MICADO notebooks refer to strehl ratio, but FieldConstantPSF does not use that (AnisocadoConstPSF does)

[hugobuddel]

Various of the MICADO notebooks set the Strehl ratio.

E.g. https://github.com/AstarVienna/irdb/blob/dev_master/MICADO/docs/example_notebooks/2_scopesim_SCAO_1.5mas_astrometry.ipynb

Given that we are observing at a non-standard broadband filter, we need to instruct the OpticalTrain to adjust the PSF strehl ratio. This is done with the !INST.psf dictionary.

cmd["!INST.psf.strehl"] = 0.1

However, MICADO uses a FieldConstantPSF as PSF, which does not use this parameter. The AnisocadoConstPSF does use the Strehl ratio, and is described in the FAQ https://github.com/AstarVienna/irdb/blob/dev_master/MICADO/docs/example_notebooks/MICADO_FAQs.ipynb

MICADO_Sci however, does use AnisocadoConstPSF, and I suppose there the parameter would be taken into account (didn't check).

The notebooks have an instructional purpose, so maybe it is best to resolve this in a way that does actually make the strehl ratio relevant. If the comment in notebook 2 is right, that "we need to adjust the PSF strehl ratio because we are observing at a non-standard broadband filter", then the best course of action might be to copy the example in the FAQ notebook to notebook 2.

The example in the MICADO FAQ:

import scopesim
from scopesim.effects import AnisocadoConstPSF

wide_psf = AnisocadoConstPSF(name="Wide_SCAO_PSF",
                             filename="MICADO/MICADO_AnisoCADO_rms_map.fits",
                             strehl=0.5,
                             wavelength=2.15,
                             psf_side_length=2048)

cmds = scopesim.UserCommands(use_instrument="MICADO", set_modes=["SCAO", "IMG_1.5mas"])
micado = scopesim.OpticalTrain(cmds)

micado.optics_manager["default_ro"].add_effect(wide_psf)

micado["relay_psf"].include = False
micado["Wide_SCAO_PSF"].include = True

Thoughts @astronomyk / @oczoske ?

[hugobuddel]

Maybe we should have an automated mechanism to discover such cmd bang-strings that accidentally do nothing, see created AstarVienna/ScopeSim#505