Rubin2020_PCW slack archives day2-tue-slot3a-commissioning 2020-07-15---2020-08-13

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Keith Bechtol Thu 2020-07-23 05:36PM

@Keith Bechtol set the channel topic: <https://project.lsst.org/meetings/rubin2020/agenda/session/rubin-commissioning-and-science-validation>

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Keith Bechtol Mon 2020-08-10 09:21PM

Here's an updated agenda for the "Commissioning and Science Validation" parallel session tomorrow.

Keith Bechtol Mon 2020-08-10 09:21PM

This reflects some recent requests. As you see, we have a full agenda!

Keith Bechtol Mon 2020-08-10 09:23PM

The speakers include @Lauren Corlies @Chris Walter @Meg Schwamb @Matt Tiscareno (he/him) @Michael Kelley @Lee Kelvin @Markus Rabus @Massimo Dall'Ora @Will Clarkson

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Keith Bechtol Mon 2020-08-10 09:24PM

My suggestion is that speakers upload slides onto the session page in advance of the session so that the slides are available in case we run into any technical glitches, and for future reference

Massimo Dall'Ora Tue 2020-08-11 11:42AM

Sorry to disturb: could someone please send a link to the template slide? Thanks!

Markus Rabus Tue 2020-08-11 12:05PM

@Massimo Dall'Ora , please feel free to copy my slides to your google drive and change the copy.
https://docs.google.com/presentation/d/1OfdhJAtPM8lYTo6aNBJmzfVCD9ARx3Mnj_5VZX-WsbM/edit?usp=sharing

Massimo Dall'Ora Tue 2020-08-11 12:06PM

Thanks!

Keith Bechtol Tue 2020-08-11 02:53PM

Starting in ~7 minutes

Keith Bechtol Tue 2020-08-11 02:55PM

Here's a google doc for minutes that should be editable by anyone with the link:
https://docs.google.com/document/d/10DpajWuYYsG7m3kXukRQXutdENtqT3n9sszIgJZaz9A/edit?usp=sharing

Jeff Carlin Tue 2020-08-11 02:56PM

Yes, I encourage you to add notes to what I will be contributing!

Djperrefort Tue 2020-08-11 02:59PM

What is the zoom link for this session?

Tom J Wilson Tue 2020-08-11 02:59PM: Zoom Link:_
https://stanford.zoom.us/j/93299144116 I believe if I've copied the right one
Ranpal (she/her/hers) Tue 2020-08-11 02:59PM: https://stanford.zoom.us/j/93299144116?pwd=cDdIb1dqZ2d5bTNHV0lJelJXK1NZdz09
Djperrefort Tue 2020-08-11 03:00PM: Thank you!

Tom J Wilson Tue 2020-08-11 03:04PM

For those of us less up to speed with current scheduling are there absolute timings for these integration tests? I.e., what real date does say early system integration occur currently?

Chuck Claver Tue 2020-08-11 03:20PM: Unfortunately, the reality is we do not know given COVID. The critical path current lies with the final assembly and test of the telescope mount assembly (TMA). We are still working with the TMA vendor for when they can get their team back into Chile to resume.
Tom J Wilson Tue 2020-08-11 03:21PM: Understandable, I'm just not 100% up on even my pre-covid schedule - full operations were going to be Oct 2022, does this run the ~8 months prior or earlier? I suppose that's my real question: is commissioning the immediate months prior to full operations or "would" there be a gap?
Chuck Claver Tue 2020-08-11 03:24PM: There should be no gap between Commissioning and the start of operations. The calendar date keeps moving as long as we are in the COVID situation. The good news is that even in the COVID conditions we are taking care of small things that should ultimately expedite the commissioning process. :crossed_fingers:
Tom J Wilson Tue 2020-08-11 03:26PM: Great, it was the lack of gap between commissioning and operations I was unsure of, thanks :slightly_smiling_face:

Alistair Walker Tue 2020-08-11 03:12PM

Have you considered not installing ConCam at all and going directly to LSSTCam, not to save the three months but to give you extra time to commission the main survey camera? Three months seems short.

