Foreman-Mackey and I spent some time discussing his robust model of photometric calibration for multi-epoch imaging surveys. The basic idea is that every star is drawn from a distribution that is a mixture of variable and non-variable stars, and that every observation of every star is drawn from a distribution that is a mixture of good (inlier) and bad (outlier) measurements. These mixtures permit the model to be most constrained by the most valuable data, but at the expense of many nuisance parameters. It works remarkably well on real data from SDSS Stripe 82, and has great general applicability in the world of time domain astrophysics. Our current goal is to understand how to model variations in calibration parameters in time and angle.
No comments:
Post a Comment