task_accum Namespace Reference

Functions
def	accum

---

Function Documentation

def task_accum.accum	(		vis = None,
			tablein = None,
			incrtable = None,
			caltable = None,
			field = None,
			calfield = None,
			interp = None,
			accumtime = None,
			spwmap = None
	)

Accumulate incremental calibration solutions into a calibration table:

Accum will interpolate and extrapolate a temporal calibration
table onto a new table that has a regularly-space time grid.

The first run of accum defines the time grid and fills this
table with the results from the input table.

Subsequent use of accum will combine additional calibration
tables onto the same grid of the initial accum table to obtain
an output accum table.  See below for a concrete example.

Keyword arguments:
vis --   Name of input visibility file
         default: none; example: vis='ngc5921.ms'
tablein -- Input cumulative calibration table
         ''=> first
           in accumtime.  Then use output table from previous runs.
accumtime -- Time sampling (sec) of the output table.
         Used only if tablein=''.
         default: 1.0
         example: accumtime=40.0
         accumtime ~ data sampling time is recommended
incrtable -- incremental calibration table name
         default: none; example: incrtable='ngc5921_phase.gcal'
           on first use of accum, incrtable will be
           resampled onto caltable with the timescale given
           by accumtime
caltable -- Output cumulative calibration table
         default: none; example: caltable='ngc5921.Cgcal'
           caltable = complex multiplication of incrtable with tablein
           tablein and caltable have the same time grid;
           incrtable time stamps are arbitrary.
field -- List of field names from tablein to process
         default: ''==>all; (most likely)
           example: field='0957+561 3C286'
           usual syntax for field selection
calfield -- List of field names in incremental table to use.
         default: ''==>all; example: calfield='0957*,3C2*'
           usual syntax for field selection
interp -- Interpolation mode to use on incremental solutions
          default: 'linear'; example: interp='nearest'
          'linear' linearly interpolates the amplitude and
            phase in incrtable to add to tablein.  RECOMMENDED
          'nearest' chooses the nearest value in incrtable to
            add to tablein
          'aipsline' is similar to linear, but does interpolated
            real and imaginary parts.  NOT RECOMMENDED
spwmap -- Spectral windows combinations to form
          default: [-1];
          default means process spws independently
             example: spwmap=[0,0,1,1] means apply results from
               spw = 0,0,1,1 to spw 0,1,2,3
               defaults is equivalent to spwmap = [0,1,2,3]
Example use:  Doing a phase cal with short solution interval and then
              an amplitude solution on a longer integration time.

   First, generate the calibration tables for phase and flux cal

   taskname = 'gaincal'
   default
   cal1 = 'J1335-331,3C286'  # phase and flux calibrator
   taskname = 'gaincal'
   default
   vis = '3C219.ms'
   gaintype = 'G'
   calmode = 'p'             # do a phase cal on raw data
   caltable = 'phase.cal'    # output phase calibration table
   field = cal1              # calibrator names
   solint = -1               # calibrate each point
   refant = 'VA04'           # reference antenna
   go

   calmode = 'ap'            # do an amp/phase cal removing first phase cal
   caltable = 'amp.cal'      # output amplitude calibration table
   solint = 0                # solution for each scan
   gaincurve = false
   opacity =0.0              # no opacity correction
   gaintable = 'phase.cal'   # First, apply previous phase calibration on the fly
   go

   taskname = 'fluxscale'    # Determine the flux of phase calibrator
   default
   vis = '3C219.ms'
   caltable = 'amp.cal'      # amp cal input
   fluxtable = 'flux.cal'    # calibration table with phase cal flux adjusted
   reference = '3C286'       # Sources to use as amplitude standard.
                                    # Should have used setjy on these sources
   transfer = 'J1335-331'    # Sources to be scaled to flux density
   go

   taskname = 'smoothcal'    # Smooth amplitude and phases
   vis = '3C219.ms'
   tablein = 'flux.cal'
   caltable = 'smooth.cal'   # smooths amplitude and phase
   field = 'J1334-331'       # Only smooth phase calibrator
   smoothtype = 'median'
   smoothtime = 600.0        # Desired smoothing time.  Usually contains
                                 # several calibration points


                             # Define accum table from first phase only cal
   taskname = 'accum'
   default
   vis = '3C219.ms'
   tablein = ''              # No input table on first run
   accumtime = -1            # grid time defaults to sampling time
   incrtable = 'phase.cal'   # Input phase cal
   caltable = 'accum1.cal'   # Output accum table with phase cal
   field = ''                # All sources in phase.cal
   interp = 'linear'
   go

   tablein = accum1.cal'     # input is output from above accum run
   incrtable = 'amp.cal'     # Input amplitude cal
   caltable = 'accum2.cal'   # Vector produce of tablein and incrtable
   field = ''                # Determine cal values for all field
   calfield = 'J1334-331'    # Only interpolate from phase cal
   interp = 'linear'
   go

#         accum2.cal contains the calibration of the raw data.  The amplitudes have
#           been smooths to 600 seconds, the phases have not.

Definition at line 5 of file task_accum.py.

Referenced by accum.accum().