We need to interpolate the aperture correction to the position of every source, and apply this correction to all appropriate fluxes.
The HSC implementation of this work (as well as that of
DM-435) was done on issue HSC-191:
There were changes to many packages, but the relevant ones for LSST are:
Note that on the LSST side, we'll want to apply the aperture corrections either within a new plugin in meas_base or as a new part of BaseMeasurementTask, not as a change to the CorrectFluxes algorithm (which will be removed in the future along with the rest of the old measurement framework in meas_algorithms).