Survey Strategy Updates
Lynne Jones (SST) and Federica Bianco (SCOC chair)
Peter Yoachim (SST)
Members of the SCOC
Timo Anguita, Franz Bauer, Louise Olivia Violet Edwards,
Saurabh Jha, Rachel Mandelbaum, Adam Miller,
Knut Olsen, Colin Slater, Steven Smartt,
Jay Strader, Rachel Street, Kat Volk
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
Reminder - Code of Conduct
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full code of conduct
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Vera C. Rubin Observatory | Operations PCW | 7-11 August 2023
Reminder - Virtual Participation
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In-person participants should speak into the room microphone(s), or the chair should repeat all questions into the microphone, so that the virtual participants can hear what is said.
Virtual participants should be muted when they’re not speaking.
In Zoom, use the chat to:
- request to unmute to ask a question, or
- type your question so someone can speak it aloud.
The Zoom “raise hand” feature is generally harder for moderators to track, and is not preferred, but may be used at the discretion of the session chair.
In the Rubin2023_PCW Slack Space, all participants can use the session’s channel for Q&A and discussion.
The channel name convention is, #day3-wed-1400-survey-strategy
Vera C. Rubin Observatory | Operations PCW | 7-11 August 2023
Outline of session
Please ask questions on the slack channel #day3-wed-1400-survey-strategy
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
Survey Scheduling Team
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Lynne Jones
Aerotek/Rubin
Lead Scheduler Scientist
Peter Yoachim
University of Washington
Scheduler Scientist
Eric Neilsen
Fermilab
Scheduler Scientist
Future member
Bryce Kalmbach
Currently Rubin commissioning;
will become Scheduler Scientist
Building the ‘brain’ of the scheduler (the FBS)
Evaluating survey strategy options
Building the tools to monitor survey progress during operations
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
The Survey Cadence Optimization Committee
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
The Survey Cadence Optimization Committee
The SCOC meets (at least) monthly
The SCOC has liaisons in each Science Collaboration: their job is to establish and maintain bilateral communication
Monthly office hour on the last monday of the month at 7 Pacific - ls.st/scocofficehour
Monthly meeting minutes available on community https://community.lsst.org/t/public-scoc-meeting-minutes
Workshops held annually in November
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
Rubin LSST Survey Strategy Optimization
ApJ Supplements focus issue
FAQ: �Does the focus issue still accept submissions?
YES! The focus issue is open for submissions that are published on a rolling basis. When we release the final survey strategy before operations we will close the issue with an SCOC led paper. Until then you can submit!
How do I submit a paper? �- Submit as a normal paper through normal ApJS;
- Use the “instrumentation lab astrophysics, software, data” track
- Include a cover note that says this “To be considered for the ApJS Rubin Cadence Focus Issues”.
https://iopscience.iop.org/journal/0067-0049/page/rubin_cadence 18 published papers! 168 authors!! And counting!
Thanks to Chris Lintott (ApJS editor) for his vision and support!
Many papers were supported by a HSF grant to the SCs (PI Street)
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
Baseline Survey Strategy Evolution
The last five years have brought changes!
�Improvement of footprint for extragalactic science, improvement of cadence on short timescales, resulting in general improvements in science metrics. Overall # of visits per pointing has dropped as visits are directed other than traditional WFD.
We are now at v3.2 of the baseline survey strategy.
V1
V2
V3
V3.2
V3.2 - 08/2023
V3.0 - 12/2022
V2.0 - 11/2021
V1.0 ~ 2018
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
SCOC Recommendations so far
Previous SCOC recommendations on survey strategy are described in PSTN-053 (Phase 1 recommendations) and PSTN-055 (Phase 2 recommendations).
Highlights from these recommendations include
V3.2 - 08/2023
V3.0 - 12/2022
V2.0 - 11/2021
V1.0 ~ 2018
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
Baseline Survey Strategy Evolution
Core SRD metrics across baselines, with error bars based on simulations using different weather histories.
