1. Cadence Workshop Plenary 1 – Organizer’s Welcome and Introduction - Draft - - Sponsoring organizations: NOAO and LSST The Organizing committee: Richard Dubois (SLAC) Eric Gawiser (Rutgers) Zeljko Ivezic (U. Washington) Ashish Mahabal (CalTech) Knut Olsen - Chair (NOAO) Steve Ridgway (NOAO) Michael Strauss (Princeton) Beth Willman (Haverford)

2. Plan for the Day Tuesday AM – Plenary 1 – Workshop motivation, objectives and methods (organizers) – How LSST will be scheduled (Steve Kahn) – Introduction to scheduling and simulation (Andrew Connolly) Tuesday PM – Plenary 2 – Introduction to metrics (Peter Yoachim) – Overview of cadence experiments (Zeljko Ivezic) – Breakout plans (organizers) Tuesday PM - Breakouts

3. Workshop Motivation – Nature of the Survey As a synoptic survey, the LSST science return will depend in large part on the temporal sequence of observations. Owing to the large number of visits (~2.5M in 10 years) the observing schedule must be fully automated. The LSST schedule will be highly integrated.

4. Workshop Motivation – The Observing Scheduler Development and operation of the scheduler is in lieu of review and scheduling of tens or hundreds of separate observing programs. As telescope commissioning approaches, the scheduler must be mature. Experiments for tuning schedule parameters for optimization underway if not complete. Scheduler development is at a level of maturity where participation of a wider community is timely (essential).

5. Workshop Motivation – Looking Ahead This workshop is the first of an expected series, at which the project will report on the status and plans for the scheduler, and solicit community advice and participation.

6. Workshop Objectives Communicate the cadence opportunities offered by the LSST survey. Access scientific expertise for the critical evaluation of schedule products, and for tools (or at least algorithms) to carry out that evaluation. Measure the productivity of simulated schedules for science. Identify competing objectives and the measures which can support trades between them. Discuss how LSST will select the scheduling algorithms and optimization of the survey. Develop an informed community that can contribute to and support the scheduling decision process.

7. Two perspectives on workshop obejctives LSST – Produce the best possible facility, survey product, and science NOAO – Engage the community early and continuously to ensure effective preparation for and utilization of survey products for science

8. Plenaries and Breakouts In the plenary sessions, there will be a modest number of introductory and overview talks. Most of the workshop time will be in breakout sessions. We will have breakout reports to the plenary. There will be plenary discussions of Deep Drilling and of special considerations for the first survey year. Thursday will end with plenary discussion of a workshop report and plans for continuing activity.

9. Thoughts for the Breakouts DRAFT

10. What do we want to achieve in breakouts? We are looking for quantitative input on how a given LSST schedule performs for specific science cases – This is the way for your input to have impact Remember that schedule has some broad constraints – Must serve four key science goals – Hardware constraints, e.g. total number of filter changes Input on alternate scheduling strategies, questioning assumptions, and other strategic advice also welcome (Wednesday in particular), but most useful if it follows from the quantitative work that we are starting now

11. Breakout group structure Each breakout group has one or more assigned leaders Tuesday breakouts (Static science, transient and variable science) are deliberately broad; it’s up to you and your leaders to decide how to structure the discussion During your discussion, bear in mind previous work when appropriate, e.g. Deep Drilling White Papers May be appropriate to consider cadence interaction with external missions

12. Breakout group deliverables A list of science cases for which the groups would like to provide metrics For those science cases, a list of variables that would enter into their performance metrics A translation of those variables into the output columns delivered by OpSim Performance metrics in rough analytical form Coded performance metrics in Python and MAF A brief oral report of the breakout group discussion We don’t expect you to be able to deliver all of these things for multiple science cases, but would be useful to identify work remaining to be done

13. Example: Magellanic Clouds science Science cases: 1.What is the full extent and structure of Magellanic Cloud populations? 1.Legacy products: The Magellanic Clouds in exquisite seeing 2.High cadence observations of the Magellanic Clouds (Szkody et al. DDF paper)

14. Example cont. What is the full extent and structure of Magellanic Cloud populations? – An all-sky problem, a subset of Galactic Structure science – Tracers: static stellar populations to stacked depths, RR Lyrae,  Scuti stars – Measurements: stacked photometry, light curves, proper motions – Some elements in potential metrics: stacked depth in ugriz, average image quality, longest time baseline, number of visits, RR Lyrae and  Scuti phase coverage TBD: analytical metrics, coded in MAF?

15. Example cont. The Magellanic Clouds in exquisite seeing – Pick the best seeing images for a small set of select field numbers – Metric elements: Number of images with seeing <~0.4 arcsec (r, scale to ugiz), calculation of depth in ugriz

16. Example cont. High cadence observations of the Magellanic Clouds – Szkody DDF TBD: turn Szkody cadence requests into performance metrics

17. Tuesday Breakouts Static science (M. Strauss, T. Tyson) Transient and variable science – Astrometry (J. Gizis) – Fast T&V (L. Walkowicz, Mansi Kasliwal) – Slow T&V (S. Howell) – Supernovae (M. Wood-Vasey, A. Kim) – Moving objects

18. Wednesday Breakouts Synthesizing main-survey cadence for transients and variables (S. Howell) – Rolling cadence vs uniform sampling, and other ideas for addressing multiple objectives Main survey: optimization and thinking outside the box – Alternate approaches to schedule optimization; questioning assumptions; overlooked issues. Mini-survey cadences (W. Clarkson – bulge and plane) – Specific proposals and cadence metrics for mini-surveys.

19. Thursday plenary discussions First survey year – All science areas would like to jump-start their science with complete data sets for some fields as early as possible in the survey – e.g. full depth, photometric calibration closure, rich time series. Should the first year cadence be designed to accommodate some of these objectives, and if so, how? Deep Drilling (L. Jones, K. Cook) – The requests for deep drilling compete with other types of mini- surveys, and possibly with completeness/uniformity of observations in the main survey. Can this competition be managed at the level of community input? Workshop report and plan – The discussion leaders will draft report elements for review and endorsement by workshop participants. A future workshop will revisit the topic of LSST cadence, perhaps in 1-2 years. What presence and activities will the participants carry forward in the interim?

20. Friday report to LSST 2014