Chuck Claver Tue 2020-08-11 03:16PM: Good question Alistair - It is fairly nuanced - ComCam also includes the refrigeration pathfinder needed commission the refrigeration system on the telescope. If we skip ComCam, we 1) we still have to commission the refrigeration system, thus we do not save much if any schedule, and 2) we will add risk to running the refrigeration on the telescope system for the first time with the science camera.
Chuck Claver Tue 2020-08-11 03:17PM: Followup - the 3 months with LSSTcam is based on lessons learned with ComCam - both instruments share the same interfaces.

Keith Bechtol Tue 2020-08-11 03:13PM

Thanks a lot @Lauren Corlies for the EPO perspectives

parejkoj Tue 2020-08-11 03:16PM

For EPO generation of color images: I moved the Lupton (2004) RGB algorithm from the LSST Science Pipelines to astropy a few years ago. I think the main algorithmic thing it's missing is good interpolation of saturated pixels (for which there is an Astropy issue).
https://docs.astropy.org/en/stable/visualization/rgb.html
https://github.com/astropy/astropy/issues/5573

Amanda Bauer Tue 2020-08-11 03:18PM

is that the algorithm that DM has committed to using to combine the 6 filters?

parejkoj Tue 2020-08-11 03:23PM

This algorithm is specifically for making 3-color visualizations, not for making measurements. I don't think (but maybe @John Swinbank could say something more?) DM has any statements on the creation of color images.

parejkoj Tue 2020-08-11 03:24PM

That said, I think this is the algorithm that most people in DM do choose to use when creating color images.

Amanda Bauer Tue 2020-08-11 03:25PM

ok. the resulting images have an orange-red tint to them, so it might be that EPO wants to do something else that is more visually appealing (we also will not be making any measurements...)

parejkoj Tue 2020-08-11 03:25PM

I bring it up because its availability on astropy means it is easy for the community to access, and Rubin could invest a little more time in final improvements for the benefit of both us (in particular EPO) and the community.

parejkoj Tue 2020-08-11 03:27PM

The orange color is because that is what the "true" color of such galaxies are. I think the question EPO needs to determine is what exactly they want to represent in color images: "true color" images of many LSST fields will look very reddish, because they will consist mostly of higher redshift, redder galaxies and redder stars. Examples abound from HSC

John Swinbank Tue 2020-08-11 03:29PM

So to be clear -_this is not an algorithm that DM has committed to for providing data to EPO. The way in which images for EPO will be generated is up to the EPO team -_see in particular LSE-61/DMS-REQ-0103 and LSE-131/EP-DM-CON-ICD-0021. In particular in the latter:

Definition of EPO's color scheme, definition of the varying depth coverage, and the method for transferring the tiles to the EDC will be defined by EPO once ComCam data is available

John Swinbank Tue 2020-08-11 03:29PM

Of course, if EPO decide they want to use an off-the-shelf Astropy algorithm, that might make our lives easier. :slightly_smiling_face:

Amanda Bauer Tue 2020-08-11 03:31PM

yes, excellent. looking forward to opening up these conversations again with DM in the first half of FY21 :slightly_smiling_face:

Dan Taranu Tue 2020-08-11 03:35PM

@parejkoj what do you mean the "true" color? You can adjust the color balance any way you want.

parejkoj Tue 2020-08-11 03:36PM

In this case, I mean "the color that best represents the fluxes across the different bands".

Dan Taranu Tue 2020-08-11 03:37PM

There's no such thing though. You can rescale each filter linearly however you want.

Dan Taranu Tue 2020-08-11 03:38PM

My preference is to balance irg -> RGB so that solar colours are white but that's an arbitrary choice motivated by being ~close to human perception.

Keith Bechtol Tue 2020-08-11 03:17PM

From Zoom, to make sure we capture

Tom J Wilson Tue 2020-08-11 03:18PM

(Should probably be repeated yet again "in person" for the recording)

Keith Bechtol Tue 2020-08-11 03:19PM

Nino Cucchiara (he/him/his) Tue 2020-08-11 03:25PM

@Amanda Bauer @Lauren Corlies hello

Lauren Corlies Tue 2020-08-11 03:26PM

Moving from Zoom - As for which organizations are we partnering with, that's really ongoing work! Currently, our efforts are US-centric and we will be expanding to explicitly include Chilean organizations as these are our two funded audiences to address. However, we would definitely be open to supporting anyone who is looking to work with other groups using EPO materials.

