(back to the list of all DM-SST meeting minutes)

This week's meeting is a catch up  meeting for 2023-01-16, which was MLK day. We resume the regular cadence next week


11:00 PT



Room System

Phone Dial-in

Short : ls.st/dmsst 

Zoom: https://noirlab-edu.zoom.us/j/97839121776?pwd=K1JPeUpSMXFvSXJSa2xORGkyVk5zdz09

Zoom Meeting ID: 978 3912 1776 
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Discussion items


ItemWhoPre-Meeting NotesNotes and  Action Items
Project/Science Updates

PST news: 

  • AURA/Matt mountain encouraging people to start to prepare for the 2030 decadal. Main topic for us is what to do with Rubin Observatory after 10 yrs / after LSST. There is a the Kahn et al. PST White paper  and an aligned Snowmass paper. Discussion of options but no concrete proposal. Considered low priority by PST.
  • Rubin Key Milestones Celebration and Planning Strategy document - input from JWST is that we are already late with preparations. What kind of image will be used for first light images , how will we communicate the unique aspects of LSST?  Various committees have been set up, e.g Simonyi Naming Organizing Sub-Committee, Rubin First Light Sub-Committee (RFLC), Image group, etc. Image group is led by the PS and will feature various images and DPs from LSST. 
  • Steak alert censoring: High-level meeting to discuss the possibility if introducing more stringent cuts on the alert but no AVS at LLNL (or anywhere). The current plan is to not issue alerts for sources detected in difference images that are elongated and whose length corresponds to angular speeds greater than 30 deg. per day (10s of arc secs) but rather send them to the AVS at LLNL where they have access to classified satellites – those that do not correspond to an asset are sent back to us for release. The new proposed plan would make the cut more stringent, e.g. 5/10 deg. per day with the 80hr embargo period applied to all, but with no need to send them to LLNL (or anywhere). They all then become public after 80hrs. This is a simpler implementation but will result in more restricted images. 
  • AMCR – positive about technical progress over last month but concerned about schedule slip and remaining reserve of 6 weeks (end CY 2024). 

    high-level recommendation to change the way we report dates – replace "not earlier than" = to "no later than". A caveat is that we can do this only once. Two major events need to happen before we can change to this model 1) Dome completion actual date and 2) When will LSSTCam actually arrive on the summit. 

  • Roman issued call for input to their core community surveys

1-1s 2023

  • I have set up new times for 1-1s with everyone on 2023
  • Starting next week 2023-01-30
  • tag up on the AVS  happening now with Bob and Željko now with the agencies. 
  • NEO - will cut out some targets out that we are required to be able to detect. 
  • re Astro2030 & "what to do with Rubin after 10 yrs": LSST Narrowband Filters, Yoachim et al. 2019
Verification Status

Jeffrey Carlin has wrapped up the first acceptance test campaign. Congratulations! 

RSP-A testing is complete but some rejigging in Jira/LVV is needed so we can claim the requirements covered.VCD will be regenerated when this is complete 

Two new verification milestones:

  •  LDM-503-19a: All P1a DM requirements verified. Due date: System First Light milestone (Jul-Aug 2024). This DM milestone is tied to the System First Light milestone.

    2. LDM-503-19: All P1a,P1b DM requirements verified New Due Date: Start of Science Validation Surveys (Nov 2024-Feb 2025). This milestone is tied to the start of the commissioning SV Surveys

Test report: https://dmtr-371.lsst.io/
Debrief on discussion with DESC on non-uniform coadds Notes from a meeting with DESC on non-uniform coadds
  • Problem is really in the cadence - looking to address it from that side. 
  • What is the timeframe for a response from the DESC?
  • What is a good metric - what are the systematics induced by non-uniformity,  for what fractions of the sky? Simply using number of visits or exposure time is likely too simplistic, as there are many other observational factors that set the limiting magnitude depth uniformity at the scales of possible interest here. So it would be most helpful to understand the needed depth uniformity as a function of release and why.
  • JC: Involve galaxies SC - this affects them as well.
    • There are liaisons to all the SCs in the SCOC so they should be informed
  • Can we create survey property maps to help understand the degree and distribution of non-uniformity, or summary statistics, not just number of visits
  • CTS: what is the actual impact on science of say 15% non-uniformity becoming 30% non-uniformity  - then we can look to the mitigations that this merits. 
  • Leanne Guy Follow up with DESC on the topic of non-uniformity  
Review of status of alert packet contents 

DM-20298 - Getting issue details... STATUS

Draft doc as an MD file: https://github.com/lsst-dmsst/alert-options/blob/main/alert-options.md

Considers the science impact of options we have regarding alert contents and distribution.

