Subject: Re: [sloan-25mlog 6372] 2.5m obslog 20221127 (SJD 59911)
From: Kaike
Date: Mon, 28 Nov 2022 09:40:38 -0600
Hello All,
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> On Nov 28, 2022, at 7:16 AM, dmbiz@apo.nmsu.edu wrote:
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>                       APACHE POINT OBSERVATORY SDSS 2.5M
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>                                 OBSERVING LOG
>                          Sunday November 27, 2022
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>                                  (SJD 59911)
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> ----  Observing Team ----
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> Dmitry Bizyaev
> Audrey Oravetz
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> ---- Observing Plan ----
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> Sun 27 Nov 2022 59911 0.25 00:54 01:09 12:33 22:33 09:59 --- dark =
(11.4 h) plus 0.2 h for 12 deg design
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> ---- Observing Summary ----
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> Mostly clear night with good to decent seeing.
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> Notes
> -----
> - dust collected: 3.3K
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> - Attention to Jose. Guiding on the first bright field was a =
nightmare. Focus monitor in Boson (as well as gfa_ffwh script, same) =
determined seeing well and suggested to move the focus down, while I =
clearly saw donuts by eye in the GFAs 1, 2, & 4. Donuts grew if I moved =
focus down. I finally moved the focus up very much, and far away (550 vs =
suggested 100) stars turned points, and focus loop started converging. =
The only measuring tool for it was the APOGEE flux monitor in Kronos =
(thanks JohnD!). This explains what happened on the first field =
yesterday and its low signal - it was out of focus while software =
reported good FWHM. It would be nice if the guiding algorithm catches =
really prominent donuts and reports bad FWHM for them.=20
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This may be a feature we need to live with: Guider will not work well =
when the focus is far away. I normal manually move M2 and visually check =
one GFA images for the first field to ensure there are not donuts in GFA =
images (the =E2=80=9C+=E2=80=9D on boson guider window works for the =
work) before trust the guider auto-focus loop.=20