#
# stub function definition file for docstring parsing
#
[docs]def gaincal(vis, caltable='', field='', spw='', intent='', selectdata=True, timerange='', uvrange='', antenna='', scan='', observation='', msselect='', solint='inf', combine='', preavg=1.0, refant='', refantmode='flex', minblperant=4, minsnr=3.0, solnorm=False, normtype='mean', gaintype='G', smodel='', calmode='ap', solmode='', rmsthresh='', corrdepflags=False, append=False, splinetime=3600.0, npointaver=3, phasewrap=180.0, docallib=False, callib='', gaintable='', gainfield='', interp='', spwmap='', parang=False):
r"""
Determine temporal gains from calibrator observations
[`Description`_] [`Examples`_] [`Development`_] [`Details`_]
Parameters
 vis_ (path)  Name of input visibility file
 caltable_ (string='')  Name of output gain calibration table
 field_ (string='')  Select field using field id(s) or field name(s)
 spw_ (string='')  Select spectral window/channels
 intent_ (string='')  Select observing intent
 selectdata_ (bool=True)  Other data selection parameters
.. raw:: html
<details><summary><i> selectdata = True </i></summary>
 timerange_ (string='')  Select data based on time range
 uvrange_ (variant='')  Select data by baseline length.
 antenna_ (string='')  Select data based on antenna/baseline
 scan_ (string='')  Scan number range
 observation_ ({string, int}='')  Select by observation ID(s)
 msselect_ (string='')  Optional complex data selection (ignore for now)
.. raw:: html
</details>
 solint_ (variant='inf')  Solution interval
 combine_ (string='')  Data axes which to combine for solve (obs, scan, spw, and/or field)
 preavg_ (double=1.0)  Preaveraging interval (sec) (rarely needed)
 refant_ (string='')  Reference antenna name(s)
 refantmode_ (string='flex')  Reference antenna mode
 minblperant_ (int=4)  Minimum baselines _per antenna_ required for solve
 minsnr_ (double=3.0)  Reject solutions below this SNR
 solnorm_ (bool=False)  Normalize (squared) solution amplitudes (G, T only)
.. raw:: html
<details><summary><i> solnorm = True </i></summary>
 normtype_ (string='mean')  Solution normalization calculation type: mean or median
.. raw:: html
</details>
 gaintype_ (string='G')  Type of gain solution (G,T,GSPLINE,K,KCROSS)
.. raw:: html
<details><summary><i> gaintype = GSPLINE </i></summary>
 splinetime_ (double=3600.0)  Spline timescale(sec); All spw\'s are first averaged.
 npointaver_ (int=3)  The phaseunwrapping algorithm
 phasewrap_ (double=180.0)  Wrap the phase for jumps greater than this value (degrees)
.. raw:: html
</details>
 smodel_ (doubleVec='')  Point source Stokes parameters for source model.
 calmode_ (string='ap')  Type of solution" (\'ap\', \'p\', \'a\')
 solmode_ (string='')  Robust solving mode: (\'\', \'L1\', \'R\',\'L1R\')
 rmsthresh_ (doubleVec='')  RMS Threshold sequence (for solmode=\'R\' or \'L1R\'; see help)
 corrdepflags_ (bool=False)  Respect correlationdependent flags
 append_ (bool=False)  Append solutions to the (existing) table
 docallib_ (bool=False)  Use callib or traditional cal apply parameters
.. raw:: html
<details><summary><i> docallib = False </i></summary>
 gaintable_ (stringVec='')  Gain calibration table(s) to apply on the fly
 gainfield_ (stringVec='')  Select a subset of calibrators from gaintable(s)
 interp_ (stringVec='')  Interpolation parameters for each gaintable, as a list
 spwmap_ (any='')  Spectral window mappings to form for gaintable(s)
.. raw:: html
</details>
.. raw:: html
<details><summary><i> docallib = True </i></summary>
 callib_ (string='')  Cal Library filename
.. raw:: html
</details>
 parang_ (bool=False)  Apply parallactic angle correction
.. _Returns:
Returns
out (dict)  statistics of the solutions found, grouped by SPW and
antenna, including solutions expected, above *minblperant*, and
above *minsnr*, as well as what antennas were used as reference.
