Last September (2015), @jbosch started a discussion in the LSST Community DM forum on Baseline Plan for Blended Fitting, which led to a very useful draft document, Jim Bosch’s Blended Measurement Paper, and followup DM discussion in GitHub.
Since almost(?) every LSST science collaboration will need measurements made on blended objects, it would be useful to the community if some plenary time at the 2016 Project and Community Workshop could be devoted to a project update on the current baseline plan for measurements on blended objects and potential alternative strategies, the major open questions regarding strategy, and any related “research questions” that may be beyond the scope of the project’s current requirements, that science collaboration members could potentially help address. It would also be useful to get a very rough estimate of the time scale on which various algorithms in DM might be ready for testing. Even if the current state of the DM code is not particularly relevant for tackling open “research questions” related to measurements on blended objects, there may be specific questions science collaboration members could address outside the DM stack. Also, are there missing requirements that need to be quantified for blended objects — for example, for a “bake off” between different algorithms — that specific science collaborations should be addressing?
Perhaps some of these questions could be refined or addressed in breakouts that focus on different aspects of “blended measurements” — photometry, shapes, astrometry, … — and/or different types of fields (high Galactic latitude vs. bulge), for which different algorithms may be optimal.