LSSTDESC
Add capability for specifying clouds
We have at least one cloud model in the project that could be used for simulating observations that have some cloud cover. I don't know exactly how to parameterize this. Perhaps Peter Yoachim or Lynne Jones would have ideas. To first order it could just be a parameter indicating how thick a uniform, grey layer of clouds is. Taking it a bit further, one could potentially specify a structure function.
I'm adding some information here from a discussion with @yoachim in the #sims slack channel.
We have an all sky camera at Cerro Pachon and Peter wrote a photometric pipeline to generate transparency maps which would work with it:
https://github.com/lsst/all_sky_phot
He also says: "The all sky camera won't get you the transparency at the resolution of a focal plane, but we have that structure function lying around somewhere if you want to make high resolution clouds based on a mean transparency."
@yoachim Can you also give us a pointer to the structure function?
Adding this feature would be a nice (but non-trivial) standalone contribution if someone is looking for a project. It probably should be implemented as a standalone function in the LSST project sims repo or as an extension to the sky model so that other tools like the scheduler could also leverage it. In that configuration we would either call it in addition to the sky model or tell the sky model to include weather. Peter might comment on the best approach.
This issue is about adding clouds. Do clouds encompass all "weather" one might want to add?
@SimonKrughoff What is the project cloud model you mention in the initial comment?
@cwwalter I was referring to a cloud model that Lynne Jones produced some time back. I know she produced opacity maps, but I don't know if it was packaged up any more formally than that.
@cwwalter The code Lynne wrote is in the sims_selfcal repo. https://github.com/lsst/sims_selfcal/tree/master/python/lsst/sims/selfcal/clouds
This might have gone a bit stale, so it would be great if someone wanted to break it out and make a simulated cloud image generation repo.
Great thanks!
BTW what does the name "selfcal" mean? I mean I can guess what it literally means but I don't see what is being calibrated by itself...