Also gives information on data selection and calibration tables used.
.. _Description:
Description
The complex timedependent gains for each antenna/spwid are
determined from the ratio of the data column (raw data), divided
by the model column, for the specified data selection. The gains
can be obtained for a specified solution interval for each
spectral window, or by a spline fit to all spectral windows
simultaneously. Any specified prior calibrations (e.g., bandpass)
will be applied on the fly.
.. rubric:: Introduction
The fundamental calibration to be done on your interferometer data
is to calibrate the antennabased gains as a function of time,
using **gaincal**. Systematic timedependent complex gain errors
are almost always the dominant calibration effect, and a solution
for them is almost always necessary before proceeding with any
other calibration solve. Traditionally, this calibration type has
been a catchall for a variety of similar effects, including: the
relative amplitude and phase gain for each antenna/polarization,
phase and amplitude drifts in the electronics of each antenna,
amplitude response as a function of elevation (gain curve), and
tropospheric amplitude and phase effects. In CASA, it is possible
to handle many of these specific effects separately, as available
information, circumstances, and required accuracy warrant, but if
accuracy is not paramount it is still possible to solve for the
net effect using a quickanddirty **gaincal**. In fact,
**gaincal** is often used for an initial exploration of a dataset,
to find data problems, etc. Also, a provisional gaincal solution
can be used as prior calibration to optimize bandpass
calibration. Such gaincal solutions are typically discarded.
It is best to have determined a (constant or slowlyvarying)
bandpass from the frequency channels by solving for the
**bandpass**, and to include any other ancillary calibration that
may be available via **gencal** (e.g., gaincurve, antenna position
corrections, opacity, etc.).
.. rubric:: Common calibration solve parameters
See `Solving for
Calibration <../../notebooks/synthesis_calibration.ipynb#SolveforCalibration>`__ for
more information on the task parameters **gaincal** shares with
all solving tasks, including data selection, general solving
properties and arranging prior calibration. Also see the
**rerefant** task documentation for the behavior of reference
antenna application. Below we describe parameters unique to
**gaincal**, and those common parameters with unique properties.
.. rubric:: Gain calibration types: *gaintype*
The *gaintype* parameter selects the type of gain solution to
compute. For complex gain calibration, the choices are *'T'*,
*'G'*, and *'GSPLINE'*. The **gaincal** task also supports
rudimetary delay solutions using *'K'* and *'KCROSS'*.
.. rubric:: Polarizationdependent sampled gain (*gaintype='G'*)
Generally speaking, *gaintype='G'* can represent any
multiplicative polarization and timedependent complex gain
effect downstream of the polarizers. (Polarization and
timeindependent effects upstream of the polarizers may also be
treated implicitly with G.) Multichannel data (per spectral
window) will be averaged in frequency before solving (use
calibration type B to solve for frequencydependent effects within
each spectral window).
.. rubric:: Polarizationindependent sampled gain (*gaintype='T'*)
At high radio frequencies (>10 GHz), it is often the case that the
most rapid timedependent gain errors are introduced by the
troposphere, and are polarization*independent*. It is therefore
unnecessary to solve for separate timedependent solutions for
both polarizations, as is the case for *gaintype='G'*. Thus
*gaintype='T'* is available to calibrate such tropospheric
effects, differing from G only in that a single common solution
for both polarizations is determined. In cases where only one
polarization is observed, *gaintype='T'* is adequate to describe
the timedependent complex multiplicative gain calibration
entirely. For the dualpolarization case, it is necessary to
ensure that the two polarizations are, in fact, coherent by using
a prior G or (unnormalized) bandpass calibration.
