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Page to collect info for Zeljko & Joachim Moeyens on 

  • generating atmospheres,
  • then magnitudes for stellar SEDs, 
  • and finding out how well one can recover input atmospheric parameters from comparison of those magnitudes with standard magnitudes. 

 

Atmospheres can be generated using some of the code https://stash.lsstcorp.org/projects/SIM/repos/sims_selfcal/browse (I need to talk to Peter about what/how was translated from cgit the original repos). 

But more likely you will find the code in this repo https://dev.lsstcorp.org/cgit/LSST/sims/doc.git/ more useful. 

Read section 5.2 of the calibration paper : https://dev.lsstcorp.org/cgit/LSST/sims/doc.git/tree/level2/calib_plan.pdf (especially note equation 29 which introduces the various atmospheric components and their coefficients which we use to model the atmospheric throughput as a function of wavelength). 

Once you understand the idea of the various atmospheric components/templates and the coefficients that go with them, go have a look at the code here https://dev.lsstcorp.org/cgit/LSST/sims/doc.git/tree/level2/code/AtmoComp.py which will let you recreate atmospheres with any combination of coefficients at any airmass. Note this is not truly as accurate as a MODTRAN calculation of the atmospheric throughput. 

Then go look at the code here https://dev.lsstcorp.org/cgit/LSST/sims/doc.git/tree/level2/code/plot_dmags.py (for which you will need to install sims_photUtils .. see Catalogs and MAF installation instructions). The code in plot_dmags.py will need to be updated as there have been some small changes in sims_photUtils from the time that the code was originally written - I think this should come down to simply changing the import statements to point at lsst.sims.photUtils instead of lsst.sims.catalogs.measures - but you probably will want to modify it somewhat to generate exactly what output you want. In general, this code will let you calculate the magnitude of a set of kurucz models (plus others like MLT stars) and make plots of the color-color relations or differences in magnitude between standard/non-standard atmospheres. 

From there, (fitting the resulting stellar magnitudes and determining what input parameters you used for the atmosphere), I do not have existing code, but I'm sure Zeljko can fill in some astroML methods to use. 

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