(measured in ‘WFD’ area, median values)
1.1
0.9
better
proper motion (mas/yr)
parallax (mas)
Number of visits
better
V1.x
V2.0
V2.1
V2.2
V3.0
v3.2
1321 Upland Dr
V1.x
V2.0
V2.1
V2.2
V3.0
v3.2
V1.x
V2.0
V2.1
V2.2
V3.0
v3.2
V1.x
V2.0
V2.1
V2.2
V3.0
v3.2
Fractional change of small subset of science metrics across baselines
V1.x
V2.0
V2.1
V2.2
V3.0
v3.2
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
V3.2 Baseline - Peter Yoachim
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
Overview
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Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
Breakdown of Observing Modes
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Survey Mode | Percentage of Exposure Time | Note |
Pair_33 | 74% | Paired observations in neighboring filters (e.g., r+i) |
Pair_15 | 10% | Paired observations with 15 min gap |
DDF | 6.7% | Deep Drilling Fields |
Long Gaps | 3.8% | Paired observation, plus a third observation 3-7 hour later |
Greedy | 3.9% | Filler greedy algorithm |
Near sun quads | 1% | 1x15s exposures in twilight, mainly for inner solar system objects |
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
Updates
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V2.0 -> V3.2
V3.0 -> V3.2:
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
DDF coverage
V3 increases overall time spent in DDFs, and adds early 10-year depth coverage in COSMOS (PSTN-055 phase 2 recommendation 2.6.2-2 and 2.6.2-3)
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
Near-sun Twilight Microsurvey (v3.0 -> v3.2)
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v3.0
v3.2
Alt/az distribution of near-sun twilight observations (~1% of exposure time)
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
Near-sun Twilight Microsurvey
Goal: Improve recovery of interior-to-Earth asteroids
(PSTN-055 phase 2 recommendations 2.7.2)
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
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This V3.2 update is probably the biggest impact on all science metrics, going from detecting ~4% of objects interior to Venus to over 40% of objects with H<=20
‘Aylo’Chaxnim Completeness H<=20
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
Intra-night triplets
Return for a 3rd visit to match an earlier pair (repeat in one of the same filters - griz)
Triplet spacing between 2-7 hours
V3.0 and v3.2 have equivalent # of triplets, but v3.2 more even between 2-7 hours, one ‘set’ of triplets per nights
The “N Gaps” metric evaluate the number of times this timespan is sampled (at any particular point on the sky)
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
Intra-night triplets
Sampling 3-7 hour timescales. V3.2 shows small drop in KNe (but we are always in the low %-recovery regime with KNe).
We are sampling 3-7 hours, but more targeted science metrics would be helpful.
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
V3.2 Update footprint with Euclid swath
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Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
V3.2 Update footprint with Euclid swath
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Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
V3.2 Update footprint with Euclid swath
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Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
V3.2 Swap u with y filter (u-y) instead of z
DDF coverage depends on when/what filter is available -
DDF science depends more on cadence in z than cadence in y
No (clear) major changes in other science metrics (remember uncertainties too!)
Keeps z band filter safer
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
V3.2 Improve uniformity of first year coverage
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First year coverage in blue filters corrected
(in v3.0, fewer visits in u and g band left some parts of the sky poorly observed)
NOTE: Y1 strategy subject to change - see Early Science session (L. Guy)
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
V3.0 -> V3.2
Changes v3.0 -> v3.2
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Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
SCOC Progress and Plans - Federica Bianco
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
SCOC Pending Recommendations
PSTN-055 identified the following topics were identified where decisions remain to be finalized:
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
SCOC Pending Recommendations
PSTN-055 identified the following topics were identified where decisions remain to be finalized:
Require commissioning / on-sky data to be finalized
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
SCOC Pending Recommendations
PSTN-055 identified the following topics were identified where decisions remain to be finalized:
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
SCOC Pending Recommendations
PSTN-055 identified the following topics were identified where decisions remain to be finalized:
The SCOC offered the opportunity to share updates that impact directly the decisions that remain to be made - thank you to all respondents!�
14 respondents: AGN SC (1); DESC (3); GAL SC (1); SMWLV (5); SLSC (2); SSSC (1); TVS (5)
Topic | Responses |
DDF intranight cadence | 3 |
MW strategy | 6 |
Uniformity of coadds | 2 |
Early Science | 6 |
Availability of filters | 3 |
ToO strategy | 4 |
2x15 vs 1x30 exposure | 6 |
Filter rebalancing | 7 |
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
SCOC Pending Recommendations
Remaining survey strategy questions: SCOC TASK FORCES (agile but inclusive!)
To provide input to SCOC discussions and quantitative assessments on the scientific impact of the baseline rolling cadence on the uniformity of the annual data release coadds, and explore cadence improvements within the Phase 2 recommendation for 2 sky areas + 0.9 rolling strength.
To provide input to SCOC discussions and quantitative assessments on the scientific impact of Milky Way, Magellanic Cloud, South Celestial Pole observing strategy choices that remain to be finalized including footprint and rolling on footprint and filter balance.
