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Type:
Task
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Status: Done (View Workflow)
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Priority:
Normal
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Resolution: Done
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Component/s: ics_agccActor
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Labels:
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Sprint:PreRun23Jun2025
Copy of Robert's comment on Slack (auto-guiding channel)
Wilfred Gee and I are seeing a lot of failures in the windowedFWHM code; it seems very fragile. For example, in pfs_visit_id, agc_exposure_id = 125719, 700288 AG3, the object at xPos, yPos = (668.202640, 136.838380) has flag bit 0x8 set; running the code from a notebook the problem seems to be from NaN (coming from a negative second moment). If you take xPos, yPos = (668.01, 137.01) you get a good (and correct) value!
I think that at least part of the problem is that you initialise sx = 1.5; sy = 1.5 which is too small – it looks as if you took the value from my SDSS code with much larger pixels than the AGs; these values correspond to c. 0.4" seeing. I think that a value of around 6 is likely to be significantly more stable. Can you test that using the AG playback on a week or two of data? You should get many fewer objects with that bit set (of course some of them won't have flags == 0x0 – you'll need to check (flags & 0x8) == 0). It's possible that this won't be a sufficient fix, or cause something else to fail and we'll have to do some more thinking
- relates to
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INSTRM-2557 Feedbacks for agcc Actor centroidTool
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- Done
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