.. rubric:: Spline gains (*gaintype='GSPLINE'*)
At high radio frequencies, where tropospheric phase fluctuates
rapidly, it is often the case that there is insufficient
signaltonoise to obtain robust G or T solutions on timescales
short enough to track the variation. In this case it is desirable
to solve for a bestfit functional form for each antenna using the
GSPLINE solver. This fits a timeseries of cubic Bsplines to the
phase and/or amplitude of the calibrator visibilities.
The *combine* parameter can be used to combine data across
spectral windows, scans, and fields. Note that if you want to use
*combine='field'*, then all fields used to obtain a GSPLINE
amplitude solution must have models with accurate relative flux
densities. Use of incorrect relative flux densities will introduce
spurious variations in the GSPLINE amplitude solution.
The GSPLINE solver requires a number of unique additional
parameters, compared to ordinary G and T solving. The
subparameters are:
::
gaintype = 'GSPLINE' # Type of solution (G, T, or GSPLINE)
splinetime = 3600.0 # Spline (smooth) timescale (sec), default=1 hours
npointaver = 3 # Points to average for phase wrap
phasewrap = 180 # Wrap phase when greater than this
The duration of each spline segment is controlled by *splinetime*.
The *splinetime* will be adjusted automatically such that an
integral number of equallength spline segments will fit within
the overall range of data.
Phase splines require that cycle ambiguities be resolved prior to
the fit; this operation is controlled by *npointaver* and
*phasewrap*. The *npointaver* parameter controls how many
contiguous points in the timeseries are used to predict the cycle
ambiguity of the next point in the timeseries, and *phasewrap*
sets the threshold phase jump (in degrees) that would indicate a
cycle slip. Large values of *npointaver* improve the SNR of the
cycle estimate, but tend to frustrate ambiguity detection if the
phase rates are large. The *phasewrap* parameter may be adjusted
to influence when cycles are detected. Generally speaking, large
values (>180 degrees) are useful when SNR is high and phase rates
are low. Smaller values for *phasewrap* can force cycle slip
detection when low SNR conspires to obscure the jump, but the
algorithm becomes significantly less robust. More robust
algorithms for phasetracking are under development (including
traditional fringefitting).
.. warning:: GSPLINE solutions cannot be used in fluxscale. You should do at
least some longtimescale G amplitude solutions to establish
the flux scale, then do GSPLINE in phase before or after to fix
up the short timescale variations. Note also that the phase
tracking algorithm in GSPLINE needs some improvement.
.. rubric:: Single and multiband delay (*gaintype='K'*)
With *gaintype='K'* **gaincal** solves for simple antennabased
delays via Fourier transforms of the spectra on baselines to
(only) the reference antenna. This is not a global fringe fit but
will be useful for deriving delays from data of reasonable SNR. If
*combine* includes *'spw'*, multiband delays solved jointly from
all selected spectral windows will be determined, and will be
identified with the first spectral window id in the output
*caltable*. When applying a multiband delay table, a nontrivial
*spwmap* is required to distribute the solutions to all spectral
windows (fanout is not automatic). As of CASA 5.6, multiband
delays can be solved using heterogeneous spws (e.g., with
differing bandwidths, channelizations, etc.).
After solving for delays, a subsequent **bandpass** is recommended
to describe higherorder channeldependent variation in the phase
and amplitude.
.. rubric:: Crosshand delays (*gaintype='KCROSS'*)
With *gaintype='KCROSS',* **gaincal** solves for a global
crosshand delay. This is used only when doing polarimetry. Use
*parang=T* to apply prior gain and bandpass solutions. This mode
assumes that all crosshand data (per spw) share the same
crosshand delay residual, which should be the case for a proper
gain/bandpass calibration. See sections on polarimetry for more
information on use of this mode. Multiband crosshand delays are
only supported for homogeneous spws (same bandwidths,
channelizations, etc.).
