; FREQID
;---------------------------------------------------------------
;! Frequency Identifier for frequency, bandwidth combination
;# ADVERB CALIBRATION
;-----------------------------------------------------------------------
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;;  Associated Universities, Inc. Washington DC, USA.
;;
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;;
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;;  GNU General Public License for more details.
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;;
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;;         Postal address: AIPS Project Office
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;-----------------------------------------------------------------------
;---------------------------------------------------------------
FREQID    LLLLLLLLLLLLUUUUUUUUUUUU CCCCCCCCCCCCCCCCCCCCCCCCCCCCC
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FREQID
Type: Adverb (Scalar)
Use:  A selection adverb for the calibration tasks.  FREQID is an
      integer pointer to the desired frequency/bandwidth combination of
      data to be selected.  Data written to AIPS after 15APR89 may have
      an associated FQ table (which may be printed with PRTAB or LISTR)
      which contains frequency information relevant to the database, the
      FREQID adverb is a quick way to select the data you require and is
      an alternative to the SELBAND and SELFREQ adverbs. In fact,
      sometimes using the SELBAND/SELFREQ adverbs may result in an
      ambiguity; in which case the tasks will insist that you use FREQID.
Null value: 0 => first
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.
   VLACALIB......Runs CALIB and LISTR for VLA observation.
   VLACLCAL......Runs CLCAL and prints the results with LISTR.
   VLALIST.......Runs LISTR for VLA observation.
   VLBACALA......Applies a-priori amplitude corrections to VLBA data.
Tasks:
   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.
   ANCAL.........Places antenna-based Tsys and gain corrections in CL
                 table.
   APCAL.........Apply TY and GC tables to generate an SN table.
   ATMCA.........Determines delay/phase gradient from calibrator
                 observations.
   AVSPC.........Averages uv-data in the frequency domain.
   BASRM.........Task to remove a spectral baseline from total power
                 spectra.
   BLAPP.........Applies baseline-based fringe solutions a la BLAPP.
   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.
   BLPLT.........Plots BLCAL tables in 2 dimensions as function of
                 baseline and IF.
   BPASS.........Computes spectral bandpass correction table.
   BPCOR.........Correct BP table.
   BPEDT.........Interactive TV task to edit uv data based on BP tables.
   BPEPL.........Plots bandpass tables overlaying multiple times like
                 BPEDT.
   BPLOT.........Plots bandpass tables in 2 dimensions as function of
                 time.
   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, ..
   CALIB.........Determines antenna calibration: complex gain.
   CAPLT.........Plots closure amplitude and model from CC file.
   CLCAL.........Merges and smooths SN tables, applies them to CL tables.
   CLCOR.........Applies user-selected corrections to the calibration CL
                 table.
   CLIP..........Edits data based on amplitudes, phases, and weights out
                 of range.
   CLPLT.........Plots closure phase and model from CC file.
   CLSMO.........Smooths a calibration CL table.
   CLVLB.........Corrects CL table gains for pointing offsets in VLBI
                 data.
   COHER.........Baseline Phase coherence measurement.
   CORER.........Calculates correlator statistics and flags bad ones.
   CPASS.........Computes polynomial spectral bandpass correction table.
   CVEL..........Shifts spectral-line UV data to a given velocity.
   DECOR.........Measures the decorrelation between channels and IF of uv
                 data.
   DEFLG.........Edits data based on decorrelation over channels and time.
   DELZN.........Determines residual atmosphere depth at zenith and clock
                 errors.
   DFCOR.........Applies user-selected corrections to the calibration CL
                 table.
   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.
   EDITA.........Interactive TV task to edit uv data based on TY/SY/SN/CL
                 tables.
   EDITR.........Interactive baseline-oriented visibility editor using the
                 TV.
   ELFIT.........Plots/fits selected contents of SN, TY, SY, PC or CL
                 files.
   ELINT.........Determines and removes gain dependence on elevation.
   EVASN.........Evaluates statistics in SN/CL tables.
   EVAUV.........Subtracts & divides a model into UV data, does statistics
                 on results.
   FGCNT.........Counts samples comparing two flag tables.
   FGPLT.........Plots selected contents of FG table.
   FGPRT.........Pprints counts of selected portions of an FG table.
   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.
   GETJY.........Determines calibrator flux densities.
   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.
   LOCIT.........Fits antenna locations from SN-table data.
   LPCAL.........Determines instrumental polarization for UV data.
   MBDLY.........Fits multiband delays from IF phases, updates SN table.
   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.
   PCASS.........Finds amplitude bandpass shape from pulse-cal table data.
   PCCOR.........Corrects phases using  PCAL tones data from PC table.
   PCEDT.........Interactive TV task to edit pulse-cal (PC) tables.
   PCFIT.........Finds delays and phases using a pulse-cal (PC) table.
   PCPLT.........Plots pulse-cal tables in 2 dimensions as function of
                 time.
   PCVEL.........Shifts spectral-line UV data to a given velocity: planet
                 version.
   PDEDT.........Interactive TV task to edit polarization D-term (PD)
                 tables.
   PDPLT.........Plots selected contents of PD tables.
   PHSRF.........Perform phase-referencing within a spectral line
                 database.
   POSSM.........Task to plot total and cross-power spectra.
   PPAPP.........Applies Right minus Left phase difference to a 2nd data
                 set.
   PRTSY.........Task to print statistics from the SY table.
   QUACK.........Flags beginning or end portions of UV-data scans.
   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).
   RLCOR.........Corrects a data set for R-L phase differences.
   RLDIF.........Determines Right minus Left phase difference, corrects
                 cal files.
   RLDLY.........Fringe fit data to determine antenna R-L delay
                 difference.
   SETJY.........Task to enter source info into source (SU) table.
   SHOUV.........Displays uv data in various ways.
   SNBLP.........Plots selected contents of SN or CL files on a baseline
                 basis.
   SNCOR.........Applies user-selected corrections to the calibration SN
                 table.
   SNEDT.........Interactive SN/CL/TY/SY table editor using the TV.
   SNFIT.........Fits parabola to SN amplitudes and plots result.
   SNFLG.........Writes flagging info based on the contents of SN files.
   SNIFS.........Plots selected contents of SN, TY, SY, PC or CL files by
                 IF.
   SNPLT.........Plots selected contents of SN, SY, TY, PC or CL files
                 versus time.
   SNREF.........Chooses best reference antenna to minimize R-L
                 differences.
   SNSMO.........Smooths and filters a calibration SN table.
   SOLCL.........Adjust gains for solar data according to nominal
                 sensitivity.
   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.
   SWAPR.........Modifies UV data by swapping real and imaginary parts.
   SYPRT.........Task to print values from the SY table.
   SYSOL.........Undoes and re-does nominal sensitivity application for
                 Solar data.
   SYVSN.........Plots selected SY/TY data with SN solution values versus
                 time.
   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.
   TYAPL.........Undoes and re-does nominal sensitivity application.
   TYSMO.........Smooths and filters a calibration TY or SY table.
   UFLAG.........Plots and edits data using a uv-plane grid and the TV.
   USUBA.........Assign subarrays within a uv-data file.
   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.
   UVCOP.........Task to copy a subset of a UV data file.
   UVFIT.........Fits source models to uv data.
   UVFLG.........Flags 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.
   VLAMP.........Makes ANTAB file for phased VLA used in VLBI
                 observations.
   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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