pipeline.hifa.cli.hifa_gfluxscaleflag

hifa_gfluxscaleflag(vis=None, intent=None, phaseupsolint=None, solint=None, minsnr=None, refant=None, antnegsig=None, antpossig=None, tmantint=None, tmint=None, tmbl=None, antblnegsig=None, antblpossig=None, relaxed_factor=None, niter=None, parallel=None) → ResultsList[Results][source]

Flag the flux, diffgain, phase calibrators and check source.

This task computes the flagging heuristics on the flux, diffgain, and phase calibrators and the check source, by calling hif_correctedampflag which looks for outlier visibility points by statistically examining the scalar difference of corrected amplitudes minus model amplitudes, and flags those outliers. The philosophy is that only outlier data points that have remained outliers after calibration will be flagged. The heuristic works equally well on resolved calibrators and point sources because it is not performing a vector difference, and thus is not sensitive to nulls in the flux density vs. uvdistance domain. Note that the phase of the data is not assessed.

In further detail, the workflow is as follows: a snapshot of the flagging state is preserved at the start, a preliminary phase and amplitude gaincal solution is solved and applied, the flagging heuristics are run and any outliers are marked for flagging, the flagging state is restored from the snapshot. If any outliers were found, then these are flagged. Plots are generated at two points in this workflow: after preliminary phase and amplitude calibration but before flagging heuristics are run, and after flagging heuristics have been run and applied. If no points were flagged, the 'after' plots are not generated or displayed. The score for this stage is the standard data flagging score, which depends on the fraction of data flagged.

The preliminary phase solutions use the mapping/combine and gaintype options as established in hifa_spwphaseup.

Parameters:

  • vis --

    The list of input MeasurementSets. Defaults to the list of MeasurementSets specified in the pipeline context.

    Example: vis=['M51.ms']

  • intent --

    A string containing a comma delimited list of intents against which the selected fields are matched. If undefined (default), it will select all data with the AMPLITUDE, PHASE, and CHECK intents, except for one case: if one of the AMPLITUDE intent fields was also used for BANDPASS, then this task will select only data with PHASE and CHECK intents.

    Example: intent='*PHASE*'

  • phaseupsolint --

    The phase correction solution interval in CASA syntax.

    Example: phaseupsolint='300s'

  • solint --

    Time and channel solution intervals in CASA syntax.

    Example: solint='inf,10ch', solint='inf'

  • minsnr -- Solutions below this SNR are rejected.

  • refant --

    Reference antenna names. Defaults to the value(s) stored in the pipeline context. If undefined in the pipeline context defaults to the CASA reference antenna naming scheme.

    Example: refant='DV01', refant='DV06,DV07'

  • antnegsig --

    Lower sigma threshold for identifying outliers as a result of bad antennas within individual timestamps.

    Example: antnegsig=4.0

  • antpossig --

    Upper sigma threshold for identifying outliers as a result of bad antennas within individual timestamps.

    Example: antpossig=4.6

  • tmantint --

    Threshold for maximum fraction of timestamps that are allowed to contain outliers.

    Example: tmantint=0.063

  • tmint --

    Threshold for maximum fraction of "outlier timestamps" over "total timestamps" that a baseline may be a part of.

    Example: tmint=0.085

  • tmbl --

    Initial threshold for maximum fraction of "bad baselines" over "all baselines" that an antenna may be a part of.

    Example: tmbl=0.175

  • antblnegsig --

    Lower sigma threshold for identifying outliers as a result of "bad baselines" and/or "bad antennas" within baselines, across all timestamps.

    Example: antblnegsig=3.4

  • antblpossig --

    Threshold for identifying outliers as a result of "bad baselines" and/or "bad antennas" within baselines, across all timestamps.

    Example: antblpossig=3.2

  • relaxed_factor --

    Relaxed value to set the threshold scaling factor to under certain conditions (see task description).

    Example: relaxed_factor=2.0

  • niter --

    Maximum number of times to iterate on evaluation of flagging heuristics. If an iteration results in no new flags, then subsequent iterations are skipped.

    Example: niter=2

  • parallel --

    Process multiple MeasurementSets in parallel using the casampi parallelization framework.

    Options: 'automatic', 'true', 'false', True, False

    Default: None (equivalent to False)

Returns:

The results object for the pipeline task is returned.

Examples

1. run with recommended settings to create flux scale calibration with flagging using recommended thresholds:

>>> hifa_gfluxscaleflag()