.. rubric:: Solution normalization: *solnorm, normtype*
Nominally, gain solution amplitudes are implicitly scaled in
amplitude to satisfy the the effective amplitude ratio between the
visiibility data and model (as precorrected or precorrupted,
respectively, by specified prior calibrations). If *solnorm=True*,
the solution amplitudes will be normalized so as to achieve an
effective time and antennarelative gain calibration that will
minimally adjust the global amplitude scale of the visibility
amplitudes when applied. This is desirable when the model against
which the calibration is solved is in some way incomplete w.r.t.
the net amplitude scale, but a antenna and timerelative
calibration is desired, e.g., amplitudesensitive selfcalibration
when not all of the total flux density has been recovered in the
visibility model. The normalization factor is calculated from the
power gains (squared solution amplitudes) for all antennas and
times (per spw) according to the the setting of *normtype*. If
*normtype='mean'*, (the default), the square root of the mean
power gain is used to normalize the amplitude gains. If
*normtype='median'*, the median is used instead, which can be
useful to avoid biasing of the normalization by outlier
amplitudes. The default for *solnorm* is *solnorm=False*, which
means no normalization.
.. rubric:: Robust solving: *solmode, rmsthresh*
.. warning:: Robust solving modes in gaincal are considered experimental in
CASA 5.5. With more experience and testing in the coming
development cycles, we will provide more refined advice for use
of these options.
Nominally (*solmode=''*), gaincal performs an iterative,
steepestdescent chisquared minimization for its antennabased
gain solution, i.e., minimizaiton of the L2 norm. Visibility
outliers (i.e., data not strictly consistent with the assumption
of antennabased gains and the supplied visibility model within
the available SNR) can significantly distort the chisquared
gradient calculation, and thereby bias the resulting solution.
For an outlier on a single baseline, the solutions for the
antennas in that baseline will tend to be biased in the
direction of the outlier, and all other antenna solutions in the
other direction (by a lesser amount consistent with the fraction
of normal, nonoutlying baselines to them). It is thus
desirable to dampen the influence of such outliers, and
solmode/rmshresh provide a mechanism for achieving this. These
options apply only to *gaintype='G'* and *'T'*, and will be
ignored for other options.
Use of *solmode='L1'* invokes an approximate form of
minimization of the aggregate absolute deviation of visibilities
with respect to the model, i.e., the L1 norm. This is achieved
by accumulating the nominal chisquared and its gradient using
weights divided by (at each iteration of the steepest descent
process) the current perbaseline absolute residual (i.e., the
squareroot of each baseline's chisquare contribution). (NB:
It is not possible to analytically accumulate the gradient of L1
since the absolute value is not differentiable.) To avoid an
overreliance on baselines with atypically small residuals at
each interation, the weight adjustments are clamped to a minimum
(divided) value, and the steepest descent convergence is
repeated three times with increasingly modest clamping. The net
effect is to gently but effectively render the weight of
relative outliers to appropriately damped influence in the
solution.
Using *solmode='R'* invokes the normal L2 solution, but attempts
to identify outliers (relative to apparent aggregate rms) upon
steepest descent convergence, flag them, and repeat the steepest
descent. Since outliers will tend to bias the rms calculation
initially (and thus possibly render spuriously large rms
residuals for otherwise good data), outlier detection and
recovergence is repeated with increasingly aggressive rms
thresholds, a sequence specifiable in *rmsthresh*. By default
*(rmsthresh=[])* invokes a sequence of 10 thresholds borrowed
from a traditional implementation found in AIPS:
[7.0,5.0,4.0,3.5,3.0,2.8,2.6,2.4,2.2,2.5]. Note that the lower
threshold values are likely to cull visibilites not formally
outliers, but merely with modestly large residuals still
consistent with gaussian statistitics, and thereby unnecessarily
decrease net effective sensitivity in the gain solution (cf
normal L2), especially for larger arrays where the number of
baselines likely implies a larger number of visibility residuals
falling in the modest wings of the distribution. Thus, it may
be desirable to set *rmsthresh* manually to a more modest
sequence of thresholds. Optimization of *rmsthresh* for modern
arrays and conditions is an area of ongoing study.
