pipeline.hifa.cli.hifa_bandpass

pipeline.hifa.cli.hifa_bandpass = <pipeline.hifa.cli.hifa_bandpass._hifa_bandpass object>

hifa_bandpass —- Compute bandpass calibration solutions

The hifa_bandpass task computes a bandpass solution for every specified science spectral window. By default a ‘phaseup’ pre-calibration is performed and applied on the fly to the data, before the bandpass is computed.

The hif_refant task may be used to pre-compute a prioritized list of reference antennas.

If pipeline mode is ‘getinputs’ then None is returned. Otherwise the results object for the pipeline task is returned.

Issues: There is currently some discussion about whether or not to do an ‘ampup’ operations at the same time as the ‘phaseup’. This is not required for the bandpass computation but the amplitude information may provide a useful quality assessment measure.

The specified minsnr parameter is currently applied to the bandpass solution computation but not the ‘phaseup’ computation. Some noisy solutions in the phaseup may not be properly rejected.

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

vis List of input MeasurementSets. Defaults to the list of

MeasurementSets specified in the pipeline context.

Example: vis=[‘ngc5921.ms’]

caltable List of names for the output calibration tables. Defaults

to the standard pipeline naming convention.

Example: caltable=[‘ngc5921.gcal’]

field The list of field names or field ids for which bandpasses are

computed. Set to field=’’ by default, which means the task will select all fields.

Example: field=’3C279’, field=’3C279,M82’

intent A string containing a comma delimited list of intents against

which the selected fields are matched. Set to intent=’’ by default, which means the task will select all data with the BANDPASS intent.

Example: intent=’PHASE’

spw The list of spectral windows and channels for which bandpasses are

computed. Set to spw=’’ by default, which means the task will select all science spectral windows.

Example: spw=’11,13,15,17’

antenna Set of data selection antenna IDs hm_phaseup The pre-bandpass solution phaseup gain heuristics. The options are:

‘snr’: compute solution required to achieve the specified SNR ‘manual’: use manual solution parameters ‘’: skip phaseup

Example: hm_phaseup=’manual’

phaseupsolint The phase correction solution interval in CASA syntax.

Used when hm_phaseup=’manual’ or as a default if the hm_phaseup=’snr’ heuristic computation fails.

Example: phaseupsolint=’300s’

phaseupbw Bandwidth to be used for phaseup. Used when hm_phaseup=’manual’.

Example: phaseupbw=’’ to use entire bandpass

phaseupbw=’500MHz’ to use central 500MHz

phaseupsnr The required SNR for the phaseup solution. Used only if

hm_phaseup=’snr’.

Example: phaseupsnr=10.0

phaseupnsols The minimum number of phaseup gain solutions. Used only if

hm_phaseup=’snr’.

Example: phaseupnsols=4

hm_bandpass The bandpass solution heuristics. The options are:

‘snr’: compute the solution required to achieve the specified SNR ‘smoothed’: simple smoothing heuristics ‘fixed’: use the user defined parameters for all spws

solint Time and channel solution intervals in CASA syntax.

Default is solint=’inf’, which is used when hm_bandpass=’fixed’. If hm_bandpass is set to ‘snr’, then the task will attempt to compute and use an optimal SNR-based solint (and warn if this solint is not good enough). If hm_bandpass is set to ‘smoothed’, the task will use a smoothed solint.

maxchannels The bandpass solution smoothing factor in channels. The

solution interval is bandwidth / 240. Set to 0 for no smoothing. Used if hm_bandpass=’smoothed’.

Example: maxchannels=0

evenbpints Force the per spw frequency solint to be evenly divisible

into the spw bandpass if hm_bandpass=’snr’.

Example: evenbpints=False

bpsnr The required SNR for the bandpass solution. Used only if

hm_bandpass=’snr’.

Example: bpsnr=30.0

minbpsnr The minimum required SNR for the bandpass solution

when strong atmospheric lines exist in Tsys spectra. Used only if hm_bandpass=’snr’.

Example: minbpsnr=10.0

bpnsols The minimum number of bandpass solutions. Used only if

hm_bandpass=’snr’.

combine Data axes to combine for solving. Axes are ‘’, ‘scan’, ‘spw’,

‘field’ or any comma-separated combination.

Example: combine=’scan,field’

refant List of 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=’DV06,DV07’

solnorm Normalise the bandpass solution minblperant Minimum number of baselines required per antenna for each solve.

Antennas with fewer baselines are excluded from solutions.

minsnr Solutions below this SNR are rejected unregister_existing Unregister all bandpass calibrations from the pipeline context

before registering the new bandpass calibrations from this task.

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 user 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 Automatically accept the results of the task into the pipeline context (True)

or reject them (False).

——— examples ———————————————————–

1. Compute a channel bandpass for all visibility files in the pipeline context using the CASA reference antenna determination scheme:

hifa_bandpass()

2. Same as the above but precompute a prioritized reference antenna list:

hif_refant() hifa_bandpass()