and weights
                 out of range.
   ACSCL.........Corrects cross amplitudes using auto correlation
                 measurements.
   ALVAR.........Plots the Allan Variance statistic of a UV data set.
   ALVPR.........Prints statistics on the Allan Variance of a UV data set.
   ANBPL.........Plots and prints uv data converted to antenna based
                 values.
   AVSPC.........Averages uv-data in the frequency domain.
   BLAVG.........Average cross-polarized UV data over baselines.
   BLCAL.........Compute closure offset corrections.
   BLCHN.........Compute closure offset corrections on a
                 channel-by-channel basis.
   BLING.........Find residual rate and delay on individual baselines.
   BPASS.........Computes spectral bandpass correction table.
   BPWAY.........Determines channel-dependent relative weights.
   BPWGT.........Calibrates data and scales weights by bandpass
                 correction.
   BSCAN.........Seeks best scan to use for phase cal, fringe search, ..
   BSGRD.........Task to image beam-switched single-dish data.
   CALIB.........Determines antenna calibration: complex gain.
   CAPLT.........Plots closure amplitude and model from CC file.
   CLIP..........Edits data based on amplitudes, phases, and weights out
                 of range.
   CLPLT.........Plots closure phase and model from CC file.
   CORER.........Calculates correlator statistics and flags bad ones.
   CPASS.........Computes polynomial spectral bandpass correction table.
   DECOR.........Measures the decorrelation between channels and IF of uv
                 data.
   DEFLG.........Edits data based on decorrelation over channels and time.
   DFTIM.........Makes image of DFT at arbitrary point showing time vs
                 frequency.
   DFTPL.........Plots DFT of a UV data set at arbitrary point versus
                 time.
   DIFRL.........Divides the RR data by LL data.
   DTSUM.........Task to provide a summary of the contents of a dataset.
   EDITR.........Interactive baseline-oriented visibility editor using the
                 TV.
   EVAUV.........Subtracts & divides a model into UV data, does statistics
                 on results.
   FGCNT.........Counts samples comparing two flag tables.
   FGSPW.........Flags bad spectral windows.
   FINDR.........Find normal values for a uv data set.
   FLAGR.........Edit data based on internal RMS, amplitudes, weights.
   FLGIT.........Flags data based on the rms of the spectrum.
   FLOPM.........Reverses the spectral order of UV data, can fix VLA
                 error.
   FRING.........Fringe fit data to determine antenna calibration, delay,
                 rate.
   FRMAP.........Task to build a map using fringe rate spectra.
   FRPLT.........Task to plot fringe rate spectra.
   FTFLG.........Interactive flagging of UV data in channel-time using the
                 TV.
   FUDGE.........Modifies UV data with user's algorithm: paraform task.
   IBLED.........Interactive BaseLine based visibility EDitor.
   IMAGR.........Wide-field and/or wide-frequency Cleaning / imaging task.
   KRING.........Fringe fit data to determine antenna calibration, delay,
                 rate.
   LISTR.........Prints contents of UV data sets and assoc. calibration
                 tables.
   LPCAL.........Determines instrumental polarization for UV data.
   MAPBM.........Map VLA beam polarization.
   NOIFS.........Makes all IFs into single spectrum.
   OMFIT.........Fits sources and, optionally, a self-cal model to uv
                 data.
   PCAL..........Determines instrumental polarization for UV data.
   PCPLT.........Plots pulse-cal tables in 2 dimensions as function of
                 time.
   PHSRF.........Perform phase-referencing within a spectral line
                 database.
   POSSM.........Task to plot total and cross-power spectra.
   PRTSD.........Prints contents of AIPS single-dish data sets.
   REWAY.........Computes weights based in rms in spectra.
   RFI...........Look for RFI in uv data.
   RFLAG.........Flags data set based on time and freq rms in fringe
                 visibilities.
   RLCAL.........Determines instrumental right-left phase versus time (a
                 self-cal).
   RLDIF.........Determines Right minus Left phase difference, corrects
                 cal files.
   RLDLY.........Fringe fit data to determine antenna R-L delay
                 difference.
   SCIMG.........Full-featured imaging plus self-calibration loop with
                 editing.
   SCMAP.........Imaging plus self-calibration loop with editing.
   SDCAL.........Task to apply single dish calibration.
   SDGRD.........Task to select and image random-position single-dish
                 data.
   SDIMG.........Task to select and image random-position single-dish
                 data.
   SHOUV.........Displays uv data in various ways.
   SPCAL.........Determines instrumental polzn. for spec. line UV data.
   SPFLG.........Interactive flagging of UV data in channel-TB using the
                 TV.
   SPLAT.........Applies calibration and splits or assemble selected
                 sources.
   SPLIT.........Converts multi-source to single-source UV files w
                 calibration.
   SPMOD.........Modify UV database by adding a model with spectral lines.
   SPRMS.........Plots spectral statistics of a selected subset of a uv
                 data set.
   SUFIX.........Modifies source numbers on uv data.
   SWPOL.........Swap polarizations in a UV data base.
   TI2HA.........Modifies times in UV data to hour angles.
   TIORD.........Checks data for time baseline ordering, displays
                 failures.
   TRUEP.........Determines true antenna polarization from special data
                 sets.
   TVFLG.........Interactive flagging of UV data using the TV.
   UFLAG.........Plots and edits data using a uv-plane grid and the TV.
   UV2MS.........Append single-source file to multi-source file.
   UV2TB.........Converts UV autocorrelation spectra to tables.
   UVAVG.........Average or merge a sorted (BT, TB) uv database.
   UVBAS.........Averages several channels and subtracts from uv data.
   UVFIT.........Fits source models to uv data.
   UVFND.........Prints selected data from UV data set to search for
                 problems.
   UVFRE.........Makes one data set have the spectral structure of
                 another.
   UVGIT.........Fits source models to uv data.
   UVHGM.........Plots statistics of uv data files as histogram.
   UVHIM.........Makes image of the histogram on two user-chosen axes.
   UVHOL.........Prints holography data from a UV data base with
                 calibration.
   UVIMG.........Grid UV data into an "image".
   UVLIN.........Fits and removes continuum visibility spectrum, also can
                 flag.
   UVLSD.........Least squares fit to channels and divides the uv data.
   UVLSF.........Least squares fit to channels and subtracts from uv data.
   UVMLN.........Edits data based on the rms of the spectrum.
   UVMOD.........Modify UV database by adding a model incl spectral index.
   UVMTH......... Averages one data set and applied it to another.
   UVPLT.........Plots data from a UV data base in multiple ways.
   UVPRM.........Measures parameters from a UV data base.
   UVPRT.........Prints data from a UV data base with calibration.
   UVRFI.........Mitigate RFI by Fourier transform or fitting the circle.
   UVRMS.........Computes statistics of a selected subset of a uv data
                 set.
   VPLOT.........Plots uv data and model from CC file.
   WIPER.........Plots and edits data from a UV data base using the TV.
   XYDIF.........Find/apply X minus Y linear polarization phase
                 difference.
   XYMOD.........Compute linear polarization point source model, applies
                 to data.
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