Overview of Daily Playbook

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The Standard Routine

Here is the standard sequence of observer actions for an uneventful full night:

  • ~4 PM (before dinner): Calibration sequence
    CTIO staff will point telescope to the white spot and darken the dome. They will then turn VSUB on and initiate the prenight bias + dome sequence (can be left running while people go to dinner).
    Note that we may occasionally want other calibration sequences (darks, PTC).
    Complete the Afternoon Checklist (Dome Closed).
  • Sunset - 1 hour: Open dome
    The telescope operator will open the dome slit and vents, after insuring that DECam is safe (VSUB off).
  • Sunset + 30 minutes: Prepare instrument
    Turn VSUB on (this will take some flush images), make sure RASICAM is working, start QR, select standards fields, check dome flats.
    Complete the Start of Observing Checklist (Dome Open).
  • -10 deg twilight (~Astronomical twilight - 40 minutes) Pointing check, Photometric standards
    Follow the TCS Zeropoints instructions.
    Load and execute scripts for three standards fields, unless there are obvious major clouds - see Standard Star Instructions.
    Evaluate wind conditions and follow Windscreens advice after the standards are done.
  • -14 (-12) deg evening twilight (~Astronomical twilight - 25 minutes): Begin observations
    Start OBSTAC and let it schedule the rest of the night.
    Monitor proper functioning of OBSTAC and the instrument.
    • added 10/20/17: expert observers can be a little more aggressive (i.e. start obstac at -12).
      Pay attention to wind and clouds.
  • -14 (-12) deg morning twilight : Photometric standards
    Stop OBSTAC (it may have already stopped Survey observations if the sky is too bright).
    Lower the wind screen if it is up.
    • added 10/20/17: expert observers can be a little more aggressive (i.e. stop obstac at -12).
      Queue up and execute the end of night set of photometric standard fields, unless there are thick clouds.
  • -10 degree twilight (or whenever standards end): Out-of-focus image
    This procedure should be done only once per week: Run the script DES/defocus_nightly to take a single out-of-focus image at the pointing of the last field (just append the script to the queue, after standards).
  • -10 degree twilight (or whenever standards end): Morning calibrations
    On a normal night (dome flats successful in the evening), execute postnight bias sequence, which will then safe the camera.
    If dome flats were not obtained in the evening, let the Telescope Operator complete his/her morning checklist, then when the dome is unoccupied again have the telescope pointed to the white spot and execute the postnight bias+dome sequence.
    Ask Telescope Operator to close dome and park telescope.
  • File reports
    Finish night log entries (make sure you have reported any unusual circumstances).
    Run the Night Summary.
    Fill out the CTIO nightly observing report.
    When the calibrations complete, the Telescope Operator can complete his/her AM checklist and shutdown.
    Complete End of Night Checklist
  • Sleep

On nights where DES has only the first half of the night:

  • 6 minutes before midpoint of the night: Photometric standards
    Stop OBSTAC and take one standard star field (preferably, the high-airmass field).
  • Midpoint of night: Handoff
    Ater the last exposures have been queued, clear the proposal ID in the Observer Console.
    Hand control over to the community observers. They should be able to load and begin their observations without stopping the queue.
  • File Reports
    Finish night log entries (make sure you have reported any unusual circumstances).
    Run the Night Summary.
    Fill out the CTIO nightly observing report (but don't submit it! The observers of the 2nd half night will submit one report for the entire night).
  • Sleep

On nights where DES has only the second half of the night:

  • 5 minutes before midpoint of the night: Prepare for observations
    Check that observers from first half night are wrapping up.
    Learn if dome flats and standard stars were successfully taken in the evening.
    Verify that configuration of windscreen is adequate.
  • Midpoint of the night: Begin observations
    Verify that the proposal ID and observer fields are clear.
    Enter the DES proposal ID and other information. (This can be done while the last exposure of the 1st half observer is running.)
    Queue up one standard star field (preferably, the high-airmass field).
    Start OBSTAC and let it schedule the rest of the night.
    Ideally it is possible to transition from 1st to 2nd half without stopping the queue.
  • Proceed from this point using same routine described for the full night


  • "Nautical" twilight (Sun 12 degrees below horizon) is 25-35m before "Astronomical" twilight (Sun 18 degrees below horizon)
  • Sunset is 1h20m - 1h35m before the end of astronomical (18-degree) twilight during DES season.
  • The Run Manager will provide the clock times for starting/stopping observations for each night (run "ephem" in kentools). He/she will also provide instructions which standard star fields to use.

Observer's Monitoring Responsibilities

Here is an overview of the things the Observers should be monitoring during observations:

  • Make sure that the camera is always in use! Time=science=money, so you should always be either exposing, reading out, slewing, or trying to figure out why something is broken!
  • Wind: Watch/listen to the wind speeds and keep wind screen at recommended position & be on the lookout for possibility of wind screen blocking the beam at lower elevations.
  • Clouds: Watch RASICAM, go outside and look at the sky, and examine the incoming images to spot when there are heavily obscuring clouds. Heavily obscured or otherwise useless exposures should be noted in the log
  • Instrument and SISPI status: Pay attention to the Exposure Queue - is it still running? Most alarms are tied to audio signals but not all and sometimes a "beep" is missed. Periodically - that means several times per night - flip through the plots (all components/tabs and some pages require you to scroll to see all plots) on the telemetry viewer GUI. Note anything unusual in the logbook. If you are not sure contact the run manager.

Division of labor

An idea for describing the critical path workflow for all parties. We expect the Run Manager to start her* duties after lunch time and to be around for the first half of the night. The observers should be in the console room for the 4 pm meeting. This is only a suggestion. If shifts end up dividing it up a little differently, that's OK, too.

*previous to October 18 2017, this said "his". Of course the correct term is "their", but this particular all-female team decided to let the guys know what it feels like when inappropriately gendered language is used.

Task Observer 1 Observer 2 Run Manager TelOps
After Lunch
Address Questions/Comments from Previous Night X
Make Plan X
4pm Meeting X X X X
Organize Roles X X X
Restart SISPI (X) X
Set up O2 station X (X)
Set up O1 station (X) X
Zeros/Flats/Calib X
Load Standards Scripts X
Open Dome X
Check Zeropoints X X
Run Standards X
Run defocus_nightly after last standard X
Run Observations X X
AM Calibrations X
Night Summary X
CTIO Report X
Conclude Night X