Operational Readiness OPS-R1

The DES observation strategy tool (OBSTAC) is functional
  1. An extended set of observations (>= 1/2 of a night) with OBSTAC in control and open-shutter fraction > 75% has been completed.
  2. The OBSTAC seeing and photometry triggers are calibrated.
  3. OBSTAC successful switches between the main survey, the SN survey and back.
  4. The loop between DES DM (First Cut) and the exposure/survey table on the mountain has is closed.
  5. OBSTAC’s use of the survey table is validated and it was demonstrated that images are retaken if a failure is indicated by the exposure table flags (Abort, IH failed, DM failed)
  6. Rasicam operates as expected and the required information is sent to obstac. The quality of the Rasicam photometric flag will have been assessed (at least somewhat) during commissioning.
  7. The seeing and sky background values calculated by ImageHealth (IH) are of sufficient quality.


  • The latest version of obstac and the starfinder code have been installed at CTIO
  • RASICAM is operational


OBSTAC will already be tested at the end of commissioning when several nights are scheduled to demonstrate/evaluate the standard DES observing procedures. In order to retire OPS-R1 we have to schedule a similar full night test during SV. During this night we will exercise obstac's decision logic and the various flags in the exposure table.

We will prepare or seed the exposure table with fake (survey) history information. Tools are available to overwrite some of the information such as the ImageHealth seeing that obstac uses for its decision logic should the weather not cooperate.

The quality of the IH seeing value and RASICAM's photometric flag will be assessed by comparing them to the results DES DM processing of SV images.

During SV we establish a daily meeting between the observers/run manager and the team at CTIO to discuss results from the previous night and to prepare for the upcoming night. This includes updating the exposure table (DM Done, DM Accept columns)


Without OBSTAC we cannot start the survey.