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calibrater.calave - Function



Package synthesis
Module calibrater
Tool calibrater


Average calibration solutions over fields, spectral windows, and/or time


Synopsis
calave(tablein, tableout, fldsin, spwsin, fldsout, spwout, t, append, mode, verbose)



Arguments

tablein in Input calibration table name. No default
Allowed: String
tableout in Output calibration table name. No default
Allowed: String
fldsin in Input field id(s). No default
Allowed: Vector of integers
spwsin in Input spectral window id(s). No default
Allowed: Vector of integers
fldsout in Output field id(s). No default
Allowed: Vector of integer
spwout in Output spectral window. No default
Allowed: Integer
t in Averaging time (s). Default is to just copy solutions
Allowed: Float
Default: -1.0
append in Append to existing table?
Allowed: Boolean
Default: F
mode in
Allowed: String from RI or AP
Default: 'RI'
verbose in Write extra information to logger about proceses
Allowed: T or F
Default: 'T'


Returns
Bool



Description

This function can be used to average calibration solutions over fields, spectral windows, and/or time. It is useful for smoothing solutions in time, and for re-identifying solutions for field and spectral window, as may be required in spectral line observations where doppler tracking is used on the target source, but not on the calibrater (and hence the spectral windows for each source are different). This function currently supports averaging of calibration tables containing Jones matrices with diagonal elements only (G, B, T). For B, the averaging is done for each channel separately (there is no channel averaging). Handling of tables with off-diagonal elements (D, F) will be supported in the future.

The fldsin parameter takes a vector of integers; the fldsout parameter must be a single integer (used for all fldsin) or a vector of integers, one for each in fldsin. They must both be specified.

The spwsin parameter takes a vector of integers; currently, only one spwout can be specifed (all spwsin will be averaged to this). They must both be specified. Use append=T to write more than one output spectral window to the same file. All input and output ids must exist in the measurement set.

Use the t paramater to set the interval over which solutions from the input field ids and spectral window ids will be averaged. Note that simple solution time-averaging can be achieved by making fldsin=fldsout and spwsin=spwout. If this parameter is negative (the default) the solutions are just copied.

Use the mode parameter to choose between 'RI'= averaging real and imaginary (coherently) or 'AP'= averaging amplitude and phase (incoherently). Use 'AP' to avoid reduction in amplitude if the solution phases drift appreciably during the averaging interval, t.



Example
c:=calibrater('3C273XC1.MS');
c.calave(tablein='3C273.gcal', tableout='3C273.gcal2', 
              fldsin=[1,2],spwsin=[2,3],fldsout=7,spwout=13,
              t=300, append=F, mode='AP')
c.done();

This example will average solutions from field ids 1 & 2 in spectral windows 2 & 3 in 300 second intervals and identifies the result as field id 7 and spectral window 13. The averaging is incoherent.





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Next: calibrater.linpolcor - Function Up: calibrater - Tool Previous: calibrater.posangcal - Function   Contents   Index
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2006-10-15