Use of *solmode='L1R'* combines both the L1 and R modes
described above, with the iterative clamped L1 loop occuring
inside the R outliner excision threshold sequence loop.
.. _Examples:
Examples
To solve for G on, say, fields 1 & 2, on a 90s timescale, and do
so relative to gaincurve and bandpass corrections:
::
gaincal('data.ms',
caltable='cal.G90s', # Write solutions to disk file 'cal.G'
field='0,1', # Restrict field selection
solint='90s', # Solve for phase and amp on a 90s timescale
gaintable=['cal.B','cal.gc'], # prior bandpass and gaincurve tables
refant='3') # reference antenna
To solve for more rapid tropopheric gains (3s timescale) using the
above G solution, use *gaintype='T'*:
::
gaincal(vis='data.ms',
caltable='cal.T', # Output table name
gaintype='T', # Solve for T (polarizationindependent)
field='0,1', # Restrict data selection to calibrators
solint='3s', # Obtain solutions on a 3s timescale
gaintable=['cal.B','cal.gc','cal.G90s'], # all prior cal
refant='3') # reference antenna
To solve for GSPLINE phase and amplitudes, with splines of
duration 600 seconds:
::
gaincal('data.ms',
caltable='cal.spline.ap',
gaintype='GSPLINE' # Solve for GSPLINE
calmode='ap' # Solve for amp & phase
field='0,1', # Restrict data selection to calibrators
splinetime=600.) # Set spline timescale to 10min
.. _Development:
Development
No additional development details
.. _Details:
Parameter Details
Detailed descriptions of each function parameter
.. _vis:
 ``vis (path)``  Name of input visibility file
 Default: none
 Example: vis='ngc5921.ms'
.. _caltable:
 ``caltable (string='')``  Name of output gain calibration table
 Default: none
 Example: caltable='ngc5921.gcal'
.. _field:
 ``field (string='')``  Select field using field id(s) or field name(s)
 Default: '' (all fields)

 Use 'go listobs' to obtain the list id's or
 names. If field string is a nonnegative integer,
 it is assumed a field index, otherwise, it is
 assumed a field name.
 Examples:
 field='0~2'; field ids 0,1,2
 field='0,4,5~7'; field ids 0,4,5,6,7
 field='3C286,3C295'; field named 3C286 and
 3C295
 field = '3,4C\*'; field id 3, all names
 starting with 4C
.. _spw:
 ``spw (string='')``  Select spectral window/channels
 Default: '' (all spectral windows and channels)
 Examples:
 spw='0~2,4'; spectral windows 0,1,2,4 (all
 channels)
 spw='<2'; spectral windows less than 2
 (i.e. 0,1)
 spw='0:5~61'; spw 0, channels 5 to 61,
 INCLUSIVE
 spw='\*:5~61'; all spw with channels 5 to 61
 spw='0,10,3:3~45'; spw 0,10 all channels, spw
 3, channels 3 to 45.
 spw='0~2:2~6'; spw 0,1,2 with channels 2
 through 6 in each.
 spw='0:0~10;15~60'; spectral window 0 with
 channels 010,1560. (NOTE ';' to separate
 channel selections)
 spw='0:0~10^2,1:20~30^5'; spw 0, channels
 0,2,4,6,8,10, spw 1, channels 20,25,30
.. _intent:
 ``intent (string='')``  Select observing intent
 Default: '' (no selection by intent)
 Example: intent='*BANDPASS*' (selects data
 labelled with BANDPASS intent)
.. _selectdata:
 ``selectdata (bool=True)``  Other data selection parameters
 Default: True
 Options: TrueFalse
.. _timerange:
 ``timerange (string='')``  Select data based on time range
 Subparameter of selectdata=True
 Default = '' (all)
 Examples:
 timerange =
 'YYYY/MM/DD/hh:mm:ss~YYYY/MM/DD/hh:mm:ss'
 (Note: if YYYY/MM/DD is missing date defaults
 to first day in data set.)
