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| == Help on gaincal task: ==
| | {{gaincal}} |
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| <pre>
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| Determine temporal gains from calibrator observations
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| The complex gains for each antenna/spwid are determined from the
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| data column (raw data) divided by the model column. The gains can
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| be obtained for a specified solution interval, spw combination and
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| field combination. The GSPLINE spline (smooth) option is still under
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| development.
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| Previous calibrations (egs, bandpass, opacity, parallactic angle) can
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| be applied on the fly. At present with dual-polarized data, both
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| polarizations must be unflagged for any solution to be obtained.
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| Keyword arguments:
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| vis -- Name of input visibility file
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| default: none; example: vis='ngc5921.ms'
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| caltable -- Name of output gain calibration table
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| default: none; example: caltable='ngc5921.gcal'
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| --- Data Selection (see help par.selectdata for more detailed information)
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| field -- Select field using field id(s) or field name(s).
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| ['go listobs' to obtain the list id's or names]
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| default: ''=all fields
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| If field string is a non-negative integer, it is assumed a
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| field index, otherwise, it is assumed a field name
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| field='0~2'; field ids 0,1,2
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| field='0,4,5~7'; field ids 0,4,5,6,7
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| field='3C286,3C295'; field named 3C286 and 3C295
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| field = '3,4C*'; field id 3, all names starting with 4C
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| DON'T FORGET TO INCLUDE THE FLUX DENSITY CALIBRATOR IF YOU HAVE ONE
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| spw -- Select spectral window/channels
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| type 'help par.selection' for more examples.
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| spw='0~2,4'; spectral windows 0,1,2,4 (all channels)
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| spw='<2'; spectral windows less than 2 (i.e. 0,1)
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| spw='0:5~61'; spw 0, channels 5 to 61, INCLUSIVE
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| spw='*:5~61'; all spw with channels 5 to 61
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| spw='0,10,3:3~45'; spw 0,10 all channels, spw 3, channels 3 to 45.
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| spw='0~2:2~6'; spw 0,1,2 with channels 2 through 6 in each.
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| spw='0:0~10;15~60'; spectral window 0 with channels 0-10,15-60
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| NOTE ';' to separate channel selections
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| spw='0:0~10^2,1:20~30^5'; spw 0, channels 0,2,4,6,8,10,
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| spw 1, channels 20,25,30
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| selectdata -- Other data selection parameters
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| default: True
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| timerange -- Select data based on time range:
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| default = '' (all); examples,
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| timerange = 'YYYY/MM/DD/hh:mm:ss~YYYY/MM/DD/hh:mm:ss'
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| Note: if YYYY/MM/DD is missing date defaults to first day in data set
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| timerange='09:14:0~09:54:0' picks 40 min on first day
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| timerange= '25:00:00~27:30:00' picks 1 hr to 3 hr 30min on NEXT day
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| timerange='09:44:00' pick data within one integration of time
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| timerange='>10:24:00' data after this time
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| uvrange -- Select data within uvrange (default units meters)
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| default: '' (all); example:
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| uvrange='0~1000klambda'; uvrange from 0-1000 kilo-lambda
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| uvrange='>4klambda';uvranges greater than 4 kilo lambda
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| antenna -- Select data based on antenna/baseline
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| default: '' (all)
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| If antenna string is a non-negative integer, it is assumed an
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| antenna index, otherwise, it is assumed as an antenna name
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| antenna='5&6'; baseline between antenna index 5 and index 6.
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| antenna='VA05&VA06'; baseline between VLA antenna 5 and 6.
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| antenna='5&6;7&8'; baselines with indices 5-6 and 7-8
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| antenna='5'; all baselines with antenna index 5
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| antenna='05'; all baselines with antenna number 05 (VLA old name)
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| antenna='5,6,10'; all baselines with antennas 5,6,10 index numbers
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| scan -- Scan number range.
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| Check 'go listobs' to insure the scan numbers are in order.
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| msselect -- Optional complex data selection (ignore for now)
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| --- Solution parameters
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| gaintype -- Type of gain solution (G, T, or GSPLINE)
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| default: 'G'; example: gaintype='GSPLINE'
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| 'G' means determine gains for each polarization and sp_wid
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| 'T' obtains one solution for both polarizations; Hence. their
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| phase offset must be first removed using a prior G.
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| 'GSPLINE' makes a spline fit to the calibrator data. It is
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| useful for noisy data and fits a smooth curve through the
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| calibrated amplitude and phase. However,
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| at present GSPLINE is somewhat experimental. Use with
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| caution and check solutions.
