Bandpass: Difference between revisions

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== Help for bandpass: ==
{{bandpass}}
 
<pre>
Calculates a bandpass calibration solution
 
      Determines the amplitude and phase as a function of frequency for
      each spectral window containing more than one channel.  Strong sources
      (or many observations of moderately strong sources) are needed to obtain
      accurate bandpass functions.  The two solution choices are: Individual
      antenna/based channel solutions 'B'; and a polynomial fit over the channels
      'BPOLY'.  The 'B' solutions can determined at any specified time interval, and
      is recommended if each channel has good signal-to-noise.  Other, 'BPOLY' is
      recommended.
 
      Keyword arguments:
      vis -- Name of input visibility file
              default: none; example: vis='ngc5921.ms'
      caltable -- Name of output bandpass calibration table
              default: none; example: caltable='ngc5921.bcal'
 
      --- Data Selection (see help par.selectdata for more detailed information)
 
      field -- Select field using field id(s) or field name(s).
                [run listobs to obtain the list id's or names]
              default: ''=all fields
              If field string is a non-negative integer, it is assumed a field index
                otherwise, it is assumed a field name
              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 adn 3C295
              field = '3,4C*'; field id 3, all names starting with 4C
      spw -- Select spectral window/channels
              default: ''=all spectral windows and channels
              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
              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 0-10,15-60
                        NOTE: ';' to separate channel selections
              spw='0:0~10,1:20~30,2:1;2;3'; spw 0, channels 0-10,
                      spw 1, channels 20-30, and spw 2, channels, 1,2 and 3
      selectdata -- Other data selection parameters
              default: True
      timerange  -- Select data based on time range:
              default = '' (all); examples,
              timerange = 'YYYY/MM/DD/hh:mm:ss~YYYY/MM/DD/hh:mm:ss'
              Note: if YYYY/MM/DD is missing dat 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' data within one integration of time
              timerange='>10:24:00' data after this time
      uvrange -- Select data within uvrange (default meters)
              default: '' (all); example:
              uvrange='0~1000kl'; uvrange from 0-1000 kilo-lamgda
              uvrange='>4kl';uvranges greater than 4 kilo-lambda
      antenna -- Select data based on antenna/baseline
              default: '' (all)
              If antenna string is a non-negative integer, it is assumed an antenna index
                otherwise, it is assumed as an antenna name
              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'; baseline 5-6 and 7-8
              antenna='5'; all baselines with antenna 5
              antenna='5,6,10'; all baselines with antennas 5, 6 and 10
      scan -- Select data based on scan number - New, under developement
              default: '' (all); example: scan='>3'
      msselect -- Optional complex data selection (ignore for now)
 
      --- Solution parameters
      solint --  Solution interval (units optional)
              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='1m'; solint='60s', solint=60 --> 1 minute
                        solint='0s'; solint=0; solint='int' --> per integration
                        solint-'-1s'; solint='inf' --> ~infinite, up to boundaries
                        enforced by combine
      combine -- Data axes to combine for solving
              default: 'scan' --> solutions will break at field and spw boundaries,
                        but may extend over multiple scans (per field and spw) up
                        to solint.
              Options: '','scan','spw',field', or any comma-separated combination
              example: combine='scan,spw'  --> extend solutions over scan boundaries
                      (up to the solint), and combine spws for solving
      refant -- Reference antenna name (string)
              default: '' (no reference antenna)
                example: refant='13' (antenna with index 13)
                      refant='VA04' (VLA antenna #4)
              Use 'go listobs' for antenna listing
      minblperant -- Minimum number of baselines required per antenna for each solve
                    Antennas with fewer baaselines are excluded from solutions. Amplitude
                    solutions with fewer than 4 baselines, and phase solutions with fewer
                    than 3 baselines are only trivially constrained, and are no better
                    than baseline-based solutions.
                    default: 4
                    example: minblperant=10  => Antennas participating on 10 or more
                            baselines are included in the solve
      solnorm -- Normalize bandpass amplitudes and phase for each
              spw, pol, ant, and timestamp
              default: False (no normalization)
      bandtype -- Type of bandpass solution (B or BPOLY)
              default: 'B'; example: bandtype='BPOLY'
              'B' does a channel by channel solution for each
                  specified spw.
              'BPOLY' is somewhat experimental. It will fit an
                  nth order polynomial for the amplitude and phase
                  as a function of frequency. Only one fit is made
                  for all specified spw, and edge channels should be
                  omitted.
                Use taskname=plotcal in order to compare the results from
                  B and BPOLY.
      fillgaps -- Fill flagged solution channels by interpolation
              default: 0 (don't interpolate)
              example: fillgaps=3 (interpolate gaps 3 channels wide and narrower)
      degamp -- Polynomial degree for BPOLY amplitude solution
              default: 3; example: degamp=2
      degphase -- Polynomial degree for BPOLY phase solution
              default: 3; example: degphase=2
      visnorm -- Normalize data prior to BPOLY solution
              default: False; example: visnorm=True
      maskcenter -- Number of channels to avoid in center of each band
              default: 0; example: maskcenter=5 (BPOLY only)
      maskedge -- Fraction of channels to avoid at each band edge (in %)
              default: 5; example: maskedge=3 (BPOLY only)
      append -- Append solutions to the (existing) table
              default: False; example: append=True
 
