Date & Time
Date , NCSA-3000, 9:00 - 17:00 PT
This meeting precedes the DMLT F2F meeting
Location
Browser | Room System | Phone Dial-in |
---|---|---|
| Dial-in numbers:
Meeting ID: 103664856 |
Attendees
- Leanne Guy
- Zeljko Ivezic (attending remotely)
- Melissa Graham (attending remotely)
- Simon Krughoff
- Colin Slater
- Eric Bellm
- Michael Wood-Vasey
- Jim Bosch
- Robert Gruendl
- John Swinbank
- Wil O'Mullane
- Gregory Dubois-Felsmann
- Robert Lupton (partially and remotely from Finland)
Regrets
Pre-meeting planning
Please add ideas to the table of suggested topics
Questions to be addressed in each topic:
- Where are we now and what do we need to do to get where we want to be?
- How are we going to verify and validate the algorithmic performance (e.g requirements and anything missing for requirements)?
- What are the "success criteria" for these algorithms?
- What, if any studies do we need to do to (e.g SST study, engage science collaborations, interact with other outside groups)?
Agenda: room = NCSA 3000
Time | Topic | Chair | Notes & Actions |
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9:00 - 9:05 | Welcome | Leanne Guy |
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9:05 - 9:15 | Jira for DM Science |
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9:15 - 10:30 | Difference Imaging |
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10:30 - 10:50 | Break | ||
10:50 - 12:30 | Deblending and crowded fields |
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12:30 - 13:30 | Lunch | ||
13:30 - 15:00 | Deep object measurement |
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15:00 - 15:20 | Break | ||
15:20 - 15:50 | Background fitting |
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15:50 - 17:00 | Verification needs |
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17:00 | Close |
Session Notes
(Please correct if I have misrepresented your statements)
Image differencing & DCR
- paraphrase: Main thing is to evaluate whether we hit reqs based on AL, if not we can go onto Zogy.
- KSK: Preconvolution isn't yet working, needed to make deconvolution work
- Would be nice to do a bakeoff, but we should focus on getting AL successful as higher priority.
- Eric: "Main focus is to get in a position to hit requirements as soon as possible, with just one algorithm"
- LPG: Could we do some sort of monthly-roll up, i.e. what Meredith is generating manually? Could load the monthly run?
- KSK: There is a templated notebook system, meant for periodic reports. Would that be useful for AP?
- Eric shows 3 Decam fields of detections, show false positive features. Patch-sized problems have been fixed recently.
- ZI: Are these false positives a strong function of SNR? EB: Good question, don't know
- EB: Edge flag needs to be used to throw away those sources, but just hasn't been added to the query yet.
- DMTN-21 getting ~50 det/ccd, but current hits seems to be ~on average ~hundreds per ccd.
- RHL: Brighter Fatter? Not being corrected right now. Means the kernel is being built from bright stars and then applied to the faint stars.
DCR
- RHL: What happens if you run Ian's code on a telescope with an ADC [as a null test]? Good question, haven't tried.
- EB: Current opsims often producing pessimal image sets with the same airmasses, but opposite sign of the parallactic angle. Gives no leverage for fitting.
- Discussion: Current DCR code doesn't handle PSFs that vary between input images into the coadd. Because it's pixel-based, the pixels don't know about their objects or their PSF.
- Haven't gotten to RB yet. "What we need to train a RB model is the same as what we need to show we're meeting our requirements, i.e. a training set". Will need a larger dataset.
- RHL: have to understand the full system before we go on sky, can't pick off bits and pieces. Need to understand non-dcr data before we understand dcr data.
- MWV: Focus on good templates with ~12 images?
- RHL: That's the best case, we can do that before doing the harder part of small N. Learn different things from the two cases.
- LPG: DESC is interested in joining the image differencing effort, how can we help this?
- MWV: DESC definitely has energy on this, but are they going to inundate the AP team with questions/problems.
- JB: "We're already under a lot of known-issues, just finding more issues doesn't necessarily help".
- JB: DESC has a lot of decam experts, could they help getting obs_decam and calibrations in better shape, or is that too indirect for DESC to care. MWV: Software dev people are more from the French/CFHT side.
- Robert G: Still working on Decam issues from the DES side. Could reprocess the HITS fields with the DESDM, see if the same issues remain/is it something with the CP calibration side.
- MWV: Could produce a coherent report on the DC2 image differencing
Deblending
- SDSS deblender: Spatial symmetry constraint.