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| calmode -- Type of solution
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| default: 'ap' (amp and phase); example: calmode='p'
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| Options: 'p','a','ap'
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| solint -- Solution interval (units optional)
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| default: 'inf' (~infinite, up to boundaries controlled by combine);
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| Options: 'inf' (~infinite),
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| 'int' (per integration)
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| any float or integer value with or without units
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| examples: solint='1min'; solint='60s'; solint=60 --> 1 minute
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| solint='0s'; solint=0; solint='int' --> per integration
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| solint-'-1s'; solint='inf' --> ~infinite, up to boundaries
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| interacts with combine
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| combine -- Data axes to combine for solving
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| default: '' --> solutions will break at scan, field, and spw
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| boundaries
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| Options: '','scan','spw',field', or any comma-separated combination
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| example: combine='scan,spw' --> extend solutions over scan boundaries
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| (up to the solint), and combine spws for solving
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| refant -- Reference antenna name
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| default: '' => refant = '0' (may not be a good choice)
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| example: refant='4' (antenna with index 4)
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| refant='VA04' (VLA antenna #4)
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| Use taskname=listobs for antenna listing
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| minblperant -- Minimum number of baselines required per antenna for each solve
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| default = 4
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| Antennas with fewer baaselines are excluded from solutions.
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| example: minblperant=10 => Antennas participating on 10 or more
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| baselines are included in the solve
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| minblperant = 1 will solve for all baseline pairs, even if only
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| one is present in the data set. Unless closure errors are
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| expected, use taskname=gaincal rather than taskname=blcal to
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| obtain more options in data analysis.
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| minsnr -- Reject solutions below this SNR
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| default: 0.0 (accept all attempted solutions)
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| solnorm -- Normalize average solution amps to 1.0 after solution (G, T only)
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| default: False (no normalization)
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| append -- Append solutions to the (existing) table
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| default: False; overwrite existing table or make new table
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| splinetime -- Spline timescale (sec); used for gaintype='GSPLINE'
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| default: 3600 (1 hour); example: splinetime=1000
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| Typical splinetime should cover about 3 to 5 calibrator scans.
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| npointaver -- Tune phase-unwrapping algorithm for gaintype='GSPLINE'
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| default: 3; Keep at this value
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| phasewrap -- Wrap the phase for changes larger than this amoun (degrees)
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| default: 180; Keep at this value
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| --- Other calibrations to apply on the fly before determining gaincal solution
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| gaintable -- Gain calibration table(s) to apply
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| default: '' (none);
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| examples: gaintable='ngc5921.gcal'
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| gaintable=['ngc5921.ampcal','ngc5921.phcal']
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| gainfield -- Select a subset of calibrators from gaintable(s) to apply
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| default:'' ==> all sources in table;
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| same syntax as field
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| example: gainfield='0~2,5' means use fields 0,1,2,5 from gaintable
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| gainfield=['0~3','4~6'] means use field 0 through 3
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| from first gain file, field 4 through 6 for second.
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| interp -- Interpolation mode (in time) to use for each gaintable
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| default: '' --> 'linear' for all gaintable(s)
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| example: interp='nearest'
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| append -- Append solutions to the (existing) table
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| default: False; overwrite existing table or make new table
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| splinetime -- Spline timescale (sec); used for gaintype='GSPLINE'
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| default: 3600 (1 hour); example: splinetime=1000
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| Typical splinetime should cover about 3 to 5 calibrator scans.
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| npointaver -- Tune phase-unwrapping algorithm for gaintype='GSPLINE'
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| default: 3; Keep at this value
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| phasewrap -- Wrap the phase for changes larger than this amoun (degrees)
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| default: 180; Keep at this value
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| --- Other calibrations to apply on the fly before determining gaincal solution
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| gaintable -- Gain calibration table(s) to apply
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| default: '' (none);
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| examples: gaintable='ngc5921.gcal'
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| gaintable=['ngc5921.ampcal','ngc5921.phcal']
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| gainfield -- Select a subset of calibrators from gaintable(s) to apply
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| default:'' ==> all sources in table;
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| same syntax as field
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| example: gainfield='0~2,5' means use fields 0,1,2,5 from gaintable
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| gainfield=['0~3','4~6'] means use field 0 through 3
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| from first gain file, field 4 through 6 for second.
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| interp -- Interpolation mode (in time) to use for each gaintable
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| default: '' --> 'linear' for all gaintable(s)
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| example: interp='nearest'
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| interp=['nearest','linear']
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| Options: 'nearest', 'linear', 'aipslin'
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| spwmap -- Spectral windows combinations to form for gaintable(s)
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| default: [] (apply solutions from each spw to that spw only)
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| Example: spwmap=[0,0,1,1] means apply the caltable solutions
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| from spw = 0 to the spw 0,1 and spw 1 to spw 2,3.
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| spwmap=[[0,0,1,1],[0,1,0,1]]
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| gaincurve -- Apply internal VLA antenna gain curve correction (True/False)
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| default: False;
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| Use gaincurve=True ONLY for VLA data
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| opacity -- Opacity correction to apply (nepers)
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| default: 0.0 (no opacity correction)
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| example: opacity=0.051
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| Typical VLA values are: 5 GHz - 0.013, 8 GHz - 0.013
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| 15 GHz - 0.016, 23 GHz - 0.051, 43 GHz - 0.07
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| preavg -- Pre-averaging interval (sec)
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| default=-1 (none).
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| Rarely needed. Will average data over periods shorter than
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| the solution interval first.
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| async -- Run asynchronously
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| default = False; do not run asychronously
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| </pre>
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