Currently, we are performing user testing with a large variety of classrooms (rural/urban, private/public, a large range of demographics) to make sure our educational materials resonate with all students and teachers. We have not specifically reached out to HBCUs and HSIs or tribal colleges. As we continue to develop our program, we will continuing to reach out for this kind of testing and input from different groups.

Nino Cucchiara (he/him/his) Tue 2020-08-11 03:27PM

Thanks, so when you say "large range of demographic" what you really mean and how you measure that?

Lauren Corlies Tue 2020-08-11 03:30PM: This would include information like gender and race/ethnicity to make sure groups aren't excluded. We never require people to report this information but we offer them the chance to in the surveys we give them.
Nino Cucchiara (he/him/his) Tue 2020-08-11 03:31PM: Right, but you select the groups in some way beforehand, right? Like if I test it in Tucson will be likely different than in somewhere delaware
Lauren Corlies Tue 2020-08-11 03:33PM: Yes - the plan was always to test nationally in the US and in Chile. We have been testing with classrooms in multiple states not just in Tucson. A happy consequence of remote education. We also just ran a week-long teacher workshop that included teachers from across the entire country. Location is another piece of information we are tracking in testing.
Nino Cucchiara (he/him/his) Tue 2020-08-11 03:49PM: Great to hear, is that all you said seems very vague and I am afraid will lead to exclusions of contributors
Nino Cucchiara (he/him/his) Tue 2020-08-11 03:50PM: Is there any documentation of all EPOs activities you are taking? Rubin is truly international and right now you focus on US and Chile.
Lauren Corlies Tue 2020-08-11 03:56PM: Our program is laid out in detail in our publicly available design document: https://docushare.lsst.org/docushare/dsweb/Get/Version-64635/LEP-31.pdf
Nino Cucchiara (he/him/his) Tue 2020-08-11 04:00PM: Thanks Lauren for the document is very helpful. Do you have a link for the WCAG?
Nino Cucchiara (he/him/his) Tue 2020-08-11 04:00PM: Diversity appears only 4 times in the whole document, so more specifics would be great
Lauren Corlies Tue 2020-08-11 04:02PM: Detailed documentation of the WCAG: https://www.w3.org/TR/WCAG21/
Nino Cucchiara (he/him/his) Tue 2020-08-11 04:04PM: Thanks Lauren, I will follow up with you and Amanda on that, but the EPO design does not have any specifics of what you are actually doing, so it is hard to understand how the community at large can contribute to that and make sure the effort is truly inclusive.

Nino Cucchiara (he/him/his) Tue 2020-08-11 03:28PM

Have you plans for including community colleges which include 60%+ of hispanic and Black students

Lauren Corlies Tue 2020-08-11 03:35PM: We are testing at both private and public colleges. We've already done testing with one community college and the process is still very much ongoing!

Chuck Claver Tue 2020-08-11 03:34PM

Q: Is there any Solar System Science that could come from the statistics of meteor trails in the survey data?

Meg Schwamb Tue 2020-08-11 03:40PM: I'n not sure. There are already surveys doing this with fish-eye lenses.
Meg Schwamb Tue 2020-08-11 03:40PM: Those are definitely brighter in the fish-eye lenses.

Chuck Claver Tue 2020-08-11 03:35PM

Q: What is the angular extent of faint moons of the giant planets?

Matt Tiscareno (he/him) Tue 2020-08-11 03:45PM: Do you mean how far from the planet? Generally one to several planetary radii. The system may be small in the FOV, but see my answer to Michael Strauss for why Rubin is uniquely suited for this science.

Michael Strauss (he/his) Tue 2020-08-11 03:37PM

To what extent is Rubin the right telescope to look for faint moons? Wouldn't that science be done as easily with a telescope with a significantly smaller field of view?

Matt Tiscareno (he/him) Tue 2020-08-11 03:41PM: It's the cadence combined with the sensitivity that makes Rubin a uniquely good observatory for this particular science.
Matt Tiscareno (he/him) Tue 2020-08-11 03:44PM: Time-domain science is what we need for the orbital science here. Other observatories that are sensitive enough to detect these moons cannot offer nearly as much frequency in the observations.

Chuck Claver Tue 2020-08-11 03:38PM

@Michael Strauss (he/his) Thus my question regarding angular extent.

Michael Strauss (he/his) Tue 2020-08-11 03:39PM

I am also not convinced that this is a commissioning activity per se. It is cool science, of course, but will not obviously tell us how to do the survey going forward.

