Examples

For a MeasurementSet 'calibrated.ms', the continuum imaging sensitivity using natural weighting for field id 3 and a subset of channels in spw 0 can be obtained as follows:

aps=apparentsens(vis='calibrated.ms',
                 spw='0:0~30;40~80',
       field='3',
                 specmode='mfs',
       cell='0.007arcsec',imsize=[2048, 2048],
                 weighting='natural')

print aps

The returned dictionary is (also reported in logger):

{'relToNat': 1.0000000000089664, 'effSens': 1.0022319615408699e-05}

Note that the 'relToNat' factor is 1.0.

For the same MS and selection, but with Briggs weighting:

aps=apparentsens(vis='calibrated.ms',
                 spw='0:0~30;40~80',
       field='3',
                 specmode='mfs',
       cell='0.007arcsec',imsize=[2048, 2048],
                 weighting='briggs',
                 robust=0.5)

print aps

The returned dictionary is (also reported in logger):

{'relToNat': 1.1450564209993626, 'effSens': 1.1476121428828694e-05}

Note that Briggs weighting is ~14% less sensitive in this case.