Scalar bandpass correction

Scalar bandpass correction using autocorrelations (fit_autocorrs)

In order the improve the initial fringe-fitting processes, it is often useful to generate a scalar bandpass (amplitude only) correction using the auto-correlations. To run this step you should ensure that the auto-correlations remain unflagged (see the init_flag parameters).

Parameters

    "fit_autocorrs":{
        "select_calibrators": ["default"],
        "interp_bad_solutions": true, 
        "hpc_options":{
            "partition"     :  "default",
            "walltime"      :  "default",
            "nodes"         :   -1,
            "cpus"          :   -1,
            "mpiprocs"      :   -1,
            "nodetype"      :  "default"
        }

Recommended use: There's only a few parameters to set here. The select_calibrators parameter states which calibrators to use to derive the scalar bandpass. If "select_calibrators":["default"], then the fringe finders will be used (as set in the global parameters). Leaving this as default is usually ok as we want to ensure that the source is very bright.

The "interp_bad_solutions" parameter is often ok to be left as true. The autocorrelations will experience persist RFI in excess of the cross-correlations. This results in the RFI filter in this step flagging the channel. Keeping this parameter as true will linearly interpolate across the flagged channels.

Expected inputs

• Measurement set (<project_code>.ms)

Expected outputs

• Scalar bandpass calibration table (<project_code}.auto.bpass)