LSST2017: Deep Drilling & Mini-surveys breakout planning

Thread to help plan the “Deep Drilling and Minisurveys” breakout session at #lsst2017. Currently slated for 1:30-3:30pm Tues Aug 15, our aim for the session is to explore the tradeoffs for observing strategies for the mini-surveys and deep-drilling fields. (The current basic mini-survey regions are the Northern Ecliptic Spur, Galactic Plane, and South Celestial Cap.) Ideally, we would like the session to result in commitments from the community to develop OpSim proposals.

We welcome any suggestions for talks and points of discussion. For example: what science cases have targets that would saturate at LSST’s nominal exposure time, how does this interact with the capabilities of other surveys like VVVX, VPHAS, etc., to what extent would the proposed twilight short-exposure survey meet these requirements, and what exposure times (among those supportable by LSST) would be necessary for science tracer populations of interest?

– Will Clarkson & John Gizis (@willclarkson @jgizis)

(For any readers who prefer Slack, we have also created the Slack channel “#ddf-minisurveys2017”. We intend to keep this thread and the Slack channel in sync with each other, so that readers of one or the other do not miss information.)

Hi all,
As part of my work with the LSST DM team, together with Mario Juric we have been looking at DDF and SP data from a DM perspective. I’ve done a comprehensive review of DM documentation to create a summary of existing DM policy/plans for (a) incorporating DDF/SP data into the main survey and (b) providing tools for user-driven processing DDF/SP data with level 3. We have also have created some “case studies” that serve as little thought experiements to help us visualize all the components that would need to be in place, and further ensure that the DM system in preparation will be able to meet those needs. I could present some of this so that the community is aware of DM’s efforts in this direction. I could also prepare answers to any pre-existing questions, or processing “case studies” for specific cases. Regardless of whether there is time in the schedule, I will be in attendance out of interest!

Back in 2016, @ljones posted a helpful link to the 2011 deep drilling white papers (on this community thread
Deep drilling whitepapers )

Sadly, the link seems to be dead since it used I can tell the PDFs are still online such as

if I can guess enough of their content to use google, but is there an active site that links to all of them?



Hi John, Nick, all - see also the presentations from the SAC meeting at LSST2016 - the presentations therein should provide a good digest of the status and plans as of 2016:

Cheers - Will

Hi @ljones and @davidtrilling- are there any special considerations for the Northern Ecliptic Spur minisurvey that we should be considering at the “DDF and Minisurveys” breakout session? I’m wondering if there are any observation strategy permutations that’ll need to be submitted to OpSim when the next version is out. Thanks! – Will

I updated the DD thread (although not the original post) but you can find the original DD white papers here

I think I replied on slack only, but yes - I can talk about the NES at the breakout session.
I believe the punchline is that, while overall completeness will suffer to various extents for different populations if we have poor coverage* of the NES, what makes a huge difference is that it introduces biases into the samples, particularly for the outer solar system where objects move the most slowly.
*poor coverage should be quantized, but one extreme case would be no NES observations at all.
@davidtrilling and @mschwamb can chime in further and we’ll arrange discussion with the SSSC of course.

I don’t know much more about the NES then what’s in the cadence white paper and LSST science book at the moment. Things brings up a good point that the SSSC should be thinking about the NES. It would be good to have a discussion within the SSSC about it and defining MAFs that can estimate whether or not an iteration of the NES is successful for Solar System science or not. I’ll definitely add this to my notes and todo list.


Hi all - here is the current schedule for the Deep-drilling and Minisurveys breakout. The session will take place in the “Verbena” room from 1:30-3:00pm Tues Aug 15th. Titles are provisional.

(Edited 2017-08-11)

  • 1:30 ( 10 mins ) – Introduction (@willclarkson )
  • 1:40 ( 30 mins ) – Special Programs (@MelissaGraham)
    * Deep Drilling Fields: Policies, plans and opportunities
    * Special Programs, the DM system, and the end user
  • 2:10 ( 30 mins ) – Minisurveys:
  • 2:40 (10 mins) – Specifying altered strategies for OpSIM (@ljones )
  • 2:50 (10 mins) – Additional discussion, schedule buffer

cc @jgizis

Deep Drilling field white papers from March of 2011 are posted here:

Thanks, @sjacoby !!

@knutago and @willclarkson ,

If you are available I would love to talk to you before the meeting about how the Galactic Plane and Magellanic Clouds mini surveys might be used for micmicrolensing surveys of black holes and dark matter.


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Hi all - for info, here’s a thread on OpSim runs in the near-term (i.e. the next few months):

Hi all - to help identify commonalities between science cases for possible new OpSim runs in the near-term (and to assist planning DDF/Mini-surveys whitepapers), I’ve started a google spreadsheet at the link below.

hi @willclarkson - sorry for my late reply. one thing that has been proposed is that the NES could be observed only in r band – maximizes solar system object discovery while discarding color information (since it’s a matter of discussion how useful the colors will be for moving objects anyway). another possibility is that the NES could be observed at a different cadence than the WFD cadence – in other words, if the whole point of NES is to maximize solar system science then there might be some different flavors of observing that would be best. so, these things could/should all be studied. i’ll be at the DDF/mini-surveys session. @ljones --david

Thanks @davidtrilling - I recommend adding a line or two to the open spreadsheet we’re curating, to gather minisurvey / deep drill strategies in order to try to find common ground.

One of the intentions there is to allow selection of a few representative cases so that it would be practical to explore them with OpSim before the DDF/Minisurvey proposals are due. It’s the same link as in the entry just before your comment (google sheet “LSST_strategySuggestions_DDF_Minisurveys”).