Does not recommend proposals to:

  • remove historial DiaSource / DiaForcedSource records (Sec.2)
  • remove postage stamps (Sec.3)
  • provide large multi-resolution postage stamps (Sec.4)
  • compress alert packets (Sec.5)
  • enable multiple packet formats (Sec.6)
  • provide pre-filtered streams (Sec.7)

Does recommend distributing delayed alerts asap. (Sec.8)

Questions for DM-SST:

  1. Is this list complete, are there more to consider?
  2. Does this need to be a DMTN?
  • Previous questions on contents of the alert packet were driven by the size of the alert packets and the number of brokers we might support - we now have committed to 7 full stream brokers. 
  • No requirements changed yet on the AFS - we need to pick this up. Delegation to ANTARES  still means we will claim the AFS requirement - Eric/Leanne to pick this up 
  • No need to provide pref-filtered streams to brokers. 
  • 1 yr since discussion on  multi-resolution alerts. Brokers have done a study with ZTF - showed better classification of satellite glints, but not streaks, good paper from Fink/ZTF . Can use DR images to do larger classification - will this be fast/efficient enough. 
  • Not yet clear that multi-resolution stamps is the only way to deal with the concerns or do the science they are concerned about. 
  • Last broker technical workshop was late 2021 - many brokers have been busy with the elastic challenge  and working a lot with the ZTF infrastructure - this will be very instructive. 
  • Will get more active engagement as we stand up the alert distribution system
  • Retracting bad alerts - this is a different TN, remove  section delayed alerts from this TN

Next meeting is:   

RHL: How will we handle real built gains on the camera? Set up a meeting – Chris W Eli, Lynne (using something different), someone from Camera. Numbers currently in obs_lsst. Want to be able to version what is used when? 

ER: Aren't gains a calibration product that get measured

RHL: Yes but they are not versioned 

RFC-842 with a design proposal that is applicable to this problem. 

List of SST tasks (Confluence)

DescriptionDue dateAssigneeTask appears on
  • Robert Lupton Clarify the meaning of time in the object table. 1 sentence description in sdm_schemas, can link to a short DMTN.  Update 2022-02-09: Meeting to resolve this on 2022-02-21  
28 Feb 2022Robert Lupton2018-11-05 DM SST F2F Agenda and Meeting notes
  • Gregory Dubois-Felsmann check if SDM standardization is adequately represented in project documents, and whether DMTN-067 should be required.
31 Mar 2022Gregory Dubois-Felsmann2022-02-14 DM-SST Virtual F2F Agenda and Meeting notes
  • Steve Ritz Work with DM and Camera to develop plans for delivering a shutter position-vs-time model  
16 May 2022Steve Ritz2022-03-14 DM-SST Agenda and Meeting Notes
  • Gregory Dubois-Felsmann  / Leanne Guy Create a TN that outlines the science use cases and options for compressed PVIs from AP. Present the issue at DMLT VF2F and then the PST.   
13 Jun 2022Gregory Dubois-Felsmann2022-05-09 DM-SST Agenda and Meeting Notes
  • Eli Rykoff Report on what information DES used for their decision on using compression?  
25 Jul 2022Eli Rykoff2022-06-06 DM-SST VF2F Agenda and Meeting notes
  • Melissa Graham to draft a proposal for including pz in alert packets  
12 Sep 2022Melissa Graham2022-08-15 DM-SST Agenda and Meeting Notes
26 Sep 2022Steve Ritz2022-09-12 DM-SST Agenda and Meeting Notes
  • Gregory Dubois-Felsmann  start a technote to write down the details for science end user interface to SED corrections in catalogs  
31 Oct 2022Gregory Dubois-Felsmann2022-08-22 DM-SST Agenda and Meeting Notes
31 Dec 2022Leanne Guy2022-06-06 DM-SST VF2F Agenda and Meeting notes
28 Feb 2023Leanne Guy2023-01-23 DM-SST Agenda and Meeting Notes
  • Leanne Guy talk to Steve R about presenting plans for the ShearObject table to PST and SciCollab chairs   
20 Mar 2023Leanne Guy2023-02-27 DM-SST Agenda and Meeting Notes
31 Mar 2023Jim Bosch2023-02-27 DM-SST Agenda and Meeting Notes
  • Leanne Guy  talk to Gregory Dubois-Felsmann to review the original intent of the AFS-related Portal requirements before deciding on a course of action  
29 May 2023Leanne Guy2023-05-01 DM-SST Focus Meeting - Brokers in Commissioning
  • Leanne Guy Prepare to consult the PST on the question of providing compressed PVIs for AP outputs, to cover the period before the data become available in a DR.  
02 Jun 2023Leanne Guy2023-03-27 DM-SST Agenda and Meeting Notes
  • Jim Bosch Incorporate 30-60 day period for raws on disk into the strawman proposal and present to KT  
26 Jun 2023Jim Bosch2023-05-08 DM-SST Agenda and Meeting Notes
  • Parker Fagrelius Patrick Ingraham  how long will it take to do a scan as described? No need to scan the whole WL range but will require additional points outside nominal lambda range.  
30 Jun 2023Parker Fagrelius2023-03-27 DM-SST Agenda and Meeting Notes
31 Jul 2023Colin Slater2023-07-10 DM-SST Agenda and Meeting Notes
  • Eli Rykoff , Leanne Guy  Develop a proposal for what calibration processing, hardware, data we actually need and what will be needed for DR1. This has implications for the ORR and for prioritisation of work in commissioning  
31 Jul 2023Eli Rykoff2023-01-30 DM-SST Agenda and Meeting Notes
  • Yusra AlSayyad will look to see if there is any effort to help on option 1  
28 Aug 2023Yusra AlSayyad2023-08-14 DM-SST Agenda and Meeting Notes
  • Jim Bosch  Provide a physical example of that a  up on cell table would look like fo the Colin Slater / DAX team to review  
31 Aug 2023Jim Bosch2023-02-27 DM-SST Agenda and Meeting Notes