Melissa Brucker (she/her) Tue 2020-08-11 03:39PM: to be able to model the glare from bright sources that are nearby
Michael Strauss (he/his) Tue 2020-08-11 03:40PM: Fair enough. But most bright sources are point sources (stars), which will have a different glare pattern than a planet.
parejkoj Tue 2020-08-11 03:41PM: I think "whether we can extract useful data from significantly saturated/ghosting images" is a useful test. And I was just about to write what @Michael Strauss (he/his) just wrote re: point sources.
Chuck Claver Tue 2020-08-11 03:42PM: Once we are outside the nominal FOV it won't really matter if the offending source is point or not.
Melissa Brucker (she/her) Tue 2020-08-11 03:46PM: yes, they may have a different glare pattern since they have angular extent, so they will need to be modeled in addition to modeling stellar glare.
Matt Tiscareno (he/him) Tue 2020-08-11 04:45PM: @Michael Strauss (he/his) : Imaging a bright disk will help us probe the extreme wings of the PSF and also the response of the CCD to extreme saturation. This will yield valuable information about what we can expect from the main survey.

Chuck Claver Tue 2020-08-11 03:40PM

During Commissioning we will certainly put very bright sources (e.g. Jupiter) outside the FOV at various distances from the optical axis to characterize glints and scattered light.

Robert Lupton Tue 2020-08-11 03:50PM: My first reaction is that I'd probably prefer to use a star, as it doesn't vary and move. You can argue that it's nice to be able to go back and re-observe without the bright object, but I'm not sure it's worth it.
Worth thinking about
Matt Tiscareno (he/him) Tue 2020-08-11 03:55PM: @Chuck Claver : If the planet is outside the FOV, then it is not useful for the science I was discussing. We want to observe the close-in regular moons, not the distant irregulars. The irregulars are interesting too, though. It's just not myself who is setting up to look for them.
Chuck Claver Tue 2020-08-11 03:58PM: For Jupiter - aren't the "regulars" fairly far away from the planet? This is outside my field, so forgive my ignorance...
Matt Tiscareno (he/him) Tue 2020-08-11 04:42PM: The diameter of Jupiter as seen from Earth is 50 arcseconds at the most. The orbit of Io is 6 Jupiter radii, and the moons we want to see are inward of Io. So I think this is much smaller than the LSST FOV.
Robert Lupton Tue 2020-08-11 04:51PM: The question was probably about structure in the scattering wings (and ghosts and ghouls) at c. 6-20 arcmin
Matt Tiscareno (he/him) Tue 2020-08-11 04:53PM: If I understand correctly, that sort of thing is useful if you want to observe the distant irregular moons. I understand there are people who want to do that, but it's not me.
Robert Lupton Tue 2020-08-11 04:55PM: Oh, sorry, inward of Io. So 1-6 arcmin
Matt Tiscareno (he/him) Tue 2020-08-11 04:56PM: Yes, about that.
Matt Tiscareno (he/him) Tue 2020-08-11 04:57PM: This subthread started with the topic of putting the planet off the edge of the image and looking at the scattered light patterns that result from that. In such cases, the inner moons will also be off the edge of the image.
Robert Lupton Tue 2020-08-11 04:58PM: So it did, sorry. I don't think I'd do that, I'd image at the centre of the field and then move it off the edge. At the edge you've got a better chance of ghoulies and other horrors.
Matt Tiscareno (he/him) Tue 2020-08-11 05:00PM: I agree, but an observer might have a reason to do it.

Peter Yoachim Tue 2020-08-11 03:41PM

Right now we're avoiding Jupiter. Might be nice to look at it and see if there's a science case to just let it get observed.

Chuck Claver Tue 2020-08-11 03:42PM: We are avoiding Jupiter in the survey - Commissioning is another matter :slightly_smiling_face:
Robert Lupton Tue 2020-08-11 03:48PM: Can we track SS objects?
Matt Tiscareno (he/him) Tue 2020-08-11 03:50PM: Are you avoiding Jupiter because it might cause damage to the observatory in some way? Are you avoiding Saturn and the other planets also?
Matt Tiscareno (he/him) Tue 2020-08-11 03:51PM: Unless it is a safety issue, please do not avoid the planets! Even if we do not convince you to do this commissioning activity, we believe images of the planets will give us exactly the science results I was discussing.
Peter Yoachim Tue 2020-08-11 03:52PM: The default is to mask Venus, Mars, Jupiter. I don't think there's a risk of damage, just cutting down on the saturation streaks.
Matt Tiscareno (he/him) Tue 2020-08-11 03:52PM: But we can probably fish moons out of the gaps between the saturation streaks.
Robert Lupton Tue 2020-08-11 03:53PM: I don't think we're much more scared of Jupiter than Canopus
Peter Yoachim Tue 2020-08-11 03:53PM: Saturn moves pretty slow, so it's tough to dodge.