 timerange='09:14:0~09:54:0' picks 40 min on
 first day
 timerange= '25:00:00~27:30:00' picks 1 hr to 3
 hr 30min on NEXT day
 timerange='09:44:00' pick data within one
 integration of time
 timerange='>10:24:00' data after this time
.. _uvrange:
 ``uvrange (variant='')``  Select data by baseline length.
 Default = '' (all)
 Examples:
 uvrange='0~1000klambda'; uvrange from 01000 kilolambda
 uvrange='>4klambda';uvranges greater than 4 kilolambda
 uvrange='0~1000km'; uvrange in kilometers
.. _antenna:
 ``antenna (string='')``  Select data based on antenna/baseline
 Subparameter of selectdata=True
 Default: '' (all)
 If antenna string is a nonnegative integer, it
 is assumed an antenna index, otherwise, it is
 assumed as an antenna name

 Examples:
 antenna='5&6'; baseline between antenna
 index 5 and index 6.
 antenna='VA05&VA06'; baseline between VLA
 antenna 5 and 6.
 antenna='5&6;7&8'; baselines with
 indices 56 and 78
 antenna='5'; all baselines with antenna index
 5
 antenna='05'; all baselines with antenna
 number 05 (VLA old name)
 antenna='5,6,10'; all baselines with antennas
 5,6,10 index numbers
.. _scan:
 ``scan (string='')``  Scan number range
 Subparameter of selectdata=True
 Default: '' = all
 Check 'go listobs' to insure the scan numbers are
 in order.
.. _observation:
 ``observation ({string, int}='')``  Select by observation ID(s)
 Subparameter of selectdata=True
 Default: '' = all
 Example: observation='0~2,4'
.. _msselect:
 ``msselect (string='')``  Optional complex data selection (ignore for now)
.. _solint:
 ``solint (variant='inf')``  Solution interval
 Default: 'inf' (infinite, up to boundaries
 controlled by combine);
 Options: 'inf' (~infinite), 'int' (per
 integration), any float or integer value with or
 without units
 Examples:
 solint='1min'; solint='60s', solint=60 (i.e.,
 1 minute); solint='0s'; solint=0; solint='int'
 (i.e., per integration); solint'1s';
 solint='inf' (i.e., ~infinite, up to
 boundaries enforced by combine)
.. _combine:
 ``combine (string='')``  Data axes which to combine for solve
 Default: 'scan' (solutions will break at obs,
 field, and spw boundaries)
 Options: '','obs','scan','spw',field', or any
 commaseparated combination in a single string
 Example: combine='scan,spw'  Extend solutions
 over scan boundaries (up to the solint), and
 combine spws for solving
.. _preavg:
 ``preavg (double=1.0)``  Preaveraging interval (sec)
 Default: 1.0 (none)
 Rarely needed. Will average data over periods
 shorter than the solution interval first.
.. _refant:
 ``refant (string='')``  Reference antenna name(s); a prioritized list may be
 specified
 Default: '' (No refant applied)
 Examples:
 refant='4' (antenna with index 4)
 refant='VA04' (VLA antenna #4)
 refant='EA02,EA23,EA13' (EVLA antenna EA02,
 use EA23 and EA13 as alternates if/when EA02
 drops out)
 Use taskname=listobs for antenna listing
.. _refantmode:
 ``refantmode (string='flex')``  Reference antenna mode
.. _minblperant:
 ``minblperant (int=4)``  Minimum number of baselines required per antenna for each
 solve
 Default: 4
 Antennas with fewer baselines are excluded from
 solutions.
