Details
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Type:
Story
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Status: To Do
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Resolution: Unresolved
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Fix Version/s: None
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Component/s: meas_algorithms, meas_deblender
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Labels:None
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Team:Data Release Production
Description
When looking at the distribution of footprint sizes for "stars", here limited to those actually used in the PSF modeling, many visits display a bi-modal distribution (two separate/offset sequences of declining nPix vs. mag). During the investigation of this effect in DM-9252, the main distinction between the two branches was that those lower branch all have "parents" (i.e. have been deblended). However, in the course of that investigation, some visits also revealed a third branch which is not explained by the same parent/non-parent clause. Please investigate the cause/source of this third "mystery" branch.
The figure in DM-9252 is for visit 30490 (HSC-I). Some other visits showing this trimodal footprint size distribution are: 19696 (HSC-I), 1214 (HSC-R), 11704 (HSC-G). Others can be provided if necessary.
Attachments
Issue Links
Activity
This pathology is still observed in all of the plots mentioned above in the latest w_2020_30 RC2 processing:
https://lsst.ncsa.illinois.edu/~madamow/w_2020_30_qaPlots/HSC-I/tract-9813/visit-19696/plot-v19696-footNpix_calib_psf_used-psfMagHist.png
https://lsst.ncsa.illinois.edu/~madamow/w_2020_30_qaPlots/HSC-I/tract-9813/visit-30490/plot-v30490-footNpix_calib_psf_used-psfMagHist.png
https://lsst.ncsa.illinois.edu/~madamow/w_2020_30_qaPlots/HSC-R/tract-9813/visit-1214/plot-v1214-footNpix_calib_psf_used-psfMagHist.png
https://lsst.ncsa.illinois.edu/~madamow/w_2020_30_qaPlots/HSC-G/tract-9813/visit-11704/plot-v11704-footNpix_calib_psf_used-psfMagHist.png
and presumably in many others. Whether it’s an “issue” warranting further investigation, I defer to others to decide/prioritize.
Lauren MacArthur — is this still an issue some 3.5 years later?