pipeline.hifa.cli.gotasks.hifa_session_bandpass

pipeline.hifa.cli.gotasks.hifa_session_bandpass = <pipeline.hifa.cli.gotasks.hifa_session_bandpass._hifa_session_bandpass object>

hifa_session_bandpass —- Compute bandpass calibration solutions

Compute amplitude and phase as a function of frequency for each spectral window in each MeasurementSet.

Previous calibration can be applied on the fly.

hifa_session_bandpass 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 precompute a prioritized list of reference antennas.

Output

results – 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 The list of input MeasurementSets. Defaults to the list of

MeasurementSets specified in the pipeline context.

example: vis=[‘M51.ms’]

caltable The list of output calibration tables. Defaults to the standard

pipeline naming convention.

example: caltable=[‘M51.bcal’]

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

computed. Defaults to 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. Defaults to all data with bandpass intent.

example: intent=’PHASE’

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

computed. Defaults to all science spectral windows.

example: spw=’11,13,15,17’

antenna 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), and ‘’ (none).

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. Defaults to 500MHz.

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), and ‘fixed’ (use the user defined parameters for all spws).

solint Time and channel solution intervals in CASA syntax.

default: ‘inf’ Used for hm_bandpass=’fixed’, and as a default for the ‘snr’ and ‘smoothed’ options.

default: ‘inf,7.8125MHz’ example: solint=’inf,10ch’, solint=’inf’

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: 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’.

hm_bandtype The type of bandpass. The options are ‘channel’ and

‘polynomial’ for CASA bandpass types = ‘B’ and ‘BPOLY’ respectively.

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

‘field’ or any comma-separated combination.

example: combine=’scan,field’

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’

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

Antennas with fewer baselines are excluded from solutions. Used for hm_bandtype=’channel’ only.

minsnr Solutions below this SNR are rejected. Used for hm_bandtype=

‘channel’ only.

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

reject them (False).

parallel Execute using CASA HPC functionality, if available.

——— examples ———————————————————–

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

hifa_session_bandpass()

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

hif_refant() hifa_session_bandpass()