flint.selfcal.casa¶

Utilities related to using casa tasks to perform self-calibration.

This tooling is mostly centred on using gaincal from casatasks.

Classes¶

GainCalOptions

Options provided to the casatasks gaincal function. Most options correspond to those in gaincal.

Functions¶

`cli`(→ None)
`copy_and_clean_ms_casagain`(→ flint.options.MS)	Create a copy of a measurement set in preparation for selfcalibration
`create_spws_in_ms`(→ pathlib.Path)	Use the casa task mstransform to create nspw spectral windows
`gaincal_applycal_ms`(→ flint.options.MS)	Perform self-calibration using casa's gaincal and applycal tasks against
`get_parser`(→ argparse.ArgumentParser)
`merge_spws_in_ms`(→ pathlib.Path)	Attempt to merge together all SPWs in the input measurement

Module Contents¶

class flint.selfcal.casa.GainCalOptions(/, **data: Any)[source]¶

Bases: flint.options.BaseOptions

Options provided to the casatasks gaincal function. Most options correspond to those in gaincal.

calmode: str = 'p'[source]¶: Calibration mode.

gaintype: str = 'G'[source]¶: The gain type that would be solved for.

minsnr: float = 0.0[source]¶: Minimum signal-to-noise of the solutions. Below this the solutions and data are flagged.

nspw: int = 1[source]¶: The number of spectral windows to use during the self-calibration routine. This will be used to craft an appropriate select_spw= interval range. If larger than one, gaincal will be carried out against each interval and results will be appended to a common solutions file.

round: int = 0[source]¶: Self-calibration round. Not a gaincal option.

selectdata: bool = True[source]¶: Whether data selection actions will be applied in gaincal.

solint: str = '60s'[source]¶: Solution length interval

uvrange: str = '>200m'[source]¶: Data selected to go through calibration procedure

flint.selfcal.casa.cli() → None[source]¶

flint.selfcal.casa.copy_and_clean_ms_casagain(ms: flint.options.MS, round: int = 1, verify: bool = True, rename_ms: bool = False) → flint.options.MS[source]¶

Create a copy of a measurement set in preparation for selfcalibration using casa’s gaincal and applycal. Applycal only works when calibrating DATA and creating a CORRECTED_DATA column. Columns are removed in the copied MS to allow this.

If the MS is large the move_ms option will simply renamed the input MS, adjusting the columns appropriately. Note that this potentially involves deleting the DATA column if present and renaming CORRECTED_DATA.

Parameters:

ms (MS) – Measurement set that would go through self-calibration.
round (int, optional) – The self-calibration round. Defaults to 1.
verify (bool, optional) – Verify that copying the measurementt set (done in preparation for gaincal) was successful. Uses a call to rsync. Defaults to True.
move_ms (bool, optional) – Rather than copying the MS, simple renamed the MS and modify columns appropriately. Defaults to False.

Returns:

Copy of input measurement set with columns removed as required.

Return type:

flint.selfcal.casa.create_spws_in_ms(casa_container: pathlib.Path, ms_path: pathlib.Path, nspw: int) → pathlib.Path[source]¶

Use the casa task mstransform to create nspw spectral windows in the input measurement set. This is necessary when attempting to use gaincal to solve for some frequency-dependent solution.

Parameters:

casa_container (Path) – Path to the singularity container with CASA tooling
ms_path (Path) – The measurement set that should be reformed to have nspw spectral windows
nspw (int) – The number of spectral windows to create

Returns:

The path to the measurement set that was updated

Return type:

Path

flint.selfcal.casa.gaincal_applycal_ms(ms: flint.options.MS, casa_container: pathlib.Path, round: int = 1, gain_cal_options: GainCalOptions | None = None, update_gain_cal_options: dict[str, Any] | None = None, archive_input_ms: bool = False, raise_error_on_fail: bool = True, skip_selfcal: bool = False, rename_ms: bool = False, archive_cal_table: bool = False) → flint.options.MS[source]¶

Perform self-calibration using casa’s gaincal and applycal tasks against an input measurement set.

Parameters:

ms (MS) – Measurement set that will be self-calibrated.
round (int, optional) – Round of self-calibration, which is used for unique names. Defaults to 1.
casa_container (Path) – A path to a singularity container with CASA tooling.
gain_cal_options (Optional[GainCalOptions], optional) – Options provided to gaincal. Defaults to None.
update_gain_cal_options (Optional[Dict[str, Any]], optional) – Update the gain_cal_options with these. Defaults to None.
archive_input_ms (bool, optional) – If True, the input measurement set will be compressed into a single file. Defaults to False.
raise_error_on_fail (bool, optional) – If gaincal does not converge raise en error. If False and gain cal fails return the input ms. Defaults to True.
skip_selfcal (bool, optional) – Should this self-cal be skipped. If True, the a new MS is created but not calibrated the appropriate new name and returned.
rename_ms (bool, optional) – It True simply rename a MS and adjust columns appropriately (potentially deleting them) instead of copying the complete MS. If True archive_input_ms is ignored. Defaults to False.
archive_cal_table (bool, optional) – Archive the output calibration table in a tarball. Defaults to False.

Raises:

GainCallError – Raised when raise_error_on_fail is True and gaincal does not converge.

Returns:

The self-calibrated measurement set.

Return type:

flint.selfcal.casa.get_parser() → argparse.ArgumentParser[source]¶

flint.selfcal.casa.merge_spws_in_ms(casa_container: pathlib.Path, ms_path: pathlib.Path) → pathlib.Path[source]¶

Attempt to merge together all SPWs in the input measurement set using the cvel casa task. This can be a little fragile.

The cvel task creates a new measurement set, so there would temporially be a secondary measurement set.

Parameters:: ms_path (Path) – The measurement set that should have its SPWs merged together.
Returns:: The measurement set with merged SPWs. It will have the same path as ms_path, but is a new measurement set.
Return type:: Path