 Example: minblperant=10 > Antennas
 participating on 10 or more baselines are
 included in the solve
 minblperant = 1 will solve for all baseline
 pairs, even if only one is present in the data
 set. Unless closure errors are expected, use
 taskname=gaincal rather than taskname=blcal to
 obtain more options in data analysis.
.. _minsnr:
 ``minsnr (double=3.0)``  Reject solutions below this SNR
 Default: 3.0
.. _solnorm:
 ``solnorm (bool=False)``  Normalize (squared) solution amplitudes (G, T only)
 Default: False (no normalization)
.. _normtype:
 ``normtype (string='mean')``  Solution normalization calculation type: mean or median
 Default: 'mean'
.. _gaintype:
 ``gaintype (string='G')``  Type of gain solution (G,T,GSPLINE,K,KCROSS)
 Default: 'G'
 Example: gaintype='GSPLINE'
  'G' means determine gains for each polarization and sp_wid
  'T' obtains one solution for both polarizations;
 Hence. their phase offset must be first removed
 using a prior G.
  'GSPLINE' makes a spline fit to the calibrator
 data. It is useful for noisy data and fits a
 smooth curve through the calibrated amplitude and
 phase. However, at present GSPLINE is somewhat
 experimental. Use with caution and check
 solutions.
  'K' solves for simple antennabased delays via
 FFTs of the spectra on baselines to the reference
 antenna. (This is not global fringefitting.)
 If combine includes 'spw', multiband delays are
 determined; otherwise, perspw singleband delays
 will be determined.
  'KCROSS' solves for a global crosshand delay.
 Use parang=T and apply prior gain and bandpass
 solutions. Multiband delay solves
 (combine='spw') not yet supported for KCROSS.
.. _smodel:
 ``smodel (doubleVec='')``  Point source Stokes parameters for source model
 (experimental).
 Default: [] (use MODEL_DATA column)
 Example: [1,0,0,0] (I=1, unpolarized)
.. _calmode:
 ``calmode (string='ap')``  Type of solution" ('ap', 'p', 'a')
 Default: 'ap' (amp and phase)
 Options: 'p' (phase) ,'a' (amplitude), 'ap'
 (amplitude and phase)
 Example: calmode='p'
.. _solmode:
 ``solmode (string='')``  Robust solving mode:
 Options: '', 'L1', 'R', 'L1R'
.. _rmsthresh:
 ``rmsthresh (doubleVec='')``  RMS Threshold sequence
 Subparameter of solmode='R' or 'L1R'
 See CASA Docs for more information
 (https://casa.nrao.edu/casadocs/)
.. _corrdepflags:
 ``corrdepflags (bool=False)``  If False (default), if any correlation is flagged, treat all correlations in
 the visibility vector as flagged when solving (per channel, per baseline).
 If True, use unflagged correlations in a visibility vector, even if one or more
 other correlations are flagged.

 Default: False (treat correlation vectors with one or more correlations flagged as entirely flagged)

 Traditionally, CASA has observed a strict interpretation of
 correlationdependent flags: if one or more correlations
 (for any baseline and channel) is flagged, then all available
 correlations for the same baseline and channel are
 treated as flagged. However, it is desirable in some
 circumstances to relax this stricture, e.g., to preserve use
 of data from antennas with only one good polarization (e.g., one polarization
 is bad or entirely absent). Solutions for the bad or missing polarization
 will be rendered as flagged.
.. _append:
 ``append (bool=False)``  Append solutions to the (existing) table
 Default: False (overwrite existing table or make
 new table)
 Appended solutions must be derived from the same
 MS as the existing caltable, and solution spws
 must have the same metainfo (according to spw
 selection and solint) or be nonoverlapping.
.. _splinetime:
 ``splinetime (double=3600.0)``  Spline timescale(sec); All spw\'s are first averaged.
 Subparameter of gaintype='GSPLINE'
 Default: 3600 (1 hour)
 Example: splinetime=1000
 Typical splinetime should cover about 3 to 5
 calibrator scans.
