Subject: Re: [sloan-25mlog 3662] 2.5m obslog 20170920 (SJD 58017) From: Kaike Pan Date: Thu, 21 Sep 2017 10:16:06 -0600 I went through one week worth data on collimating. =46rom the data, I = clear see that 1) residuals depends on the telescope position, for example, the SP1 = residual was about 2 deg at the stow, but it became 5 deg after slew back to the field; 2) = Marks on the ring are not reliable in referring actual movement. For example, log stated = that a ring was moved by 4 degree, but the hartmann results indicated it was moved by +9 = degrees (i.e. residual changed by -4.5 deg). It may have something to do with the way how rings = was tied down (different observers may do differently) or simply the focus ring position did = repeat well for loosening/tied down operation.=20 Here is what I suggest we should follow:=20 1) if you need to adjust focus ring during nights, slew the telescope = back to stow position, take a quick hartmann to get your reference residuals, move = the ring, take a hartmann to verify that you get the residual you want.=20 For example, in the field, SP2 residual was 4.5 deg, you need to move = the focus ring about +2 degrees so that the residual will be 3.5 deg. After you = slew to the stow, the first hartman may show the residual is 2 deg instead of 4.5 deg. If this = happen, you still need to move the ring to get a residual of 1 deg at the stow position = before you =E2=80=9Cgoto Field=E2=80=9D again.=20 2). I will setup focus ring positions this afternoon. You may see = residual could be as low as -5 deg=20 during your evening checkout, but this may be fine since the residual = got during afternoon checkout=20 are usually very different from night ones. If you think that a focus = ring needs to be moved during afternoon checkout, please check with me before you actually move the ring (in = last week, one focus ring was adjusted during afternoon checkouts in three days, the ring was actually = moved in backward direction during nights).=20 Let me know if you have questions on this message. Thanks, -kaike =20 > On Sep 21, 2017, at 6:50 AM, elenam@apo.nmsu.edu wrote: >=20 >=20 > APACHE POINT OBSERVATORY SDSS 2.5M >=20 > OBSERVING LOG > Wednesday September 20, 2017 >=20 > (SJD 58017) >=20 > ---- Observing Team ---- >=20 > Katie Grabowski > Elena Malanushenko >=20 >=20 > ---- Observing Plan ---- >=20 >=20 > Wed 20 SEP 2017 58017.0 0.00 02:11 11:44 19:08 04:42 = ---- =20 > eBOSS until 07:26 ( 5.3 h), then MaNGA ( 4.3 h)=20 >=20 >=20 > ---- Observing Summary ---- >=20 > Clear sky and good seeing.=20 > eBoss lost 34 min for hartmann b-rings,=20 > and 12 min for Netburner error. I guess,=20 > we can consider it as hardware problems,=20 > 46 minuts total.=20 >=20 > eBOSS: > =3D=3D=3D=3D=3D=3D=3D > Cart 10, Plate 8533, 3x900s, complete! > Cart 12, Plate 9231; 2x900s, complete! > Cart 14, Plate 9239; 2x900s, not done > Cart 11, Plate 7702; 4x900s, complete! > Cart 16, Plate 9348; 2x900s, complete! >=20 > MaNGA: > =3D=3D=3D=3D=3D=3D =20 > Cart 1, Plate 8656; 1xNSE+N, apogee 4xAB, not done > Field name: MJ6.84307-0.05313=20 > Missing fibers: [273] > Faint fibers: [2, 121, 123, 126, 129, 148, 211, 227] >=20 > Cart 5, Plate 8079; 2xNSE+NS, apogee 8xAB, not done > Field name: MJ42.27307-0.00000 > Missing fibers: [211, 273] > Faint fibers: [121, 128, 159, 245] >=20 > Problems > =3D=3D=3D=3D=3D=3D=3D=3D > 1. Slew was out of closed loop (01:31, no time lost).=20 > 2. Netburner error (03:43) and sop restart during calibrations. Lost = 12 minutes. > 3. Had problems with calibration of cart 12. Adjusted sp1 by -8 = degrees during=20 > afternoon checkout, and adjusted +8 degrees back during observations.=20= > Lost 34 minutes for such adjustments.=20 > I expected sop will not move spectro pistons if hartmann failed,=20 > but it did move indeed.=20 > 4. The Sec orient piston position on Cart 5 was close to its home = limit > position, we have unchecked scale auto correction. The temperature = difference > for this night and design was 8 degrees. =20 >=20