Refactor hour angle calculation

[aknierim]

This replaces the loops in the hour angle calculation

ha_all = Angle(
    [t.sidereal_time("apparent", "greenwich") - src_crd.ra for t in time]
)

in observation.py and data_set.py with array operations

ha_all = time.sidereal_time("apparent", "greenwich") - src_crd.ra.to(
    un.hourangle
)

resulting in a (small) performance boost of the code.

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 100.00%. Comparing base (3fc7db5) to head (434af1a).
Report is 61 commits behind head on main.

Additional details and impacted files

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  Coverage   100.00%   100.00%           
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  Files            4         4           
  Lines           77        77           
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  Hits            77        77           

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[Kevin2]

How did you test the calculations to guarantee that the refactoring still works? Could we use some of these tests as tests in the workflow?

[aknierim]

We should definitely think of tests for this in the future

[maxnoe]

Is this computing local hour angle for a source?

If yes, It think the correct solution would be to use astropy coordinate transformation into the correspondig frame, not by hand computations using time.

I think the correct frame is: https://docs.astropy.org/en/stable/api/astropy.coordinates.HADec.html#astropy.coordinates.HADec

[aknierim]

Is this computing local hour angle for a source?

Yes, relative to Greenwich.

If yes, It think the correct solution would be to use astropy coordinate transformation into the correspondig frame, not by hand computations using time.

I think the correct frame is: https://docs.astropy.org/en/stable/api/astropy.coordinates.HADec.html#astropy.coordinates.HADec

I was actually looking for something like this. Will give it a try, thank you.

[Kevin2]

what is the state of this idea? is it easy to try or should we focus on different stuff for now?

[aknierim]

For some reason my current implementation of the GHA implementation off by one hour to the implementation on the main branch. We should look into why that is.