The current DPDD https://docushare.lsst.org/docushare/dsweb/Get/Version-60783/LSE-163_dpdd_rel3.4_20190729.pdf Table 6 for the Source table requests sky, the "Estimated background (sky) surface brightness at the position (centroid) of the source". I believe this is supposed to be the evaluation of the total background model at the location of the source. (Currently, in https://github.com/lsst/obs_subaru/blob/master/policy/Source.yaml this is interpreted as the local background residual). This ticket is to write a plugin for meas_base to evaluate the background model at the position of each source.