.. _npointaver:
 ``npointaver (int=3)``  Tune phaseunwrapping algorithm
 Subparameter of gaintype='GSPLINE'
 Default: 3; Keep at this value
.. _phasewrap:
 ``phasewrap (double=180.0)``  Wrap the phase for jumps greater than this value
 (degrees)
 Subparameter of gaintype='GSPLINE'
 Default: 180; Keep at this value
.. _docallib:
 ``docallib (bool=False)``  Control means of specifying the caltables
 Default: False (Use gaintable, gainfield, interp,
 spwmap, calwt)
 Options: FalseTrue
 If True, specify a file containing cal library in
 callib
.. _callib:
 ``callib (string='')``  Specify a file containing cal library directives
 Subparameter of docallib=True
.. _gaintable:
 ``gaintable (stringVec='')``  Gain calibration table(s) to apply on the fly
 Default: '' (none)
 Subparameter of docallib=False
 Examples:
 gaintable='ngc5921.gcal'
 gaintable=['ngc5921.ampcal','ngc5921.phcal']
.. _gainfield:
 ``gainfield (stringVec='')``  Select a subset of calibrators from gaintable(s)
 Default: '' (all sources on the sky)
 'nearest' ==> nearest (on sky) available field in
 table otherwise, same syntax as field
 Examples:
 gainfield='0~2,5' means use fields 0,1,2,5
 from gaintable
 gainfield=['0~3','4~6'] means use field 0
 through 3
.. _interp:
 ``interp (stringVec='')``  Interpolation parmameters (in time[,freq]) for each gaintable, as a list of strings.
 Default: '' > 'linear,linear' for all gaintable(s)
 Options: Time: 'nearest', 'linear'
 Freq: 'nearest', 'linear', 'cubic',
 'spline'
 Specify a list of strings, aligned with the list of caltable specified
 in gaintable, that contain the required interpolation parameters
 for each caltable.

  When frequency interpolation is relevant (B, Df,
 Xf), separate timedependent and freqdependent
 interp types with a comma (freq after the
 comma).
  Specifications for frequency are ignored when the
 calibration table has no channeldependence.
  Timedependent interp options ending in 'PD'
 enable a "phase delay" correction per spw for
 nonchanneldependent calibration types.
  For multiobsId datasets, 'perobs' can be
 appended to the timedependent interpolation
 specification to enforce obsId boundaries when
 interpolating in time.
  For multiscan datasets, 'perscan' can be
 appended to the timedependent interpolation
 specification to enforce scan boundaries when
 interpolating in time.
  Freqdependent interp options can have 'flag' appended
 to enforce channeldependent flagging, and/or 'rel'
 appended to invoke relative frequency interpolation
 Examples:
 interp='nearest' (in time, freqdep will be
 linear, if relevant)
 interp='linear,cubic' (linear in time, cubic
 in freq)
 interp='linearperobs,splineflag' (linear in
 time per obsId, spline in freq with
 channelized flagging)
 interp='nearest,linearflagrel' (nearest in
 time, linear in freq with with channelized
 flagging and relativefrequency interpolation)
 interp=',spline' (spline in freq; linear in
 time by default)
 interp=['nearest,spline','linear'] (for
 multiple gaintables)
.. _spwmap:
 ``spwmap (any='')``  Spectral window mappings to form for gaintable(s)
 Only used if callib=False
 default: [] (apply solutions from each calibration spw to
 the same MS spw only)
 Any available calibration spw can be mechanically mapped to any
 MS spw.
 Examples:
 spwmap=[0,0,1,1] means apply calibration
 from cal spw = 0 to MS spw 0,1 and cal spw 1 to MS spws 2,3.
 spwmap=[[0,0,1,1],[0,1,0,1]] (use a list of lists for multiple
 gaintables)
.. _parang:
 ``parang (bool=False)``  Apply parallactic angle correction
 Default: False
 If True, apply the parallactic angle correction
 (required for polarization calibration)
"""
pass