Examples

Given a 'G' table, 'cal.G', containing solutions for a flux density calibrator, 3C286, and for two fields with unknown flux densities (0234+285 and 0323+022):

fluxscale(vis='data.ms',
          caltable='cal.G',                  # Select input table
          fluxtable= 'cal.Gflx',             # Write scaled solutions to cal.Gflx
          incremental=True,                  # Generate an incremental output table
          reference='3C286',                 # 3C286 = flux calibrator
          transfer='0234+258, 0323+022')     # Select calibrators to scale

The output table, cal.Gflx, contains per-field, per-spw scaling factors alone to be used along with the input gain table cal.G in subsequent operations, e.g., applycal. If incremental=False had been used, the output fluxtable should be used in place of the input caltable in subsequent operations.

If transfer of the flux density scale among spws is required, use refspwmap. For example:

fluxscale(vis='data.ms',
          caltable='cal.G',                  # Select input table
          fluxtable= 'cal.Gflx',             # Write scaled solutions to cal.Gflx
          reference='3C286',                 # 3C286 = flux calibrator
          transfer='0234+258,0323+022'       # Select calibrators to scale
          refspwmap=[0,0,0])                 # Use spwid 0 scaling for spwids 1 & 2

will use the reference field gain amplitudes from spw=0 to scale the transfer field gain amplitudes in spws 0, 1 & 2.

If the flux density calibrator is resolved, and an adequate model is not available, use antenna and uvrange selection in gaincal to limit the gain solutions to baselines satisfying the point-source assumption. For example, solve for the flux density calibrator (3C286) only, with limited data:

gaincal(vis='data.ms',
        caltable='cal.G',        # write solutions to cal.G
        field='3C286'            # Select the flux density calibrator
        selectdata=True,         # Expand other selectors
        antenna='0~7',           # antennas 0-7,
        uvrange='0~15klambda',   # limit uvrange to 0-15klambda
        solint=90)               # on 90s timescale

Then solve for the other (presumably point-like) calibrators using all antennas and baselines, and append to the same caltable:

gaincal(vis='data.ms',
        caltable='cal.G',           # write solutions to cal.G
        field='0234+258,0323+022', # point-like calibrators with unknown f.d.
        solint=90,
        append=True)                   # append to the same table

Finally, run fluxscale on the aggregate caltable:

fluxscale(vis='data.ms',
          caltable='cal.G',      # Input table with unscaled cal solutions
          fluxtable='cal.Gflx', # Write scaled solutions to cal.Gflx
          reference='3C286',     # Use 3c286 as ref with limited uvrange
          transfer='0234+285,0323+022')   # Transfer scaling