The current status of the LSST Commissioning planning is summarised in a presentation that Chuck Claver (LSST System Scientist) and Beth Willman (LSST Deputy Director) gave to the  meeting of the LSST Science Advisory Committee on 5 March 2017, which is itself summarised (with some additions) below.

Commissioning Phases

The commissioning is divided into three phases, each of which starts with a series of engineering activities and concludes with a sustained observing campaign. All dates below are approximate, of course. 

Phase I: Early System Assembly, Integration & Test with ComCam (January - September 2020)

Goal is to test Data Management software on science images from ComCam (which is one detector raft - i.e. 1/21 of the number of detectors in LSSTCam and which will be mounted on-axies).

Observing: Early Science Verification with ComCam (May-July 2020). Three components (of ~4 weeks duration each) listed:

• Key performance metrics: image quality, depth, astrometry, photometry
• 20-year depth test: exploring range of conditions
• Scheduler tests: nominal cadence, ToOs, environmental conditions

Phase II: Full System AI&T with LSSTCam (October 2020 - March 2021)

Observing: Early Science Verification with LSSTCam (Feb 2021-March 2021). This consists of repeating with LSSTCam the first two components from the Early Science Verification with ComCam, with a focus on delivered performance over the full FoV. 

Phase III: Science Verification (April 2021 - June 2021)

Observing: Final Science Verification with Mini-Surveys (April 2021-June 2021). This comprises Mini-Surveys exercising the Level 1 and Level 2 production systems, respectively. 

• Mini-Survey 1: Wide-Area Alert Production.
  This is split into two parts: three weeks generating the a set of template images followed (once Mini-Survey 2 has been performed) by three weeks of second-epoch data allowing the generation of alerts. In each of these two parts, ~1600 sq deg (i.e. ~165 fields) will receive 15 visits* in each of the six filters, thereby covering ~10% of the survey footprint to a depth equivalent to 1 year of the Wide-Fast-Deep Survey. The intention is to observe a long equatorial strip to sample a range of source densities.
• Mini-Survey 2: 10-year Depth Survey.
  This will last 6 weeks and its goal is to characterise the Level 2 data quality expected at full survey depth in a scientifically-meaningful fashion - e.g. "source detection completeness, star-galaxy separation, photo-z, weak-lensing null tests, cluster weak lensing". About 30 fields (i.e. ~300 sq deg or ~1% of survey footprint) will get the default ~825 visits divided over the six filters. The fields will be selected on the basis of existing ancillary data. 

(*N.B. recall that a visit comprises two exposures, and the Science Requirements Document gives 5 sigma point source limits per exposure in each filter as u=23.9, g=25.0, r=24.7, i=24.0,  z=23.3 and y=22.1)

Field selection

No field selection is noted for the observing campaigns in any of the three phases, but the presentation includes the following plot of well-known fields:

N.B. this includes the four Deep Drilling Fields already announced, namely COSMOS, ELAIS S1, Chandra DFS and XMM-LSS; the first and fourth of those are also HSC Ultra-Deep Fields. 

Providing Input to the Commissioning Team

The final slide contains the following three paragraphs on the scope for influencing the details of commissioning:

The Commissioning team’s priority during the entire Commissioning period will be integrating and testing the hardware and software systems to ensure that they will deliver on the scientific requirements defined for the 10-year survey

The Commissioning team may have some flexibility in the observing strategy and/or target fields to be implemented in each of the three commissioning phases. To prepare for this possibility, we plan to invite commissioning suggestions in 2018.

The LSST Commissioning lead, with support from LSST’s Science Advisory Commilee and Project Science Team, will evaluate community commissioning suggestions to determine which of them would drive the system to operational maturity most efficiently. LSST might not guarantee that any particular observations or observing strategies will be implemented during commissioning. 

Notes from the SAC discussion

The Minutes of the SAC meeting include two recommendations relating to this presentation, namely:

• The SAC endorses the proposal that commissioning data be made public to the LSST data rights community. We recommend that no restriction be placed on the authorship of scientific papers within that commmunity, including LSST project personnel. We also recommend that the SAC develop a mechanism for people from the community to report problems they find in the commissioning data; this will give a different perspective on the commissioning process.
• The LSST will include a limited events broker, with additional brokers developed within the community. Given that most users will use these community brokers, they will need to be commissioned as well. In this spirit, we recommend that the LSST commissioning team work to engage those community broker developers that they are aware of, to make sure they can coordinate their commissioning activities with the project.

These are both of relevance to LSST:UK. On the first of these, it is thought that the commissioning data will be released 3-6 months after end of each commissioning Phase (i.e. not 3-6 months after the data are taken). The Level 1 alert stream will, presumably, be issued in near-real-time, but this does mean that Mini-Survey 1 would not provide a realistic test of those analyses that make use of the Level 1 database, into which data is ingested the day after observation. The second recommendation suggests that LSST:UK will need to interact closely with the commissioning team if we are to run a broker.