pipeline.hif.cli.hif_lowgainflag

hif_lowgainflag(vis=None, intent=None, spw=None, refant=None, flag_nmedian=None, fnm_lo_limit=None, fnm_hi_limit=None, tmef1_limit=None) → ResultsList[Results][source]

Flag antennas with low or high gain.

Deviant antennas are detected by outlier analysis of a view showing their amplitude gains, pre-applying a temporary bandpass and phase solution. This view is a list of 2D images with axes 'Scan' and 'Antenna'; there is one image for each spectral window and intent. A flagcmd to flag all data for an antenna will be generated by any gain that is outside the range [fnm_lo_limit * median, fnm_hi_limit * median].

Parameters:

  • vis --

    The list of input MeasurementSets. Defaults to the list of MeasurementSets specified in the <hifa,hifv>_importdata task. '': use all MeasurementSets in the context

    Examples: 'ngc5921.ms', ['ngc5921a.ms', ngc5921b.ms', 'ngc5921c.ms']

  • intent -- A string containing the list of intents to be checked for antennas with deviant gains. The default is blank, which causes the task to select the 'BANDPASS' intent.

  • spw --

    The list of spectral windows and channels to which the calibration will be applied. Defaults to all science windows in the pipeline context.

    Examples: spw='17', spw='11, 15'

  • refant --

    A string containing a prioritized list of reference antenna name(s) to be used to produce the gain table. Defaults to the value(s) stored in the pipeline context. If undefined in the pipeline context defaults to the CASA reference antenna naming scheme.

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

  • flag_nmedian -- Whether to flag figures of merit greater than fnm_hi_limit * median or lower than fnm_lo_limit * median. (default: True)

  • fnm_lo_limit -- Flag values lower than fnm_lo_limit * median (default: 0.5)

  • fnm_hi_limit -- Flag values higher than fnm_hi_limit * median (default: 1.5)

  • tmef1_limit -- Threshold for "too many entirely flagged" - the critical fraction of antennas whose solutions are entirely flagged in the flagging view of a spw for this stage: if the fraction is equal or greater than this value, then flag the visibility data from all antennas in this spw (default: 0.666)

Returns:

The results object for the pipeline task is returned.

Examples

  1. Flag antennas with low or high gain using recommended thresholds:

>>> hif_lowgainflag()