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  1. Data Management
  2. DM-12783

Normalize weights differently for morphology and SED updates

    Details

    • Type: Story
    • Status: Done
    • Resolution: Done
    • Fix Version/s: None
    • Component/s: meas_deblender
    • Labels:
      None
    • Templates:
    • Story Points:
      1
    • Sprint:
      DRP F17-6
    • Team:
      Data Release Production

      Description

      It is believed that the problems with bad colors in HSC-Z and Y that we observed in DM-12776 are due to the way we are using inverse variance maps to weight gradient steps in the deblender. When two bands have substantially different mean variance, certain colors converge more quickly than other colors, and at all times are capable of taking larger steps toward the minimum, which we believe results in poor colors in the bands with higher variance. Similarly, images with widely varying pixel variances could also see some pixels reaching convergence more quickly than others (although we have not observed this directly).

      To combat this Peter Melchior and I propose to normalize the weights for SED updates along each band, so that only pixel by pixel variations are weighted for each SED update, and normalize the weights for morphologies along each single band image. This should give us more uniform convergence and hopefully solve DM-12776 as well.

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              • Assignee:
                fred3m Fred Moolekamp
                Reporter:
                fred3m Fred Moolekamp
                Reviewers:
                Peter Melchior
                Watchers:
                Fred Moolekamp, Peter Melchior
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                • Created:
                  Updated:
                  Resolved:

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