`SkycalcTERCurve` does not offer a possibility to change parameters programmatically

[oczoske]

skycalc has many parameters that can be used to tune the conditions under which the atmospheric spectra are to be computed. However, the Scopesim effect SkycalcTERCurve does not expose these parameters in a user-friendly way. They can be set when the effect is instantiated individually (this is tested to a limited extent in test_SkycalcTERCurve.py). They can also be set in a yaml file, although Armazones.yaml does not actually do that. There is, as far as I can tell, no way to change the parameters in the UserCommands or in the effect once the OpticalTrain has been built. This would be useful to study the influence of atmospheric conditions on the data.

• The easiest way to do it might be an .update(**kwargs) method, which accepts skycalc parameters and triggers a new query to the skycalc server. Validating the kwargs might be a bit tricky.
• In UserCommands it may or may not be possible to accept the parameters in the !ATMO category. Do they need to be predefined somewhere?
• The docstring of SkycalcTERCurve should have a list of accepted skycalc parameters, or point to the appropriate skycalc documentation.

There's some relation to #804 .

[teutoburg]

Validating the kwargs might be a bit tricky.

I suggest delegating this to skycalc_ipy, see attached sub-issue.

• In UserCommands it may or may not be possible to accept the parameters in the !ATMO category. Do they need to be predefined somewhere?

We can put whatever we want in there, as long as it doesn't conflict with anything else (obviously). Might even create a separate "!ATMO.skycalc" to keep things separate and organised.

• The docstring of SkycalcTERCurve should have a list of accepted skycalc parameters, or point to the appropriate skycalc documentation.

Again I's say document this in skycalc_ipy itself and in the effect put a big red arrow pointing there...