Observing Plan for MJD 56324 (starting evening of January 31 2013)


Observer 1 Observer 2 Run Manager
Old/Rooney March Soares-Santos

DECam Configuration and Setup

SISPI Configuration File sv.ini
Proposal ID 2012B-0003
Image Processing (Calibration) NCSA
Image Processing (First Cut) NCSA

Almanac and Weather

Twilight Evening: 01:12 UT
Twilight Morning: 08:42 UT
Moon Rise: 22:32
Moon Set: 11:28
Moon Illum.: 95 %
Middle of night hand over to community at 01:57

Plan and Goals for the Night

  1. Afternoon calibration data:
    1. dome flats including u-band in case we get to the half-chip SNe observations.
  2. Calibration observations (Douglas Tucker):
    1. Attached (FebStds.txt) is a list of night-by-night suggestions for the rest of the DES time, assuming the normal evening twilight times and a single standard star field just before middle-of-the-night switchover.
    2. Currently, we are observing 3 standard star fields in evening twilight -- at least one and preferably more in SDSS Stripe 82 -- and one more just before switchover. For the 3 standard fields observed during evening twilight, one should be at low airmass (<1.25), one at medium airmass (1.25-1.65), and one at high airmass (1.65-2.10).
    3. BEFORE taking/queuing the evening twilight standards tonight, do a quick check by running on observer2:
      source ~/dtucker/bin/setup_StdStarFieldPicker.csh (or .bash if you are using bash shell) --UT='2013/01/30 00:43' (replacing the time with the anticipated time that the standards sequence will start)

      and, if SDSSJ0100-0000 does not appear in the resulting table, replace it with an observation of the E2-A prenight script
  3. Obstac (Eric Neilsen):
    If seeing is <1.3 arcsec, run in auto-mode to observe SPT-E mini-survey.
  4. Half-chip SN observations (Huan Lin):
    Exposures of each SN field taken with 1/2-chip shift from normal pointings, to reconcile the photometric systems. They can be done in poor seeing but should not have clouds. On the night these are done, you will need to take u-band dome flats and add u-band to the standards as well. These exposures are lower priority than obtaining the regular SN observations above.
    1. X3, (VVDS, CDFS)
    2. X1, (recent AAT redshifts)
    3. X2, S1, S2, E1, E2 (only if there is time; check if not too low)
  5. AOS test (Kevin Reil): inserting 3 consecutive short u-band exposures into the queue. (We will try this right before the switch over, after standards)
    This will put the AOS in a situation where there are not enough stars in the image to determine a good correction for the hexapod. We discovered a few weeks back that extended u-band exposures caused it to behave badly. We've since added and tested code to make the AOS behave sensibly in this situation by simply doing nothing (zero tweaks). A second small improvement to that code was made recently but has only been tested in simulation mode. I'm fairly certain that you cannot "break it" but if you did, 3x the maximum allowed hexapod tweaks would be less than 1 mm of motion. Recovery would require two or three normal (30-60s) r,g or z band exposures. If it works properly (almost certainly) no recovery time is needed since the hexapod tweaks will simply be zero for the three u-band exposures.

Notes from the 4PM Meeting and Additional Comments

  • please keep an eye on the guider traces and try to estimate the rate at which oscillations appear vs declination of the target. We would like to see how the horseshoe damper motor upgrade is influencing tracking issues.
  • When observing the SN fields, please record in the e-log the offsets that you apply to the pointings (via the observer's console) and the results of the "center" command. There should no longer be any need for cos(dec) corrections. Also please do not iterate more than once on the SN field pointings; this consumes a lot of time.
  • No need to fine-tune the pointings for the SN exposures that will have the half-chip shifts.
  • Keep an eye on the wind speed, especially when the dome is facing upwind (usually North). Alistair noted winds easily inducing telescope motion (again you can watch the guider traces). Basic instructions: for winds > 5-8 mph, raise the wind blind to cover ~ 30% of the telescope. For winds >15 mph, close the louver windows in the dome as well.
  • See the SV "extended SV schedule" page for instructions on how soon you can begin standards and sky observations.