{"action":"created","issue":{"url":"https://api.github.com/repos/LSSTDESC/DC2_Repo/issues/145","repository_url":"https://api.github.com/repos/LSSTDESC/DC2_Repo","labels_url":"https://api.github.com/repos/LSSTDESC/DC2_Repo/issues/145/labels{/name}","comments_url":"https://api.github.com/repos/LSSTDESC/DC2_Repo/issues/145/comments","events_url":"https://api.github.com/repos/LSSTDESC/DC2_Repo/issues/145/events","html_url":"https://github.com/LSSTDESC/DC2_Repo/issues/145","id":307088527,"number":145,"title":"downscaled Run 1.2p that is still useful for validation?","user":{"login":"rmandelb","id":1454906,"avatar_url":"https://avatars3.githubusercontent.com/u/1454906?v=4","gravatar_id":"","url":"https://api.github.com/users/rmandelb","html_url":"https://github.com/rmandelb","followers_url":"https://api.github.com/users/rmandelb/followers","following_url":"https://api.github.com/users/rmandelb/following{/other_user}","gists_url":"https://api.github.com/users/rmandelb/gists{/gist_id}","starred_url":"https://api.github.com/users/rmandelb/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/rmandelb/subscriptions","organizations_url":"https://api.github.com/users/rmandelb/orgs","repos_url":"https://api.github.com/users/rmandelb/repos","events_url":"https://api.github.com/users/rmandelb/events{/privacy}","received_events_url":"https://api.github.com/users/rmandelb/received_events","type":"User","site_admin":false},"labels":[{"id":826236129,"url":"https://api.github.com/repos/LSSTDESC/DC2_Repo/labels/discussion","name":"discussion","color":"169193","default":false}],"state":"open","locked":false,"assignee":null,"assignees":[],"milestone":null,"comments":22,"created_at":"2018-03-21T00:47:56Z","updated_at":"2018-03-22T21:27:03Z","closed_at":null,"author_association":"CONTRIBUTOR","body":"Based on the discussions in the DC2 slack channel, it seems likely that the next PhoSim run will be based on the PhoSim configuration from test 33 or 34, which do not use the quick background mode.  Our original estimate of Run 1.1/1.2 size (see plan [here](https://docs.google.com/document/d/1aQOPL9smeDlhtlwDrp39Zuu2q8DKivDaHLQX3_omwOI/edit#)) was based in part on how much computational resources we wanted to use, and we had assumed a run time based on use of quick background.  This leads to the following question: should our next PhoSim run follow the original Run 1.1 design (->consume more resources than planned for testing and validation) or should it be downscaled in some way to take up roughly the same computational resources as before?  My question is currently aimed at the *analysis working groups*: we want to use these test runs to ensure that DC2 sims will enable you to achieve your DC2 needs, so the question is whether a downscaled version will still provide enough test data for you to check it out?\r\n\r\nAs a reminder, Run 1.1 was designed to cover 5x5 deg^2 of WFD, of which the 1.1x1.1 deg^2 uDDF is a subset.  It includes all 6 bands.  To quote the document, \"The WFD visits will be the first 750 visits that overlap the main survey region. We follow Twinkles and choose 586 Deep Drilling Field visits that fall on the uDDF survey region. This is done by choosing unique combinations of night and filter bandpass, so that the visit list is not exhausted at the beginning of the survey.\"\r\n\r\nI can think of a few ways to reduce this, with my preference being for option 3 for reasons described below:\r\n\r\n1. *Reduce area*: If we want to do things like check the galaxy populations and even maybe run a cluster-finder to check that the sims are useful for the various analysis WGs, then reduced area might make validation challenging.\r\n\r\n2. *Reduce the numbers of bands*: I think we do want to check multi-band photometry, so we at least need a few bands, but I would prefer to keep all 6, in case there are wavelength-dependent issues that we could identify with this test run.\r\n\r\n3. *Reduce the depth*: at least for WFD, this seems like the safest way to do a validation test that is less expensive yet still will give us the info that we need.  Even with a factor of 3 fewer exposures, we'd be reaching a depth that should enable interesting tests of galaxy photometry, cluster-finding, etc. - it's still ~3-year depth. For uDDF, I would imagine some useful validation could also be done with fewer visits, though I would like to hear from @rbiswas4 @jbkalmbach about this assumption (and whether there are any tricky issues having to do with selecting the visits in a way that enables sufficient tests of the transient populations).\r\n\r\nAgain, while comments are welcome from anybody, I would particularly like to hear from the analysis WGs, who need to use these test runs to check whether the sims will meet their DC2 needs.  Paging a few people: @rbiswas4 @jbkalmbach @fjaviersanchez (wearing an LSS hat for the moment :) @rmjarvis @erykoff @dannygoldstein @joezuntz -- happy to hear from anybody else.\r\n\r\nAlso, if @fjaviersanchez (wearing his SSim hat now :) can comment on whether the changes we discuss have an impact on the effectiveness of the planned validation tools, that would be helpful.  My feeling about the exposure checker is that even 1/4-1/3 of the planned number of visits is plenty; it works at the level of 1/2-chips and so even the kind of downscaling we might do will provide a huge number of 1/2-chips.  What about some of the other tools?"},"comment":{"url":"https://api.github.com/repos/LSSTDESC/DC2_Repo/issues/comments/375463138","html_url":"https://github.com/LSSTDESC/DC2_Repo/issues/145#issuecomment-375463138","issue_url":"https://api.github.com/repos/LSSTDESC/DC2_Repo/issues/145","id":375463138,"user":{"login":"rmandelb","id":1454906,"avatar_url":"https://avatars3.githubusercontent.com/u/1454906?v=4","gravatar_id":"","url":"https://api.github.com/users/rmandelb","html_url":"https://github.com/rmandelb","followers_url":"https://api.github.com/users/rmandelb/followers","following_url":"https://api.github.com/users/rmandelb/following{/other_user}","gists_url":"https://api.github.com/users/rmandelb/gists{/gist_id}","starred_url":"https://api.github.com/users/rmandelb/starred{/owner}{/repo}","subscriptions_url":"https://api.github.com/users/rmandelb/subscriptions","organizations_url":"https://api.github.com/users/rmandelb/orgs","repos_url":"https://api.github.com/users/rmandelb/repos","events_url":"https://api.github.com/users/rmandelb/events{/privacy}","received_events_url":"https://api.github.com/users/rmandelb/received_events","type":"User","site_admin":false},"created_at":"2018-03-22T21:27:03Z","updated_at":"2018-03-22T21:27:03Z","author_association":"CONTRIBUTOR","body":"Thanks Bryce.  I confess I didn't fully understand the description of the way the uDDF visits were selected in the Note, so I am hoping Rahul or somebody else can clarify whether there is an easy way to prune the uDDF visit list in a way that will achieve my intended goal: reduce data volume by factor of 3, and hence the number of transients by a factor of 3, while retaining the level of light curve sampling for those that we do simulate."}}
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