KimMcAlpine
commented
3 years ago Besides pre-apply, does the usual apply also need to update weights? This comment hints at it :-D
I don't think the usual apply needs to update the weights. I think in some far distant past there was an idea that the L1 / corrected visibilities would be streamed to somewhere useful for later use, in this case it would make sense to also update the weights. However we now use katdal for generating the L1 product and in our current model there are only two uses for the usual apply ( i.e not a pre-apply step in a solver)
1.) To apply the calibration solutions before flagging, I don't think the weights are considered by the flagger so it won't make any difference if you don't update the weights here
2.) To make summary scans of the calibrated data to plot in the report. Mostly you are just plotting the visiblities here, but some of these scans are combined in weighted average at the end so this might make a small difference but I suspect the effect is fairly minor. I'll look into this a bit
Update weights when pre-applying solutions to improve the robustness of the solutions to poor antennas.