To provide input to SCOC discussions and quantitative assessments on the scientific impact of intranight cadence in choices on the Deep Drilling Fields (DDFs) including filter sequences, and distribution of observations within the 10 years (within the constraints of PSTN-055)
Recommendations to SCOC planned by end of 2023 (MW and Uniformity) + 2024 Q1 (DDF)
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
SCOC Pending Recommendations
Remaining survey strategy questions: SCOC TASK FORCES
Observing strategy and photometric calibration session on Monday
#day1-mon-1400-obs-strat-phot-cal
Peter Yoachim (chair)
Eli Rykoff
Loredana Prisinzano
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
SCOC Pending Recommendations
Remaining survey strategy questions: Target of Opportunity
The SCOC is working toward the organization of a community workshop to deliver this decision via a white paper co-written at the workshop by community members, Rubin Obs members, and the SCOC.
To make the workshop inclusive, the SCOC is seeking support and funding - Berkeley will kindly host us!
Likely early 2024 - hybrid format (limited in person capacity)- stay tuned! - contacts: SCOC + Igor Andreoni
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
Early Science
Commissioning, science validation and verification, and the first year of operations will tell us a lot about Rubin’s capabilities and operations
Questions addressed in time period:
→ evaluate the distribution of visits between filters (filter balance)
→ e.g., should templates be maximized over area or over multiple filters?
SCOC recognizes and values previously gathered feedback; will solicit more
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
The SCOC in Operations (work in progress)
Expected concerns for the SCOC during operations:
How will the SCOC recognize them and address them?
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
Timeline
Yearly call for feedback to SCOC
Current status: v3.2 baseline
End of 2023: MW and Uniformity TF reports
Spring 2024: �DDF TF report
End of 2024:
updates on Early science, incorporate commissioning updates
2025: Survey Start
Start + 6 months:
DR1 data cutoff
Start + 1 year:
DR2 data cutoff
Today
During Y1:
Microsurvey Y2 call + SCOC recommendations
ToO workshop+ recommendation
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
Questions from slido (not previously addressed)
There were questions about timelines and priorities which were hopefully addressed in previous slides. Additional Slido questions include:
No, and there is no compelling reason to. The questions that remain to be answered require input from the community and we are working with the community. Rushing the decisions that are not needed by 2023 by the Observatory would put unnecessary pressure on the community.
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
Questions from slido (not previously addressed)
There were questions about timelines and priorities which were hopefully addressed in previous slides. Additional Slido questions include:
Obviously we would like to make the survey as useful as possible, including the near-sun twilight survey, and presumably the optimization for this microsurvey is within a fairly limited ‘box’.
The SCOC will be taking feedback yearly after operations start, so the timeline for when and how to adjust the microsurvey is worth considering - the SST would anticipate at least some adjustments to this microsurvey during commissioning as we learn more about twilight sky brightness, telescope efficiency at the very ends of the night, and the state of satellite constellations.
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
Questions from slido (not previously addressed)
There were questions about timelines and priorities which were hopefully addressed in previous slides. Additional Slido questions include:
YES!
They are a bit scattered in location at the moment (reflecting a limited set of changes from v3.0 to v3.2) but see for example - https://github.com/lsst-sims/sims_featureScheduler_runs3.2/blob/main/maf/quick_look.ipynb
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
Questions from slido (not previously addressed)
There were questions about timelines and priorities which were hopefully addressed in previous slides. Additional Slido questions include:
The SCOC membership is generally renewed on a 2-year appointment basis. We expect some SCOC members to stay on for 2 terms and some to rotate off. At a minimum we expect 5 members of the SCOC who are already on their second term to rotate off but transfer of knowledge and continuity are ensured by the other members.
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
Questions and Discussion
Please ask questions into the microphone whenever possible (or remind speakers to repeat question)
Please ask questions on the slack channel (rather than bluejeans) -
rubin2023pcw #day3-wed-1400-survey-strategy
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
Backup Slides
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
V3.0 -> V3.2
Changes v3.0-> v3.2
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Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023
Microsurveys
Current strategy is conservative on microsurvey commitment, recognizing that efficiency of telescope operations is still uncertain.
Pending survey progress in first year, the SCOC anticipate making a call for microsurvey proposals ~6 mo after survey start to select Y2/3 microsurveys
We may only be able to select a few and only select what is to start in Y2
The SCOC is planning to hold annual calls for feedback throughout operations and may issue more specific calls for micro/nano surveys
Vera C. Rubin Observatory | 2023 Project and Community Workshop | August 9, 2023