Details
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Type:
Bug
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Status: Done
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Resolution: Done
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Fix Version/s: None
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Component/s: ap_association, ap_pipe
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Labels:
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Story Points:4
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Epic Link:
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Sprint:AP F18-3, AP F18-4, AP F18-5
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Team:Alert Production
Description
While testing ap_verify_ci_hits2015, a set of six overlapping exposures across three epochs, for DM-15142, I got the following source matching statistics:
- 1600 DiaObjects with 1 DiaSource
- 82 DiaObjects with 2 DiaSources
- 0 DiaObjects with 3 DiaSources
The issue appears whether I run ap_pipe all at once or in order of increasing visit ID, so it does not appear to be a concurrency bug in the database. On the other hand, the dataset footprint is known to include "messy" chips, so it's possible that many of the DiaSources are transient artifacts rather than real sources.
Pair-investigate the properties of the images and DiaObjects to figure out what is happening.
Attachments
Issue Links
- relates to
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DM-15142 Create CI-sized DECam Dataset
- Done
We found that part of the problem is that CCDs 58 and 62 do not overlap with the other images (because I was comparing a East-is-left focal plane map to an East-is-right image of the HiTS 2015 dataset). Looking at only the two visits with CCDs 5 and 10 in a slightly different reduction, we see:
Meredith Rawls thinks the ~10% repeat DiaSources despite the ~100% overlap is because most of the sources are image differencing artifacts; we will make plots of number of sources on the sky for each individual visit to test this hypothesis.