pipeline.hifa.cli.gotasks.hifa_gfluxscale

pipeline.hifa.cli.gotasks.hifa_gfluxscale = <pipeline.hifa.cli.gotasks.hifa_gfluxscale._hifa_gfluxscale object>

hifa_gfluxscale —- Derive flux density scales from standard calibrators

Derive flux densities for point source transfer calibrators using flux models for reference calibrators.

Flux values are determined by:

o computing complex gain phase only solutions for all the science spectral windows using the calibrator data selected by the ‘reference’ and ‘refintent’ parameters and the ‘transfer’ and ‘transintent’ parameters, and the value of the ‘phaseupsolint’ parameter.

o computing complex amplitude only solutions for all the science spectral windows using calibrator data selected with ‘reference’ and ‘refintent’ parameters and the ‘transfer’ and ‘transintent’ parameters, the value of the ‘solint’ parameter.

o transferring the flux scale from the reference calibrators to the transfer calibrators using refspwmap for windows without data in the reference calibrators

o extracted the computed flux values from the CASA logs and inserting them into the MODEL_DATA column.

Resolved calibrators are handled via antenna selection either automatically, hm_resolvedcals=’automatic’ or manually, hm_resolvedcals=’manual’. In the former case antennas closer to the reference antenna than the uv distance where visibilities fall to ‘peak_fraction’ of the peak are used. In manual mode the antennas specified in ‘antenna’ are used.

Note that the flux corrected calibration table computed internally is not currently used in later pipeline apply calibration steps.

Issues

Should we add a spw window selection option here?

The code which extracts the flux scales from the logs needs to be replaced with code which uses the values returned from the CASA fluxscale task.

——— parameter descriptions ———————————————

vis The list of input MeasurementSets. Defaults to the list of MeasurementSets

specified in the pipeline context

example: [‘M32A.ms’, ‘M32B.ms’]

reference A string containing a comma delimited list of field names

defining the reference calibrators. Defaults to field names with intent ‘AMP’.

example: reference=’M82,3C273’

transfer A string containing a comma delimited list of field names

defining the transfer calibrators. Defaults to field names with intent ‘PHASE’.

example: transfer=’J1328+041,J1206+30’

refintent A string containing a comma delimited list of intents

used to select the reference calibrators. Defaults to ‘AMPLITUDE’.

example: refintent=’’, refintent=’AMPLITUDE’

transintent A string containing a comma delimited list of intents

defining the transfer calibrators. Defaults to ‘PHASE,BANDPASS,CHECK,POLARIZATION,POLANGLE,POLLEAKAGE’.

example: transintent=’’, transintent=’PHASE,BANDPASS’

refspwmap Vector of spectral window ids enabling scaling across

spectral windows. Defaults to no scaling.

example: refspwmap=[1,1,3,3] - (4 spws, reference fields in 1 and 3, transfer

fields in 0,1,2,3

reffile Path to a file containing flux densities for calibrators unknown to

CASA. Values given in this file take precedence over the CASA-derived values for all calibrators except solar system calibrators. By default the path is set to the CSV file created by hifa_importdata, consisting of catalogue fluxes extracted from the ASDM and / or edited by the user.

example: reffile=’’, reffile=’working/flux.csv’

phaseupsolint Time solution intervals in CASA syntax for the phase solution.

example: phaseupsolint=’inf’, phaseupsolint=’int’, phaseupsolint=’100sec’

solint Time solution intervals in CASA syntax for the amplitude solution.

example: solint=’inf’, solint=’int’, solint=’100sec’

minsnr Minimum signal to noise ratio for gain calibration solutions.

example: minsnr=1.5, minsnr=0.0

refant A string specifying the reference antenna(s). By default this is read

from the context.

example: refant=’DV05’

hm_resolvedcals Heuristics method for handling resolved calibrators. The

options are ‘automatic’ and ‘manual’. In automatic mode antennas closer to the reference antenna than the uv distance where visibilities fall to ‘peak_fraction’ of the peak are used. In manual mode the antennas specified in ‘antenna’ are used.

antenna A comma delimited string specifying the antenna names or ids to be

used for the fluxscale determination. Used in hm_resolvedcals=’manual’ mode.

example: antenna=’DV16,DV07,DA12,DA08’

peak_fraction The limiting UV distance from the reference antenna for antennas

to be included in the flux calibration. Defined as the point where the calibrator visibilities have fallen to ‘peak_fraction’ of the peak value.

pipelinemode The pipeline operating mode. In ‘automatic’ mode the pipeline

determines the values of all context defined pipeline inputs automatically. In interactive mode the user can set the pipeline context defined parameters manually. In ‘getinputs’ mode the users can check the settings of all pipeline parameters without running the task.

dryrun Run the commands (True) or generate the commands to be run but do not

execute (False).

acceptresults Add the results of the task to the pipeline context (True) or

reject them (False).

——— examples ———————————————————–

1. Compute flux values for the phase calibrator using model data from the amplitude calibrator:

hifa_gfluxscale()