- Scarlet: Assumes each component in a source has the same morphology across bands, but different fluxes. Includes spatial symmetry and radial flux monotonicity constraints.
- KSK: What about objects with multiple physical components, bulge+disk.
- JB: Need a way to tell it that that is ok, but theoretically it could.
- Without constraints, failure mode is the big objects eat the flux from all their neighbors. Some concerns about what monotonicity means, implementation-wise. Still working on that.
- Currently identifying peaks and then deblending with fixed set of peaks, but doesn't necessarily have to be that way (but other ways are probably harder).
- Tried implementing some algorithms that don't work on the deblended pixels, only the direct pixels in the very central region of the peak. Good for colors for photo-z, but no hope at getting the total flux right.
- LPG: slide says not the best for all cases, examples?
- JB: Works best for weakly blended galaxies, wrong one for stellar fields and galaxy clusters.
- Biggest cost probably comes in the per-step convolution process. Need to reduce the number of steps by having better initial guesses.
- JB: Would like to have the computational performance optimization first, too hard to do scientific optimization now when the runtime is bad.
- KSK: Mentioned earlier that if we don't need multifit then we can give that back to deblending
- JB: And scarlet will happily eat all of that compute.
- LPG: Need to get metrics to know whether we actually fit in the compute budget, especially w.r.t. multifit.
- LPG: Has there been work on GPU?s
- JB: Not so far, some of the other projects have been using frameworks like tensorflow to enable easy switching to GPUs. Would be super interesting for someone to try a GPU implementation.
- KSK: Could we make this pluggable, or is the interface not definable enough?
- JB: Could be, but worried that there might still be incompatibilities.
List of SST tasks (Confluence)
Description | Due date | Assignee | Task appears on |
---|---|---|---|
| 28 Feb 2022 | Robert Lupton | 2018-11-05 DM SST F2F Agenda and Meeting notes |
| 31 Mar 2022 | Gregory Dubois-Felsmann | 2022-02-14 DM-SST Virtual F2F Agenda and Meeting notes |
| 28 Feb 2023 | Leanne Guy | 2023-01-23 DM-SST Agenda and Meeting Notes |
| 20 Mar 2023 | Leanne Guy | 2023-02-27 DM-SST Agenda and Meeting Notes |
| 31 Mar 2023 | Jim Bosch | 2023-02-27 DM-SST Agenda and Meeting Notes |
| 29 May 2023 | Leanne Guy | 2023-05-01 DM-SST Focus Meeting - Brokers in Commissioning |
| 02 Jun 2023 | Leanne Guy | 2023-03-27 DM-SST Agenda and Meeting Notes |
| 26 Jun 2023 | Jim Bosch | 2023-05-08 DM-SST Agenda and Meeting Notes |
| 30 Jun 2023 | Parker Fagrelius | 2023-03-27 DM-SST Agenda and Meeting Notes |
| 31 Jul 2023 | Colin Slater | 2023-07-10 DM-SST Agenda and Meeting Notes |
| 31 Jul 2023 | Eli Rykoff | 2023-01-30 DM-SST Agenda and Meeting Notes |
| 28 Aug 2023 | Yusra AlSayyad | 2023-08-14 DM-SST Agenda and Meeting Notes |
| 31 Aug 2023 | Jim Bosch | 2023-02-27 DM-SST Agenda and Meeting Notes |
| 30 Nov 2023 | Jeffrey Carlin | 2023-10-23 DM-SST vF2F Agenda and Meeting Notes |
| 30 Nov 2023 | Gregory Dubois-Felsmann | 2023-10-23 DM-SST vF2F Agenda and Meeting Notes |
| 30 Nov 2023 | Leanne Guy | 2023-10-23 DM-SST vF2F Agenda and Meeting Notes |
| 30 Nov 2023 | Jeffrey Carlin | 2023-10-23 DM-SST vF2F Agenda and Meeting Notes |
| 31 Jan 2024 | Jim Bosch | 2023-12-04 DM-SST Agenda and Meeting Notes |
| 31 Jan 2024 | Jeffrey Carlin | 2023-12-04 DM-SST Agenda and Meeting Notes |
| Gregory Dubois-Felsmann | 2023-10-23 DM-SST vF2F Agenda and Meeting Notes |
Overdue or Undated DM Science Team tickets
LIT tickets of interest to DM Science