Project: datamanagement
Issue DM-4768: Port W16 CModel improvements from HSC
Three significant changes were made to CModel in [HSC-1339|https://hsc-jira.astro.princeton.edu/jira/browse/HSC-1339]. They were described by [~jbosch] in a [post to {{hsc_software}}|http://jeeves.astro.princeton.edu/pipermail/hsc_software/all/4568.html]. They include: * Changing the method by which the initial approximation is determined; * Changing the determination of the pixel region to use in fitting; * A new prior on ellipticity and radius. Please port these changes to LSST. Also include the results of fixing the bug described in [HSC-1384|https://hsc-jira.astro.princeton.edu/jira/browse/HSC-1384].
Story points: 4