I'll add masking Jupiter to the list of open questions the SCOC should weight in on!
Robert Lupton Tue 2020-08-11 03:53PM: We will be modelling wings of stars which is of relevance here. We'd have to convolve the models with the planetary disk, but that's doable
Chuck Claver Tue 2020-08-11 03:54PM: @Robert Lupton Yes - we can track non-sidereal objects. As far as the TMA is concerned there is no control difference between "slewing" and "tracking" - it is just a matter of axis rates.
Robert Lupton Tue 2020-08-11 03:56PM: And a planetary ephemeris, with correction for parallax, aberration, etc.
Chuck Claver Tue 2020-08-11 03:56PM: Yep :slightly_smiling_face: . part of the pointing kernel.
Meg Schwamb Tue 2020-08-11 03:58PM: It's worth noting that there might be some science that can be done if say Jupiter and Saturn are imaged in commissioning and not imaged often or at all in the WFD. (If there's a way to make it work in commissioning).
Matt Tiscareno (he/him) Tue 2020-08-11 03:59PM: @Robert Lupton : Yes, obtaining the EPSF from a bright star and then convolving with the planetary disk would help a great deal. However, there might be non-linearities in the EPSF and/or saturation when you have a disk source, and it might be good to have at least one disk-source image for comparison.
Robert Lupton Tue 2020-08-11 04:00PM: Umh, what non-linearities are you worrying about? Saturation is a problem for both point sources and disks.
Chuck Claver Tue 2020-08-11 04:01PM: @Meg Schwamb Can you write something up? Doesn't have to be long.
Meg Schwamb Tue 2020-08-11 04:02PM: Yes. I'll get the SSSC (and really @Matt Tiscareno (he/him) who is very interested in this) to write something up. I was hoping we could do that, plus imaging an OSOSS field, etc as part of the commissioning note due in November. Does that timeline work for you?
Chuck Claver Tue 2020-08-11 04:17PM: Yes - timescale of Nov. would be foine :slightly_smiling_face: :pray:
Matt Tiscareno (he/him) Tue 2020-08-11 04:35PM: Meg, you said "there might be some science that can be done if say Jupiter and Saturn are imaged in commissioning and not imaged often or at all in the WFD"
Yes, there is some value in a single image from Commissioning, but what makes LSST really valuable for this science is the high cadence. The main value of doing it in Commissioning would be helping us (and perhaps others with similar science) know what to expect in the main survey.
Matt Tiscareno (he/him) Tue 2020-08-11 04:37PM: @Robert Lupton : The CCD response to extreme saturation often does unexpected things in our experience. Also, the far wings of the PSF add up to something important when you have a bright disk, in a way that is hard to get at with a point-source PSF. You would need accuracy to one part in 1e6 or better in your point-source PSF.
Robert Lupton Tue 2020-08-11 04:54PM: I agree that video chains can misbehave at very high signal levels, but I don't think that that can matter here. We're comparing imaging a 1st magnitude star with Jupiter, not a regular unsaturated 17th mag one (e.g. we observed Arcturus, the Hokule`a, when commissioning HSC, and I think DECam looked at canopus)
Matt Tiscareno (he/him) Tue 2020-08-11 05:08PM: Point-source PSFs, even of very bright stars, do not give you everything you need to know about the response to a bright disk, in our experience. Perhaps I'll try to document that claim in the report I've been asked to write.
Robert Lupton Tue 2020-08-11 05:08PM: That'd be very interesting -- thanks

