Run P-AIRCARS Pipeline

Basic run

To run P-AIRCARS pipeline, with default settings for full analysis, run the following command from terminal. Work directory needs not to be created before hand, but the path where it will be created should exist.

run-mwa-paircars </full/path/to/data_directory> --workdir </full/path/to/work_directory> --outdir </full/path/to/output_product_directory> --cal_datadir </full/path/to/calibrator_data_directory>

Note

User needs to provide full path. Providing short path or only the directory name will cause error.

Advanced run

For advanced run, user is requested to first check the parameters of run-mwa-paircars.

run-mwa-paircars -h

Multiple options demonstrated below can be combined to have all of them together.

  1. To view details of measurement set:

    show-paircars-ms </full/path/to/measurement_set>
    

Runs with advanced calibration paramaters

  1. If one do not have calibrator observations:

    run-mwa-paircars </full/path/to/data_directory> --workdir </full/path/to/work_directory> --outdir </full/path/to/output_product_directory>
    

    Note

    P-AIRCARS will self-calibrate and perform flux-density and polarisation calibration based on some assumptions. In these cases, absolute values of the quantities should be carefully considered.

  2. If user wants to provide specific path to target and calibrator metafits file

    run-mwa-paircars </full/path/to/data_directory> --target_metafits </full/path/to/data_metafits> --workdir </full/path/to/work_directory> --outdir </full/path/to/output_product_directory> --cal_datadir </full/path/to/calibrator_data_directory> --cal_metafits </full/path/to/calibrator_metafits>
    
  3. If user wants to run with multiple target and calibrator observations

    run-mwa-paircars </full/path/to/data_directory_1>,</full/path/to/data_directory_2> --workdir </full/path/to/work_directory> --outdir </full/path/to/output_product_directory>  --cal_datadir </full/path/to/calibrator_data_directory_1>,</full/path/to/calibrator_data_directory_2>
    
  4. Do calibration with custom calibration parameters. There are two parameters: cal_uvrange and solint which can be changed. Example, run the following command to perform gain solutions at 10second interval and >200lambda data:

    run-mwa-paircars </full/path/to/data_directory> --workdir </full/path/to/work_directory> --outdir </full/path/to/output_product_directory> --cal_datadir </full/path/to/calibrator_data_directory> --solint "10s" --uvrange ">200lambda"
    
  5. By default for full-polar data, polarization calibration will be performed. To disable it:

    run-mwa-paircars </full/path/to/data_directory> --workdir </full/path/to/work_directory> --outdir </full/path/to/output_product_directory> --cal_datadir </full/path/to/calibrator_data_directory> --no_polcal
    

Runs with advanced imaging paramaters

  1. Run pipeline to image specific time and frequency range. Default is to use entire time and frequency range. Example for imaging two time ranges given in UTC and frequency ranges given in MHz:

    run-mwa-paircars </full/path/to/data_directory> --workdir </full/path/to/work_directory> --outdir </full/path/to/output_product_directory> --cal_datadir </full/path/to/calibrator_data_directory> --timerange "2024/06/10/09:00:00~2024/06/10/09:30:00,2024/06/10/10:15:00~2024/06/10/10:45:00" --freqrange 100~150,200~230
    
  2. Run imaging with custom time and frequency resolution. Default is to use each 1.28 MHz coarse bands and 10s of integration. Example run for imaging at 0.5 second time resolution and 160 kHz (0.16 MHz) frequency resolution:

    run-mwa-paircars </full/path/to/data_directory> --workdir </full/path/to/work_directory> --outdir </full/path/to/output_product_directory> --cal_datadir </full/path/to/calibrator_data_directory> --image_timeres 0.5 --image_freqres 0.16
    
  1. Default is to make only Stokes I images if do_polcal=False and Stokes IQUV, if do_polcal=True. To run only Stokes I imaging, even if do_polcal=True, run:

    run-mwa-paircars </full/path/to/data_directory> --workdir </full/path/to/work_directory> --outdir </full/path/to/output_product_directory> --cal_datadir </full/path/to/calibrator_data_directory> --pol I
    

Similarly, all other advanced imaging parameters can be used.

Switching off particular pipeline step(s)

By default, all steps will be performed by pipeline. Even pipeline was run upto certain stages and then stopped, all steps from beginning will be performed to avoid any potential issue in failure in previous runs. If user is certain that previous run was successful upto certain stages, those stages can be switched.

Caution

User should not modify any file and directory structure in the work directory. Switching off certain parameters will only allow to run the pipeline forward, if the expected output products from those steps are present with appropriate name in appropriate directory. Otherwise, it will fail.

Take a look at the Advanced pipeline parameters in the help page of run-mwa-paircars. Each parameters are self explanatory. Some examples are given below:

  1. To switch off self-calibration:

    run-mwa-paircars </full/path/to/data_directory> --workdir </full/path/to/work_directory> --outdir </full/path/to/output_product_directory> --cal_datadir </full/path/to/calibrator_data_directory> --no_selfcal
    
  2. To stop final imaging:

    run-mwa-paircars </full/path/to/data_directory> --workdir </full/path/to/work_directory> --outdir </full/path/to/output_product_directory> --cal_datadir </full/path/to/calibrator_data_directory> --no_imaging
    
  3. To switch off self-calibration and final imaging

    run-mwa-paircars </full/path/to/data_directory> --workdir </full/path/to/work_directory> --outdir </full/path/to/output_product_directory> --cal_datadir </full/path/to/calibrator_data_directory> --no_selfcal --no_imaging