Subject: Re: [sloan-25mlog 4088] Re: 2.5m obslog 20180520 (SJD 58259)
From: Kaike Pan
Date: Mon, 21 May 2018 08:58:58 -0600
Yes. What I mean is that If we know it will stop at the same place, no =
point to try more times, and we just need to be care to proceed with the =
telescope at 5.5 deg.=20
> On May 21, 2018, at 8:54 AM, John Downey  wrote:
>=20
> The telescope would not go to 5 degrees because the flat field petals =
could not be fully closed.  Since there was no real harm in trying a =
couple times I didn't make a point of trying to break in to explain why =
it was stopping where it was.  It does no harm to try a couple times if =
you like, but there is not much point to it, the PLC usually stops the =
telescope where it does for a reason, only rarely is it due to a fault.
>=20
>> On May 21, 2018, at 7:31 AM, Kaike Pan  wrote:
>>=20
>> Totally understand. I mentioned the information, because observers =
attempted to have the telescope goto the 5 degrees several times (and =
didn=E2=80=99t get there). In such cases, we can excise the procedure =
(with the ladder) after two attempts or so.
>>=20
>>> On May 21, 2018, at 8:19 AM, John Downey  =
wrote:
>>>=20
>>> Given what Dmitry reported concerning clearance, any time the =
enclosure bypass is used I would like a person on a ladder as they did =
last night to be absolutely sure there will be no collision with the =
building.  While the enclosure may clear at 6 degrees with the door =
fully open, please remember that the enclosure bypass also bypasses the =
door position switch, so there is nothing to stop the enclosure from =
moving with the door down an extra 6 inches and the telescope at 5.5 =
degrees.  This is why the interlock was changed from 6 degrees to 5, for =
a margin of safety.
>>>=20
>>> With two observers available for emergency closing, it is really not =
difficult to exercise some sensible precautions like this one.
>>>=20
>>> John
>>>=20
>>>> On May 21, 2018, at 7:11 AM, Kaike Pan  wrote:
>>>>=20
>>>> Thank you for being caution. Just for information, we should be =
able to open/close with the telescope at 6 degree. We did that for a =
short period of time after the modification of the FFS motor system, =
decided to change to 5 degree to give more clear space.
>>>>=20
>>>>> On May 21, 2018, at 5:05 AM, dmbiz@apo.nmsu.edu wrote:
>>>>>=20
>>>>>=20
>>>>>                   APACHE POINT OBSERVATORY SDSS 2.5M
>>>>>=20
>>>>>                             OBSERVING LOG
>>>>>                      Sunday May 20, 2018
>>>>>=20
>>>>>                              (SJD 58259)
>>>>>=20
>>>>> ----  Observing Team ----
>>>>>=20
>>>>> Karen Kinemuchi
>>>>> Dmitry Bizyaev
>>>>>=20
>>>>> John Downey (over the phone)
>>>>>=20
>>>>> ---- Observing Plan ----
>>>>>=20
>>>>> Sun 20 MAY 2018    58259.0   0.34    03:19  10:42    12:10  19:35  =
   ----  =20
>>>>> MaNGA until 08:07 ( 4.8 h), then eBOSS ( 2.6 h)=20
>>>>>=20
>>>>> ---- Observing Summary ----
>>>>>=20
>>>>> Clear night with high humidity in the first part.=20
>>>>> FFS hardware problem stopped observations early.=20
>>>>>=20
>>>>>=20
>>>>> eBOSS
>>>>> -----
>>>>> 17 10925  eBOSS  3x900s  not finished
>>>>>=20
>>>>>=20
>>>>> Notes:
>>>>> * 1-m port: 2:30Z - 10:53Z
>>>>> * dust accumulated: ~4000
>>>>> * Serious problem with FFS power supply, see log. In combination =
with=20
>>>>> high humidity, we lost 3h51m to the FFS problem, and 3h29m to=20
>>>>> bad weather.
>>>>> By-survey break down is tricky, since we had to observe eBOSS =
plates
>>>>> during official MANGA time, and MANGA plates during eBOSS time =
because of the=20
>>>>> gaps in plates for both surveys. Based on the actual *ability* to =
observe,
>>>>> we propose to count that eBOSS lost 2h 47 min to the weather (from=20=
>>>>> stopping to the end of cart 13). MANGA lost 42 min to weather, and =
3h11m
>>>>> to the hardware problem. APOGEE lost 40m of time between the =
15-deg and 8-deg
>>>>> twilight to the hardware problem.=20
>>>>>=20
>>>>> * Attention to JohnB/IT: the weather page for the 2.5m showed ~50% =
humidity
>>>>> all night long, dropping sharply from ~80% to this value within a =
few minutes.  =20
>>>>> At the same time, the 3.5m part suggested very high humidity, the =
enclosure=20
>>>>> doors were damp, and the reader inside the 2.5m enclosure showed =
close to 100%=20
>>>>> value. Please check if the humidity sensor behaves.=20
>>>>>=20
>>>>> ---- Observing Log ----
>>>>>=20
>>>>=20
>>>> ____________________________________________________________
>>>> Logs of Nightly APO Activities
>>>> =
https://trac.sdss.org/tracmailman/browser/private/sloan-25mlog/index.html
>>>=20
>>=20
>=20