Nicholas Walton Tue 2020-08-11 03:43PM

Q: In commissioning good to make sure you get fields heavily polluted with near earth constellations - Starlink, OneWeb and the like - to make sure the s/w to deal with these in the processing is well tested. (See @Tony Tyson 's nice talk day 1 for background - also Mark McCaughrean's talk at EAS2020 - slides on twitter at https://threadreaderapp.com/thread/1279107663327039495.html )

mrawls Tue 2020-08-11 03:43PM

Q: any plans yet for observing LEOsats during commissioning? .... ah, jinx w/ the above comment :slightly_smiling_face:

Tue 2020-08-11 03:43PM

@Tony Tyson has joined the channel

Chuck Claver Tue 2020-08-11 03:45PM

I think we will get the LEOs as a matter of course. What we will have to do is verify/validate any avoidance strategy we develop.

mrawls Tue 2020-08-11 03:46PM: I'm also wondering about ghosts etc. from LEOsats - we can characterize e.g. crosstalk ahead of time but not glints/scattered light
Nicholas Walton Tue 2020-08-11 03:47PM: @Chuck Claver : good to make sure you actively go for dense coverage of LEOs for a small part of commissioning.
mrawls Tue 2020-08-11 03:48PM: Sadly will probably happen whether we want it to or not :grimacing:
mrawls Tue 2020-08-11 03:48PM: But yes, would be good to do so intentionally so we have various life cycle phases, phase angles, etc.
ajc Tue 2020-08-11 03:49PM: might be worth also defining a twilight survey as part of our validation surveys (I know we have plans to work in twilight but we could define the strategy for that as a separate program)
Chuck Claver Tue 2020-08-11 03:51PM: @Nicholas Walton I would be interested to learn more what you want to get - as of now our estimates are that we would only get one or two LEOs per visit even in the worst cases. The high density we see now is part of the system deployment.
Nicholas Walton Tue 2020-08-11 04:02PM: @Chuck Claver - good to get observations of the LEO's at differing altitudes for instance (e.g. OneWeb is quite a bit higher altitude than Starlink) - then map how they appear with airmass for instance. Good to get these observations in a formal way rather than having them in drips and drabs through the rest of commissioning. you'll then be able to study the impact of these LEO's and the goodness of the processing to remove them from the data (as much as possible).
Nacho Sevilla Tue 2020-08-11 04:04PM: 2 cents. Ideally one would be able to get some orbital predictions beforehand and observe them around 'calibrated' fields, ie, well known weak lensing fields, known LSB objects, etc, in the case of extragalactic objects. And reobserve without the trails.
Tony Tyson Tue 2020-08-11 06:18PM: The challenge is masking these trails, since they are 30 arcsec wide at the surface brightnesses we care about. Ideally want to test modeling-subtraction-masking. The SATCON1 report shows the problem in Subaru HSC image of a LEOsat trail. So I believe that is what we want to test in COMCAM commissioning.
Tony Tyson Tue 2020-08-11 06:18PM: A scary read: https://www.linkedin.com/pulse/new-fcc-processing-round-prompts-license-requests-frhr-von-der-ropp

A Emery Watkins Tue 2020-08-11 03:48PM

I assume imaging of Uranus/Neptune etc. to measure the extended PSF also could be used in conjunction with efforts at modeling the PSF for LSB studies?

Morgan Schmitz Tue 2020-08-11 03:50PM: I was wondering the same thing. I feel like the SED would be very different, and this might impact extended PSF modelling?
This is something we hope to test very soon in our DM extended PSF modelling efforts from existing surveys (HSC), using bright stars with different colors. I am not sure we have any planet image to see how far off we are in terms of extended PSF
Robert Lupton Tue 2020-08-11 03:51PM: I commented in a different thread. I think I'd prefer a star, but this would have the advantage that we could go back later and get the uncontaminated image

Nicholas Walton Tue 2020-08-11 03:53PM

Q: Is there a plan to coordinate the science publications coming out of the commissioning/ sci ver phase? Higher impact if all papers appear at once in a special issue somewhere.

Tom J Wilson Tue 2020-08-11 03:55PM: Also any consideration to "high impact" publication biases out of larger consortiums or collaborations versus "smaller teams"? Or is everything already "pre assigned" so this is not necessarily an issue?