      --- Other calibrations to apply on the fly before determining bandpass solution
 
      gaintable -- Gain calibration table(s) to apply
              default: '' (none);
              examples: gaintable='ngc5921.gcal'
                        gaintable=['ngc5921.ampcal','ngc5921.phcal']
      gainfield -- Select a subset of calibrators from gaintable(s)
              default:'' ==> all sources in table;
              same syntax as field
              example: gainfield='0~3'
                        gainfield=['0~3','4~6']
      interp -- Interpolation mode (in time) to use for each gaintable
                default: '' --> 'linear' for all gaintable(s)
                example: interp='nearest'
                        interp=['nearest','linear']
                Options: 'nearest', 'linear', 'aipslin'
      spwmap -- Spectral windows combinations to form for gaintable(s)
                default: [] (apply solutions from each spw to that spw only)
                Example:  spwmap=[0,0,1,1] means apply the caltable solutions
                          from spw = 0 to the spw 0,1 and spw 1 to spw 2,3.
                          spwmap=[[0,0,1,1],[0,1,0,1]]
      append -- Append solutions to the (existing) table
              default: False; example: append=True
 
      --- Other calibrations to apply on the fly before determining bandpass solution
 
      gaintable -- Gain calibration table(s) to apply
              default: '' (none);
              examples: gaintable='ngc5921.gcal'
                        gaintable=['ngc5921.ampcal','ngc5921.phcal']
      gainfield -- Select a subset of calibrators from gaintable(s)
              default:'' ==> all sources in table;
              same syntax as field
              example: gainfield='0~3'
                        gainfield=['0~3','4~6']
      interp -- Interpolation mode (in time) to use for each gaintable
                default: '' --> 'linear' for all gaintable(s)
                example: interp='nearest'
                        interp=['nearest','linear']
                Options: 'nearest', 'linear', 'aipslin'
      spwmap -- Spectral windows combinations to form for gaintable(s)
                default: [] (apply solutions from each spw to that spw only)
                Example:  spwmap=[0,0,1,1] means apply the caltable solutions
                          from spw = 0 to the spw 0,1 and spw 1 to spw 2,3.
                          spwmap=[[0,0,1,1],[0,1,0,1]]
      gaincurve -- Apply internal VLA antenna gain curve correction  (True/False)
              default: False;
              Use gaincurve=True ONLY for VLA data
      opacity -- Opacity correction to apply (nepers)
              default: 0.0 (no opacity correction)
              example: opacity=0.051
              Typical VLA values are: 5 GHz - 0.013, 8 GHz - 0.013
              15 GHz - 0.016, 23 GHz - 0.051, 43 GHz - 0.07
      parang -- If True, apply the parallactic angle correction (required
              for polarization calibration)
              default: False
</pre>

Latest revision as of 19:24, 6 May 2015