fluxscale – Bootstrap the flux density scale from standard calibrators – calibration task

Description

Bootstrap the flux density scale from standard calibrators:

After running gaincal on standard flux density calibrators (with or without an image model), and other calibrators with unknown flux densities (assumed 1 Jy), fluxscale applies the constraint that net system gain was, in fact, independent of field, on average, and that field-dependent gains in the input caltable are solely a result of the unknown flux densities for the calibrators. Using time-averaged gain amplitudes, the ratio between each ordinary calibrator and the flux density calibrator(s) is formed for each antenna and polarization (that they have in common). The average of this ratio over antennas and polarizations yields a correction factor that is applied to the ordinary calibrators’ gains. (See also more detailed discussion in Example section below.)

Parameters

Title
Parameter	Default	Description
vis	`''`
caltable	`''`
fluxtable	`''`
reference	`numpy.array( [ ] )`
transfer	`numpy.array( [ ] )`
listfile	`''`
append	`False`
refspwmap	`numpy.array( [ ] )`
gainthreshold	`float(-1.0)`
antenna	`''`
timerange	`''`
scan	`''`
incremental	`False`
fitorder	`int(1)`
display	`False`
fluxd	`[ ]`

Parameter Explanations

vis

''

Name of input visibility file (MS)

caltable

''

Name of input calibration table

fluxtable

''

Name of output, flux-scaled calibration table

reference

numpy.array( [ ] )

Reference field name(s) (transfer flux scale FROM)

transfer

numpy.array( [ ] )

Transfer field name(s) (transfer flux scale TO), '' -> all

listfile

''

Name of listfile that contains the fit information. Default is ‘’ (no file).

append

False

Append solutions?

refspwmap

numpy.array( [ ] )

Scale across spectral window boundaries. See help fluxscale

gainthreshold

float(-1.0)

Threshold (% deviation from the median) on gain amplitudes to be used in the flux scale calculation

antenna

''

antennas to include/exclude

timerange

''

sub selection by timerange

scan

''

sub selection by scan

incremental

False

incremental caltable

fitorder

int(1)

order of spectral fitting

display

False

display some statistics of flux scaling

fluxd

[ ]

Dictionary containing the transfer fluxes and their errors.