Will Clarkson Tue 2020-08-11 03:57PM

Comment (on Massimo's talk) in Zoom by Mike Rich: "the Blanco DECam Bulge Survey has all 6 bands to 21 mag over 200 sq deg"

Massimo Dall'Ora Tue 2020-08-11 04:06PM: That's true, and it is one of the reasons to focus on Bulge: we have a more than robust benchmark to test all the pipelines, from the calibration, to the variable stars detection, to the PSF pipelines to measure sources fainter than the DECam limit
Will Clarkson Tue 2020-08-11 04:12PM: Right, I view the two as complementary (particularly since BDBS has y and covers an enormous area).
Will Clarkson Tue 2020-08-11 04:12PM: It's a big enough galaxy for both studies!

Markus Rabus Tue 2020-08-11 03:57PM

Kathy Vivas Tue 2020-08-11 04:03PM

Observing Fornax during commissioning will allow to uncover the population of the faint SX Phe, which is still unknown.

Massimo Dall'Ora Tue 2020-08-11 04:06PM: that's absolutely true
Ilaria Musella Wed 2020-08-12 12:44PM: This project is very interesting and we propose it also in the paper submitted to Call for White Papers on LSST Cadence Optimization ( https://arxiv.org/abs/1812.03298 )

Tom J Wilson Tue 2020-08-11 04:04PM

For Galactic plane science I think that "middling" crowding but still Galactic plane observations (not bulge, but l=130, b=0 kinda crowding), as well as perhaps towards the anticentre or up to b=5-10 for reduced-but-still-in-the-plane-kinda crowding will be crucial - and this will test the star-galaxy separation towards b=10 or so

Will Clarkson Tue 2020-08-11 04:06PM: @Tom J Wilson I think you just volunteered to join the SMWLV observing strategy task force that we're in the process of re-constituting
Tom J Wilson Tue 2020-08-11 04:08PM: Darn, I knew I should have kept quiet :wink:

Nicholas Walton Tue 2020-08-11 04:05PM

thanks for a great session

Keith Bechtol Tue 2020-08-11 04:05PM

To make sure we don't miss

Robert Lupton Tue 2020-08-11 04:06PM

I'm worried about fields with n_star ~ 10 n_gal --- at very high stellar densities we pretty much know what to do.

Will Clarkson Tue 2020-08-11 04:06PM: right - intermediate density fields (when there's some possibility that the more clever deblending methods will work and lots of background galaxies are visible) will be tricky
Robert Lupton Tue 2020-08-11 04:07PM: If we deliver code that overlaps over a significant range of stellar density I'll be happy.
Tom J Wilson Tue 2020-08-11 04:07PM: Perhaps my b=10 was not quite the right ballpark (I binned anything that looked galaxy-like in my work at that galactic latitude...), but that was the sentiment behind that part of my above!
Will Clarkson Tue 2020-08-11 04:08PM: It sounds like a field of the kind of density you are (both) suggesting would be a good candidate for commissioning just from a software perspective alone.
Robert Lupton Tue 2020-08-11 04:09PM: I'm worried about the science, not (just) the code!
Will Clarkson Tue 2020-08-11 04:11PM: Well, right - we are too! :slightly_smiling_face: - but the one requires the other
Will Clarkson Tue 2020-08-11 04:15PM: @Robert Lupton I don't think I said in the algorithms workshop yesterday, but BTW thank you and the DM team very much for pursuing the crowded field work!

Meg Schwamb Tue 2020-08-11 04:10PM

Thanks @Keith Bechtol and @Chuck Claver . A virtual workshop would be great or maybe focusing on different subareas in 1 hour miniworkshops as a follow-up to this session.

Meg Schwamb Tue 2020-08-11 04:22PM

I would recommend disseminating a short template for the feedback you are looking for and a deadline. Is it 1 page per target, 2 pages per SC for everything? As an SC chair that would be help me encourage the collaboration to continue the brainstorming and and start dialoguing more with our commissioning liaisons.

jgizis Wed 2020-08-12 09:37AM

Is the recording of this session going to be posted?

Ranpal (she/her/hers) Wed 2020-08-12 09:39AM: It will be hopefully some time today, Sorry for the delay, getting videos posted by next day is perhaps a bit more work than we thought...
jgizis Wed 2020-08-12 09:40AM: I hear you! Thanks so much for a very fine meeting.
Ranpal (she/her/hers) Wed 2020-08-12 02:28PM: Recording is now posted https://youtu.be/IrbWwk60Cj8

Ranpal (she/her/hers) Thu 2020-08-13 05:31AM

The recording of the live session is here: https://youtu.be/IrbWwk60Cj8