FlagTask

FlagTask provides basic threshold-based on the fly flagging. Thresholds can be specified separately for auto-correlations and cross-correlations. No threshold specified means no flagging done based on that threshold. Flagged data can be optionally zeroed (handy, if flagging is done to regularise monitoring of spectrum-averaged visibilities).

Configuration Parameters

The program requires a configuration file be provided on the command line. This section describes the valid parameters. In addition to mandatory parameters which are always required, individual tasks often have specific parameters which need to be defined only if a particular task is used. As for all tasks, parameters are taken from keys with tasks.name.params prefix (not shown in the table below) where name is an arbitrary name assigned to this task and used in tasklist (this allows us to run the same task more than once with different parameters). The type of the task defined by tasks.name.type should be set to FlagTask.

Parameter Type Default Description
threshold.crosscorr float None Threshold for cross-correlations. Any cross-correlation amplitude exceeding this threshold will be flagged. If this parameter is undefined, no flagging of cross-correlations is done
threshold.autocorr float None Threshold for auto-correlations. Any auto-correlation visibility exceeding this threshold will be flagged. If this parameter is undefined, no flagging of auto-correlations is done
zeroflagged boolean false If true, the flagged visibilites are also zeroed. This is handy if averaging in spectral domain follows (e.g. for monitoring).

Example

########################## FlagTask ##############################

tasks.tasklist = [MergedSource, Merge, CalcUVWTask, FringeRotationTask, MSSink, FlagTask, TCPSink]

# note the order of tasks in tasklist, flagging only affects monitoring (i.e. data distributed via TCPSink)

# threshold for cross-correlations, no flagging based on auto-correlations
tasks.FlagTask.params.threshold.crosscorr = 10
# zero flagged visibilities
task.FlagTask.params.zeroflagged = true
# type of the task
tasks.FlagTask.type = FlagTask

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